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A new chemonuclear system fission fragments and fluorocarbons

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Title:
A new chemonuclear system fission fragments and fluorocarbons
Creator:
Gurley, Richard Norwood, 1935-
Place of Publication:
Gainesville
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publisher not identified
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Language:
English
Physical Description:
viii, 188 l. : illus. ; 28 cm.

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Nuclear activation analysis ( lcsh )
Irradiation ( lcsh )
Fluorocarbons ( lcsh )
Nuclear Engineering Sciences thesis Ph. D ( lcsh )
Dissertations, Academic -- Nuclear Engineering Sciences -- UF ( lcsh )
Fluorocarbons. ( fast )
Irradiation. ( fast )
Nuclear activation analysis. ( fast )
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bibliography ( marcgt )
non-fiction ( marcgt )

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Thesis:
Thesis - University of Florida.
Bibliography:
Includes bibliographical references (leaves 184-187).
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Manuscript copy.
General Note:
Vita.

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University of Florida
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University of Florida
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Full Text
A NEW CHEMONUCLEAR SYSTEM
FISSION FRAGMENTS AND FLUOROCARBONS
By
RICHARD NORWOOD GURLEY
A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA August, 1967




ACKNOWLEDGMENTS
The author wishes to express his appreciation to Dr. John A. Wethington, Jr., chairman of the supervisory committee, for his guidance and assistance throughout the course of this study. Sincere thanks are expressed to Professor G. J. Schoessow and Doctors M4. J. Ohanion, R. G. Blake, and F. E. Dunnam who served on the author's supervisory committee.
The assistance of Mr. J. A. MacLean in the performance of the
gamma irradiations and the assistance of Mr. John Hancock and Mr.- Jim Hollis in the performance of the reactor irradiations is acknowledged.
The author is indebted to Mr. Harvey Norton, Health Physicist, for his assistance in monitoring, handling, and storing the irradiated capsules.
A special note of thanks is due to Mr. George M4. Fay for his
overall assistance in the preparation of the samples, in the irradiation of the capsules, in the analysis of the contents of the capsules, and in-the somewhat tedious calculations. Thanks are also extended to Dr. Richard S. Denning for his help with the analogue model.
The author wishes to thank the Oak Ridge Institute of Nuclear Studies for the fellowship assistance.
Finally, the encouragement, help, and patience of the author's wife, Mary, during the entire graduate residence are gratefully acknowledged.
ii




TABLE OF CONTENTS
Page
Acknowledgments .................................. ii
List of Tables -------------------------------------------iv
List of Figures --------------------------------..------- vi
Abstract ----------------------------------------------- vii
Chapter:
I Introduction -----.------------------------- I
II Previous Chemonuclear Work ------------------- 5
III Experimental Procedure ---------------------- 15
IV Experimental Results ------------------------ 27
V Discussion of Results .----------------------- 45
VI Conclusions ---------------------------------83
Appendices:
A Calculations --------------------------------- 87
B Evidence that Xenon-Fluorine Compounds Were
Formed During the Reactor Irradiation of
CF4-UF6-Xe -----------.---.-------------------- 101
C Disappearance of Xenon in the Reactor
Irradiation of CF4-UF6-Xe ------------------- 103
D Experimental Data ---------------------------- 106
List of References ------------------------------------ 184
Biographical Sketch ---------------------------------- 188
iii




LIST OF TABLES
Table Page
I Impurities in Be, N2, and Ar --------------------- 15
2 Impurities in Materials -------------------------- 16
3 Gamma Irradiation of Standards ------------------- 29
4 Reactor Irradiation of Standards------------------ --- 29
5 Gamma Irradiation of CF4 ------------------------- 30
6 Gamma Irradiation of CF4-UF6 --------------------- 31
7 Gamma Irradiation of CF4-UF6-N2 --------- 32
8 Gamma Irradiation of CF4-UF6-Ar--..................-33
9 Gama rraiaton f C4-UF6-Ar----------------------34
9 Gamma Irradiation of CF4-UF6-Xe ------------------ 34
10 Gamma Irradiation of CF4-UF6-SP6 ----------------- 35
11 Gamma Irradiation of CF4-U74C------------------- 36
12 Reactor Irradiation of CF4---------------------- ----37
13 Reactor Irradiation of CF4-UF6 ------------------- 38
14 Reactor Irradiation of CF4-UF6-A1 Shavings ------- 39
15 Reactor Irradiation of CF4-UF6-N2 ---------------- 40
16 Reactor Irradiation of CF4-UF6-Ar --------------- 41
17 Reactor Irradiation of CF4-UF6-Xe ...- 42
18 Reactor Irradiation of CF4-UF6-SF6 --------------- 43
19 Reactor Irradiation of CF4-UF4-C ----------------- 44
20 Gamma Irradiation Rate Constants for the
Destruction of CF4 ----------------------------- 58
iv




Table page
21 Gamma and Reactor Irradiation Rate
Constants for the Destruction of CF4 ------------ 75
22 Electron Density of Various Materials ----------- 96
23 Reactor Irradiation of CF4-UF6-Xe
Xenon Chromatogram Area ------------------------ 103
v




LIST OF FIGURES
Figure Page
1. Metal Vacuum System ----------------------------- 18
2. Capsule Fluorination System ---------------------- 20
3. Gamma and Reactor Irradiations of Standards ------ 46
4. Gamma Irradiation of CF4 ------------------------- 51
5. Gamma Irradiation of CF4-UF6 --------------------- 52
6. Gamma Irradiation of CF4-UF6-N2 ------------------- 53
7. Gamma Irradiation of CF4-UF6-Ar ------------------ 54
8. Gamma Irradiation of CF4-UF6-Xe ------------------ 55
9. Gamma Irradiation of CF4-UF6-SF6 ---------------- 56
10. Gamma Irradiation of CF4-UF4-C ------------------- 57
11. Reactor Irradiation of CF4 ----------------------- 64
12. Reactor Irradiation of CF4-UF6 -------------------- 65
13. Reactor Irradiation of CF4-UF6-Al Shavings ------- 66
14. Reactor Irradiation of CF4-UF6-N2 ----------------- 67
15. Reactor Irradiation of CF4-UF6-Ar ---------------- 68
16. Reactor Irradiation of CF4-UF6-Xe ---------------- 69
17. Reactor Irradiation of CF4-UF6-SF6 --------------- 70
18. Reactor Irradiation of CF4-UF4-C ---------------- 71
19. G (-CF4) Values--Reactor Irradiations ------------- 79
20. G (-CF4) Values--Reactor Irradiations ------------ 80
21. G (-CF4) Values--Reactor Irradiations ------------ 81
22. Disappearance of Xe in the Reactor
Irradiation of CF4-UF6-Xe ------------------------ 105
vi




Abstract of Dissertation Presented to the Graduate Council
in Partial Fulfillment of the Requirements for
the Degree of Doctor of Philosophy
A NEW CHEMONUCLEAR SYSTEM
FISSION FRAGMENTS AND FLUOROCARBONS By
Richard Norwood Gurley
August, 1967
Chairman: Dr. John A. Wethington, Jr. Major Department: Nuclear Engineering Sciences
The radiolysis of (a) CF4, (b) CF4-UF6, (c) CF4-UF6-N2,
(d) CF4-UF6-Ar, (e) CF4-UF6-Xe, (f) CF4-UF6-SF6, and (g) CF4-UF4-C by gamma photons and by reactor irradiations was studied. The radiolysis of CF 4-UF6-Al shavings by reactor irradiations was also studied. The principal product was C2F4 with traces of C2F60
and C3F80. The parent material, CF4, was also recovered.
For the gamma irradiations, expressions were derived which related the fraction of CF4 remaining after exposure to a known dose. It was found that the charcoal used in the gamma irradiations of CF -UF6-C acted as a scavenger of fluorine.
For the reactor irradiations, a mathematical model which related the fraction of CF4 remaining after exposure to a known dose was obtained. It was found that the C, N2, and Xe in the CF4-UF4-C, CF4-UF6-N2, and CF4-UF6-Xe series acted as scavengers of fluorine.
vii




In the nitrogen experiments, NF3 was produced; in the Xe experiments, XeF2 and XeF4 were produced.
The addition of Al shavings to capsules which contained CF 4-UP6 and subsequent reactor irradiations of these capsules resulted in an increased CF4 destruction rate as compared to the reactor irradiations of capsules which contained only CF4-UF6.
viii




CHAPTER I
Introduction
For some time, interest has been developing in the field of applied radiation chemistry, i.e., the use of ionizing radiation to break chemical bonds, thereby producing chemical products. A chemonuclear reactor has been discussed; this reactor would use radiation-induced chemical reactions or dissociation to produce desired chemical compounds. During 1962, the United States Atomic Energy Commission asked Brookhaven National Laboratory to conduct a study of the United States' research relating to chemonuclear uses of nuclear reactors and to recommend areas where basic and applied research and exploratory development work should be under(1)
taken. Brookhaven National Laboratory suggested that the major
efforts should be concentrated on (1) studying the fundamental radiation chemistry effects peculiar to fission fragments, (2) determining yields, reaction mechanisms, conversions and kinetics for systems that appeared promising, and (3) developing necessary general technology which is unique to the chemonuclear field. Since 1962, chemonuclear research has proceeded at an accelerated pace (refer to Chapter II).
During the past ten years, concurrent to the chemonuclear
-1-




-2
development, there has been a large-scale development of fluorocarbons, and,as early as 1962, it was suggested that an uranium hexafluoride, UF6, fluorocarbon system should be studied for chemo(2)
nuclear possibilities. The uranium hexafluoride-fluorocarbon system would have several distinct chemonuclear features or advantages. First of all, it might be possible to produce fluorocarbons which cannot be produced by conventional chemical processes because of the nonreactive chemical nature of the fluorocarbons. The extreme quantities of energy associated with the fission fragments resulting from the fissioning of uranium in a solution could induce decomposition of the fluorocarbons, and perhaps the subsequent decomposition products would recombine in the form of new fluorocarbons. Secondly, an advantage would be the elimination of the technical problems associated with the range of the fission fragments (average distance fission fragments travel before giving up their total energy to the surrounding matter) within conventional fuel elements. The uranium hexafluoride-fluorocarbon system would have the advantage that the fission fragments would be deposited directly in the fluorocarbon medium. A final possible advantage of such a system would be the fact that UF6 is the uranium compound used in the gaseous diffusion process for producing enriched uranium. Thus, the material
could be used without further processing, thereby eliminating the conversion and fuel-fabrication costs.




-3
Obviously, much information regarding the performance of uranium haxafluoride-fluorocarbon systems in the presence of radiation must be obtained before the desirability of the method as a chemonuclear system can be evaluated. The types of information needed fall under the guidelines outlined by Brookhaven
National Laboratory. Such information should include rates of fluorocarbon decomposition, products formed, G values (molecules of a product obtained or destroyed per 100 ev of energy absorbed), chemical kinetics, etc.
Objectives
The purpose of this work was to study two unique systems which satisfied the requirement that the fission fragments must be deposited directly within the medium of interest. These systems were uranium (VI) fluoride homogeneously mixed with gaseous carbon tetrafluoride, CF and a heterogeneous mixture of solid uranium (IV) fluoride, UP4, mixed with gaseous carbon tetrafluoride. The systems were studied according to the following.
System One:- Uranium hexafluoride was mixed with CF4 and irradiated. The radiolysis products were analyzed for higher molecular weight materials. Since UF6 is an active fluorinating
agent, one might have predicted that no reaction products would result; however, this speculation had to be confirmed by




-4
experiment. This study was followed by experiments designed to study the effect of an increase in the available surface area in the above CF 4-UF6 system. Further work was undertaken in which a third component was added to the CF4-UF6 mixture. Materials tried were nitrogen, argon, xenon, and sulphur hexafluoride.
System Two,- The fluorinating agent UP6, present in the experiments proposed under Plan One, could have immediately fluorinated the ions and radicals formed from the parent material; consequently, CF4would reappear. The compound uranium tetrafluoride, however, is not a fluorinating agent; if UF4 was used, the ions and radicals would be available for reaction with themselves and with other added materials. A CF4-UF4-C system was thus studied to determine if any type of higher molecular weight material could be produced. Elementary carbon
(3)
was included as it was known to be a trap for free fluorine.




CHAPTER II
Previous Chemonuclear Work
Basic and applied research in radiolysis has been carried out over the past fifteen to twenty years by a number of Atomic Energy Commission, university, and industrial organizations. It was not, however, until the fall of 1962 that a coordinated and
(1)
cooperative effort in the chemonuclear area was begun. For
the past five years the chemonuclear interest has been in the production of chemicals through the utilization of the kinetic energy of the recoiling fission fragments. Since 1962, informal meetings of the major research groups involved in fission-frag(4)
ment radiolysis have been held. These groups are divisions
of: Brookhaven National Laboratory, Rennsselar Polytechnic Institute, Union Carbide Corporation, and Aerojet-General Nucleonics. Within the past several years, other research groups associated with Esso Laboratories, Hercules Powder Company, the University of Florida, Illinois Institute of Technology Research Institute, Princeton University, Notre Dame University, and the
University of Michigan have also worked in the radiation chemistry area.
-5-




-6
(1)
Manowitz et al., in their 1962 report to the Atomic Energy Commission, summarized the important chemonuclear areas (see Chapter I),thereby suggesting an orderly sequence of basic, applied, and exploratory research. Manowitz pointed out that the experimental work, up to 1962, with fission-fragment systems had been very limited in scope and essentially exploratory in nature. Nevertheless, because of their high linear energy transfer, LET, fission fragments offered the possibility of being used more effectively than any of the other common forms of radiation. Manowitz also listed several chemicals proposed for chemonuclear production: nitrogen dioxide, carbon suboxide, ethylene glycol, propylene glycol, hydrogen peroxide, hydrazine, and ozone.
Brookhaven National Laboratory Program
(1, 5)
The Brookhaven National Laboratory group is concerned
with the direct and indirect applications of radiation. For the indirect program, they use a Co60 source and generally restrict their attention toI exothermic systems. For their direct radiation program they are concerned with fission fragment studies. They have studied or are studying
(1) N 20, in capsule experiments, to determine its usefulness for dosimetryi
(2) the development of thin fuel bodies,




-7
(3) fission-fragment chemical yields, and
(4) engineering aspects of chemonuclear
production in an in-pile loop.
(6)
Meyer Steinberg of Brookhaven National Laboratory has pointed out that the use of the fissiochemonuclear process for the fixation of nitrogen and the production of synthesis gas (carbon monoxide and hydrogen) is sufficiently interesting from a longtime national goals point-of-view to provide incentive for a continued development of the science and technology of this field.
(7)
Steinberg pointed out that the above products, by chemonuclear processes, can be produced in large quantities at costs which are competitive with the production costs in conventional (8, 9)
processes. Steinberg also suggested chemonuclear systems
for the production of formic acid, formaldehyde, acetylene, nitrous oxide, ammonia, nitrogen dioxide, phenol, carbon suboxide, and (6, 10, 11, 12, 13)
polyethylene. Beller and Steinberg proposed
that ozone produced by the chemonuclear process of irradiating air or oxygen be used for water purification and pollution control.
Rennsselar Polytechnic Institute Program
(1, 5)
The Rennsselar Polytechnic Institute program is proceeding on many fronts. Their personnel have studied or are studying
(1) the irradiation of gases,
(2) N20 to determine its usefulness for dosimetry,




-8
(3) conversions in carbon dioxide-air mixtures at high temperatures,
(4) solid arrays of U235 bearing materials
immersed in gaseous reactants,
(5) ionic reactions of CO2 and N2-O2 mixturesP
(6) ionic reactions using the gases in (5) above with admixtures of rare gases,
(7) the dissociation of N2 molecules in the irradiation of nitrogen,
(8) the dissociation of CO2 in the irradiation
of C02, and
(9) in-pile loop studies of N2, 02, and other gases at various pressures where the loop is loaded with enriched uranium glass fibers.
(14)
Harteck and Dondes have studied nitrous oxide dosimeters in the range of 5 X 104 to almost 1010 roentgen. Neutron fluxes were measured by adding small amounts of U235 to the dosimeter, and neutron dosages at elevated temperatures ( > 2000F)
(15)
were readily determined. Harteck and Dondes studied the irradiation of nitrogen-oxygen mixtures. The data obtained for air and two to one nitrogen to oxygen mixtures showed that, under the proper irradiation conditions, all the oxygen was con(16)
sumed to form nitrogen dioxide and nitric oxide. Dondes et al.




-9
also studied the radiolysis of carbon monoxide in the presence of rare gases. The influence of various rare-gas additives was considered in terms of energy transfer from primarily excited rare gas atoms resulting in the formation of excited carbon monoxide, CO*, followed by dissociation or reaction with another CO molecule. The important discovery was that excited CO molecules reacted with other CO molecules to produce carbon dioxide and car(17)
bon suboxide polymer. Harteck and Dondes studied the fixation of nitrogen in capsule irradiations of nitrogen and oxygen. These men also studied two other systems for fixing nitrogen--the nitrogen-hydrogen system for producing ammonia and the nitrogensulfur system for producing N4S4--and concluded that both were less promising than the nitrogen-oxygen system. Harteck and Dondes also studied the irradiation of gaseous and liquid ammonia for the production of hydrazine.
(18)
Within the past two years, Harteck at al. have explained the decomposition of ozone by ionizing radiation with
(19)
the negative ion-chain reaction mechanism of Fueki and Magee.
(20)
Also within the past two years, Dondes et al. have made a
spectroscopic study of the luminescence produced by Po210 alpha particles in purified noble gases, noble gas-nitrogen mixtures, purified nitrogen, and nitrogen-oxygen mixtures. A major observation was that very small concentrations of impurities or additives--Hg, Ar, Kr, Ne, H2, 02, and NO--increased the luminescence.




-10
(21)
Work at Rennsseler Polytechnic Institute is concurrently
proceeding in the basic-research areas of the carbon suboxide system, the reaction of nitrous sulfide and oxygen atoms, and chemoluminescent studies of the preceding gas mixtures excited by the radiations from a nuclear reactor.
Aerojet-General Nucleonics and Union Carbide Program
The Aerojet-General Nucleonics and Union Carbide groups have
(22)
cooperated, to a great extent, in chemonuclear research, These
(1, 5)
companies have studied or are studying
(1) radiolysis of liquid ammonia,
(2) the energy spectra of fission fragments
escaping from fully enriched U02 powders and plates,
(3) fission-fragment dosimetry, radiation chemistry mechanisms of N2H4 formation,: and new products produced by the irradiation of nitrogen-oxygen-fluorine mixtures, iMand
(4) in-pile loop production of hydrazine from ammonia.
(23, 24, 25, 26)
J. H. Cusack and P. A. King, fissiochemical
program managers for Aerojet-General Nucleonics and Union Carbide
(27)
Corporation, respectively, and Fritsch et al. of Aerojet-General
Nucleonics, have outlined the major studies covering the chemonuclear activities of their companies. Statements or summaries




of the results of these activities are:
(a) While the overall understanding of fissionfragment physical behavior, track effects, chemical reactions amendable to fissiochemical induction, :etc,,were extended, current industrial forecasting techniques showed that no fuel/product combination had economic potential.
(b) General fission-fragment energy equations and the determination of energy-deposition efficiencies for'a number of solid fuel compositions and shapes were obtained.
(c) Ceramic and metallic fibrous fuels for reactor use were developed,with the most promising being ZrO2-UO2.
(d) A number of basic radiation chemistry investigations involving nitrogen or ethylene were conducted. It was found, based on
Co60, electron, and fission-fragment radiolysis of ethylene, that reactions of electronically excited molecules are only slightly affected by pressure or by LET and that an increasing LET increases radicalradical reactions and decreases ionic reactions.




-12
(e) The operation involving the CH4-N2 system in the gas-phase fissiochemical loop showed that the HCN yield varied directly with temperature and flow and inversely with pressure and CH4 concentration. The conclusion was that the fissiochemical production of HCN would be economically marginal at best.
(f) Loop irradiations of CO2 and CH4-C02 mixtures indicated G(CO) values could be as high as ten.
(g) An unexpected fission-fragment induced reaction between CO2 and N2 was discovered. The elemental composition of the resulting solid corresponded to an empirical formu between C4H5N308 and C5H5N404. Aerojet-General Nucleonics is currently studying fission(28, 29)
fragment radiolysis of NF3 and fluorine. Miller et eL have reported the formation of an unidentified nitrogen-fluorine compound resulting from the fission-fragment radiolysis of a mix(29)
ture of NF3 and F2 that is stable at room temperature. Miller is also studying the fissiochemical reaction of nitrogen with carbon monoxide.




-13
Other Fissiochemical Research Programs
(3G)
Princeton and Notre Dame Universities, University of
(31)
Michigan, Stanford Research Institute, Esso Laboratories, and
Hercules Powder Company groups are engaged in basic radiation chemistry studies which are not directly aimed at the development of chemonuclear reactors. Work which is directly associated with the chemonuclear development field has been done by personnel at the Illinois Institute of Technology Research Institute and the University of Florida.
(32)
The Illinois Institute of Technology Research Institute group studied the dependence of the yield of hydrazine on total dose in the fission-fragment irradiation of liquid ammonia. The experiments were conducted in a nuclear reactor where the fission fragments were produced by the bombardment of U235 with thermal neutrons. The most significant result was the fact that large
G(hydrazine) values could be obtained but only at relatively small total doses.
The University of Florida group has studied and is studying (1) the basic effects of radiation on fluorocarbons and (2) fluorocarbon irradiations based on a fluorocarbon-chemonuclear concept.
(33)
Reed et al. of the University of Florida have irradiated samples of pure fluorocarbons. They observed the formation
(3) (33)
of higher molecular weight compounds. Askew and Reed et al.
demonstrated that mixtures of solid carbon and CF4 produced




-14
heavier saturated fluorocarbons when subjected to ionizing radiation. The results indicated that CF4 acted as a fluorinating agent
(34)
for the solid carbon. Reed is presently studying the irradiation of gaseous fluorine-containing moleculeep, such as BF3, SF6, and SiF4, with solid carbon. Other solid substrates such as sulfur and silicon are being investigated.
(35)
Scott of the University of Florida has studied
(1) the radiolysis of perfluorodimethylcyclohexane, C8F16, by gamma photons,
(2) the radiolysis of C8F16 by reactor irradiations, and
(3) the radiolysis of C8F16 by fission-fragments.
The products from the gamma radiolysis of C8F16 were mainly dimers of the parent molecule. The reactor exposure of C F16 gave dimeric products plus gaseous products--mainly CF4 and C2F6--in the ratio of four to one. In the fission-fragment irradiation of C8F16, Scott found no polymeric materials. The products were CF4 and C2F6 in equal amounts,with smaller amounts of C3F .




CHAPTER III
Experimental Frocedure
Starting Materials
The gases helium, nitrogen, and argon were obtained from the Linde Company, a division of Union Carbide Corporation. The purity and moisture content of the gases were as follows.
TABLE I
IMPURITIES IN He, N2, AND Ar
Purity Moisture Content (H20)
Gas % Impurity grains/1000 NPT ft3
He 99.99 H20 5
N2 99.995 H20 5
Ar 99.996 < 0.003 % 02
Xenon was obtained from the Matheson Company, Inc. The gas had a known impurity of 5 ppm krypton with the balance being xenon.
The carbon which was used in several of the experiments was Adsorbite activated charcoal which was obtained from W. H. Curtin and Company. The enriched (93.16 percent U 235) uranium hexafluoride was obtained on loan from the United States Atomic Energy Commission.
-15-




-16
The normal (0.72 percent U235) uranium tetrafluoride powder was obtained from Nuclear Fuel Services, Inc. The radioactive gold foils which were used in the counter efficiency determination (see Appendix A) were obtained from Argonne National Laboratory.
Tetrafluoromethane was obtained from the Matheson Company, Inc. The gas was found to be chromatographically pure and was used without further purification. Sulfur hexafluoride, SF6, was also obtained from the Matheson Company, Inc. This gas contained approximately 1.9 percent carbon tetrafluoride. Perfluoroethane, C2F perfluoropropane, C3F8, perfluoropropene, C F6, and perfluorocyclobutane, C4F8, which were used as standards were all obtained from the Matheson Company, Inc. Information about these materials is tabulated in Table 2.
TABLE 2
IMPURITIES IN MATERIALS
Material Mole % Impurity
CF4 None detected
SF6 1.9, CF4
C2F6 None detected
C3F8 Trace C3F6
C3F6 None detected
C4F8 None detected




-17
Perfluoroethylene, C2F4, which was also used as a standard was obtained from Dr. T. M. Reed of the Department of Chemical Engineering at the University of Florida and was prepared by the vacuum pyrolysis of Teflon. This method, by proper control of the heating procedure, gave approximately 98 percent C2F4, with the remaining
2 percent consisting of higher boiling materials.
Air was removed from the compounds by alternately thawing,
freezing, and pumping on the compounds in a vacuum system until no residual pressure was detected over the condensed compounds. Water was removed from the argon and nitrogen by passing the gases through liquid nitrogen cold traps. The degassed compounds were then stored as gases in storage bulbs on the vacuum system until needed. Fluorination
As UF6' a strong fluorinating agent, was to be used in most of the experiments, it was necessary to fluorinate all the surfaces which were to be exposed to UF6. This fluorination formed a protective fluoride film which prevented the reaction of UF6 with
(36)
the metal surface to produce UF4. Uranium tetrafluoride,
UF4, would adhere to the surfaces and cause difficulties in sample transfers.
" The vacuum system, shown in Figure 1, was fluorinated using fluorine gas from a one-pound cylinder obtained from the Matheson Chemical Company. All the components except the bellows seal




To the chromatograph
. To vacuum pump Sgas sampling valve To vacuum pump
Chromatograph sample Liquid nitrogen
line vacuum cold trap
To glass vacuum
system Carrier gas to Heated
He lium chromatograph HeNaF
NaF
Heating tape
UF NaF
_ Heated
6 trap
Loading Storage tank
and unloading
ports
Calibrated
tanks
Hg manometer Capsule
for
analysis
Figure 1. Metal Vacuum System0
I




-19
valves, Nupro type B-4H, were carefully degreased in chloroform. The bellows seal valves were cleaned by the manufacturer. The trans(35)
fer system was fluorinated by Scott.
Figure 2 shows the system which was used to fluorinate capsules, valves, and other fittings. The copper capsules and all the aluminum and copper fittings were fluorinated in a reaction vessel, while the larger capsules and all the valves were fluorinated by insertion into a nitrogen-fluorine stream.
The capsule fluorination system, as shown in -Figure 2, was pressure tested at 55 psig (i.e., the system was isolated) for a 12-hour period. At the end of the test period, the pressure was
released. Pressurization and release operations were repeated three times to purge the air from the system. The glass bubbler (see Figure 2) was connected, and a steady flow of nitrogen was established. The fluorine pressure on the regulator outlet was raised to 12 psigi, and fluorine was introduced into the system by opening the outlet valve for a period of one second at intervals of 30 seconds. This procedure was continued until a definite temperature change was detected in the sodium chloride trap. At this time, the system was purged with nitrogen for about ten minutes. The glass bubbler was removed and the previously described pressurization and release operations twe carried out three times.




Valves to be
fluorinated.
Whitey I VS4 Al
Whitey I V4, AI Small capsules Gas regulators
Whnity 1 VM4 and fittings to
Wupro~~T vente lornae
vessel' "loar -----Fluorine La apsules to be fluorinated cylinder
cylinder
~~vessel...
gaol trap P bb~hdoxdPtassium ovn
Figure 2. Capsule Fluorination System




-21
Capsule Fabrication
Capsules for Gamma Irradiations:The capsules for the gamma irradiations were fabricated from five-inch sections of one-half inch copper or aluminum 60-61 tubing. One end of the capsule was crimped, and depending on whether it was a copper or aluminum tube, it was either silver soldered or heli-arc welded so as to seal that end. The excess flux was removed by immersion in boiling water. The capsules were then degreased with chloroform and fluorinated. The open ends were sealed with either a brass valve (1-VM 4) or an aluminum valve (i-VM 4 Al) attached to the tube by means of brass or aluminum Swagelock fittings. The valves and fittings had also been degreased and fluorinated. The capsules were then pressure tested (300 psig, nitrogen) and vacuum tested.
Capsules for Reactor Irradiations:The aluminum capsules, as described above, were also used for heterogeneous reactor irradiation involving UF4. Additional capsules were fabricated from five and one-quarter inch sections of three-inch 60-61 aluminum pipe. The diameter selection was based
upon knowledge of the range of fission fragments in the component materials. The capsule ends were sealed with 60-61 aluminum end plates which were heli-arc welded to the capsule body. The end plates had one-fourth inch 60-61 aluminum tube inserts heli-arc




-22
welded into them. After the capsules had been degreased and fluorinated, one end was completely sealed by using a one-fourth inch fluorinated aluminum cap or by crimping the insert tube and heliarc welding this tube. The other end of the capsule was sealed with an aluminum valve (I-VS 4 Al) attached to the one-fourth inch welded insert tube with fluorinated aluminum Swagelock fittings. The capsules were then pressure tested (300 psig, nitrogen) and vacuum tested. If the capsule, valve, or valve connections leaked, the faulty part, or parts, were discarded. Sample Preparation
All the samples were prepared using the vacuum system as
shown in Figure 1. The capsule to be loaded was attached to the
system via a loading port, and the system was then both pressure and vacuum tested. Most of the components, which were to be loaded, contained some dissolved air; therefore, the procedure for removing air as discussed under Starting Materials had been performed, and these compounds were already stored in storage bulbs either on the metal system or the connecting glass vacuum system (not shown in Figure 1).
The UF storage tank and the capsule to be loaded were connected through the vacuum system (the volume of the capsule had previously been determined by nitrogen volume expansion using the ideal gas law), and the system was allowed to equilibrate for five




-23
minutes at room temperature. The capsule was then closed, and the remaining UP6 was recondensed into the storage tank by applying liquid nitrogen to the nipple of the tank. Using the vapor pres.
sure for UF6, as given in Reference (37) for the observed room temperature, the weight of the UP6 in the capsule was calculated by the ideal gas law.
Second and third components which could be condensed by liquid nitrogen--CF4, Xe, and SF6--were loaded as follows. A calibrated tank, either the 758 cc or the 60 cc tank (as shown in Figure 1), was loaded to the desired pressure by volume expansion from a storage bulb. The calibrated tank was then closed, and the remaining gas in the system was recondensed into the storage bulb. Liquid nitrogen was placed around the capsule, and after some three minutes the capsule and the calibrated tank were connected through the system. After the gas had been transferred, the capsule valve was closed, and the capsule was removed from the system. If the capsule was to be exposed to reactor irradiation, a gold wire weighing
approximately two milligrams, weighed to the nearest 0.001 milligram,, was wrapped in filter paper and attached to the capsule with tape. This wire served as a flux monitor.
The loading of argon or nitrogen as a third component was not accomplished by a freezing method. A calibrated tank was loaded with either argon or nitrogen, and after the UF6 was condensed in the capsule, the calibrated tank and the capsule were




-24
interconnected in order to allow volume expansion. The pressure was read before cooling occurred. The ideal gas law was then used to calculate the amount of gas that was loaded.
The capsules which contained CF, TJF4, and C were loaded differently. As the UF4 and C were solids, they were first mixed, and the capsules were then loaded to the desired weight. The capsule was attached to the vacuum system and baked at 1100 C and pumped. Then, the above procedure for loading a third component was carried out.
The volumes of the above-mentioned calibrated tanks were found by filling the tank with water in a constant temperature bath. Subtraction of the empty tank weight from the full tank
weight gave the weight of the water in the tank. This weight was converted to volume using the density of water at the temperature of the bath.
Irradiations
Gamma Irradiations:
The gamma irradiations were performed in the University of Florida C60food irradiator. The source was in the form of 96
plates which were arranged so that a relatively flat gamma flux was obtained. The capsule was placed in a container, and this container was lowered into the irradiator and exposed to the desired dose.
(38)
The gamma dose was measured by the Fricke dosimetry method.




-25
University of Florida Training Reactor Irradiations:The reactor irradiations were performed in the thermal
column of the University of Florida Training Reactor which has been
(39)
described by Boynton.
The plastic handles on the capsule valves were removed. A four-foot section of a graphite stringer with a 4 X 4 inch cross section was removed from the thermal column. The stringer was immediately adjacent to a 12 X 8 X 4 inch lead gamma shield which was adjacent to the reactor core. The capsule was inserted into the stringer void. The reactor was brought to full powerwith the absorbed dose being controlled by the time of the irradiation.
Upon removal from the reactor, the capsule was monitored and stored in a fuel storage pit until the radiation intensity had dropped to a level which permitted handling of the capsule in order to connect it to the vacuum system.
Analysis
The use of chromotography to analyze fluorocarbon systems (3, 33, 34, 35, 40, 41)
has been reported by several persons. In
this study the analysis of the samples was performed with a Model 700 F ond M Chromatograph coupled with a Model 240 F and M Temperature Programmer. This instrument had thermal conductivity detectors.
The capsules which were to be analyzed were connected to the vacuum system through a controlled temperature sodium fluoride




-26
trap. The trap was used to remove the UF6 and the fission fragments from the sample. The sample was transferred to the vacuum system and checked for residual radioactivity. If fission fragment or UF6 passage occurred, the sample was transferred back through the sodium fluoride trap. No sample required more than three passes.
.The sample was allowed to stand for approximately one hour in the vacuum system so that equilibrium could be established. The sample was then chromatographed several times via a chromatograph gas sampling valve using a 10 cc gas sample loop. The pressure of the sample was controlled to obtain the maximum chromatographic sensitivity. A silica gel column (see Appendix D) was used for this analysis.




CHAPTER IV
Experimental Results
The experimental results, calculated from the experimental data as given in Appendix D, are tabulated in Tables 3 through 19. The composition of each sample in a given table is approximately the same (the details are given in Appendix D). Tables 3 and 4 present the results of the gamma and reactor irradiations of the standards which contained only air at atmospheric pressure. These tests were made to determine if the Teflon valve packing and the valve stem tips would decompose during radiolysis. Tables 5 through 11 give the results of the gamma irradiation of (a) CF4, (b) CF4-UF6,
(c) CF4-UF6-N2, (d) CF4-UF6-Ar, (e) CF4-UF6-Xe, (f) CF4-UF6-SF6, and
(g) CF4-UF4-C. The following explanation is given for the various table headings. In the gamma irradiations the doses in ev were
calculated (see Appendix A) from the doses in rads as determined by
(38)
Fricke dosimetry. The percentage of the CF4 that was converted
into C2F4 was based on a carbon balance. Sample calculations for these percentages are shown in Appendix A.
Tables 5 through 11 also show selected G values for the gamma irradiations. The G value is defined as the number of molecules of
-27-




-28
a given substance that is produced or destroyed per 100 ev of energy absorbed in the sample. For example, for sample No. 116, Table 6, G (C2F4) is 0.454, and,accordingly, approximately one-half molecule of C2F4 was produced per 100 ev of energy absorbed by the CF4. The disappearance of CF4 is given as G (-CF4)--the number of CF4 molecules lost per 100 ev of energy absorbed in the CF4. A sample calculation for the G values is given in Appendix A. It should be noted that the G values were dose dependent; consequently one must be careful about speaking of a G value for a given system.
Tables 12 through 19 present the results for the University of Florida Training Reactor irradiations of (a) CF4, (b) CF4-UF6,
(c) CF4-UF6-Al shavings, (d) CF4-UF6-N2, (e) CF4-UF6-Ar, (f) CF4UF6-Xe, (g) CF4-UF6-SF6, and (h) CF4-UF4-C. The method used for calculating the integrated thermal neutron flux and absorbed energy is outlined in Appendix A. One additional experimental series, as compared to the gamma study, was irradiated with the reactor. This'series, CF 4-UF 6-Al shavings, was included to demonstrate the effects of surface area on the irradiation induced reactions.
The range of error for the decomposition and the G values as given in Tables 3 through 19 is estimated to be on the order of 10 to 15 percent based upon an analysis of variance.




-29
TABLE 3
GAMMA IRRADIATION OF STANDARDS
Capsule Gamma Dose Units of Fluorocarbon
No. (Rads X 10-8). Recovered--Chromatogram
101 0 0
102 1.0 0
103 2.5 0
TABLE 4
REACTOR IRRADIATION OF STANDARDS
Integrated Thermal
Capsule Neuton Flux Units of Fluorocarbon
No. (n/cm2 X 10"14) Recovered--Chromatogram
104 0 0
105 4.42 0
106 16.0 0
107 4.59 0
108 17.2 0




TABLE 5
GAMMA IRRADIATION OF CF4
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
109 0 100
110 6.61 99.6 0.4 0.510 0.255
111 16.6 99.4 0.6 0.307 0.153
* For the details of the calculations, see Appendix A.
0




TABLE 6
GAMMA IRRADIATION OF CF4-UF6
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
115 0 99.8 0.2
116 5.25 99.4 0.6 0.908 0.454
117 10.0 99.0 1.0 0.795 0.398
118 15.3 98.7 1.3 0.783 0.392
8
L*
8




TABLE 7
GAMMA IRRADIATION OF CF4-UF6-N2
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
119 0 100
120 6.67 99.6 0.4 0.582 0.291
121 16.5 99.4 0.6 0.350 0.175
a
t.3
a




TABLE 8
GAMMA IRRADIATION OF CF4-UF6-Ar
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
122 0 100
123 7.21 99.4 0.6 0.862 0.431
124 18.0 98.5 1.5 0.863 0.431
I
wu




TABLE 9
GAMMA IRRADIATION OF CF 4-UF6-Xe
Gamua Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
125 0 99.8 0.2
126 9.92 99.2 0.8 0.797 0.398
127 14.7 98.8 1.2 0.806 0.403
S




TABLE 10
GAMMA IRRADIATION OF CF4-UF6-SF6
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-20) CF4 C2F4 of CF4 of C2F4
128 0 100
129 14.3 99.6 0.4 0.276 0.138
V1
tI




TABLE 11
GAMMA IRRADIATION OF CF4-UF4-C
Gamma Dose Percentage of CF4 Recovered G Values
Capsule to CF4 as Decomposition Formation
No. (ev X 10-19) CF4 C2F4 of CF4 of C2F4
130 0 100
131 1.04 98.3 1.7 164.9 82.5
132 3.35 96.0 4.0 120.5 60.2
-%~




TABLE 12
REACTOR IRRADIATION OF CF4
Integrated Thermal Percentage of CF4 Recovered
Capsule Neutron Flux as
No. (n/cm2 X 10-14) CF4 C2F4 C2F60 C3F80
112 0 100
113 1.15 99.9 0.1 Trace
114 3.11 99.8 0.2 Trace -




TABLE 13
REACTOR IRRADIATION OF CF4-UF6
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-21) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
133 0 99.8 0.2
134 0.676 95.8 4.2 6.92 3.46
135 0.983 92.3 7.7 8.35 4.18
136 1.04 91.8 8.2 Trace 8.14 4.07
137 2.35 86.0 13.0 1.0 6.03 2.80
138 3.78 86.7 13.3 Trace 3.54 1.77
139 4.80 86.9 12.9 0.2 2.98 1.47
140 5.11 87.4 12.6 Trace 2.43 1.22
141 8.11 88.6 10.5 Trace 0.9 1.44 0.661
LCo
I




TABLE 14
REACTOR IRRADIATION OF CF4-UF6-AL SHAVINGS
Energy Absorbed Percentage OF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-19) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
142 0 99.3 0.7 Trace
143 3.58 96.7 3.3 Trace Trace 96.6 48.3
144 5.22 95.3 4.7 Trace Trace 95.7 47.9
145 13.5 93.9 6.1 Trace Trace 48.0 24.0
146 24.8 92.6 7.1 0.3 31.7 15.2
147 26.5 92.4 7.6 Trace Trace 29.0 14.5
S
'0




TABLE 15
REACTOR IRRADIATION OF CF4-UF6-N2
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-21) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
148 0 100
149 1.00 97.1 2.1 Trace Trace 3.00 1.09
150 2.40 95.1 4.9 Trace Trace 2.20 1.10
151 3.66 94.1 4.4 1.5 1.67 0.621
152 4.71 94.1 4.3 Trace 1.6 1.39 0.506
153 9.80 88.8 11.2 1.27 0.605
0
O
s




TABLE 16
REACTOR IRRADIATION OF CF4-UF6-Ar
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-21) CF4 C2F4 C2F60 C3F80 of CF4 of C 2F4
154 0 99.6 0.4
155 0.762 97.4 2.6 3.43 1.72
156 2.19 92.3 7.7 Trace 3.61 1.90
157 3.13 89.9 9.8 0.3 3.38 1.64
158 4.68 91.7 8.3 Trace Trace 1.85 0.924
159 5.48 92.5 6.3 Trace 1.2 1.47 0.616
4




TABLE 17
REACTOR IRRADIATION OF CF4-UF6-Xe
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-21) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
160 0 99.4 0.6
161 0.970 88.0 12.0 Trace 12.5 6.25
162 2.54 77.9 22.1 Trace 8.75 4.38
163 3.82 64.7 33.8 1.5 9.13 4.34
164 5.87 54.4 43.8 1.8 8.52 4.09
165 7.74 46.6 55.4 Trace Trace 6.36 3.30
I
1%)
a




TABLE 18
REACTOR IRRADIATION OF CF4-UF6-SF6
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-21) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
166 0 100
167 1.13 90.1 6.63 3.27 9.97 3.34
168 2.71 87.2 12.8 Trace Trace 5.49 2.75
169 3.56 81.6 6.20 Trace 12.2 6.13 0.979
170 4.25 83.7 10.1 Trace 6.2 4.00 1.24
171 9.09 87.1 5.7 Trace 7.2 1.47 0.325




TABLE 19
REACTOR IRRADIATION OF CF4-UF4-C
Energy Absorbed Percentage CF4 Recovered G Values
Capsule by CF4 as Decomposition Formation
No. (ev X 10-19) CF4 C2F4 C2F60 C3F80 of CF4 of C2F4
172 0 100
173 0.622 100
174 1.53 99.7 0.3 20.3 10.2
175 1.74 99.4 0.6 35.7 17.9
176 2.94 99.4 0.6 21.6 10.8
177 6.00 99.4 0.6 10.6 5.30
I




CHAPTER V
Discussion of Results
Introduction
Figure 3 shows the results of the gamma and reactor irradiations of standard capsules. These capsules contained air at atmospheric pressure. These irradiations were undertaken to evaluate to what extent, if any, the Teflon packing and stem tips of the valves incorporated into the experimental capsules would decompose. As seen in Figure 3, no fluorocarbon products were detected. This indicated that the valve stem packing and stem tips did not add to the fluorocarbon products during radiolysis of the experimental capsules.
Gamma Irradiations
Radiolysis Products and Reaction Mechanisms:The gamma irradiations of (a) CF4, (b) CF4-UF6,
(c) CF4-UF6-N2, (d) CF4-UF6-Ar, (e) CF4-UF6-Xe, (f) CF4-UF6-SF6, and (g) CF4-UF4-C yielded primarily the unsaturated compound C2F4 and traces of C2F60 and C3F80. The reactant material CF4 was also recovered. The results of these irradiations are listed in Tables
5 through 11, and the experimental data are listed in Appendix D.
-45-




e-46
0 Capsuls 01
0 c
102 o 103
4
*r4
1.0 2.0
Gamma dose to t120 at location of Capsule (RdsX10-8)
1
o o 0 0---w Capsules 104
t105 0 103
M
DC
4I
1.0 2.0
Gamma dose to H20 at location of Capsule
(RadsXlO18)
14
0 0Capsules 104 105
106
4 rI
0 0
0 -4
0
0
10
5.0 10.0s15.00.0
Integrated thermal nesutron flux
.(n/cm 2X10O1 )
Figure 3. Gamma and Reactor Irradiations of Standards




a47
The formation of the radiolysis product C2F4 can be explained by the following combinations of reactions:
a. radical formation (1) followed by a disproportionation reaction (2)
b. molecular expulsion of F2 (3) followed by radical recombination (4)
CF4 -CF3 + F (1)
2CF3 C2F4 + F2 (2)
CF4 -CF2 + F2 (3)
2CF2 C2F4 (4)
Other possible reactions are: C2F4 + 2F2 2CF4 (5)
CF3 + F CF4 (6)
CF2 + F2 1-CF4 ,(7)
The material C2F4 also underwent radiolysis, and these products reacted with fluorine to produce CF4. These mechanisms for the
production of C2F4 and reformation of CF4 are proposed for demonstration only and do not necessarily include all the possible reactions.
The above reactions that produced CF4 required fluorine as a reactant. During gamma radiolysis the only sources of fluorine were the radiolysis of CF4 UF6' and UF 4, the natural




radioactive decay of UF6 or UP4, and the spontaneous fission of the uranium nuclei.
The oxygen in the radiolysis products of C2 F 60 and
C3F80 (refer to Appendix D) came from dissolved or adsorbed oxygen in the components. Aluminum oxides on the inner surfaces of the capsules were not oxygen sources, as the capsules were fluorinated before being used. The random variation in the amount of radiolysis products that contained oxygen indicated that the amount of oxygen varied from capsule to capsule.
Justification of Components:(3)
Askew found that the presence of CO and C in the gamma and reactor irradiations of CF4 resulted in the destruction of CF4 and the creation of higher molecular weight compounds. He concluded that C acted as a scavenger for fluorine during the
(42) (43)
radiolysis. Simons and Reed both indicated that N2 might
act like C during radiolysis. This present study was, in part, designed to capitalize on the mechanism of tying-up the fluorine with carbon or nitrogen. If fluorine were not available, the back reactions producing CF4 would not occur, and the destruction of CF4 would lead to higher molecular weight compounds or unique compounds.
The materials Ar, Xe, and SF6 were used to determine if compounds containing these materials could be produced. There




-49
was no reason to believe that Ar or SF6 could act as scavengers of fluorine.
Gamma Radiolysis Model:If one writes the overall radiolysis reaction for CF4
ajs k1
2CF4 a C2F4 + F2
Ok2
where kI is the rate constant for the forward reaction and k2 is the rate constant for the two back reactions, and if one assumes that very little free fluorine and C2F4 were produced during the gamma radiolysis experiments, then the back reactions involving k2 were very slow. Thus the number of CF4 molecules destroyed was proportional to the number of CF4 molecules present and to the dose received, or
dN C< NdD
dN/dD 0> N
where N = number of molecules of CF4
dN/dD = rate of disappearance of CF4 D = total dose
then dN/dD = -kiN.
The minus sign indicates that dN is the number of molecules lost. Rearranging and integrating from N = No to N = N and from D = 0 to D = D gives




-50
In (N/N0) = -kID
(NIN0) = e kID
100 (NI 0) l0e'k D
logl0 [(N/NO) I00].= -KD + 2
where K k1/2.303.
The results of the gamma irradiations are plotted in
Figures 4 through 10 as logl0 [(N/N0) 1003 versus the total absorbed energy, D in ev, in the CF4. The symbol N/N0 is the fraction of the CF4 that was recovered after the radiolysis. The plotted points are the experimental data points, and the solid lines resulted from least-square fits to the experimental points. The reaction rate constants, K, are given for the various experimental systems. Knowing K, one is able to predict the number of molecules of CF4 remaining after the sample has received a known dose of gamma radiation. As the dimensionless ratio, N/NO, is used, the units for N or No may be any convenient unit which is related to the number of molecules.
Discussion of Figures 4 Through 10:Figure 4 shows the results of the gamma irradiations of capsules which contained CF4. For zero dose, there was essentially 100 percent recovery of CF4. As the irradiation process




-51
1ogl0[(Ni/N.)1oo] -KD + 1.9997 K =1.510X10- *4v1
2.0
00
0
~. 1.990Capsules 109
o 110
1.98 0 II
0 5.0 10.0 15.0 20.0
*Gammna dose to CF4 (evXlO-2 )
Figure 4. Gamma Irradiation of CF 4




-52
2.000 logo0 o[( )1o0 -K + 1.9991
(L 0-24 -1
K = 3.192X10 ev
00
o
S1.990
Capsules 115 116
.117
118
1.980 I I I I
0 5.0 10.0 15.0 20.0
Gamma dose to CF4
-20
(evXlO0 )
Figure 5. Gamma Irradiation of CF4-UF6




-53
2.000log10 [(N/N0)100) KD + 1.9997
K =1.515X10 e
0
0
6, 1.990 Capsules 119
L --- j120 0 121
1. 980 II
0 5.0 10.0 15.0 20.0
Gammna does to CF4 (evXlO- 20)
Figure 6. Ga ma Irradiation of CF4- -N




-54
2.000 log10 (NI/N0 )100 -KD + 2.0000
K = 3.646X10 ev
0
o
0
z
1.990 Capsules 122
123
" 124
1.980, I I I
0 5.0 10.0 15.0 20.0
Gamma dose to CF4
-20
(evXlO )
Figure 7. Gamma Irradiation of CF4-UF6-Ar




-55
2. 000 10gl [e(YN)100] -ID + 1.9992
K -2.923X1024ev-1
0
1.990Capsules 125 o 126
60 127
1.980 II
0 5.0 10.0 15.0 20.0
Gamma dose to CF4 (evXlO- 20)
Figure 8. Gazua Irradiation of CF4-UF6 -Xe




-56
iog1o [(N0 )1001 -KD + 2.0000
2.00N K = 1.218X1024ev-1
1.8
00. 00 502.
Gam0oet F
zeX02
Figure 9.GmaIrdapsule 128P-F6-S




-57
2.000 lol [IN0 )100o1 = -KD + 1.9992
-22 -1
K 5. 154X10-e
0o 0
0
z I Capsules 130
'6. 1990 131
132
0
1.980 "I
0 1.0 2.0 3.0 4.0
Gaimma dose to CF 4 (evXlO 19)
Figure 10. Gammna Irradiation of CF4-TJF4-C




-58
continued, small amounts of CF4 were destroyed. It is known that
the strength of the first C-F bond in CF is more than 6.68 ev/mole(44)
cule, which is greater than in any other fluorocarbon. Accord(3)
ingly, Figure 4 shows this stability of CF4. Askew and Reed et
(33)
al. have obtained similar results.
As can be seen for the zero dose situation in Figures
5 and 8, the addition of UF6 and subsequent storage of the capsule
for 60 days resulted in the destruction of very small amounts of
CF4. This phenomenon was not observed in the experimental series
shown in Figures 4, 6, 7, 9, and 10. These very small amounts of
CF4 destroyed at zero dose can be explained by the natural radioactivity of UF6 and by the spontaneous fission of the uranium
nuclei in the UF6.
The rate constants for the destruction of CF in the
gamma experimental series are listed in Table 20.
TABLE 20
GAMMA IRRADIATION RATE CONSTANTS FOR THE DESTRUCTION OF CF4
-1
System K, ev 1
-24
CF4 1.510X10
-24
CF4-UF6 3.192X10
CF4 1-UF6 .515X10-24
CF4-UF6-Ar 3.646X1024
-24
CF4 -UF6-Xe 2.923X10
-24
CF4-UF6-SF6 1.218X10
-22
CF4-UF4-C 5.154X10




-59
The experimental series CF4-UF6, CF4-UF6-N2, CF4-UF6-Ar, CF4-UF6-Xe, and CF4-UF6-SF6 contained the same number of starting CF4 and UF6 molecules; therefore, they can be compared with one another. The experimental series C74 and CF4-UF6 contained the same number of starting CF4 molecules, thus they can be compared with each other.
For all the samples, except CF4-UF4-C, the statistics do not justify the conclusion that a real difference exists in the reaction rate constants. Nevertheless, it appears that the UF6 in the CF4-UF6, CF4-UF6-Ar, and CF4-UF6-Xe series did somewhat increase-the CF4 destruction rate. The natural radioactivity of the UF6 and the spontaneous fission of the uranium nuclei cannot be cited as the reason for this reaction rate difference. By referring to Appendix D, it can be seen that traces of the oxygen compounds C2F60 and C3F80 were found in the CF4-UF6, CF4-UF6-Ar, and CF4-UF6-Xe series,whereas the results of the CF4, CF4-UF6-N2, and CF4-UF6-SF6 series did not show oxygen compounds. The difference that existed in the reaction rates can be explained by the fact that the capsules which contained the greater amounts of adsorbed or dissolved oxygen would result in the larger CF4 destruction rates.
For the experimental tests which Qontained CF4-UF6-N2, it is not evident that N2 acted as a scavenger of fluorine. There is also no real evidence of any reactions involving Ar, Xe, and SF6.




-60
From the zero dose case as shown in Figure 10, it can be seen that the 1UF4 and C in the capsules containing CF4-UF4-C did not induce the destruction of CF From Table 20 it can be seen that the rate constant for the CF4-UF4-C series is some 100 times larger than the other experimental rate constants. It is therefore hypothesized that the carbon and perhaps the UF4 acted as scavengers of fluorine and thereby reduced the back reactions, which yielded CF4, to essentially zero. Thus an increased CF4 destruction rate occurred.
Gamma Irradiations, G (-CF4) Values:Tables 5 through 11 list the G (-CF4) and the G (C2F4) values for the various gamma experimental series. The 'data show that (1) the G values were dose dependent and (2) the G (-CF4) values for the CF4-UF4-C series were larger by a factor of 100 than the G values obtained in the homogeneous experiments. This latter fact indicates that an accelerated reaction rate occurred in the CF4-UF4-C series. This validates the hypothesis that carbon acted as a scavenger of fluorine causing a greater rate of destruction of CF4.




Reactor Irradiations
Radiolysis Products and Reaction Mechanisms:The reactor irradiations of (a) CF4, (b) CF4-UF6,
(c) CF4-UF6-Al shavings, (d) CF4-UF6-N2, (e) CF4-UF6-Ar, (f) CF4-UF6-Xe, (g) CF4-UF6-SF6, and (h) CF4-UF4-C gave the same products as were found in the gamma radiolysis experiments. Traces of C2F60 and C3F80 were produced in all of. the reactor tests, except for the CF4-UF4-C series, as can be observed in Tables 12 through 19. The reasons why traces of the oxygen compounds were not found in the CF4-UF4-C series were the slow reaction rates of this series and the fact that air is not soluble in UF4.
The mechanisms for the formation and destruction of C2F4 as discussed in the Gamma Irradiations section are considered to be valid for the reactor irradiation experiments. The rate of C2F4 destruction depended upon the concentration of free fluorine and the rate of energy deposition in the system. As will be discussed later, more and more free fluorine was available as the reactor irradiations continued. Thus the back reactions that produced CF4 were very important in the reactor experiments.
Justification of Components:The series (a) CF4, (b) CF4-UF6, (c) CF4-UF6-Al shavings, (d) CF4-UF6-N2, (e) CF4-UF6-Ar, (f) CF4-UF6-Xe, (g) CF4-UF6-SF6,




-62
and (h) CF4-UF4-C were selected for reactor irradiations. The reasons why these mixtures were chosen, ,except for the CF4-UF6-AI shavings mixture, have been discussed in the gamma analysis section.
(3)
Askew reported that the presence of aluminum powder in the gamma and neutron radiolysis of CF4 increased the yield of all the products. The reason cited for this increase was that surfaces affect gas phase radiolysis in which free atoms are in(3, 45)
termediates. The series CF4-UF6-Al shavings was included
in the reactor irradiations in order to evaluate the Al surface area effect.
Reactor Radiolysis Model:As the reactor irradiations continued, more and more free fluorine became available in the capsule. The concentration of the fluorine resulted from several independent sources. The radiolysis of CF4 produced fluorine. Each uranium atom that fissioned released six fluorine ions or atoms, and apart from the
(46)
fissioning process, it has been reported that the neutron irradiation of UF6 yields UF5 and F2. Thus the concentration of F2 was directly proportional to the energy received.
The differential equations which describe the system
2 CF4 k C2F4 + 2 F2
k2




-63
are
dA/dD = k2DB kjA dB/dD = k1A k2DB where A = number of molecules of CF4
B = number of molecules of C2F4 dA/dD = rate of disappearance of CF4 dB/dD = rate of disappearance of C2 F4 D = total dose.
If the F2 produced is not scavenged, then the rate of the back reactions producing CF4 is large. For this situation, the solutions to the above equations are not readily tractable. The set of equations can be solved, however, by the use of the analogue computer. If the free fluorine is removed by a scavenger, the back reactions are very slow, and the equation
dA/dD = -klA
gives the solution
log10 [(A/A0) 100 1 = -KD + 2
where Ao = starting number of molecules of CF4
K = kl/2.303.
The results of the reactor irradiations are plotted in Figures 11 through 18. Figures 12, 13, 15, and 17 are plotted as the fraction of the CF4 recovered, A/Ao, versus the total absorbed




-64
2.000 -0
0
0
4. 1.990
it Capsules 112
o 113
114
1.980o I I I
0 1.0 2.0 3.0
Integrated thermal neutron flux (n/cm2XlO"14)
Figure 11. Reactor Irradiation of CF4




-65
dA/dD =k2DB k IA dB/dD = k1A k2DB
1.0 =l 8.00X1023e1w
k= 1.1OX1O-22ev-1
S0.9
V 0
.01
"0.8
o Capsules 133
0 134
'F.' 135
136
r-, o.7137 ~ 0.7138 139
140
141
0.6
0.5I I
0 2.0 4.0 6.0 8.0
Energy absorbed by CF4 GV1-21
Figure 12. Reactor Irradiation of CF4-UF6




-66
dA/dD k2DB klA dB/dD = k1A k2DB ki 8.00X10-220v1l k2=2.50X1022 ev
10
S0.9
0
9
.4Capsules 142
u 143
* 144
0.8 145
4I4 146
a 147
0
0 5.0 10.0 15.0 20.0 25.0
Energy absorbed by CF4 (evXlO -19 )
Figure 13. Reactor Irradiation of CF4-11F6-Al shavings




-67
2.000 (0
1.990 0logl0 (A/Ao)100] = -KD + 1.9961
K = 5.066X10-24ev-1
Capsules 148 149
1.980 150
0 151
8 152
153
0
-1.970
0
,,-4
1.960
1.950
0
1.940 I I I
0 2.5 5.0 7.5 10.0
Energy absorbed by CF4 (evXlO-19
Figure 14. Reactor Irradiation of CF4-UF6-N2




-68
dA/dD = k2DB -klA dB/dD = klA -k2DB ki= 6.OOX1O-2 ev k= 1.60X1022ev-l
1.0
0.
Capsules 154 155
o 156
* 157
4 0.8 158
159
0
0
U
0. 6L
0 1.0 .2.0 3.0 4.0 5.0
Energy absorbed by CF4 Ovl- 21
Figure 15. Reactor irradiation of CF4-UF6 -Ar




-69
2.000 -log10 [(A/A.)loo] --KD + 1.9905
K 4.273X1023ev1
Capsules 160 r 1.900 161
o 162
-% 163
0
164
165
o 1.800
1.700
1.600 II
0 2.0 4.0 6.0 8.0
Energy absorbed by CF4 Ovl- 21
Figure 16. Reactor Irradiation of CF4-UF6-Xe




dA/dD = k2DB k1A dB/dD k 1A k2DB k= 7.50X10-2 ev
-22 -1
k= 0.785X10 ev
1.0
00
00
0.0
0 167
00 cd0.7
o4 171
0
0.6 II
0 2.0 4.0 6.0 8.0
Energy absorbed by CF4 (evXlO-2 )
Figure 17. Reactor Irradiation of CF4-'UF6-SF6




-71
2.000 (O O O
000
logl0 [(A/Ao)100] = -KD + 1.9994 o -25 -1
K = 4.503X10 ev o1.990
Capsules 172
o 173
e 174
175
176
177
1.980
I I i I
0 1.0 2.0 3.0 4.0 5.0
Energy absorbed by CF4
-21
(evXlO )
Figure 18. Reactor Irradiation of CF 4-UF 4-C




-72
energy, D in ev, in the CF4. The plotted points are the experimental data points, and the solid lines resulted from curve fitting the experimental data points. This was accomplished by using the analogue computer and the basic reaction model as described above. The reaction rate constants kI and k2 are given for the various experimental series.
Figures 11, 14, 16, and 18 give the results of the reactor irradiations of the CF4, CF4-UF6-N2, CF4-UF6-Xe, and CF4-UF6-C series. These results are plotted as log 10 [(A/A0) 100] versus the total absorbed energy, D in ev, in, the CF4. The fraction of the CF4 that was recovered after radiolysis is represented by A/A The plotted points are the experimental data points, and the solid lines resulted from a least-square fit to the experimental data points. The reaction rate constants, K, are also given.
Discussion of Figures 11 Through 18:The negative slopes shown in Figures 11 through 18 were expected by analogy with the gama irradiation experiments. Figure 11, the reactor irradiation of CF4, shows the stability of CF4 to reactor irradiation. This was as expected by analogy with the gamma irradiation of CF4, Figure 4.
The results as presented in Figures 14, 16, and 18 show the effect of fluorine removal. The conclusion is that N2, X, and C acted as scavengers of fluorine and thus removed the fluorine




-73
which was necessary for the back reactions. These results in the (3,
cases of the C and N2 series were not unexpected. Other workers 33)
have reported that carbon acted as a scavenger of fluorine in the gamma and reactor radiolysis of CF4, and for the CF4-UF6-N2 series, the high energy environment is necessary for NF3 formation. The somewhat surprising result was the fact that Xe acted as a scavenger of fluorine. An extensive effort was made (see Append'ices B and C) to validate this conclusion. The results of this investigation indicated that xenon compounds, probably XeF2 and XeF4, were formed during the radiolysis experiments. It is not certain at this time whether or not other xenon compounds were also formed.
Figures 12, 13, 15, and 17 show the results of the reactor irradiations of CF4-UF6, CF4-UF6-Al shavings, CF4-UF6-Ar, and CF4-UF6-SF6. The CF4-UF6, CF4-UF6-Ar, and CF4-UF6-SF6 results show the effect of the absence of a scavenger of fluorine. As the irradiation continued, an increased rate of CF4 production by the back reactions occurred. Figures 12, 15, and 17 have the same general shape in that (1) the minimum percentage of the CF4 molecules recovered as C2F4 was on the order of 88 percent and (2) the minimum in the curves occurred at approximately 3.5 X 1021 to
21
4.5 X 10 ev of energy absorbed in the CF4. The discussion of the CF4-UF6-Al shavings series will be made in terms of a reaction
rate comparison with the CF4-UF6 series.




..74
The reaction rate constants for the destruction of CF4 for the reactor experiments are presented in Table 21. This table also contains the rate constants for the gamma experiments. It can be seen from Table 21 that the rates of destruction of the CF4 for the reactor irradiated series, except for the CF4-UF4-C series, were approximately ten times the reaction rates for the gamma series. This was expected due to the fact that a fission process was occurring in the reactor experimental capsules. The fission fragments deposited more energy per unit track length, greater LET, as compared to the gamma photons. Thus the probability of CF4 destruction was greater in the reactor experiments.
From Table 21 it can be seen that the addition of Al shavings to an experimental CF4-UF6 series increased the CF4 destruction rate by approximately a factor of ten. As discussed in
(3)
the section Justification of Components, Askew reported similar results. A possible explanation for this increased reaction rate is as follows. The fission fragments bombarded the fluorinated Al shavings and destroyed the aluminum fluoride surface. Free fluorine was used to refluorinate the surface. Thus there was less fluorine available for the back reactions, and this resulted in a larger CF4 destruction rate. In essence, the Al shavings acted as a scavenger of fluorine. As the irradiation continued, the surface fluorination process did not keep pace with the free fluorine formation, thus there was free fluorine available for




-75
TABLE 21
GAMMA AND REACTOR IRRADIATION RATE CONSTANTS
FOR THE DESTRUCTION OF CF4
K (except where noted kor k2,ev System Reactor Gamma
- -24
CF4 1. 51OX1O
-23 -24
CF4-UF6 kl= 8.OOX1O 3.192X10
-22
k2= 1.10X10
- 22
CF4-UF6-A1 shavings kl= 8.OOX1O
- 22
k2= 2.50X10
CF4-UF6-N2 5.066X10-2 1.515X10-2
-23 -24
CF4-UF6-Ar kl= 6900X10 3.646X10
-22
k2= 1.60X10
-23 -24
CF4-UF6-Xe 4.273X10 2.923X10
.-23 -24
CF4-UF6-SF6 kl= 7.50X10 1.218X10
-22
k2= O.785XI0
_25 -22
CF4-UF4-C 4.503X10 5.154X10




-76.
the back reactions. This can be seen by comparing k2 for the CF4-UF6-A1 shavings series with k2 for the CF4-UF6 series. These constants are of the same order of magnitude.
The reaction rate constants for the series CF4-UF6, CF4-UF6-Ar, and CF4-UF6-SF6 are approximately the same. The k2 value for the CF4-UF6-SF6 series is somewhat smaller than the other k2 values. The CF4-UF6-SF6 reactor irradiations resulted in larger
yields of the C3F80 oxygen compound. The oxygen compounds are not as reactive as C2F4. Thus, for the CF4-UF6*SF6 series, the reactions producing CF4 were slowed by the presence and formation of the oxy(35)
gen compounds. Scott also found that the oxygen compounds did
not readily react during radiolysis,
A comparison of the reaction rate constants, for the CF4-UF6-N2 and CF4-UF6-Xe series shows that the CF4 destruction rate for the Xe series was approximately ten times as large as the
CF4 destruction rate in the nitrogen series. This can be explained by the fact that XeF2 and XeF4 are more easily made than the postulated NF3.
The reactor capsule series as discussed above contained the same number of starting CF4 and UF6 molecules. The CF4-UF4-C series contained the same number of CF4 starting molecules, but since it contained UF4, it cannot be directly compared with the
other series,as the concepts are different. This series can be compared, however, to the gamma CF4-UF4-C series,as the makeup of




-77
the two series was identical. From Table 21 it can be seen that the reaction rate constant for the gamma irradiated series is 1000 times as large as the reaction rate constant for the reactor irradiated series. This can be explained by the fact that the UF4 and the C in the reactor irradiated series were solids. Most of the fission fragments were contained in the solid phase. Only a small fraction of the energy was dissipated in the gas phase; however, the rate constant calculations assumed that all of the fission fragment energy was deposited in the gas phase. Gamma radiolysis
was not very important in the reactor tests, as a core gamma shield was present while the experiments were being run (see Experimental Procedure). Thus in the reactor CF4-UF4-C series, the CF4 destruction process was very inefficient,whereas in the gamma radiolysis of CF4-UF4-C, an efficient CF4 destruction occurred.
Reactor Irradiation, G (-CF4) Values:The G values, G (-CF4), for the reactor irradiations
are plotted in Figures 19 through 21. The G (-CF4) values for the CF4-UF6-Al shavings and CF4-UF6-Xe series reflect the large CF4 destruction rates. The G (-CF4) values also reflect the larger than usual amount of C3 F 80 which was formed in the CF4-UF6 -SF6 experimental series.
Several points of interest with reference to the G (-CF4) values as plotted in Figures 19, 20, and 21 are:




-78
(1) The G (-CF4) values, as was found in the gamma experiments, were dose dependent.
(2) The trend of the G (-CF4) values was to decrease with an increasing dose. This
(3,
agrees with the findings of other workers. 32, 33, 35)
(3) The G (-CF4) values except for the CF4-UF4-C series were larger than the G (-CF4) values obtained in the gamma irradiation experi(3, 32, 33)
ments. Other workers have reported similar findings.
General Comments
(3, 33)
A closing point of interest is that previous workers
have reported that the saturated compound C2F6 was produced in the gamma and neutron irradiation of CF In this study the
4.
primary product was found to be the unsaturated compound C2F4. "' A comparison between the referenced works and the present study is not justifiedas the studies were basically different in components and in experimental context. Nevertheless, a plausible explanation as to why C2F4 was produced in the present study can be found in the concept of the interaction between high energy particles, such as gamma photons and fission frag(47)
ments, and materials. It is known from pyrolysis studies
in the fluorocarbon area that within the temperature range of 3000




SyblSeries -79A CF4-UF6-Xe
83 CF4-UF6-SF6
12 0 CF4-UF6
0 CF4-UF6 -Ar 0 CF 4-UPF6-N 2
L1O
0
0
0
8
rE4
0
4
0
00
28
09.
0 2.0 4.0 6.0 8.0
Energy absorbed by CF4 (evXlO-2 ) Figure 19. G1(-CF4) Values--Reactor Irradiations




-80
100 00 Series: CF4-TJP6A1sais
0"1114
0
. 0 I0
10
> 0
01
2. 0. 502002.
Enry bore b F
(evl1 60
Fiue2.3 -Y Vle-RatrIrdain




-81
40 Serie: CF4..UFg.C
0
2a 0
0
0
r40
0 2.0 4.0 6.0 8.0
Energy absorbed by CF4 (evXlo' 9)
Figure 21. G 2(.CF4) Values--Reactor Irradiations




-82
to 7000 C the predominant fluorocarbon products are the unsaturated compounds. For this study the temperatures of the gamma and reactor irradiations were 250 and 360 C respectively (see Appendix A). Nevertheless, the energy equivalent temperatures as calculated from
(48)
heat capacity considerations corresponds to the temperatures
that would result in the formation of the unsaturated compound C2F4.




CHAPTER VI
Conclusions
Gamma Irradiations
The gaseous products formed in the gamma irradiation of the experimental series (a) CF4, (b) CF4-UF6, .(c) CF4-UF6-N2,
(d) CF4-UF6-Ar, (e) CF4-UF6-Xe, (f) CF4-UF6-SF6, and (g) CF4-UF4-C were the unsaturated compound C2F4 and the oxygen compounds C2 F60 and C3F80 The breakdown of CF4, going primarily to C2F 4, was on the order of one-tenth to 2 percent except for the CF4-UF4-C series,where the CF breakdown ran as high as 4 percent. The oxygen compounds came from oxygen reactions where the oxygen. was dissolved in the components or adsorbed on the surface of the components. Expressions were derived which related the fraction of the CF4 remaining after an exposure to a given dose of gamma irradiation.
No evidence was found that any of the CF admixtures
--UF6, N2, Ar, Xe, SF6--acted as scavengers of fluorine. The
presence of a scavenger of fluorine would have resulted in a larger C2F4 yield. It is probable that the C in the CF4-UF 4-C series
-83-




-84
acted as a scavenger of fluorine. This conclusion agrees with the findings of other workers who have investigated the gamma radiolysis of CF4-C series. The magnitude of G values for the destruction of CF in the CF 4-UP 4-C series also validates the conclusion that C acted as a scavenger of fluorine.
For the above experimental series, a gamma chemonuclear
system for the production of higher molecular weight compounds or for the production of unique compounds does not appear promising nor attractive.
Reactor Irradiations
The gaseous products formed in the reactor irradiation
of the experimental series (a) CF4, (b) CF4-UF6, (c) CF4-UF6-A1 shavings, (d) CF4-UF6-N2, (e) CF4-UF6-Ar, (f) CF4-UF6-Xe, (g) CF4UF6-SF6, and (h) CF4-UF4-C corresponded to those formed in the gamma irradiation experiments. This work showed that homogeneous and heterogeneous mixtures of the fluorocarbon CF4 with UF6 or UF4 and a third component--A1 shavings, N2, Ar, Xe, SF6, or C--can be reactor irradiated without any abnormal reaction occurring. The separation of the irradiated fluorocarbons from the fission fragMents and UF6 was 'accomplished by passing the gaseous products through a sodium fluoride trap. A model was developed which related the fraction of the CF4 remaining after an exposure to a given reactor irradiation dose.




-85
The addition of Al shavings to a CF4-UF6 series increased the destruction rate of the CF4., This phenomenon has also been reported by other investigators. In general, the CF4 destruction rates in the reactor irradiated series were approximately ten times as large as the CF4 destruction rates in the gamma irradiated series. This was due to the concentrated amounts of energy deposited by the fission fragments.
For the experimental series containing UF6, Ar, and
SF6, no trap existed for the fluorine. As the irradiation continued CF4 was produced rather than destroyed. In the series containing the Al shavings, the destruction of C2F4 was much less pronounced, due to the increased CF4 destruction rate.
It was found that both N2 and C acted as scavengers of fluorine. In these experiments, the buildup of C2F4 continued throughout the duration of the irradiation. An unexpected result was the formation of XeF2 and XeF4 in the CF4-UF 6-Xe experimental reactor tests. The Xe acted as a scavenger of fluorine. This formation of Xe compounds is a major chemonuclear find.
The G values for. the destruction of CF4 in the reactor
irradiation experiments agree with the values reported by other workers. In the series where there were fluorine traps, the G values reflected the increased CF4 destruction.
From the chemonuclear production standpoint, the only




-86.
interesting reactor test series were those which contained N2, C, and Xe, i.e., scavengers of fluorine. The series that truly warrent future study are (a) reactor irradiations where Xe and N2 are used as an admixture and (b) the gamma and reactor irradiations of CF4-UF4 and CF4-C. From a basic standpoint, however, it would be interesting to repeat the reactor studies of the series involving N2, C, and Xe. In these tests, the reaction temperature, capsule pressure, or the reaction surface area could be varied. It would also be interesting to test other fluorocarbons, perhaps C2F6 or C3F8. A fourth component, oxygen, could also be tested to see if unique oxygen compounds can be produced.




APPENDIX A
Calculations
Calculation of Percentage of Gaseous Products Formed During Irradiation
The calculations will be performed for Sample No. 164, one of the UF6-CF4 -Xe series subjected to reactor irradiations, using the data for this sample as listed in Appendix D. A chromatographic analysis was required for the sample. From the chromatogram, the area under each gaseous product peak was fund by graphical integration. The component percentage was the ratio of the area for a given product to the total area multiplied by 100. These percentages for each sample are listed in Appendix D.
As the above mentioned component areas, or percentages,
represent the amount of the products present, these percentages must be converted into an equivalent percentage of CF4. Assuming that two molecules of CF4 are needed to make one molecule of C2F4 or C2F60, that three molecules of CF4 are needed to make one molecule of C3F80, etc., the percentage of CF4 in the sample recovered as CF4, C2F4, C2F60, etc., is calculated as




-88
% CF
% CF4 as CF4= % CF4 +(2)% C2F4+ (2) % C2F60 + ....X 100,
(2) % C2F4
% CF4as CF (2)7 C2F4 X 100
2%4 CF4+ (2) % C2F4+ (2) % C2F60 +...
(2) % C2F60
% CF4 as C2F60 a gCF4+ (2) % C2F4 + (2) % C2F60 +. X 100.
For Sample No. 164
CF4 as CF4 = 54.4%,
CF4 as C2F4 43.8%,
CF4 as C2F60 = 1.8%, and
CF as C3F80 = trace.
These percentages for each sample are summarized in Chapter IV.




-89
Calculation of the Energy Deposited in the Sample--Gamma Irradiation
The gamma irradiations were performed in the University of Florida food irradiator. The gamma doses were measured by Fricke
(38)
dosimetry. The dose in the capsule is related to the measured
dose, in water, by the equation
dose (capsule) = dose(H20) X
electron density (component ) X mass fraction (component) ii
electron density (H20) Using as an example capsule No. 126 which contained CF4-UF6-Xe
dose (capsule) = dose (H20) X
electron density (CF4) X mass fraction (CF4)
+ electron density (UF6) X mass fraction (UF6)
electron density (H20) + electron density (Xe) X mass fraction (Xe)




-90
Dose (capsule) = 1.69 X 108 rads X
(2.87) (0.757) + (2.52) (0.109) + (2.71) (0.134) x 10o23
3.34 X 1023
dose (capsule) a 1.42 X i0 rads.
The dose absorbed by the CF4 in the capsule can then be calculated as
dose (CF4) = dose (capsule) X
[ electron density (CF4) X grams (CF4)
electron density components1) X grams components1)
i
dose (CF4) 1.42 X 10 X
(2.87 X 1023) (1.164 X 10-3) (88)
(2.87 X 1023) (1.164 X 10-3) (88) + (2.52 X 1023) (5.94 X 10-5) (349)
+ (2.71 X 1023) (1.95 X 10-4) (131.3) 3




In terms of ev, the dose (CF4) is
dose (CF4) : dose (CF4) rads X
100 erga 1 ev
X X
gram red 1.6 X 10-12 erg
1.64 X 103 moles X 88 gram mole
20
dose (CF4) a 9.92 X 10 ev.




-92
Calculation of Integrated Thermal Neutron Flux
Standard gold disks, irradiated in the Argonne standard
(49)
pile, were used to calibrate the counting equipment. A
cross calibration between the gold disks and a standard capsulereference gold wire was also obtained by irradiating both standards in the University of Florida Training Reactor. From the disk calibrations and the cross calibration, a counter efficiency for the capsule-monitor gold wires was obtained. This efficiency was found to be 12.80 percent which gave a count-rate correction factor of 7.82.
The counting equipment included the following:
Hamner
High Voltage Power Supply NV-15,
Amplifier LA 110, Scaler NS-10, and
Mechanical Timer NT-10.
Atomics Accessories, Inc.
Geiger Tube EWX-116, 65-47 EWH-108, 65-52.
References f39) and (50) give the following relationship for calculating' the thermal neutron flux.
AMX CF
NG'OI l-exp( T J




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A NEW CHEMONUCLEAR SYSTEM FISSION FRAGl\1:ENTS AND FLUOROCARBONS By RICHARD NORWOOD GURLEY A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA August, 1967

PAGE 2

ACKNOWLEDGMENTS The author wishes to express his appreciation to Dr. John A. Wethington, Jr., chairman of the supervisory committee, for his guidance and assistance throughout the course of this study. Sin cere thanks are expressed to Professor G. J. Schoessow and Doctors M. J, Obanion, R. G. Blake, and F, E, Dunnam who served on the author's supervisory connnittee. The assistance of Mr. J, A. MacLean in the performance of the gamma irradiations and the assistance of Mr. John Hancock and Mr. Jim Hollis in the performance of the reactor irradiations is acknowledged. The author is indebted to Mr, Harvey Norton, Health Physicist, for his assistance in monitoring, handling, and storing the irradi ated capsules. A special note of thanks is due to Mr. George M. Fay for his overall assistance in the preparation of the samples, in the irradi ation of the capsules, in the analysis of the contents of the cap sules, and in the somewhat tedious calculations. Thanks are also extended to Dr. Richard S. Denning for his help with the analogue model. The author wishes to thank the Oak Ridge Institute of Nuclear Studies for the fellowship assistance. Finally, the encouragement, help, and patience of the author's wife, Mary, during the entire graduate residence are gratefully acknowledged. ii

PAGE 3

TABLE OF CONTENTS Acknowledgments -------------------------------------List of Tables ------. ---------------------------------List of Figures ---------------------------------------ii iv vi Abstract ---------------------------------------------vii Chapter: I II III IV V VI Introduction --------------------------------Previous Chemonuclear Work -----------------Experimental Procedure -------------------Experimental Results -------------------Discussion of Results ---------------------Conclusions ---------------------------------Appendices: A B C D Calculations Evidence that Xenon-Fluorine Compounds Were Formed During t h e Reactor Irradiation of CF4-UF6-Xe --------------------------------Disappearance of Xenon in the Reactor Irradiation of CF4-UF6Xe -------------------Experimental Data ---------------------------l 5 15 27 45 83 87 101 103 106 List of References ------------------------------------184 Biographical Sketch -----------------------------------188 iii

PAGE 4

Table 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 LIST OF TABLES Impurities in He, N 2 and Ar -------------------Impurities in Materials ------------------------Gamma Irradiation of Standards Reactor Irradiation of Standards Gamma Irradiation of CF 4 -----------------------Gamma Irradiation of CF4-UF 6 --------------------Gamma Irradiation of CF 4 -UF 6 -N 2 -----------------Gamma Irradiation of CF 4 -UF 6 -Ar -----------------Gamma Irradiation of CF4-UF6Xe -----------------Gamma Irradiation of CF4 UF6 SF6 ----------------Gamma Irradiation of CF 4 -UF 4 -c -----------------Reactor Irradiation of CF 4 ---------------------Reactor Irradiation of CF 4 -UF 6 Reactor Irradiation of CF 4 -UF 6 -Al Shavings Reactor Irradiation of CF 4 -UF 6 -N 2 Reactor Irradiation of CF 4 -UF 6 -Ar Reactor Irradiation of CF 4 -UF 6 -xe ----------~----Reactor Irradiation of CF 4 -UF 6 -sF 6 Reactor Irradiation of CF 4 -UF4-C Gamma Irradiation Rate Constants for the Destruction of CF 4 -----------------------------iv 15 16 29 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 58

PAGE 5

Table 21 22 23 Gamma and Reactor Irradiation Rate Constants for the Destruction of CF4 -----------Electron Density of Various Materials ---------Reactor Irradiation of CF 4 -UF 6 -xe Xenon Chromatogram Area -----------------------V 75 96 103

PAGE 6

Figure l. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19, 20. 21. 22. LIST OF FIGURES Metal Vacuum System -----------------------------Capsule Fluorination System -------------------Gamma and Reactor Irradiations of Standards Gamma Irradiation of CF 4 -----------------------Gamma Irradiation of CF 4 -UF6 -------------------Gamma Irradiation of CF4-UF6-N2 ------------------Gamma Irradiation of CF4-UF6Ar -----------------Gamma Irradiation of CF4-UF 6 -Xe -----------------Gamma Irradiation of CF4-UF6-SF6 ----------------Gamma Irradiation of CF 4 -UF4-C ------------------Reactor Irradiation of CF4 Reactor Irradiation of CF4-UF 6 ------------------Rector Irradiation of CF 4 -UF 6 -Al Shavings Reactor Irradiation of CF4-UF6N2 ---------------Reactor Irradiation of CF 4 -UF 6 -Ar ---------------Reactor Irradiation of CF 4 -UF 6 -Xe ---------------Reactor Irradiation of CF 4 -UF 6 -sF 6 --------------Reactor Irradiation of CF 4 -UF4-C ----------------G (-CF 4 ) Values--Reactor Irradiations ------------G (-CF 4 ) Values--Reactor Irradiations -----------G (-CF 4 ) Values--Reactor Irradiations -----------Disappearance of Xe in the Reactor Irradiation of CF 4 -UF 6 -Xe -----------------------vi 18 20 46 51 52 53 54 55 56 57 64 65 66 67 68 69 70 71 79 80 81 105

PAGE 7

Abstract of Dissertation Presented to the Graduate Council in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy A NEW CHEMONUCLEAR SYSTEM FfSSION FRAGMENTS AND_ FLUOROCARBONS By Richard Norwood Gurley August, 1967 Chairman: Dr. John A. Wethington, Jr. Major Department: Nuclear Engineering Sciences The radiolysis of (a) CF 4 {b) CF 4 -UF 6 (c) CF 4 -UF 6 -N 2 (d) CF4-UF 6 -Ar, (e) CF 4 -UF 6 -Xe, (f) CF 4 -uF 6 -sF 6 and (g) CF 4 -UF 4 -c by gannna photons and by reactor irradiations was studied. The radiolysis of CF 4 -UF 6 -Al shavings by reactor irradiations was also studied. The principal product was c 2 F 4 with traces of c 2 F 6 o and c 3 F 8 o. The parent material, CF 4 was also recovered. For the gamma irradiations, expressions were derived which related the fraction of CF 4 remaining after exposure to a known dose. It was found that the charcoal used in the gamma irradia tions of CF 4 -UF 6 -c acted as a scavenger of fluorine. For the reactor irradiations, a mathematical model which re lated the fraction of CF 4 remaining after exposure to a known dose was obtained. It was found that the C, N 2 and Xe in the CF4-UF4-C, CF 4 -UF 6 -N 2 and CF 4 -UF 6 -xe series acted as scavengers of fluorine. vii

PAGE 8

In the nitrogen experiments, NF 3 was produced; in the Xe experiments', XeF 2 and XeF 4 were produced. The addition of Al shavings to capsules which contained CF 4 -UF 6 and subsequent reactor irradiations of these capsules resulted in an increased cr 4 destruction rate as compared to the reactor irradia tions of capsules which contained only CF 4 -UF 6 viii

PAGE 9

CHAPTER I Introduction For some time, interest has been developing in the field of applied radiation chemistry, i.e., the use of ionizing radiation to break chemical bonds, thereby producing chemical products. A chemonuclear reactor has been discussed; this reactor would use radiation-induced chemical reactions or dissociation to produce desired chemical compounds. During 1962, the United States Atomic Energy CODmlission asked Brookhaven National Laboratory to conduct a study of the United States' research relating to chemonuclear uses of nuclear reactors and to recommend areas where basic and applied research and exploratory development work should be under(1) taken. Brookhaven National Laboratory suggested that the major effqrts should be concentrated on (1) studying the fundamental radiation chemistry effects peculiar to fission fragments, (2) de termining yields, reaction mechanisms, conversions, and kinetics for systems that appeared promising, and (3) developing necessary genera~ technology which is unique to the chemonuclear field. Since 1962, chemonuclear research has proceeded at an accelerated pace (refer to Chapter II). During the past ten years, concurrent to the chemonuclear -1

PAGE 10

-2development, there has been a large-scale development of fluoro carbons, and,as early as 1962, it was suggested that an uranium hexafluoride, UF 6 fluorocarbon system should be studied for chemo(2) nuclear possibilities. The uranium hexafluoride-fluorocarbon system would have several distinct chemonuclear features or ad vantages. First of all, it might be possible to produce fluoro carbons which cannot be produced by conventional chemical pro cesses because of the nonreactive chemical nature of the fluorocarbons. The extreme quantities of energy associated with the fission fragments resulting from the fissioning of uranium in a solution could induce decomposition of the fluorocarbons, and per. haps the subsequent decomposition products would recombine in the form of new fluorocarbons. Secondly, an advantage would be the elimination of the technical problems associated with the range of the fission fragments (average distance fission fragments travel before giving up their total energy to the surrounding matter) within conventional fuel elements. The uranium hexaflu oride-fluorocarbon system would have the advantage that the fis sion fragments would be deposited directly in the fluorocarbon medium. A final possible advantage of such a system would be the fact that UF 6 is the uranium compound used in the gaseous diffu sion process for producing enriched uranium. Thus, the material could be used without further processing, thereby eliminating the conversion and fuel-fabrication costs.

PAGE 11

-3Obviously, much information regarding the performance of uranium hexafluoride-fluorocarbon systems in the presence of radiation must be obtained before the desirability of the method as a chemonuclear system can be evaluated. The types of informa tion needed fall under the guidelines outlined by Brookhaven National Laboratory. Such information should include rates of fluorocarbon decomposition, products formed, G values (molecules of a product obtained or destroyed per 100 ev of energy absorbed), chemical kinetics, etc. Objectives The purpose of this work was to study t:wo unique systems which satisfied the requirement that the fission fragments must be deposited directly within the medium of interest. These systems were uranium (VI) fluoride homogeneously mixed with gas eous carbon tetrafluoride, cr 4 and a heterogeneous mixture of solid uranium (IV) fluoride, UF 4 mixed with gaseous carbon tetra fluoride. The systems were studied according to the following. System One: Uranium hexafluoride was mixed with CF 4 and irradiated. The radiolysis products were analyzed for higher molecular weight materials. Since UF 6 is an active fluorinating agent, one might have predicted that no reaction products would result; however, this speculation had to be confirmed by

PAGE 12

experiment. This study was followed by experiments designed to study the effect of an increase in the available surface area in the above CF 4 -UF 6 system. Further work was undertaken in which a third component was added to the CF 4 -UF 6 mixture. Materials tried were nitrogen, argon, xenon, and sulphur hexafluoride. -4System Two: The fluorinating agent UF 6 present in the experiments proposed under Plan One, could have immediately fluorinated the ions and radicals formed from the parent mate rial; consequently, CF 4 would reappear. The compound uranium tetrafluoride, however, is not a fluorinating agent; if UF 4 was used, the ions and radicals would be available for reaction with themselves and with other added materials. A CF4-UF4-C system was thus studied to determine if any type of higher molecular weight material could be produced. Elementary carbon (3) was included as it was known to be a trap for free fluorine.

PAGE 13

CHAPTER II Previous Chemonuclear Work Basic and applied research in radiolysis has been carried out over the past fifteen to twenty years by a number of Atomic Energy Commission, university, and industrial organizations, It was not, however, until the fall of 1962 that a coordinated and (1) cooperative effort in the chemonuclear area was begun, For the past five years the chemonuclear interest has been in the production of chemicals through the utilization of the kinetic energy of the recoiling fission fragments, Since 1962, informal meetings of the major research groups involved in fission-frag(4) ment radiolysis have been held, These groups are divisions of: Brookhaven National Laboratory, Rennsselar Polytechnic In stitute, Union Carbide Corporation, and AerojetGeneral Nucleon ics. Within the past several years, other research groups asso ciated with Esso Laboratories, Hercules Powder Company, the University of Florida, Illinois Institute of Technology Research Institute, Princeton University, Notre Dame University, and the University of Michigan have also worked in the radiation chemistry area1, -5

PAGE 14

(1) Manowitz et al., in their 1962 report to the Atomic Energy Commission, swmnarized the important chemonuclear areas (see Chapter I), thereby suggesting an orderly sequence of basic, applied, and exploratory research. Manowitz pointed out that -6the experimental work, up to 1962, with fission-fragment systems had been very limited in scope and essentially exploratory in nature. Nevertheless, because of their high linear energy trans fer, LET, fission fragments offered the possibility of being used more effectively than any of the other common forms of radiation. Manowitz also listed several chemicals proposed for chemonuclear production: nitrogen dioxide, carbon suboxide, ethylene glycol, propylene glycol, hydrogen peroxide, hydrazine, and ozone. Brookhaven National Laboratory Program (1, 5) The Brookhaven National Laboratory group is concerned with the direct and indirect applications of radiation. For the indirect program, they use a co 60 source and generally restrict their attention to exothermic systems. For their direct radia tion program they are concerned with fission fragment studies. They have studied or are studying (1) N 2 o, in capsule experiments, to determine its usefulness for dosimetry; (2) the development of thin fuel bodies,

PAGE 15

(3) fission-fragment chemical yields, and (4) engineering aspects of chemonuclear production in an inpile loop. ~) Meyer Steinberg of Brookhaven National Laboratory has pointed out that the use of the fissiochemonuclear process for the fix ation of nitrogen and the production of synthesis gas (carbon monoxide and hydrogen) is sufficiently interesting from a long time national goals point-of-view to provid~ incentive for a con tinued development of the science and technology of this field. (7) Steinberg pointed out that the above products, by chemonuclear processes, can be produced in large quantities at costs which are competitive with the production costs in conventional (8, 9) processes. Steinberg also suggested chemonuclear systems -7for the production of formic acid, formaldehyde, acetylene, nitrous oxide, ammonia, nitrogen dioxide, phenol, carbon suboxide, and (6, 10, 11, 12, 13) polyethylene. Beller and Steinberg proposed that ozone produced by the chemonuclear process of irradiating air or oxygen be used for water purification and pollution control. Rennsselar Polytechnic Institute Program (1, 5) The Rennsselar Polytechnic Institute program is proceeding on many fronts. Their personnel have studied or are studying (1) the irradiation of gases, (2) N 2 o to determine its usefulness for dosimetry,

PAGE 16

(3) conversions in carbon dioxide-air mixtures at high temperatures, (4) solid arrays of u 235 bearing materials innnersed in gaseous reactants, -8 (5) ionic reactions of CO 2 and Nz-0 2 mixtures, (6) ionic reactions using the gases in (5) above with admixtures of rare gases, (7) the dissociation of Nz molecules in the irradiation of nitrogen, (8) the dissociation of CO 2 in the irradiation of CO 2 and (9) in-pile loop studies of N 2 o 2 and other gases at various pressures where the loop is loaded with enriched uranium glass fibers. (14) Harteck and Dondes have studied nitrous oxide dosimeters in the range of 5 X 10 4 to almost 10 10 roentgen, Neutron fluxes were measured by adding small amounts of u 235 to the dosi meter, and neutron dosages at elevated temperatures ( > 200F) (15) were readily determined, Harteck and Dondes studied theirradiation of nitrogen-oxygen mixtures The data obtained for air and two to one nitrogen to oxygen mixtures showed that, under the proper irradiation conditions, all the oxygen was con(16) sumed to form nitrogen dioxide and nitric oxide, Dondes et a 1. ..

PAGE 17

-9also studied the radiolysis of carbon monoxide in the presence of rare gases. The influence of various rare-gas additives was con sidered in terms of energy transfer from primarily excited rare gas atoms resulting in the formation of excited carbon monoxide, CO'k, followed by dissociation or reaction with another CO mole cule. The important discovery was that excited CO molecules re acted with other CO molecules to produce carbon dioxide and car(17) hon suboxide polymer. Harteck and Dondes studied the fixation of nitrogen in capsule irradiations of nitrogen and oxygen. These men also studied two other systems for fixing nitrogen--the nitrogen-hydrogen system for producing aunnonia and the nitrogen sulfur system for producing N 4 s 4 --and concluded that both were less promising than the nitrogen-oxygen system, Harteck and Dondes also studied the irradiation of gaseous and liquid ammonia for the production of hydrazine. (18) Within the past two years, Harteck ,!!, have explained the decomposition of ozone by ionizing radiation with (19) the negative ion-chain reaction mechanism of Fueki and Magee. (20) Also within the past two years, Dondes et al. have made a -210 spectroscopic study of the luminescence produced by Po alpha particles in purified noble gases, noble gas-nitrogen mixtures, purified nitrogen, and nitrogen-oxygen mixtures. A major obser vation was that very small concentrations of impurities or addi tives--Hg, Ar, Kr, Ne, H 2 o 2 and NO--increased the luminescence.

PAGE 18

-10(21) Work at Rennsseler Polytechnic Institute is concurrently proceeding in the basic-research areas of the carbon suboxide sy~~ tem, the reaction of nitrous sulfide and oxygen atoma, and chemolum inescent studies of the preceding gas mixtures excited by the rad iations from a nuclear reactor. Aerojet-General Nucleonics and Union Carbide Program The Aerojet-General Nucleonics and Union Carbide groups have (22) cooperated, to a great extent, in chemonuclear research. (1, 5) companies have studied or are studying (1) radiolysis of liquid ammonia, (2) the energy spectra of fission fragments These escaping from fully enriched uo 2 powders and plates; (3) fission-fragment dosimetry, radiation chem istry mechanisms of N 2 H 4 formation, : and new products produced by the irradiation of nitrogen-oxygen-fluorine mixtures, i and (4) in-pile loop production of hydrazine from annnonia. (23, 24, 25, 26) J. H. Cusack and P.A. King, fiasiochemical program managers for Aerojet-General Nucleonics and Union Carbide (27) Corporation, respectively, and Fritsch,!!.!!. of Aerojet-General Nucleonics, have outlined the major studies covering the chemo nuclear activities of their companies. Statements or summariea

PAGE 19

-11of the results of these activities are: (a) While the overall understanding of fission fragment physical behavior, track effects, chemical reactions amendable to fissiochem ical induction, 2 etc.,were extended, current industrial forecasting techniques showed that no fuel/product combination had econ omi~ potentil (b) General fission-fragment energy equations and the determination of energy-deposition efficiencies for a number of solid fuel compositions and shapes were obtained. (c) Ceramic and metallic fibrous fuels for re actor use were developed,with the most promising being Zro 2 -uo 2 (d) A number of basic radiation chemistry in vestigations involving nitrogen or ethylene were conducted. It was found, based on co 60 electron, and fission-fragment radio lysis of ethylene, that reactions of electronically excited molecules are only slightly affected by pressure or by LET and that an increasing LET increases radical radical reactions and decreases ionic re actions.

PAGE 20

-12(e) The operation involving the CH 4 -N 2 system in the gas-phase fissiochemical loop showed that the HCN yield varied directly with temperature and flow and inversely with pressure and CH 4 concentration. The con clusion was that the fissiochemical produc tion of HCN would be economically marginal at best. (f) Loop irradiations of CO 2 and CH4-CO 2 mix tures indicated G(CO) values could be as high as ten, (g) An unexpected fission-fragment induced re action between CO 2 and N 2 was discovered. The elemental composition of the resulting solid corresponded to an empirical formu1a Aerojet-General Nucleonics is currently studying fission (28, 29) fragment radiolysis of NF 3 and fluorine. Miller ~s!L have reported the formation of an unidentified nitrogen-fluorine compound resulting from the fission-fragment radiolysis of a mix (29) ture of NF 3 and F 2 that is stable at room temperature. Miller is also studying the fissiochemical reaction of nitrogen with carbon monoxide.

PAGE 21

Other Fissiochemical Research Programs (3G) Princeton and Notre Dame Universities, University of (31) -13Michigan, Stanford Research Institute, Essa Laboratories, and Hercules Powder Company groups are engaged in basic radiation chemistry studies which are not directl y aimed at the development of chemonuclear reactors. Work which is directly associated with the chemonuclear development field has been done by personnel at the Illinois Institute of Technology Research Institute and the University of Florida. (32) The Illinois Institute of Technology Research Institute group studied the dependence of the yield of hydrazine on total dose in the fission-fragment irradiation of liquid annnonia. The experiments were conducted in a nuclear reactor where the fission 235 fragments were produced by the bombardment of U with thermal neutrons. The most significant result was the fact that large G(hydrazine) values could be obtained but only at relatively small total doses. The University of Florida group has studied and is studying (1) the basic effects of radiation on fluorocarbons and (2) fluorocar bon irradiations based on a fluorocarboncheroonuclear concept, (33) Reed et al. of the University of Florida have irradiated samples of pure fluorocarbons. of higher molecular weight compounds. They observed the formation (3) (33) Askew and Reed !.!, demonstrated that mixtures of solid carbon and CF 4 produced

PAGE 22

-14heavier saturated fluorocarbons when subjected to ionizing radia tion. The results indicated that CF 4 acted as a fluorinating agent (34) for the solid carbon. Reed is presently studying the irradiation of gaseous fluorine-containing molecule ;; such as BF 3 SF 6 and SiF4, with solid carbon. Other solid aubetrates such as sulfur and silicon are being investigated, (35) Scott of the University of Florida has studied (1) the radiolysis of perfluorodimethylcyclohex ane, c 8 F 16 by gaunna photons, (2) the radiolysis of c 8 F 16 by reactor irradiations, and (3) the radiolysis of c 8 F 16 by fission-fragments. The products from the gamma radiolysis of c 8 F 16 were mainly dimers of the parent molecule. The reactor exposure of c 8 F 16 gave dimeric products plus gaseous products--mainly CF 4 and c 2 r 6 --in the ratio of four to one. In the fission-fragment irrad iation of c 8 F 16 Scott found no polymeric materials. The prod ucts were CF 4 and c 2 F 6 in equal amounts,with smaller amounts of

PAGE 23

CHAPTER III Experimental Frocedure Starting Materials The gases helium, nitrogen and argon were obtained from the Linde Company, a division of Union Carbide Corporation, The purity and moisture content of the gases were as follows, Gas He Nz Ar TABLE 1 IMPURITIES IN He, Nz, AND Ar Purity % Impurity 99.99 HzO 99,995 HzO 99.996 < 0,003 % o 2 Moisture Content grains/1000 NPT 5 5 Xenon was obtained from the Matheson Company, Inc. The gas had a known impurity of 5 ppm krypton with the balance being xenon. The carbon which was used in several of the experiments was Adsorbite activated charcoal which was obtained from W. H. Curtin (HzO) ft 3 and Company. 235 The enriched (93.16 percent U ) uranium hexafluoride was obtained on loan from the United States Atomic Energy Connnission. -15

PAGE 24

The normal (0.72 percent u 235 ) uranium tetrafluoride powder was ob tained from Nuclear Fuel Services, Inc, The radioactive gold foils which were used in the counter efficiency determination (see Appen dix A) were obtained from Argonne National Laboratory. -16Tetrafluoromethane was obtained from the Matheson Company, Inc, The gas was found to be chromatographically pure and was used with out further purification. Sulfur hexafluoride, SF 6 was also ob tained from the Matheson Company, Inc. This gas contained approxi mately 1.9 percent carbon tetrafluoride. Perfluoroethane, c 2 F 6 perfluoropropane, c 3 F 8 perfluoropropene, c 3 F 6 and perfluorocyclo butana. c 4 F 8 which were used as standards were all obtained from the Matheson Company, Inc. Information about these materials is tabulated in Table 2. TABLE 2 IMPURITIES IN MATERIALS Material CF4 SF 6 CzF6 C3Fa C3F6 C4Fs Mole % Impurity None detected 1.9, CF4 None detected Trace c 3 F 6 None detected None detected

PAGE 25

-17Perfluoroethylene, c 2 F 4 which was also used as a standard was ob tained from Dr. T. M. Reed of the Department of Chemical Engineer ing at the University of Florida and was prepared by the vacuum pyrolysis of Teflon. This method, by proper control of the heating procedure, gave approximately 98 percent c 2 F 4 with the remaining 2 percent consisting of higher boiling material. Air was removed fr~ the compounds by alternately thawing, freezing, and pumping on the compounds in a vacuum system until no residual pressure was detected over the condensed canpounds. Water was removed from the argon and nitrogen by passing the gases through liquid nitrogen cold trap,. The degassed compounds were then stored as gases in storage bulbs on the vacuum system until needed. Fluorination As UF 6 a strong fluorinating agent, was to be used in most of the experiments, it was necessary to fluorinate all the surfaces which were to be exposed to UF 6 This fluorination formed a pro tective fluoride film which prevented the reaction of UF 6 with (36) the metal surface to produce UF 4 Uranium tetrafluoride, UF 4 would adhere to the surfaces and cause difficulties in sample transfers. The vacuum system, shown in Figure 1, was fluorinated using fluorine gas from a one-pound cylinder obtained from the Matheson Chemical Company. All the components except the bellows seal

PAGE 26

--To the chromatograph gas sampling valve Chromatograph sample line vacuum To glass vacuum Heating tape Loading and unloading ports LU Hg manometer Calibrated tanks To vacuum pump Carrier gas to chromatograph UF6 Storage tank Liquid nitrogen cold trap Heated NaF trap Heated NaF trap Capsule for analysis Figure 1. Metal Vacuum System I .... 00 I

PAGE 27

-19valves, Nupro type B-4H, were carefully degreased in chloroform. The bellows seal valves were cleaned by the manufacturer. The trans (35) fer system was fluorinated by Scott. Figure 2 shows the system which was used to fluorinate cap sules, valves, and other fittings. The copper capsules and all the aluminum and copper fittings were fluorinated in a reaction vessel, while the larger capsules and all the valves were fluorinated by insertion into a nitrogen-fluorine stream. The capsule fluorination system, as shown in Figure 2, was pressure tested at 55 psig (i.e., the system was isolated) for a 12-hour period. At the end of the test period, the pressure was released. Pressurization and release operations were repeated three times to purge the air from the system. The glass bubbler (see Figure 2) was connected, and a steady flow of nitrogen was estab lished. The fluorine pressure on the regulator outlet was raised to 12 psig~ and fluorine was introduced into the system by open ing the outlet valve for a period of one second at intervals of 30 seconds. This procedure was continued until a definite temper ature change was detected in the sodium chloride trap. At this time, the system was purged with nitrogen for about ten minutes. The glass bubbler was removed and the previously described pressur ization and release operations were carried out three times.

PAGE 28

Valves to be fluorinated Whitey 1 VS4 Al Whitey 1 VM4 Al Whitey 1 VM4 Nupro B 4H Small capsules and fittings to be fluorinated Lar capsules to be fluprinated NaCl trap Gas regulators Reaction vessel Reaction vessel Figure 2. Capsule Fluorination System Fluorine cylinder Nitrogen cylinder Potassium hydroxide bubbler To vent I "' 0

PAGE 29

-21Capsule Fabrication Capsules for GaDDa Irradiations: The capsules for the gamma irradiations were fabricated from five-inch sections of one-half inch copper or aluminum 60-61 tubing. One end of the capsule was crimped, and depending on whether it was a copper or aluminum tube, it was either silver soldered or heli-arc welded so as to seal that end. The excess flux was removed by immersion in boiling water, The capsules were then degreased with chloroform and fluorinated. The open ends were sealed with either a brass valve (lVM 4) or an aluminum valve (1-VM 4 Al) attached to the tube by means of brass or aluminum Swagelock fittings. The valves and fittings had also been de greased and fluorinated. The capsules were then pressure tested (300 psig, nitrogen) and vacuum tested, Capsules for Reactor Irradiationa:The aluminum capsules, as described above, were also used for heterogeneous reactor irradiations involving UF 4 Additional capsules were fabricated from five and one-quarter inch sections of three-inch 60-61 aluminum pipe, The diameter selection was based upon knowledge of the range of fission fragments in the component materials. The capsule ends were sealed with 60-61 aluminum end plates which were heliarc welded to the capsule body, The end plates had one-fourth inch 60 aluminum tube inserts heli-arc

PAGE 30

-22welded into them. After the capsules had been degreased and fluor inated, one end was completely sealed by using a one-fourth inch fluorinated aluminum cap or by crimping the insert tube and heli arc welding this tube. The other end of the capsule was sealed with an aluminum valve (1-VS 4 Al) attached to the one-fourth inch welded insert tube with fluorinated aluminum Swagelock fittings. The capsules were then pressure tested (300 psig, nitrogen) and vacu um tested. If the capsule, valve, or valve connections leaked, the faulty part, or parts, were discarded, Sample Preparation All the samples were prepared using the vacuum system as shown in Figure 1. The capsule to be loaded was attached to the system via a loading port, and the system was then both pressure and vacuum tested. Most of the components, which were to be loaded, contained some dissolved air; therefore, the procedure for removing air as discussed under Starting Materials had been performed, and these compounds were already stored in storage bulbs either on the metal system or the connecting glass vacuum system (not shown in Figure 1). The UF 6 storage tank and the capsule to be loaded were con nected through the vacuum system (the volume of the capsule had previously been determined by nitrogen volume expansion using the ideal gas law), and the system was allowed to equilibrate for five

PAGE 31

-23minutes at room temperature. The capsule was then closed, and the remaining UF 6 was recondensed into the storage tank by applying liquid nitrogen to the nipple of the tank, Using the vapor pres sure for U1'6, as given in Reference (37) for the observed room temper~ ature, the weight of the UF 6 in the capsule was calculated by the idea 1 gas law. Second and third components which could be condensed by liquid nitrogenCF4, Xe, and SF6ware loaded as follows, A calibrated tank, either the 758 cc or the 60 cc tank (as shown in Figure 1), was loaded to the desired pressure by volume expansion from a stor age bulb, The calibrated tank was then c!osed, and the remaining gas in the system waa recondensed into the storage bulb, Liquid nitrogen was placed around the capsule, and after some three minutes the capsule and the calibrated tank were connected through the sys tem. After the gas had been transferred, the capsule valve was closed, and the capsule was removed from the system. If the capsule was to be exposed to reactor irradiation, a gold wire weighing approximately two milligrams, weighed to the nearest 0.001 milli gram 1 1 was wrapped in filter paper and attached to the capsule with tape. This wire served as a flux monitor, The loading of argon or nitrogen as a third component was not accomplished by a freezing method, A calibrated tank was loaded with either argon or nitrogen, and after the UF6 was con densed in the capsule, the calibrated tank and the capsule were

PAGE 32

-24interconnected in order to allow volume expan~ion. The pressure was read before cooling occurred. The ideal gas law was then used to calculate the amount of gas that was loaded. The capsules which contained CF4, UF4, and C were loaded dif ferently. As the UF 4 and C were solids, they were first mixed, and the capsules were then loaded to the desired weight. The capsule was attached to the vacuum system and baked at 110 C and pumped, Then, the above procedure for loading a third component was carried out. The volumes of the above-mentioned calibrated tanks were found by filling the tank with water in a constant temperature rath. Subtraction of the empty tank weight from the full tank weight gave the weight of the water in the tank. This weight was converted to volume using the density of water at the temperature of the bath. Irradiations Gannna Irradiations:The ganuna irradiations were performed in the University of Florida co 60 food irradiator. The source was in the form of 96 plates which were arranged so that a relatively flat gannna flux was obtained. The capsule was placed in a container, and this container was lowered into the irradiator and exposed to the desired dose. ( 38) The gamma dose was measured by the Fricke dosimetry method.

PAGE 33

University of Florida Training Reactor Irradiations:The reactor irradiations were performed in the thermal column of the University of Florida Training Reactor which has been (39) described by Boynton. The plastic handles on the capsule valves were removed, A four-foot section of a graphite 1tringer with a 4 X 4 inch cross section was removed frooi the thermal column The stringer was im mediately adjacent to a 12 X 8 X 4 inch lead gamma shield which was adjacent to the reactor core. The capsule was inserted into the stringer void. The reactor was brought to full powe~with the ab sorbed dose being controlled by the time of the irradiation. Upon removal from the reactor, the capsule was moni tored and stored in a fuel storage pit until the radiation intens ity had dropped to a level which permitted handling of the capsule in order to connect it to the vacuum system. Analysis The use of chromatography to analyze fluorocarbon systems (3, 33, 34, 35, 40, 41) has been reported by several persons, In this study the analysis of the samples was performed with a Model 700 F Jnd M Chromatograph coupled with a Model 240 F and M Temper ature Programmer. This instrument had thermal conductivity detectors. The capsules which were to be analyzed were connected to the vacuum system through a controlled temperature sodium fluoride

PAGE 34

trap. The trap was used to remove the UF 6 and the fission fFag ments from the sample. The sample was transferred to the vacuum system and checked for residual radioactivity. If fission frag ment or UF 6 passage occurred, the sample was transferred back through the sodium fluoride trap. No sample required more than three passes The sample was allowed to stand for approximately one hour in the vacuum system so that equilibrium could be established. -26The sample was then chromatographed several times via a chromato graph gas sampling valve using a 10 cc gas sample loop. The pressure of the sample was controlled to obtain the maximum chroma tographic sensitivity. A silica gel column (see Appendix D) was used for this analysis.

PAGE 35

CHAPTER IV Experimental Results The experimental results, calculated from the experimental data as given in Appendix D, are tabulated in Tables 3 through 19. The composition of each sample in a given table is approximately the same (the details are given in Appendix D). Tables 3 and 4 present the results of the gannna and reactor irradiations of the standards which contained only air at atmospheric pressure. These tests were made to determine if the Teflon valve packing and the valve stem tips would decompose during radiolysis. Tables 5 through 11 give the results of the gamma irradiation of (a) CF 4 (b) CF 4 -UF 6 (c) CF 4 -UF 6 -N 2 (d) CF 4 -UF 6 -Ar, (e) CF 4 -UF 6 -Xe, (f) CF 4 -uF6-SF 6 ~ and (g) CF 4 -UF 4 -c. The following explanation is given for the various table headings. In the ganuna irradiations the doses in ev were calculated (see Appendix A) from the doses in rads as determined by (38) Fricke dosimetry. The percentage of the CF 4 that was converted into c 2 Flf was based on a carbon balance. Sample calculations for these percentages are shown in Appendix A. Tables 5 through 11 also show ~elected G values for the garrana irradiations. The G value is defined as the number of molecules of -27

PAGE 36

-28a given substance that is produced or destroyed per 100 ev of energy absorbed in the sample. For example, for sample No, 116, Table 6, G (C 2 F 4 ) is 0.454, and,accordingly, approximately one-half molecule ~f c 2 F 4 was produced pet 100 ev of energy absorbed by the CF 4 The disappearance of CF 4 is given as G (-CF 4 )--the number of CF 4 molecules lost per 100 ev of energy absorbed in the CF 4 A sample calculation for the G values is given in Appendix A. It should be noted that the G values were dose dependent; consequently one must be careful about speaking of a G value for a given system. Tables 12 through 19 present the results for the University of Florida Training Reactor irradiations of (a) CF 4 (b) CF 4 -UF 6 (c) CF 4 -UF 6 -Al shavings, (d) CF 4 -UF 6 -N 2 (e) CF 4 -UF 6 -Ar, (f) CF 4 UF6-Xe, (g) CF 4 -UF 6 -SF 6 and (h) CF 4 -UF 4 -c. The method used for calculating the integrated thermal neutron flux and absorbed energy is outlined in Appendix A. One additional experimental series, as compared to the gamma study, was irradiated with the reactor. This series, CF 4 -UF 6 -Al shavings, was included to demon strate the effects of surface area on the irradiation induced reactions. The range of error for the decomposition and the G values as given in Tables 3 through 19 is estimated to be on the order of 10 to 15 percent based upon an analysis of variance.

PAGE 37

Capsule No. 101 102 103 Capsule No, 104 105 106 107 108 -29TABLE 3 GAMMA IRRADIATION OF STANDARDS Gamma Dose Units of Fluorocarbon (Rads X 10-8) Recovered--Chromatogram 0 0 1.0 0 2.5 0 TABLE 4 REACTOR IRRADIATION OF STANDARDS Integrated Thermal Neuton Flux (n/cm 2 X 10 14 ) 0 4.42 16.0 4.59 17.2 Units of Fluorocarbon Recovered--Chromatogram 0 0 0 0 0

PAGE 38

Capsule No. 109 110 111 TABLE 5 GAMMA IRRADIATION OF CF4 Ganma Dose Percentage of CF 4 Recovered "' G Values to CF4 as Decomposition Formation (ev X 1020 ) CF4 C2F4 of CF4 of C2F4 0 100 6.61 99.6 0.4 0.510 0.255 16.6 99.4 0.6 0.307 0.153 For the details of the calculations, see Appendix A. w 0 t

PAGE 39

Gaimoa Dose Capsule to CF 4 No. (ev X 10-20) 115 0 116 5.25 117 10.0 118 15.3 TABLE 6 GAMMA IRRADIATION OF CF4-UF6 Percentage of CF4 Recovered as CF4 C2F4 99.8 0.2 99.4 0.6 99.0 1.0 98.7 1.3 G Values Decomposition Formation of CF 4 0.908 0.795 0.783 of C2F4 0.454 0.398 0.392 w ....

PAGE 40

Gamma Dose Capsule to CF4 No. (ev X 102 0) 119 0 120 6.67 121 16.5 TABLE 7 Percentage of CF 4 Recovered as 100 99.6 99.4 0.4 0.6 G Values Decomposition Formation 0.582 0.350 0.291 0.175 t w N

PAGE 41

Gamma Dose Capsule to CF4 No. (ev X 10) 122 0 123 7.21 124 18.0 TABLE 8 GAMMA IRRADIATION OF CF4-UF6Ar Percentage of CF4 Recovered as CF4 C2F4 100 99.4 0.6 98.5 1.5 G Values Decomposition of CF4 0.862 0.863 Formation of C2F 4 0.431 0.431 w w

PAGE 42

Ganaa Dose Capsule to CF 4 No. (ev X 10-20) 125 0 126 9.92 127 14.7 TABLE 9 GAMMA IRRADIATION OF CF 4 -UF 6 -Xe Percentage of CF 4 Recovered as CF4 C2P'4 99.8 0,2 99.2 0.8 98.8 1.2 G Values Decomposition of CF4 0.797 0.806 Formation of C2F4 0.398 0.403 I w .p,. I

PAGE 43

Capsule No. 128 129 Gan:ana Dose to CF4 (ev X 10) 0 14.3 TABLE 10 Percentage of CF4 Recovered as 100 99.6 0.4 G Values Decomposition Formation 0.276 0.138 I w VI I

PAGE 44

Gamma Dose Capsule to CF 4 No. (ev X 1019 ) 130 0 131 1.04 132 3.35 TABLE 11 GAMMA IRRADIATION OF CF 4 UF 4 -C Percentage of CF 4 Recovered as CF4 C2F4 100 98.3 1. 7 96.0 4.0 G Values Decomposition Formation of CF4 of C2F4 164.9 82.5 120.5 60.2 I.,) 0\ I

PAGE 45

TABLE 12 REACTOR IRRADIATION OF CF 4 Integrated Thermal Capsule Neutron Flux No. (n/cm 2 X 10-14) 112 0 113 1.15 114 3.11 Percentage of CF4 Recovered as CF4 C2F4 C2F6O C3F 8 0 100 99.9 0.1 Trace 99.8 0.2 Trace I w ...., I

PAGE 46

TABLE 13 REACTOR IRRADIATION OF CF 4 -UF 6 Energy Absorbed Percentage CF 4 Recovered Capsule by CF4 as No. (ev X 10-21) CF4 C2F4 C2F60 c 3 F 8 o 133 0 99.8 0.2 134 0.676 95.8 4.2 135 0.983 92.3 7.7 136 1.04 91.8 8.2 Trace 137 2.35 86.0 13.0 1.0 138 3.78 86.7 13.3 Trace 139 4.80 86.9 12.9 0.2 ., 140 5.11 87.4 12.6 Trace 141 8.11 88.6 10.5 Trace 0.9 G Values Decomposition Formation of CF4 6.92 8.35 8.14 6.03 3.54 2.98 2.43 1.44 of C2F4 3.46 4.18 4.07 2.80 1. 77 1.47 1. 22 0.661 I w CX> I

PAGE 47

REACTOR Energy Absorbed Capsule by CF4 No. (ev X 10) 142 0 143 3.58 144 5.22 145 13.5 146 24.8 147 26.5 TABLE 14 IRRADIATION OF CF4-UF 6 -A1 SHAVINGS Percentage OF 4 Recovered as CF 4 C2F4 c 2 F 6 o c 3 F 8 o 99.3 0.7 Trace 96. 7 3.3 Trace Trace 95.3 4.7 Trace Trace 93.9 6.1 ?race Trace 92.6 7.1 0.3 92.4 7.6 Trace Trace G Values Decomposition of CF 4 96.6 95. 7 48.0 31. 7 29.0 Formation of c 2 F 4 48.3 47.9 24.0 15.2 14.5 I l.,J I

PAGE 48

TABLE 15 REACTOR IRRADIATION OF CF4-UF6-N2 Energy Absorbed Percentage CF 4 Recovered Capsule by CF 4 as No. (ev X 10) CF4 C2F4 C2F60 C3F80 148 0 100 149 1.00 97.1 2.1 Trace Trace 150 2.40 95.1 4.9 Trace Trace 151 3.66 94.1 4.4 1.5 152 4. 71 94.1 4.3 Trace 1.6 153 9.80 88.8 11.2 G Values Decomposition Formation of CF4 3.00 2. 20 1.67 1.39 1. 27 of C2F4 1.09 1.10 0.621 0.506 0.605 I ::,. 0 I

PAGE 49

REACTOR Energy Absorbed Capsule by CF4 No. (ev X 10) 154 0 155 0.762 156 2.19 157 3.13 158 4.68 159 5.48 TABLE 16 IRRADIATION OF CF4-UF6-Ar Percentage CF4 Recovered as CF4 C2F4 C2F 6 0 C3F80 99.6 0.4 97.4 2.6 92.3 7.7 Trace 89.9 9.8 0.3 91. 7 8.3 Trace lrrace 92.5 6.3 Trace 1.2 G Values Decomposition Formation of CF4 3.43 3.61 3.38 1.85 1.47 of c 2 F 4 1. 72 1.90 1 64 0.924 0.616 I ,$:' ,_. I

PAGE 50

TABLE 17 REACTOR IRRADIATION OF CF 4 -UF 6 -Xe Energy Absorbed Percentage CF 4 Recovered Capsule by CF4 as No. (ev X 10 21 ) CF4 C2F4 C2F60 C3F 8 0 160 0 99.4 0.6 161 0.970 88.0 12 0 Trace 162 2.54 77. 9 22.1 Trace 163 3.82 64.7 33.8 1.5 164 5.87 54.4 43.8 1.8 165 7.74 46.6 55.4 Trace Trace G Values Decomposition Formation of CF4 12.5 8. 75 9.13 8.52 6.36 of C2F4 6.25 4.38 4.34 4.09 3.30 .i::-N I

PAGE 51

TABLE 18 REACTOR IRRADIATION OF CF4-UF6-SF6 Energy Absorbed Percentage CF4 Recovered Capsule by CF4 as No. (ev X 10-21) CF4 C2F4 C2F60 C3F 8 0 166 0 100 167 1.13 90.1 6.63 3.27 168 2.71 87.2 12.8 Trace Trace 169 3.56 81.6 6.20 Trace 12.2 170 4.25 83.7 10.1 Trace 6.2 171 9.09 87.1 5.7 Trace 7.2 G Values Decomposition Formation of CF4 9 97 5.49 6.13 4.00 1.47 of C2F4 3.34 2. 75 0.979 1.24 0.325 I w I

PAGE 52

TABLE 19 Energy Absorbed Percentage CF4 Recovered G Values Capsule by CF4 as Decomposition Formation No. (ev X 10-19) CF4 C2F4 C2F 6 0 C3F 8 0 of CF4 of c 2 F4 172 0 100 173 0.622 100 174 1.53 99.7 0.3 20.3 10.2 175 1. 74 99.4 0.6 35.7 17.9 176 2. 94 99.4 0.6 21.6 10.8 177 6.00 99.4 0.6 10.6 5.30

PAGE 53

CHAPTER V Discussion of Results Introduction Figure 3 shows the results of the gannna and reactor irradia tions of standard capsules. These capsules contained air at at mospheric pressure. These irradiations were undertaken to eval uate to what extent, if any, the Teflon packing and stem tips of the valves incorporated into the experimental capsules would de compose. As seen in Figure 3, no fluorocarbon products were de tected. This indicated that the valve stem packing and stem tips did not add to the fluorocarbon products during radiolysis of the experimental capsules. Gamma Irradiations Radiolysis Products and Reaction Mechanisms:The gamma irradiations of (a) CF 4 (b) CF 4 -UF 6 (c) CF 4 -UF 6 -N 2 (d) CF 4 -UF 6 -Ar, (e) CF 4 -UF 6 -Xe, (f) CF 4 -UF 6 -SF 6 and (g) CF 4 -uF 4 -c yielded primarily the unsaturated compound c 2 F 4 and traces of c 2 F 6 o and c 3 F 8 o. The reactant material CF 4 was also recovered. The results of these irradiations are listed in Tables 5 through 11, and the experimental data are listed in Appendix D. -45

PAGE 54

1 ] M Q) :> 0 0 u GI i,.. ffl .C M 1-1 00 a, 0 u .u 0 a, ij 1 ;:I M ,t:: llMO 0 g) .u -~ : 0 1.0 Capsules 101 102 103 2.0 Gamma dose to H 2 o at location of Capsule (Radsx10 8 ) --Capsules Capsules s.o 10.0 15 .o Integrated thermal neutron flux (n/cm 2 x1014 ) 104 105 106 107 108 20.0 Figure 3. Gamma and Reactor Irradiations of Standards -46

PAGE 55

The formation of the radiolysis product c 2 r 4 can be explained by the following combinations of reactions: a. radical formation (1) followed by a disproportionation reaction (2) b. molecular expubion of F 2 (3) followed by radical recombination (4) CF4~CF3+F 2CF3 --C2F4 + F2 CF4~CF2 + F2 2CF2 -----; C2F4 Other possible reactions are: CzF4 + 2F2--~ 2CF 4 CF3 + F CF4 CF2 + F2 CF4. (1) (2) (3) (4) (5) (6) (7) The material c 2 F 4 also underwent radiolysis, and these products reacted with fluorine to produce CF 4 These mechanisms for the production of c 2 F 4 and reformation of CF 4 are proposed for demon stration only and do not necessarily include all the possible reactions. The above reactions that produced CF 4 required fluor ine as a reactant. During gamma radiolysis the only sources of fluorine were the radiolysis of CF 4 UF 6 and UF 4 the natural

PAGE 56

. -4~radioactive decay of UF 6 or ur 4 and the spontaneous fls1lon of the uranium nuclei, The oxygen in the radiolysis products of c 2 F 6 o and c 3 F 8 o (refer to Appendix D) came from dissolved or adsorbed oxygen in the components, Aluminum oxides on the inner surfaces of the capsules were not oxygen sources,as the capsules were fluorinated before being used. The random variation in the amount of radiolysis products that contained oxygen indicated that the amount of oxygen varied from capsule to capsule, Justific ation of Components:(3) Askew found that the presence of CO and C in the gamma and reactor irradiations of CF 4 resulted in the destruction of CF 4 and the creation of higher molecular weight compounds. He concluded that C acted as a scavenger for fluorine during the (42) (43) radiolysis. Simons and Reed both indicated that N 2 might act like C during radiolysis. This present study was, in part, designed to capitalize on the mechanism of tying-up the fluorine with carbon or nitrogen. If fluorine were not available, the back reactions producing CF 4 would not occur, and the destruction of CF 4 would lead to higher molecular weight compounds or unique compounds, The materials Ar, Xe, and SF 6 were used to determine if compounds containing these materials could be produced, There

PAGE 57

_ ,.49 .. was no reason to believe that Ar. or SF 6 could act as scavengers of fluorine. Gamma Radiolysis Model:If one writes the overall radiolysis reaction for CF 4 ~k2 where k 1 is the rate constant for the forward reaction and k 2 is the rate constant for the two back reactions, and if one assumes that very little free fluorine and c 2 F 4 were produced during the gamma radiolysis experiments, then the back reactions involving k 2 were very slow. Thus the number of CF 4 molecules destroyed was propor tional to the number of CF 4 molecules present and to the dose re ceived, or where then dN o< NdD dN/dD o( N N = number of molecules of CF4 dN/dD = rate of disappearance of CF 4 D = total dose The minus sign indicates that dN is the number of molecules lost. Rearranging and integrating from N m N 0 to N = N and from D 0 to D = D gives

PAGE 58

-soln (N/No) = -k 1 D (N/N 0 ) -k D = e 1 100 (N/N 0 ) -k D = l00e 1 loglO [ (N/No) 100] = -KD + 2 where K = k 1 /2.303. The results of the gamma irradiations are plotted in Figures 4 through 10 as log 10 [(N/N 0 ) 100] versus the total absorbed energy, Din ev, in the CF 4 The symbol N/N 0 is the fraction of the CF 4 that was recovered after the radiolysis. The plotted points are the experimental data points, and the solid lines resulted from least-square fits to the experimental points. The reaction rate constants, K, are given for the various experimental systems. Knowing K, one is able to predict the number of molecules of CF 4 remaining after the sample has received a known dose of gan:nna radiation. As the dimensionless ratio, N/N 0 is used, the units for Nor N 0 may be any convenient unit which is related to the number of molecules. Discussion of Figures 4 Through 10:Figure 4 shows the results of the gamma irradiations of capsules which contained CF 4 For zero dose, there was essen tially 100 percent recovery of CF 4 As the irradiation process

PAGE 59

,---, 0 0 .... 0 z c 0 .... 00 3 1,990 lo g 1o[
PAGE 60

.---, 0 0 ..-1 0 z ---3 1.990 '--log 10 [(N/N 0 )100] -KD + 1.9991 -24 -1 = 3.192X10 ev ~---------0 -Capsules 115 116 117 118 1. 980 ....._ ____ ..__ ____ __.__ ____ __... ____ __., __ 0 s.o 10.0 15. 0 GaDUDa dose to CF 4 -20 (evXl0 ) Figure 5. Gamma Irradiation of CF 4 -UF 6 20.0 -52

PAGE 61

2.000 r---1 g ,-1 0 z ...___ e 1.990 0 ,-1 .9 1.980 0 s.o log 10 [(N/N 0 )100] = -KD + 1.9997 K = l.515Xl0. 24 ev-l 0--10.0 Capsules 119 120 121 Gmm:na dose to CF 4 (evXlo20 ) 20,0 -53

PAGE 62

,---, 0 0 .... 0 z -....... c 1.990 log 10 [ (N/N 0 )100] = -KD + 2.0000 K = 3.646Xlo24 evl Capsules 122 123 124 ..... .... 1.980 ------.L.-----~----....1.-----...L--0 5.0 10.0 15.0 Gamma dose to CF 4 -20 (evXlO ) Figure 7. Gamma Irradiation of CF 4 -UF 6 -Ar 20.0 .. 54_

PAGE 63

2.000 r---, 0 0 .... 0 z e 1.990 0 .... 3 1.980 0 5.0 loglo [ (N/No)lOO] = -~ + 1.9992 K 2.923X10 24 ev 1 ...._ Capsules 10.0 15.0 Gamma dose to CF4 (evx10 20 ) -.. 125 126 127 20.0 Figure 8. Gamma Irradiation of CF 4 -UF 6 -xe -55

PAGE 64

r---, 0 0 .... 0 log 10 [(N/N 0 )100) = -KD + 2.0000 2.000 0-K = 1.21sx10 24 ev 1 ---------0e 1.990 Capsules 128 129 1.980 __________ ____. _____ _,_ ________ 0 s.o 10.0 15.0 Gamma dose to CF 4 (evx10 20 ) 20.0 -56

PAGE 65

2.000 ..----, 0 0 0 e 1.990 0 00 .s 1.980 0 0 1.0 log 10 [ (N/N 0 )100] = -KD + 1. 9992 K 5.154Xl022 ev-l 2.0 Capsules 130 131 132 3.0 Gamma dose to CF 4 (evXlo19 ) 4.0 Figure 10. Gamma Irradiation of CF4-UF4C -57

PAGE 66

-58continued, small amounts of CF 4 were destroyed. It is known that the strength of the first C-F bond in CF 4 is more than 6.68 ev/mole (44) cule, which is greater than in any other fluorocarbon. Accordingly, Figure 4 shows this stability of CF4. (33) al. have obtained similar results. (3) Askew and Reed et As can be seen for the zero dose situation in Figures 5 and 8, the addition of UF 6 and subsequent storage of the capsule for 60 days resulted in the destruction of very small amounts of CF 4 This phenomenon was not observed in the experimental series shown in Figures 4, 6, 7, 9, and 10. These very small amounts of CF4 destroyed at zero dose can be explained by the natural radio activity of UF6 and by the spontaneous fission of the uranium nuclei in the UF 6 The rate constants for the destruction of CF 4 in the gamma experimental series are listed in Table 20. TABLE 20 GAMMA IRRADIATION RATE CONSTANTS FOR THE DESTRUCTION OF CF 4 System CF4 CF4-UF6 CF4 -UF6 N.z CF 4 UP' 6 -Ar CF 4 -UF 6 -Xe CF4 -UF6 -SF6 CF4-UF4-C -1 K 1 ev -24 1.510Xl0 -24 3.192X10 -24 1.515Xl0 -24 3.646X10 -24 2.923Xl0 -24 1. 218Xl0 -22 5.154Xl0

PAGE 67

-59The experimental series CF 4 -UF 6 CF 4 -UF 6 -N 2 CF 4 -UF 6 -Ar, CF 4 -UF 6 -Xe, and CF 4 -UF 6 -sF 6 contained the same number of starting CF 4 and UF 6 molecules; therefore, they can be compared with one another. The experimental series CF 4 and CF4-UF 6 contained the same number of starting CF 4 molecules, thus they can be compared with each other. For all the samples, except CF 4 -UF 4 -c, the statistics do not justify the conclusion that a real difference exists in the reaction rate constants. Nevertheless, it appears that the UF 6 in the CF 4 -UF 6 CF 4 -UF 6 -Ar, and CF 4 -UF 6 -Xe series did somewhat in crease the CF 4 destruction rate. The natural radioactivity of the UF 6 and the spontaneous fission of the uranium nuclei cannot be cited as the reason for this reaction rate difference. By referring to Appendix D, it can be seen that traces of the oxygen compounds c 2 F 6 0 and c 3 F 8 0 were found in the CF 4 -UF 6 CF4-UF 6 -Ar, and CF4-UF 6 -Xe series,whereas the results of the CF 4 CF 4 -UF 6 -N 2 and CF 4 -UF 6 -sF 6 series did not show oxygen compounds. The difference that existed in the reaction rates can be explained by the fact that the cap sules which contained the greater amounts of adsorbed or dissolved oxygen would result in the larger CF 4 destr~ction rates. For the experimental tests which Qontained CF4-UF6N2, it is not evident that Nz acted as a scavenger of fluorine. There is also no real evidence of any reactions involving Ar, Xe, and

PAGE 68

From the zero dose case shown in Figure 10, it can be seen that the ~ iJF 4 and C in the capsules containing CF 4 -ur 4 -c did not induce the destruction of CF 4 From Table 20 it can be seen that the rate constant for the CF 4 -UF 4 -c series is some 100 times larger than the other experimental rate constants. It is therefore hypothesized that the carbon and perhaps the UF 4 acted as scavengers of fluorine and thereby reduced the back reactions, which yielded CF 4 to essentially zero. Thus an increased CF 4 de struction rate occurred. Gamma Irradiations, G (-CF 4 ) Values:Tables 5 through 11 list the G (-CF4) and the G (C2F4) values for the various gannna experimental series. The'data show that (1) the G values were dose dependent and (2) the G (-CF 4 ) values for the CF 4 -UF 4 -c series were larger by a factor of 100 than the G values obtained in the homogeneous experiments. This latter fact indicates that an accelerated reaction rate occurred in the CF 4 -UF 4 -c series. This validates the hypothesis that car bon acted as a scavenger of fluorine causing a greater rate of destruction of CF 4

PAGE 69

Reactor Irradiations Radiolysis Products and Reaction Mechanisms:The reactor irradiations of (a) CF4, (b) CF4-UF6, (c) CF 4 -UF 6 -Al shavings, (d) CF 4 -UF 6 -N 2 (e) CF 4 -UF 6 -Ar, (f) CF 4 -UF 6 -Xe, (g) CF 4 -UF 6 -sF 6 and (h) CF 4 -UF 4 -c gave the same products as were found in the gamma radiolysis experiments. Traces of CzF60 and C3F 8 0 were produced in all of, the reactor tests, except for the cF 4 ~UF 4 -c series, as can be observed in Tables 12 through 19. The reasons why traces of the oxygen com pounds were not found in the CF4-UF4-C series were the slow re action rates of this series and the fact that air is not soluble in UF4. The mechanisms for the formation and destruction of C2F4 as discussed in the Gamma Irradiations section are consid ered to be valid for the reactor irradiation experiments. The rate of c 2 F 4 destruction depended upon the concentration of free fluorine and the rate of energy deposition in the system. As will be discussed later, more and more free fluorine was available as the reactor irradiations continued. Thus the back reactions that produced CF 4 were very important in the reactor experiments. Justification of Components:The series (a) CF4, (b) CF4UF6, (c) CF4-UF6-Al shav ings, (d) CF 4 -UF 6 -N 2 (e) CF 4 -UF 6 -Ar, (f) CF 4 -UF 6 -Xe, (g) CF4-UF6-SF6,

PAGE 70

and (h) CF4-UF4-C were selected for reactor irradiations, The reasons why these mixtures were chosen, except for the CF4-UF6Al -62shavings mixture, have been discussed in the gamma analysis section, (3) Askew reported that the presence of aluminum powder in the gannna and neutron radiolysis of CF 4 increased the yield of all the products. The reason cited for this increase was that surfaces affect gas phase radiolysis in which free atoms are in(3, 45) termediates, The series CF4-UF 6 -A1 shavings was included in the reactor irradiations in order to evaluate the Al surface area effect, Reactor Radiolysis Model:As the reactor irradiations continued, more and more free fluorine became available in the capsule, The concentration of the fluorine resulted from several irdependent sources. The radiolysis of CF4 produced fluorine, Each uranium atom that fis sioned released six fluorine ions or atoms, and apart from the (46) fissioning process, it has been reported that the neutron irradiation of UF 6 yields UF 5 and F 2 Thus the concentration of F 2 was directly proportional to the energy received, The differential equations which describe the system k2

PAGE 71

-63are dA/dD = where A = number of molecules of CF 4 B = number of molecules of C2F4 dA/dD = rate of disappearance of CF 4 dB/dD = rate of disappearance of C2F4 D = total dose, If the F 2 produced is not scavenged, then the rate of the back re actions producing CF 4 is large. For this situation, the solutions to the above equations are not readily tractable. The set of equa tions can be solved, however, by the use of the analogue computer. If the free fluorine is removed by a scavenger, the back reactions are very slow, and the equation gives the solution log 10 [ (A/A 0 ) 100] = -KD + 2 where = starting number of molecules of CF4 The results of the reactor irradiations are plotted in Figures 11 through 18. Figures 12, 13, 15, and 17 are plotted as the fraction of the CF 4 recovered, A/A 0 versus the total absorbed

PAGE 72

r--, 0 0 .... 0 2.000 ~ lo990 0 .... J 1.980 0 ----o--,__ _____ 0---1.0 2.0 Capsules 112 113 114 3.0 Integrated thermal neutron flux (n/cm 2 x10 14 ) Figure 11. Reactor Irradiation of CF 4 -64

PAGE 73

M Ix (.) CIJ fj l,M 0 .... .u u CII M 1.0 0.9 0.8 0.7 0.6 0.5 0 dA/dD c k 2 DB k 1 A dB/dD k 1 A k 2 DB k1 = 8.00Xlo23 ev 1 k 2 = 1 1ox10-22ev-l Capsules 133 134 135 136 137 138 139 140 141 2.0 4.0 6.0 Energy absorbed by CF 4 (evx10 21 ) Figure 12. Reactor Irradiation of CF 4 -UF 6 -658.0

PAGE 74

1.0 ~o < 0.6 0 0......._ 0 5.0 10.0 dA/dD = k 2 DB k1A dB/dD = k 1 A k 2 DB kl= 8.00Xl022 av 1 k2 = 2.50Xlo22 ev-l Capsules 142 143 144 145 146 147 15 .o 20.0 Energy absorbed by CF 4 (evXlo19 ) 25 0 Figure 13. Reactor Irradiation of CF 4 -UF 6 -Al shavings -66

PAGE 75

I 2;000 01.990 1.980 ,---, 8 ,-4 ~o < L...--11. 970 C ,-4 3 1.960 1.950 1.940 0 0 2.5 los10 [ (A/Ao)lOO] = -KD + 1.9961 K = S.066Xl024 evl 0 Capsules 148 149 150 151 152 153 0 \ '\ s.o 7.5 10.0 Energy absorbed by CF 4 (evx10 19 ) Figure 14. Reactor Irradiation of CF 4 -UF 6 -N 2 -67

PAGE 76

1.0 0 < < .. 1 1-f g 0.9 J-4 ~-,j' t.) ., -B 0.8 'M 0 l::l 0 o,-l ,I.I u llS 1-1 0.7 a:.. 0.6 0 1.0 dA/dD = k 2 DB k1A dB/dD = k 1 A kzDB 2,0 k 1 = 6.oox10 23 ev~ 1 k 2 = l,60Xl0-22ev 1 Capsules 154 155 156 157 158 159 3,0 4.0 Energy absorbed by CF 4 (evx10 21 ) 0---0-5.0 Figure 15. Reactor Irradiation of CF 4 -UF 6 -Ar -68

PAGE 77

2.000 ..--, 1. 900 0 0 ....
PAGE 78

-10-.. dA/dD = k 2 DB k 1 A dB/dD = k 1 A k 2 DB -23 -1 kl= 7.50Xl0 ev -22 -1 kz = 0.785Xl0 ev 1.0 0 < < .. 1 0.9 M ,,. g 0 .. M r,..-:t 0 (.J 0 J! 0.8 .l,J 1.1-l Capsules 166 0 167 c:: 168 0 .... 169 .l,J u 0.7 170 Cd M 171 0.6 0 2.0 4.0 6 0 8.0 Energy absorbed by CF 4 (evXlo21 ) Figura 17. Re.actor Irradiation of CF4-UF 6 -sF6

PAGE 79

r--. 0 0 .... ..,,.,.01. 990 $ '----' 1.980 0 1.0 0 0 log 10 [ (A/ A 0 ) 100 ] = -KD + 1. 9994 K = 4.503Xl0. 25 evl 2.0 3.0 Capsules 172 173 174 175 176 177 4.0 Energy absorbed by CF 4 -21 (evXl0 ) 5.0 Figure 18. Reactor Irradiation of CF 4 -ur 4 -c -710

PAGE 80

energy, D in ev, in the CF 4 The plotted points are t~e experi mental data points, and the solid lines resulted from curve fitting the experimental data points. This was accomplished by using the analogue computer and the basic reaction model as described above. The reaction rate constants k 1 and kz are given for the various experimental series. Figures 11, 14, 16, and 18 give the results of the re actor irradiations of the cr 4 CF 4 -UF 6 -N 2 CF 4 -UF 6 -xe, and CF 4 -UF 6 -c series. These results are plotted as log 10 (CA/A 0 ) 100] versus the total absorbed energy, Din ev, in the CF 4 The fraction of the cr 4 that was recovered after radiolysis is represented by A/A 0 The plotted points are the experimental data points, and the solid lines resulted from a least-square fit to the experimental data points. The reaction rate constants, K, are also given. Discussion of Figures 11 Through 18:The negative slopes shown in Figures 11 through 18 were expected by analogy with the gamma irradiation experiments, Fig ure 11, the reactor irradiation of CF 4 shows the stability of CF4 to reactor irradiation. This was as expected by analogy with the gamma irradiation of CF 4 Figure 4. The results as presented in Figures 14, 16, and 18 show the effect of fluorine removal. The conclusion is that N 2 Xa, and C acted as scavengers of fluorine and thus removed the fluorine

PAGE 81

~73which was necessary for the back reactions, These results in the cases of the C and N 2 series were not unexpected, 33) Other workers (3. have reported that carbon acted as a scavenger of fluorine in the gamma and reactor radiolysis of CF 4 and for the CF 4 -UF 6 -N 2 series, the high energy environment is necessary for NF 3 formation. The somewhat surprising result was the fact that Xe acted as a sc~venger of fluorine. An extensive effort was made (see Append~ices Band C) to validate this conclusion. The results of this investi gation indicated that xenon compounds, probably XeF 2 and XeF 4 were formed during the radiolysis experiments. It is not certain at this time whether or not other xenon compounds were also formed. Figures 12, 13, 15, and 17 show the results of the re show the effect of the absence of a scavenger of fluorine. As the irradiation continued, an increased rate of CF 4 production by the back reactions occurred. Figures 12, 15, and 17 have the same general shape in that (1) the minimum percentage of the CF 4 mole cules recovered as c 2 F 4 was on the order of 88 percent and (2) the minimum in the curves occurred at approximately 3.5 X 10 21 to 21 4.5 X 10 ev of energy absorbed in the CF 4 The discussion of th~ CF 4 -UF 6 -Al shavings series will be made in terms of a reaction rate comparison with the CF 4 -UF 6 series.

PAGE 82

.. 74 .. The reaction rate constants for the destruction of CF 4 for the reactor experiments are presented in Table 21, This table also contains the rate constants for the gamma experiments. It can be seen from Table 21 that the rates of destruction of the C 0 F 4 for the reactor irradiated series, except for the CF 4 -UF 4 -c series, were approximately ten times the reaction rates for the gamma series. This was expected due to the fact that a fission process was occur ring in the reactor experimental capsules. The fission fragments deposited more energy per unit track length, greater LET as com pared to the gamma photons. Thus the probability of CF4 destruc tion was greater in the reactor experiments. From Table 21 it can be seen that the addition of Al shavings to an experimental CF4-UF6 series increased the CF4 de struction rate by approximately a factor of ten. As discussed in (3) the section Justification of Components, Askew reported similar results. A possible explanation for this increased reaction rate is as follows. The fission fragments bombarded the fluorinated Al shavings and destroyed the aluminum fluoride surface. Free fluorine was used to re(luorinate the surface. Thus there was less fluorine available for the back reactions, and this resulted in a larger CF 4 destruction rate. In essence, the Al shavings acted as a scavenger of fluorine. As the irradiation continued, the surface fluorination process did not keep pace with the free fluorine formation, thus there was free fluorine available for

PAGE 83

TABLE 21 GAMMA AND REACTOR IRRADIATION RATE CONSTANTS FOR THE DESTRUCTION OF CF 4 -75( -1 K except where noted k 1 or k 2 ), ev System Reactor Gamma CF4-UF6-N2 CF4-UF6-Ar CF4-UF6-Xe CF4-UF6SF6 -23 k1 = 8.00XlO -22 k2 = 1.lOXlO -22 k1 = 8.00XlO -22 k2 = 2.50Xl0 5.066Xl0 24 -23 k1 = 6,00XlO -22 k2 = 1.60Xl0 -23 4.273Xl0 -23 k1 = 7.50Xl0 -22 k2 = 0.785Xl0 -25 4.503Xl0 24 1. SlOXlO. -24 3.192Xl0 -24 1.515Xl0 -24 3.646Xl0 -24 2.923Xl0 -24 1. 218X10 -22 5.154Xl0

PAGE 84

the back reactions, This can be seen by comparing k 2 for the CF 4 -UF 6 -Al shavings series with k 2 for the CF 4 -UF 6 series, These constants are of the same order of magnitude, The reaction rate constants for the series CF 4 -ur 6 CF4-UF6Ar, and CF4-UF6-SF6 are approximately the same, The k 2 value for the CF 4 -UF 6 -sr 6 series is somewhat smaller than the other k 2 values, The CF 4 -UF 6 -sF 6 reactor irradiations resulted in larger yields of the c 3 F 8 0 oxygen compound. The oxygen compounds are not as reactive as c 2 F 4 Thus, for the CF 4 -UF 6 SF 6 series, ~he reactions producing CF 4 were slowed by the presence and formation of the oxy(35) gen compounds. Scott also found that the oxygen compounds did not readily react during radiolysis. A comparison of the reaction rate constants for the rate for the Xe series was approximately ten times as large as the CF 4 destruction rate in the nitrogen series. This can be explained by the fact that XeF 2 and XeF 4 are more easily made than the postu lated NF 3 The reactor c apsule series as discussed above contained the same number of starting CF4 and UF6 molecules. The CF4UF4-C series contained the same number of CF 4 starting molecules, but since it contained UF4, it cannot be directly compared with the other series,as the concepts are different. This series can be compared, however, to the gamma CF 4 -UF 4 -c series,as the makeup of

PAGE 85

-11the two series was identical. From Table 21 it can be seen that the reaction rate constant for the gannna irradiated series is 1000 times as large as the reaction rate constant for the reactor irradiated series. This can be explained by the fact that the UF 4 and the C in the reactor irradiated series were solids. Most of the fission fragments were contained in the solid phase. Only a small fraction of the energy was dissipated in the gas phase; how ever, the rate constant calculations assumed that all of the fission fragment energy was deposited in the gas phase, Gamma radiolysis was not very important in the reactor tests, as a core gamma shield was present while the experiments were being run (see Experimental Procedure). Thus in the reactor CF4-UF4-C series, the CF 4 destruc' tion process was very inefficient,whereas in the gamma radiolysis of CF4-UF 4 -c, an efficient CF 4 destruction occurred, Reactor Irradiation, G (-CF4) Values:The G values, G (-CF 4 ), for the reactor irradiations are plotted in Figures 19 through 21. The G (-CF 4 ) values for the CF4-UF6-Al shavings and CF4-UF6-Xe series reflect the large CF4 destruction rates. The G (-CF 4 ) values also reflect the larger than usual amount of c 3 F 8 o which was formed in the CF 4 -UF 6 -sF 6 ex perimental series. Several points of interest with reference to the G (-CF4) values as plotted in Figures 19, 20, and 21 are:

PAGE 86

(1) The G (CF 4 ) values, as waa found in the g8111Da experiments, were dose dependent. (2) The trend of the G (CF 4 ) values was to decrease with an increasing dose. This (3, agrees with the findings of other workers. 32, 33, 35) (3) The G (-cF 4 ) values except for the CF 4 -UF 4 -c series were larger than the G (-CF 4 ) value, obtained in the gamma irradiation experi(3, 32, 33) ments. Other workers have re ported similar findings. General Comments (3, 33) A closing point of interest is that previous workers have reported that the saturated compound c 2 F 6 was produced in th~ gaDDDa and neutron irradiations of CF 4 In this study the primary product was found to be the unsaturated compound c 2 F 4 A comparison between the referenced works and the present study is not justified, as the studies were basically different in components and in experimental context. Nevertheles1, a plaus ible explanation as to why c 2 F 4 was produced in the present study can be found in the concept of the interaction between high energy particles, such as g&DID& photons and fission frag (47) menta, and materials It is known from pyrolysis studies -78in the fluorocarbon area that within the temperature range of 300

PAGE 87

Symbol Series -79A CF4-UF6Xe El CF4-UF6-SF6 12 0 CF4-UF 6 CF4-UF 6 -Ar 0 CF 4 -ur 6 -N 2 -a 1 10 0 II,) t 0 0 .... -a 8 ., t.u II,) QI ,-c, 8. .............. ...::t i:r.. 6 u I .... :, u QI .... a 4 QI :, .-4 ell l> c., 2 C::l 0 0 0 2.0 4.0 6.0 8.0 Energy absorbed by CF 4 (avx10 21 ) Figure 19. G (-CF 4 ) Values--Reactor Irradiations

PAGE 88

_ 100 "' 0 Series: CF4-UF6Al shavings GI ,e 0 !I) ,.Q CIS t 80 0 0 ... ....... 'i 1-1 60 ._i :i "ti f&.i..:;t tJ 0 co II ... ::, 40 i ... -~ ..... I II ::, ... CIS > 20 t.!) o ___ ....., ________________ _... _____ .__ __ 2.0 5.0 10.0 15. ci 20.0 Energy absorbed by CF 4 (evx10 19 ) 25.0 Figure 20. G (-cF 4 ) Values--Raactor Irradiations -80

PAGE 89

40 '!:I GJ ,Q 1-4 0 Ct:I ,Q 30 QI t 0 0 ........ 1 g, 20 1-4 .&J II> ti '!:I a, 10 QI .... .... I ti ::I 0 .... 111 :> <.!) 0 2.0 Series: CF 4 -UF 4 -c 4.0 6.0 Energy absorbed by CF 4 (evx10 19 ) ..... ........ 8.0 Figure 21. G (-CF 4 ) Valuas--Reactor Irradiations -81

PAGE 90

-82to 700 C the predominant fluorocarbon products are the unsaturated compounds. For this study the temperatures of the gamma and reactor irradiations were 25 and 36 C respectively (see Appendix A). Nevertheless, the energy equivalent temperatures as calculated from (48) heat capacity considerations corresponds to the temperatures that would result in the formation of the unsaturated compound c 2 r 4

PAGE 91

CHAPTER VI Conclusions Gamma Irradiations The gaseous products formed in the g8DIDa irradiation of the experimental series (a) CF 4 (b) CF 4 -UF 6 .(c) CF 4 -ur 6 -N 2 (d) CF4-UF 6 -Ar, (e) CF 4 -UF 6 -xe, (f) CP 4 -UF 6 -sr 6 and (g) CF 4 -UF 4 -c were the unsaturated compound CF and the oxygen compounds CFO 2 4 2 6 and c 3 F 8 o. The breakdown of cr 4 going primarily to c 2 r 4 was on the order of one-tenth to 2 percent except for the CF 4 -UF4C series,where the CF 4 breakdown ran as high as 4 percent. The oxygen c01Dpounds came from oxygen reactions where the oxygen was dissolved in the components or ; adsorbed on the surface of the components. Expressions were derived which related the fraction of the cr 4 remaining after an exposure to a given dose of gamma irradiation. No evidence was found that any of the CF 4 admixtures -UF 6 N 2 Ar, Xe, sr 6 --acted as scavengers of fluorine. The presence of a scavenger of fluorine would have resulted in a larger c 2 r 4 yield. It is probable that the C in the cr 4 -UF 4 -c series -83

PAGE 92

-84acted as a scavenger of fluorine. This conclusion agrees with the findings of other workers who have investigated the gamna radiolysis of CF4-C series. The magnitude of G values for the destruction of CF 4 in the CF 4 -UF 4 -c series also validates the conclusion that C acted as a scavenger of fluorine. For the above experimental aeriu, a gamma chemonuclear system for the production of higher molecular weight compounds or for the production of unique compounds does not appear promising nor attractive. Reactor Irradiations 'lbe gaseous products formed in the reactor irradiation of the experimental series (a) CF4, (b) CF4-UF6, (c) CP'4-UF6Al shavings, (d) CF 4 -UF 6 -N 2 (e) CF 4 -UF 6 -Ar, (f) CF 4 -UF 6 ~Xe, (g) CF 4 UF6-SF6, a~d (h) CF4UF4-C corresponded to those formed in the gamma irradiation experiments. This work showed that homogeneous and heterogeneous mixtures of the fluorocarbon CF4 with UF6 or UF4 and a third component--Al shavings, N 2 Ar, Xe, SF 6 or c--can be reactor irradiated without any abnormal reaction occurring. The separation of the irradiated fluorocarbons froin the fission frag ments and UF 6 was accomplished by passing the gaseous products through a sodium fluoride trap. A model was developed which re lated the fraction of the CF 4 remaining after an exposure to a given reactor irradiation dose.

PAGE 93

-85l'he addition of Al shavings to a CF 4 -UF 6 series in creased the destruction rate of the CF4, This phenomenon has also been reported by other investigators, In general, the CF4 destruc tion rates in the reactor irradiated series were approximately ten times as large as the CF4 destruction rates in the gamma irradiated series. This was due to the concentrated amounts of energy depos ited by the fission fragments, For the experimental series containing UF 6 Ar, and SF 6 no trap existed for the fluorine. As the irradiation contin ued CF4 was produced rather than destroyed. In the series contain ing the Al shavings, the destruction of CzF4 was much less pro nounced,due to the increased CF 4 destruction rate, It was found that both N 2 and C acted as scavengers of fluorine, In these experiments, the buildup of CzF4 continued throughout the duration of the irradiation, An unexpected result was the formation of XeF 2 and XeF 4 in the CF 4 -UF 6 -Xe experimental reactor tests. The Xe acted as a scavenger of fluorine. This formation of Xe compounds is a major chemonuclear find, The G values for the destruction of CF 4 in the reactor irradiation experiments agree with the values reported by other workers. In the series where there were fluorine traps, the G values reflected the increased CF4 destruction, From the chemonuclear production standpoint, the only

PAGE 94

-86 interesting reactor test series were those which contained N 2 C, and Xe, i.e scavengers of fluorine. The series that truly war rent future study are (a) reactor irradiations where Xe and N 2 are used as an admixture and (b) the gamma and reactor irradiations of CF 4 -UF 4 and CF 4 -c. From a basic standpoint, however, it would be interesting to repeat the reactor studies of the series involving N 2 C, and Xe. In these tests, the reaction temperature, capsule pressure, or the reaction surface area could be varied. It would also be interesting to test other fluorocarbons, perhaps c 2 F 6 or c 3 F 8 A fourth component, oxygen, could also be tested to see if unique oxygen compounds can be produced.

PAGE 95

APPENDIX A Calculations Calculation of ~ercentage of Gaseous Products Formed During Irradiation The calculations will be performed for Sample No. 164, one of the ur 6 -cF 4 ~xe series subjected to reactor irradiations, using the data for this sample as listed in Appendix D. A chromatograph ic analysis was required for the sample, From the chromatogram, the area under each gaseous product peak was found by graphical integration. The component percentage was the ratio of the area for a given product to the total area multiplied by 100. These percentages for each sample are listed in Appendix D. As the above mentioned component areas, or percentages, represent the amount of the products present, these percentages must be converted into an equivalent percentage of CF4. Assum ing that two molecules of CF are needed to make one molecule 4 of C2F4 or CzF60, that three molecules of CF4 are needed to make one molecule of c 3 r 8 o, etc., the percentage of CF 4 in the -87

PAGE 96

-88% CF 4 % CF 4 as CF 4 :: --,-,----,-""""'""---------X 100 % CF 4 +(2)% c 2 F 4 + (2) % c 2 F 6 o + .. .. % CF 4 as c 2 F 4 a (2) % c 2 F 4 % CF 4 + (2) % c 2 F 4 + (2) % c 2 F 6 o + ... X 100, (2) % c 2 r 6 o % CF 4 as c 2 r 6 o ii= X 100. i. CF4+ (2) % c 2 F 4 + (2) % c 2 F 6 0 + For Sample No. 164 CF 4 as CF 4 = 54.4%, CF 4 as C2F4 43.8%, CF 4 as c 2 F 6 o 1.8%, and CF 4 as c 3 F 8 0 trace These percentages for each sample are summarized in Chapter IV.

PAGE 97

Calculation of the Energy Deposited in the Sample--Gat1111a Irradiation The gamma irradiations were performed in the University of Florida food irradiator. The gamma doses were measured by Fricke (38) -89dosimetry. The dose in the capsule is related to the measured dose, in water, by the equation dose (capsule) : dose(H 2 o) X ( el~ctron density (componen\) X mass fraction (c01Ilponent 1 )) 0 electron density (H 2 0) Using as an example capsule No. 126 which contained CF 4 -UF 6 -xe dose (capsule)= dose (H20) X --( electron density (CF 4 ) X mass fraction (CF 4 ) + electron density (UF 6 ) X mass fraction (UF 6 ) electron density (H20) --+ electron density (Xe} X mass fraction (Xe) )

PAGE 98

-908 Dose (capsule): 1.69 X 10 rads X [ (2.87) (0. 757) + (2.52) (0. 109) + (2. 71) (0.134) j X 3.34 X 10 23 J 1023 dose (capsule)= 1.42 X 10 8 rads. The dose absorbed by the CF 4 in the capsule can then be calculated as dose (CF4) = dose (capsule) X [ electron density (CF4) X grams (CF4) 1:electron density (componenti) X grams (com i 8 dose (CF 4 ) 1.42 X 10 X [ --(2.87 X 1023) (1.164 X 10-3) (88) + (2.52 X 10 2 3) (5.94 X 105 ) (349) ] + (2. 71 X 10 23 ) (1.95 X 10 4 ) (131.3)]

PAGE 99

In terms of ev, the dose (CF 4 ) is 100 ergs 1 ev X gram rad 1.6 X 1012 erg 1.64 X 103 moles X 88 grams mole 20 dose (CF4) s 9,92 X 10 ev. -91X

PAGE 100

Calculation of Integrated Thermal Neutron Flux pile, Standard gold disks, irradiated in the Argonne standard (49) were used to calibrate the counting equipment. A cross calibration between the gold disks and a standard capsule reference gold wire was also obtained by irradiating both stand ards in the University of Florida Training Reactor. From the disk calibrations and the cross calibration, a counter efficiency for the capsule-monitor gold wires was obtained. This efficiency was found to be 12.80 percent which gave a count-rate correction factor of 7.82. The counting equipment included the following: Hamner High Voltage Power Supply NV-15, Amplifier LA 110, Scaler NS-10, and Mechanical Timer NT-10. Atomics Accessories, Inc. Geiger Tube EWX-116 65-47 EWH-108, 65-52. -92References {39) and (50) give the following relationship for calculating the thermal neutron flux. = AM X CF

PAGE 101

.93_ where (/) = thermal neutron flux in neutrons/cm 2 sec, A activity of foil in disintegrations/ sec at the end of an irradiation, M = 197 atomic weight of the monitor element (Au ) in grams, N = Avogadro~ number times the weight of sample in grams, U activation cross section for Au 197 in cm 2 T~ = half life of isotope in hours, t = irradiation time in hours, 0 isotopic abundance of the target element, and CF = correction factor, 7.82. The monitor foil was counted at intervals of two days until the activity dropped below 1,000 counts per minute. Three counts of one minute each were taken each time the foils were counted. A graph of count rate versus time was plotted whereby the foil count rate at reactor shutdown was determined. For sample No. 164, the foil counting rate at reactor shut6 down was 6,10 X 10 counts/minute. The gold monitor foil weighed 3,080 0.001 milligrams; the irradiation time was two hours; the half life of Au 198 is 64.8 hours; the isotopic abundance of Au 19 7 is 100 percent; the activation cross section for Au 197 is 99 X 10 -24 cm 2 {SO, Sl) -..e thermal ~11 flux for the irradiation is thus calculated as

PAGE 102

= (6.10 X 10 6 ) (1/60) (197) (7,82) 1 1 exp [ (-0.693) (2)] 64.8 X Finally, the integrated flux over the twOhour irradiation is rl-\ [ neutrons sec \fJ 2 X 3600 -X 2 hours cm sec hour = 2.92 X 10 14 neutrons/cm 2 -94

PAGE 103

Calculation of the EnerQ Deposited in the Sample--Reactor Irradiations -95The energy deposited in the sample was calculated by assum ing that the fission energy other than the energy of the emitted neutrons, gaI11Da photons, and neutripos was deposited in the sample. The energy deposited in the CF4 is related to the en~rgy deposited in the sample by the equation ev (CF 4 ) = ev (sample) X [ electron density (CF 4 ) X grams (CF 4 ) l Lelectron density (componenti) X grams (componenti)j. i The electron density can be calculated for CF 4 as electron density (CF4) 10 23 molecules X 42 6.023 X 23 mole grams 88mole electron density (CF4) = 2.87 X 10 electrona/gram. electrons molecule

PAGE 104

A list of electron densities as calculated or as obtained from Reference (33) is shown in Table 22. Thus the energy absorbed Material Ar Al C C2F4 C2F6 c 2 F60 C3F 8 0 H20 Nz SF 6 UF4 UF6 Xe TABLE 22 ELECTRON DENSITY OF VARIOUS MATER!~ Electron Density electrons/gram X 10 23 3.01 2.90 3.01 2,87 2.89 2.88 2.89 2.90 3.34 2. 71 2.89 2.45 2.52 2. 71 by the CF 4 in Sample No. 164 is -96

PAGE 105

ev (CF 4 ) =ev (sample) X [ (2.87 X 10 2 + (2.52 X 10 23 ) (2.01 X 103 ) (349) +(2.71 X 10 23 ) (1.69 X 10" 4 ) (131.30)]. The calculation for ev (sample) is as follows. The number of atoms/cc of uranium in the sample is NU= (2.01 X 103 moles UF) (1/volume capsule) X 6 23 (6.023 X 10 molecules/mole) where NU~ atoms uranium/cc. 'l'ha total number of fissions in the capsule is given by fissions =(V capsule>[ (t)] (t)
PAGE 106

1:f = [ = f = macroscopic fission cross section for 93.16 % u 235 enriched uranium. N235 (J 235 + N238 U 238 f f NU (0.9316 6, 235 + 0.0684 U 238 ) f f where uf = 2 average fission cross section in cm. For the Uf values, Reference (36) gives 6= f where f = non 1/v correction = 0.981, and U = fission cross section, at 2200 m/sec, in cm 2 2200 Reference (51) gives 235 = 582 barns 238 = o. Therefore the calculation for Lf is (0.9316) (582) (fi) (293,2)~ (0.981)] X 10 2 4 2 309 The energy released per fission is 185 Mev; thus the total ener gy absorbed by the sample is 6 ev (sample)= (fissions) (185 X 10 ev/fission). Collecting all the terms, the energy absorbed by samp l e No. 164 was

PAGE 107

22 ev (sample)~ 2,93 X 10 ev Using the equation on page 97, the energy absorbed by the CF 4 in sample No, 164 was found to be 22 ev (CF 4 ) = 0.587 X 10 ev. -99

PAGE 108

Calculation of G Values As the G value is defined as the number of molecules of product formed or destroyed per 100 ev of energy absorbed in the CF 4 or in the c 2 F 4 its calculation, once the molecules formed or destroyed and the energy absorbed are known, is (regardless of the type of irradiation) G = molecules (product) formed or destroyed energy absorbed (ev) X (1/100 ev) Again using sample No. 164 {1.82 X 103 ) (6.023 X 10 23 ) (0.456) (5.87 X 10 21 ) (l/100) = 8.52 and (1.82 X 103 ) (6.023 X 10 23 ) (0.438) (5.87 X 10 21 ) (1/100) = 4.09. -100

PAGE 109

APPENDIX B Evidence that Xenon-Fluorine Compounds Were Formed During the Reactor Irradiation of CF4-UF6Xe From the results of the ~eactor irradiation of CF 4 -UF 6 -Xe, it was evident that (1) xenon disappeared from the gas phase (see Appendix C) and (2) CF4 destruction occurred at a constant rate. This latter fact indicated that fluorine had been scavenged. Chromatograms of the gases did not show any xenon compounds nor any unexplained products. The irradiated capsules were evacuated and allowed to stand for 30and 60-day periods; no gaaea were detected at the end of these periods. This indicated that if solid xenon-fluorine com pounds were formed during radiolysi&, they exerted no vapor pres sure and did not decompose. Two experimental capsules were cut apart and solid material was observed on the inner walls of the capsules. However, the walls were highly contaminated with fission fragments, and the amounts of the observed material were small. Several of the capsules were then analyzed as follows. The capsule was evacuated and placed in liquid nitrogen. Fifty cc of water were introduced into the capsule, and it was allowed to come to room temperature. The capsule was shaken, stored for 30 min utes, and then reshaken. It was connected to the vacuum transfer -101.

PAGE 110

~102system, and the water was frozen by surrounding the capsule with a dry ice-acetone mixture. Tha volatile gasea were chromatographed, and the chromatograms showed that xenon was present, More xenon was recovered from the capsule which received the larger radiation dose than from th@ capsule which received lesa radiation. It was clearly evident that solid xenon-fluorine compounds were formed during radiolysis. These compounds were such that they exerted a very small vapor pressure at room temperature, Two {52) likely candidates that fit this vapor pressure requirement are

PAGE 111

APPENDIX C Disappearance of Xenon in the Reactor Irradiation of CF4-UF6-Xe After the previous studies had been completed, it was ob served that a quantitative interpretation of the xenon data in the reactor irradiation of CF 4 -ur 6 -Xe could be formulated. The amount of xenon in the sample was assumed to be directly propor tional to the area of the xenon chromatogram peak. These areas are given in Table 23. Capsule No. 160 161 162 163 164 165 TABLE 23 REACTOR IRRADIATION OF CF4-UF6-Xe XENON CHROMATOGRAM AREA Xe Chromatogram Area (square inches) 18.20 16.00 15.56 11. 90 11.28 8.18 The number of xenon atoms which reacted was proportional to the xenon concentration and to the concentration of the free flu orine atoms. The free fluorine atoms were proportional to the

PAGE 112

total energy absorbed in the CF 4 Thus where dXe CX XedD Xe= number of atoms of Xe dXe/dD = rate of disappearance of Xe D = total energy absorbed by CF 4 Rearranging and integrating from Xe= Xe 0 to Xe= Xe and from D =Oto D = D gives log 10 [ (Xe/Xe 0 ) 100] = -KD + 2 where K = k/2.303. -104The results of the disappearance of xenon in the reactor irradia tion of CF 4 -UF 6 -Xe is shown in Figure 22 as log 10 [
PAGE 113

r---, 0 S 1. 900 0 ft \ I< I ~ L....-..J .S 1. aoo co .S 1.700 1.600 0 Figure 22. loglO [(Xe/Xe 0 )100 ] = -KD + 1. 9994 K 4.172Xlo23 ev-l Xe/Xe 0 = Fraction of the Xe that was recovered after radiolysis D = Total energy absorbed by the CF 4 0 Capsules 160 161 162 163 164 165 0 0 2.0 4.0 6.0 8.0 Energy absorbed by cr 4 (evXlo21 ) Disappearance of Xe in the Reactor Irradiation of CF4-UF6Xe -105'

PAGE 114

APPENDIX D Experimental Data The following are the data for each capaul that was subjected to gamma or reactor irradiation. The measured temperature of the capsules undergoing gamma irradiation was 25c. The temperature of the capsules undergoing reactor irradiation was 36c. Data that were the same for each capsule regardless of its contents or irradiation plan are as follows: Volume of gas chromatographed: 10 cc Temperature of the gas chromatographed: room tempera ture Column: copper Length: 40 inches Packing: Silica Gel 30/60 mesh Inlet pressure: 54.7 psia Outlet pressure: 14.7 psia Gas flow rate: SO 4c/minute at 35c, He Temperatures: Injection port: 35c Detector: 35c Oven: 35~ 200c; 10 /minute Filament current: 225 milliamperes Time to fill sample loop: one minute Chromatograph chart speed: one inch/minute The pages that follow give the breakdown of the important data for each capsule. -106

PAGE 115

Sample No. 101; Capsule size: 11.1 cc; Irradiation type: none Contents: Material air Form gas Gram Moles (atmospheric pressure) Pressure of Gas Sample chromatographed: 80 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -107Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88

PAGE 116

Sample No. 102; Capsule size: 10.9 cc; Irradiation type: gamma Contents: Material air Form gas Gram Moles (atmospheric pressure) 8 Gamma dose to water (at location of capsule) lXlO rads Pressure of Gas Sample Chromatographed: 80 Dill Hg -108 Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88

PAGE 117

-109Sample No. 103: Capsule size: 11.1 cc; Irradiation type: gamma Contents: Material air gas Gram Moles (atmospheric pressure) Gamma dose to water (at location of capsule) 2.sx10 8 rads Pressure of Gas Sample Chromatographed: 80 mm Hg Compound Air Appearance Time (minutes) 0.88 %, gas phase, Fluorocarbon (from chromatogram)

PAGE 118

Sample No, 104; Capsule size: 378 cc; Irradiation type: none Contents: Material air Form gas Gram Moles (atmospheric pressure) Pressure of Gas Sample Chromatographed: 70 mm Hg Conunents: Sample was chromatographed after 30 days and again after 60 days. -110Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88

PAGE 119

-111Sample No, 105; Capsule size: 371 cc; Irradiation type: reactor Contents: Material air Form gas Gram Moles (atmospheric pressure) Irradiation time: 1 hour; Power: 100 kw 14 2 Integrated thermal flux: 1.23Xl0 n/cm Pressure of Gas Sample Chromatographed: 70 UDD Hg Compound Air Appearance Time (minutes) 0,88 %, gas phaie, Fluorocarbon (from chromatogram)

PAGE 120

-112Sample No. 106; Capsule size: 377 cc; Irradiation type: reactor Contents: Material air Form gas Gram Moles (atmospheric pressure) Irradiation time: 3 hours; Power: 100 kw 14 2 Integrated thermal flux: 4.43X10 n/cm Pressure of Gas Sample Chromatographed: 70 mm Hg Compound Air Appearance Time (minutes) 0.88 %, gas phase, Fluorocarbon (from chromatogram)

PAGE 121

-113Sample No. 107; Capsule size: 11.1 cc; Irradiation type: reactor Contents: Material air gas Gram Moles (atmospheric .. pressure) Irradiation time: 1 hour; Power: 100 kw 14 2 Integrated thermal flux: l.28Xl0 n/cm Pressure of Gas Sample Chromatographed: 80 mm Hg Compound Air Appearance Time (minutes) 0.88 %, gas phase, Fluorocarbon (from chromatogram)

PAGE 122

-114Sample No. 108; Capsule size: 10.8 cc; Irradiation type: reactor Contents: Material air Form gas Gram Moles (atmospheric pressure) Irradiation time: 3 hours; Power: 100 kw 14 2 Integrated thermal flux: 4.78Xl0 n/cm Pressure of Gae Sample Chromatographed: 0 mm Hg Compound Air Appearance Time (minutes) 0.88 %, gas phase, Fluorocarbon (from chromatogram)

PAGE 123

Sample No. 109; Capsule size: 10.8 C C; Irradiation type: Contents: Material Form Gram Moles -3 CF 4 gas l.40Xl0 Pressure of Gas Sample Chromatographed: 140, 132 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -115none Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) CF 4 0.88 1. 7 100

PAGE 124

-116Sample No. 110; Capsule size: 10.8 cc; Irradiation type: gamma Contents: Material Form Energy absorbed by: 8 capsule 0.859Xl0 rads 8 CF 0.859Xl0 rads 4 Gram Moles -3 1. 40X10 20 6.61Xl0 ev Pressure of Gas Sample Chromatographed: 141 mm Hg Compound Air CF 4 C F 2 4 Appearance Time (minutes) 0.88 1.7 5.8 o/., gas phase, Fluorocarbon (from chromatogram) 99.8+ 0.2

PAGE 125

-117Sample No. 111; Capsule size: 11.1 cc; Irradiation type: gamma Contents: Material Form Gram Moles CF 4 gas 1.41Xlo3 Energy absorbed by: capsule 2. 1sx10 8 rads 8 20 CF4 2.15Xl0 rads 16.6Xl0 ev Pressure of Gas Sample Chromatographed: 140 mm Hg Compound Appearance Time o/., gas phase, Fluorocarbon (minutes) (from chromatogram) Air 0.88 CF 4 1. 7 99.7 C2F4 5.8 0.3

PAGE 126

Sample No. 112; Capsule size: 376 cc; Irradiation type: none Contents: Material CF 4 Form gas Gram Moles l.74X10 3 Pressure of Gas Sample Chromatographed: 81, 73 m Hg Comments: Sample was chromatographed after 30 days and again after 60 days. 11 8Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 127

-119Sample No. 113; Capsule size: 375 cc; Irradiation type: reactor Contents: Material Form gas Gram Moles 1. 73Xl03 Irradiation time: 1 hour; Power: 100 kw Integrated thermal flux: 14 2 1. 15Xl0 n/cm Pressure of Gas Sample Chromatographed: 80 mm Hg Compound Air Appearance Time (minutes) 0,88 1. 7 5.8 6.5 %, gas phase, Fluorocarbon (from chromatogram) Trace

PAGE 128

-120Sample No. 114; Capsule size: 377 cc; Irradiation type: reactov Contents: Material Form gas Gram Moles 1. 73x10 3 Irradiation time: 3 hours; Power: 100 kw Integrated thennal flux: 3.11Xlo 14 n/cm 2 Pressure of Gas Sample Chromatographed: 81 mm Hg Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1.7 5,8 6.5 99.9 0,1 Trace

PAGE 129

sample No. 115; Capsule size: 10.8 cc; Irradiation type: Contents: Material Form Gram Moles CF gas 1. 4ox10 3 4 UF gas 5. 9ox10 5 6 Pressure of Gas Sample Chromatographed: 110, 96 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -121none Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 6.5 99.9 0.1 Trace

PAGE 130

Sample No. 116; Capsule size: 12.5 cc; Contents: Material Form CF 4 gas UF6 gas Energy absorbed by: capsule 0.843Xl0 8 rads CF 4 O. 723Xl0 8 rads Pressure of Gas Sample Chromatographed: Appearance Time Compound (minutes) Air 0,88 CF4 1.7 C2F4 5.8 C2F60 6.5 C3F 8 0 10.5 -122Irradiation type: gamma Gram Moles l,32Xl0-J 6.30Xl0-S 20 5.25Xl0 ev 111 mm Hg %, gas phase, Fluorocarbon (from chromatogram) 99.7 0.3 Trace Trace

PAGE 131

-123Sample No. 117; Capsule size: 11.8 cc; Irradiation type: gamma Contents: Material !!?.!!!! CF4 gas UF6 gas Energy absorbed by: capsule l.60Xl08 rads 1. 38Xl0 8 rads Gram Moles l,32Xl0 -3 5.92Xl0 -5 10, ox10 20 ev Pressure of Gas Sample Chromatographed: 107 mm Hg Compound Air CF 4 C2F4 C2F60 C3F 8 0 Appearance Time {minutes) 0.88 1.7 5.8 6,5 10.5 %, gas phase, Fluorocarbon (from chromatogram) 99.48 0.52 Trace

PAGE 132

Sample No. 118; Capsule size: 12.3 cc; Contents: Energy Pressure of Compound Air Material !2!!! CF 4 gas UF6 gas absorbed by: capsule 2 11x10 8 rads CF l,83Xl0 8 rads 4 Gas Sample Chromatographed~ Appearance Time (minutes) 0.88 1. 7 5.8 6.5 -124Irradiation type: gamna Gram Moles 1.53Xlo 3 6.73Xl0-S 15.3Xlo 2 0 ev 111 mm Hg %, gas phase, Fluorocarbon (from chromatogram) 99.3 0,7 Trace

PAGE 133

Sample No. 119; Capsule size: 10. 2 cc; Irradiation type: Contents: Material !2!!. Gram Moles CF gas 1. 6ox103 4 UF gas 5.61Xl0-S 6 N gas s.s1x10 5 2 Pressure of Gas Sample Chromatographed: 111, 103 mm Hg CODDDents: Sample was chromatographed after 3~ days and again after 60 days. -125none Compound Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 134

Sample No. 120; Capsule size: 10.3 cc; Contents: Material .f.2.!!! CF 4 gas UF gas 6 N gas 2 Energy absorbed by: capsule O. 846Xl0 8 rads CF 4 0.753Xl0 8 rads Pressure of Gas Sample Chromatographed: Compound Appearance Time (minutes) 0.88 1. 7 5.8 -126Irradiation type: gamma Gram Moles l.61Xl03 s. nxio5 5. 91Xlo-S 20 6.67xl0 ev 108 mm Hg %, gas phase, Fluorocarbon (froru chromatogram) 99.8 0.2

PAGE 135

Sample No. 121; Capsule size: 10.7 cc; Contents: Material Form CF gas 4 UF gas 6 N gaa 2 Energy absorbed by: capsule 2. 11x10 8 rads CF 4 l.87Xl0 8 rads Pressure of Gas Sample Chromatographed: Compound Appearance Time (minutes) 0.88 1. 7 5.8 -127Irradiation type: gamma Gram Moles l.60Xlo 3 5. 88Xl0-S 6.0JXl05 16.sx10 20 ev 111 mm Hg %, gas phase, Fluorocarbon (from chromatogram) 99.7 0.3

PAGE 136

Sample No. 122; Capsule 1ize: 10.0 cc; Irradiation type: none Contents: Material Gram Moles CF gas 1. 12x103 4 UF gas s.s1x105 6 Ar gas l.19Xl0-S Pressure of Gas Sample Chromatographed: 110, 101 DIii Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -128Compound Air, Ar Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 137

-129Sample No. 123; Capsule size: 10.1 cc; Irradiation type: gamma Contents: Material Gram Moles CF 4 gas 1.12x10 3 UF6 gas 5.40Xl0 .. s Ar gas 1.19Xl0 .. 5 Energy absorbed by: capsule 0.849Xl0 8 rads CF 4 O. 763Xl0 8 rads 1.21x10 20 ev Pressure of Gas Sample Chromatographed: 113 mm Hg Compound Air, At: Cl'4 C2F4 C2F 6 0 C3F 8 0 Appearance Time (minutes) 0.88 1. 7 5.8 6.5 10.5 %, gas phase, Fluorocarbon (from chromatogram) 99.75 0.25 Trace Trace

PAGE 138

Sample No, Contents: Energy Pressure of Compound Air, Ar CF4 C2F4 C2F60 C3F 8 0 -130124; Capsule size: 10.0 cc; Irradiation type: gamma Material Gram Moles CF 4 gas 1. 719Xlo 3 UF6 gaa s.4ox10 5 Ar gas 1.188Xl0-S absorbed by: capsule 2.12Xl0 8 rads CF 4 l.90Xl0 8 rads 20 18.0Xl0 ev Gas Sample Chromatographed: Appearance Time (minutes) 0,88 1. 7 5.8 6.5 10.5 119 1I1D Hg %, gas phase, Fluorocarbon (from chromatogram) 99.13 0,87 Trace Trace

PAGE 139

-131Sample No. 125; Capsule size: 12.0 cc; Irradiation type: none Contents: Material !2!!!! Gram Moles CF 4 gas 1.89Xl03 UF6 gas 6.6ox10 5 Xe gas 1. 9sx10 4 Pressure of Gas Sample Chroma tographed: 87, 72 DID Hg CODJDents: Sample was chromatographed after 30 days and again after 60 days. Compound Air CF 4 Xe Appearance Time (minutes) 0.88 1. 7 3.0 5.8 %, gas phase, Fluorocarbon (from chromatogram) 99,9+ 0.1

PAGE 140

Sample No. 126; Capsule 1ize: 10.8 cc; Irradiation type: gamna Content : Material Form CF gas 4 UF gas 6 Xe gas Energy absorbed by: capsule 1.42Xl0 8 rads CF 4 1 10x10 8 rads Gram Moles 1. 64x103 s. 94x10 5 1.9sx10 4 9.92 x10 20 ev Pressure of Gas Sample Chromatographed: 90 11DI1 Hg Compound Air CF4 Xe C2F4 C2F6O Appearance Time (minutes) 0.88 1. 7 3.0 5.8 6.5 %, gas ph~e, Fluorocarbon (from chromatogram) 99.6 0,4 Trace

PAGE 141

-133Sample No. 127; Capsule size: 11.1 cc; Irradiation type: gamma Contents: Material Form Gram Moles CF 4 gas l.64Xlo 3 UF6 gas 6.oox10 4 Xe gas 1. 95x10 4 Energy absorbed by: capsule 2.10x10 8 rads CF 1. 62Xl0 8 rads 14.7Xlo 20 ev 4 Pressure of Gas Sample Chromatographed: 81 IIlll Hg Compound Air CF4 Xe C2F4 C2F 6 0 Appearance Time (minutes) 0.88 1.7 3.0 5,8 6.5 %, gas phase, Fluorocarbon (from chromatogram) 99.4 0.6 Trace

PAGE 142

Sample No. 128; Capsule size: 11.1 cc; Irradiation Contents: Material Form Gram Moles CF gas 1.64Xl03 4 UF gas 6.oox10 5 6 SF gas 2.1ox10 4 6 Pressure of Gas Sample Chromatographed: 87, 71 mm Hg Comments: type: none Sample was chromatographed after 30 days and again after 60 days. -134Compound Air Appearance Time (minutes) 1., gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.1 100

PAGE 143

-135Sample No. 129; Capsule size: 11.6 cc; Irradiation type: gamma Contents: Material Form Gram Moles CF 4 gas 1.64Xlo 3 UF6 gaa 6.00XlO-S SF 6 gas 2.lOXl04 Energy absorbed by: capsule 2,12Xlo 8 rads CF 4 1.58Xlo 8 rads 14.3Xlo 20 ev Pressure of Gas Sample Chromatographed: 90 mm Hg Compound Air Appearance Time (minutes) 0.88 1. 7 5,1 5,8 %, gas phase, Fluorocarbon (from chromatogram) 99,8 0.2

PAGE 144

Sample No. 130; Capsule size: 12.1 cc; Irradiation Contents: Material !2!:!!! Gram Moles CF 4 gas l.675Xlo3 UF solid 2.55X102 4 C solid 2.sox10 1 Pressure of Gas Sample Chromatographed: 110, 88 11DD Hg Comments: type: none Sample was chromatographed after 30 days and again after 60 days. -136Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 145

-137Sample No. 131; Capsule size: 12.l cc; Irradiation type: gamma Contents: Material Form Gram Moles CF gas 1.675Xl0 3 4 UF 4 solid 2.ssx10 2 C solid 2.sox10 1 Energy absorbed by: capsule 0.780Xl0 8 rads CF 4 0.0114Xl0 8 rads 1.04Xl0 19 ev Pressure of Gas Sample Chromatographed: 111 mm Hg Compound Air Appearance Time (minutes) 0.88 1.7 5.8 6.5 %, gas phase, Fluorocarbon {from chromatogram) 99.l 0.9 Trace

PAGE 146

Sample No. 132; Capsule size: 12.1 cc; Irradiation type: gamma Contents: Material Form CF 4 gas UF solid 4 C solid Energy absorbed by: capsule l.95Xl0 8 rads 0.0364Xl0 8 rads Gram Moles l.675X10 3 2.55X10 2 2.sox10 1 19 3.35Xl0 ev Pressure of Gas Sample Chromatographed: 108 mm Hg Compound Air Appearance Time (minutes) 0.88 1.7 5,8 6.5 o/., gas phase, Fluorocarbon (from chromatogram) 98.0 2.0 Trace

PAGE 147

Sample No. 133; Capsule size: 374 cc; Irradiation type: none Contents: Material Form Gram Moles CF 4 gas l. 715Xlo 3 UF6 gas 2.04Xlo 3 Pressure of Gas Sample Chromatographed: 78, 62 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -139Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 l. 7 5.8 99.9 0.1

PAGE 148

Sample No. 134; Capsule size: 397 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas l.85Xlo 3 ur6 gas 2,18Xlo 3 Irradiation time: 0.25 hour; Power: 100 k~ Integrated thermal flux: 3.17Xlo 13 n/cm 2 Energy absorbed by: capsule 3.45 x10 21 ev 0.676Xl0 21 ev Pressure of Gas Sample Chromatographed: 90 mm Hg -140type: reactor Compound Air Appearance Time (minutes) %, gaa phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 97,9 2.1

PAGE 149

Sample No. 135; Capsule size: 395 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. nx10 3 UF6 gas 2.11x10 3 Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal flux: 4.78Xlol3 n/cm2 Energy absorbed by: capsule CF 4 5.17Xlo21 ev 0.983Xl0 21 ev Pressure of Gas Sample Chromatographed: 82 mm Hg -141 type: reactor Appearance Time %, gas pha1e, Fluorocarbon Compound (minutes) (from chromatogram) Air o.aa CF 4 1. 7 96.0 C2F4 5.8 4.0

PAGE 150

-142Sample No. 136; Capsule size: 373 cc; Irradiation type : reactor Contents: Material Form Gram Moles CF 4 gas 1. nsx10 3 UF 6 gas 2.04Xl0 3 Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal flux: S.27Xlo 13 n/cm 2 Energy absorbed by : capsule S.36Xlo 21 ev l.04Xl0 21 ev Pressure of Gas Sample Chromatographed: 80 mm Hg Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0,88 1. 7 5.8 6.5 95.2 4,8 Trace

PAGE 151

Sample No. 137; Capsule size: 366 cc; Irradiation Contents: Material Gram Moles CF 4 gas l.68Xlo 3 UF 6 gas 2.01x10 3 Irradiation time: 1.3 hours; Power: 75 kw 13 2 Integrated thermal flux: 12.3Xl0 n/cm Energy absorbed by: capsule 12.3Xlo 21 ev 2.35Xlo 21 ev Pressure of Gas Sample Chromatographed: 73 mm Hg -143type: reactor Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (fran chromatogram) 0.88 1. 7 5.8 10.S 92.6 7.0 0.4

PAGE 152

Sample No. 138; Capsule size: 367 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas l.67Xl03 UF 6 gas 2.01x10 3 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux: 19.6Xlo 13 n/cm 2 Energy absorbed by: capsule 19. 6Xl0 21 3. 78Xl0 21 ev ev Pressure of Gas Sample Chromatographed: 73 mm Hg -144type: reactor Compound Air Appearance Time (minutes) %, gas phaae, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 10.5 92.9 7.1 Trace

PAGE 153

Sample No. 139; Capsule size: 369 cc; Irradiation Contents: Material Form Gram Moles CF4 gas l.81Xl0 UF6 gas 2.02Xl0 Irradiation time: 2 hours; Power: 100 kw Integrated thermal flux: 23.2Xlo 13 n/cm 2 Energy absorbed by: capsule 23.4Xlo 21 ev 4. 80Xl0 21 ev -3 -3 Pressure of Gas Sample Chromatographed: 78 mm Hg -145type: reactor Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 10.5 93.0 6.9 0.1

PAGE 154

Sample No. 140; Capsule size: 374 cc; Irradiation Contents: Material !2!]! Gram Molee CP 4 gas l.64Xl03 UF gas 2.osx10 3 6 Irradiation time: 2 hours; Power: 100 kw Integrated thermal flux: 26.8Xtol3 n/cm2 Energy absorbed by: capsule CF 4 27 .4x10 21 s. 11x10 21 ev ev Pressure of Gas Sample Chromatographed: 80 mm Hg -146type: reactor Compound Air Appearance Time (minutes) % 1 gas phase, Fluorocarbon (from chromatogram) 0.88 1.7 5.8 6.5 93,3 6.7 Trace

PAGE 155

-147Sample No. 141: Capsule size: 374 cc; Irradiation type : reactor Contents: Material Gram Moles CF 4 gas l .695X10 3 UF6 gas 2.osx10 3 Irradiation time: 4 hours; PowerJ 7' ltw Integrated thermal flux: 41,3Xlol3 n/cm2 Energy absorbed by capsule 42.2Xlo21 ev 8 .11x1021 ev Pressure of Gas Sample Chromatographedt 82 unn Hg Appearance Time Compound {minutes) %, gas phase, Fluorocarbon (from chromatogram) Air CF 4 C2F4 c 2 F 6 o c 3 v 8 o 0.88 1. 7 5.8 6.5 10.5 94.1 5.6 Trace 0,3

PAGE 156

. Sample No. 142; Capsule size: 388 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas l.765Xlo 3 UF6 gas 2.13x10 3 Al shavings 6.oox10 1 Pressure of Gas Sample Chromatographed: 88, 70 mm Hg Comments: type: Sample was chromatographed after 30 days and again after 60 days. -148none Compound Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air 0.88 1.7 5.8 6.5 99.7 0.3 Trace

PAGE 157

-149Sample No. 143; Capsule size: 390 cc; Irradiation type: reactor Contents: Material Form Gram Moles CF 4 gas l.74Xlo 3 UF6 gas 2.14Xlo 3 Al shavings 6.oox10 1 Irradiation time: 0.25 hour; Power: lOO ~ kw Integrated thermal flux: 3.77Xlo 13 n/cm 2 Energy absorbed by : capsule 4.02x10 21 3.58Xl0 19 ev ev Pressure of Gas Sample Chromatographed: 83 tlDII Hg Appearance Time Compound (minutes) %, gas phase, Fluorocarbon {from chromatogram) Air CF 4 C2F4 c 2 r 6 o C 3 F 8 o 0.88 1. 7 5.8 6.5 10.5 98.3 1. 7 Trace Trace

PAGE 158

-150Sample No. 144; Capsule size: 387 cc; Irradiation type: reactor Contents: Material !2!!.. Gram Moles CF4 gas 1. 765x10 3 UF6 gas 2. 13x10 3 Al shavings 6.oox10 1 Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal flux: 5.22Xlo 13 n/cm 2 Energy absorbed by: capsule 5.54Xl0 21 ev CF4 5.01Xlo 19 ev Pressure of Gas Sample Chromatographed : : 79 1Illll Hg Compound Air CF4 C2F4 c 2 F60 C3F 8 0 Appearance Time (minutes) 0.88 1. 7 5.8 6.5 10.5 %, gas phase, Fluorocarbon {from chromatogram) 97.6 2.4 Trace Trace

PAGE 159

Sample No. 145; Capsule size: 391 cc; Irradiation Contents: Material Form Gram Molea CF 4 gas 1. 765Xto 3 UF6 gas 2. 15x10 3 Al shavings 6.oox10 1 Irradiation time: 1 hour; Power: lOOkw Integrated thermal flux: 13.9Xlo 1 3 n/cm2 Energy absorbed by: capsule 14. 9Xl0 21 13.5x10 19 ev ev Pressure of Gas Sample Chromatographed: 80 mm Hg type: reactor Appearance Time '7.' gas phase, Fluorocarbon Compound (minutes) (from chromatogram) Air 0.88 CF 4 1. 7 96,9 C2F4 5.8 3. 1 c 2 F 6 o 6.5 Trace C 3 F 8 o 10.5 Trace

PAGE 160

Sample No. 146; Capsule size: 388 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. 765x10 3 UF 6 gas 2.13x10 3 Al shavings 6.oox10 1 Irradiation time: 2 hours; Power: 100 kw Integrated thermal flux: 24.8Xlo 13 n/cm 2 Energy absorbed by : capsule 26.3X10 21 23.8Xl0 19 ev ev Pressure of Gas Sample Chromatographed: 85 mm Hg -152type: reactor Compound Air Appearance Time (minutes) o/., gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 10.5 96.1 3.8 0.1

PAGE 161

Sample No. 147; Capsule size: 389 cc; Irradiation Contents: Material !.2.!!! Gram Moles CF 4 gas 1. 68Xl03 UF6 gas 2. ux10 3 Al shavings 6.oox10 1 Irradiation time: 3 hours; Power: 100 kw Integrated thermal flux : 29. ox10 13 n/cm 2 Energy absorbed by: capsule 30.ax10 21 ev 26,5X10 19 ev Pressure of Gas Sample Chromatograp~: 69 mm Hg -153type: reactor Appearance Time %, gas phase, Fluorocarbon Compound (minutes) (from chromatogram) Air 0.88 CF 4 1. 7 96.0 C2F4 5.8 4.0 C2F 6 0 6.5 Trace c 3 F 8 o 10.5 Trace

PAGE 162

Sample No. 148; Capsule size: 376 cc; Irradiation type: none Contents: Material Form Gram Moles CF 4 gas 1. 12x10 3 UF6 gas 2.06Xlo 3 N2 gas 2.a1x10 4 Pressure of Gas Sample Chromatographed~ 117, 108 11111 Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -154 Compound Appearance Time (minutes) %, gu phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 163

Sample No. 149; Capsule size: 375 cc; Irradiation Contents: Material Form Gram Moles -3 CF 4 gas 1. 718X10 -3 UF6 gas 2,06Xl0 N2 gas 2,63Xl0 -4 Irradiation time: 0.5 hour; Power: '. too kw Integrated thermal flux : 5. 07Xl0 13 n/cm2 Energy absorbed by : capsule CF 4 5. 21x10 21 1.oox10 21 av ev Pressure of Gas Sample Chromatographed: 117 DDD Hg -155type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air, N2 CF 4 C2F4 c 2 F 6 o c 3 F 8 0 0.88 1. 7 5.8 6.5 10.5 98.5 1.5 Trace Trace

PAGE 164

Sample No. 150; Capsule size: 370 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas l,79Xlo 3 UF6 gas 2.03Xlo 3 N2 gas 2,99Xlo 4 Irradiation time: 1 hour; Power: 100 kw Integrated thermal flux~ ll.8Xlo 13 n/cm 2 Energy absorbed by: capsule CF 4 11. 9x10 21 2.40Xl0 21 ev ev Pressure of Gas Sample Chromatographed: 111 mm Hg -156type: reactor ; Appearance Time Compound (minutes) o/., gas phase, Fluorocarbon (from chromatogram) Air, N2 cr 4 C2F4 c 2 F 6 o c 3 r 8 o 0.88 1. 7 5.8 6,5 10.5 97.5 2.5 Trace Trace

PAGE 165

Sample No. 151; Capsule size: 373 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. nsx10 3 UF6 gas 2. 043x103 N2 gas 3.015Xl0"" 4 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux: 18.6Xl0 13 n/cm 2 Energy absorbed by: capsule CF 4 18. 9x10 21 3.66Xlo 21 ev ev Pressure of Gas Sample Chromatographed: 108 mm Hg -157 type: reactor Compound Appearance Time (mi nu tea) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5. 8 10.5 97.2 2.3 0,5

PAGE 166

Sample No, 152; Capsule size: 380 cc; Irradiation Contents: Material Gram Moles CF 4 gas l.84Xl03 UF6 gas 2.08x10 3 N2 gas 2.97Xlo 4 Irradiation time: 2 hours; Power~ 100 kw Integrated thermal flux ~ 22.5Xlo 13 n/cm2 Energy absorbed by: capsule 23.3Xl0 21 ev 21 4. 71Xl0 ev Pressure of Gas Sample Chromatographed: 110 mm Hg -158type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air, N2 CF 4 C2F4 C 2 F60 c 3 F 8 o 0.88 1. 7 5.8 6.5 10.5 97.3 2.2 Trace 0.5

PAGE 167

Sample No. 153; Capsule size: 368 cc; Irradiation Contents: Material Gram Moles CF gas 1. 758Xlo 3 4 UF 6 gas 2.02x10 3 N gas 3.01x10 4 2 Irradiation time: 4 hours; Power : '100 ,. kw Integrated thermal flux: 48.9Xlo 13 n/cm 2 Energy absorbed by : capsule CF 4 49.3X10 13 ev 9,80Xlo 13 ev Pressure of Gas Sample Chromatographed: 114 mm Hg -159type: reactor Compound Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0,88 1.7 5.8 94.1 5.9

PAGE 168

Sample No. 154; Capsule size: 376 cc; Irradiation type: none Contents: Material !2!!!! Gfam Moles CF 4 gas l,67Xl0 3 UF6 gas 2.03Xl0 3 Ar gas 3.02x10 4 Pressure of Gas Sample Chromatographed: 114, 90 mm Hg COJIDDents : Sample was chromatographed after 30 days and again after 60 days. -160Compound Air, Ar Appearance Time (minutes) %, gas phase, Fluorocarbon (from chr0111&togram) 0.88 1. 7 5.8 98,8 0.2

PAGE 169

Sample No. 155; Capsule size: 373 cc; Irradiation Contents: Material Form Gram Moles CF4 gas l.672X10 3 UF6 gas 2.03Xl03 Ar gas 3.015X104 Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal fluxi 4.00Xlo 13 n/cm 2 Energy absorbed by: capsule 4. 05Xlo 21 ev O. 762Xl0 21 ev Pressure of Gas Sample Chr~atographedc 111 DD Hg -161type: reactor Compound Air, Ar Appearance Time (minutes) o/., gas phase, Fluorocarbon (from chromatogram) 0,88 1. 7 5.8 98.7 1.3

PAGE 170

Sample No. 156; Capsule size: 370 cc; Irradiation Contents: Material Gram Moles CF4 gas 1. 799x10-3 UF6 gas 2,0l7Xl0 Ar gas 2.99Xl0 Irradiation time: 1 hour; Pow~ 100 kw Integrated thermal flux: 10.9Xl0 13 n/cm 2 Energy absorbed by: capsule CF 4 11. ox10 21 ev 2. l 9Xl0 21 ev Pressure of Gas Sample Chromatographed; 107 mm Hg -162type: reactor Compound Air, Ar Appearance Time (minutes) %, gas pha e, Fluorocarbon (from chromatogram) 0,88 1. 7 5.8 6.5 96,5 3.,5 Trace

PAGE 171

Sample No. 15 7; Capsule size: 3 71 cc; Irradiation Contents: Material Gram Moles CF 4 gas l.74Xlo 3 UF6 gas 2.02x10 3 Ar gae 2.90Xto 4 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux: 16.0Xl0 13 n/cm 2 Energy absorbed by : capsule 16. 1x10 21 ev 3.31Xl0 21 ev Pressure of Gas Sample Chromatographed: 112 U1D Hg -163type : reactor Compound Air, Ar Appearance Time (minutes) %, gas phase, Fluorocarbon {from chromatogram) CF 4 C2F4 .C F O 3 8 0.88 1. 77 5.8 10.5 94.7 5.2 0.1

PAGE 172

-164Sample No. 158; Capsule size: 372 cc; Irradiation type : reactor Contents: Material Form Gram Moles CF4 gas 1. 73x10 3 UF6 gas 2.03X10 3 Ar gas 3. 11x10 4 Irradiation time; 2 hours; Power: 100 kw Integrated thermal flux: 23.8X10 13 n/cm 2 Energy absorbed by : capsule CF 4 24. 1x10 21 4.68X10 21 ev ev Pressure of Gas Sample Chromatographed: 119 mm Hg Compound Air, Ar CF4 C2F4 C 2 F 6 o c 3 F 8 0 Appearance Time (minutes) 0.88 1. 7 5.8 6,5 10.5 %, gas phase, Fluorocarbon (from chromatogram) 95. 7 4.3 Trace Trace

PAGE 173

Sample No. 159; Capsule size: 371 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. 778Xlo 3 UF6 gas 2.022x10 3 Ar gas 3.2ox10 4 Irradiation time: 3 hours; Power: 100 kw Integrated thermal flux: Energy absorbed by: capsule 13 2 27.4Xl0 n/cm 27.6Xl0 21 ev 5.48Xlo 21 ev Pressure of Gas Sample Chromatographad: 12111111 Hg -165type: reactor Appearance Time Compound (minutes) % 1 gas phaee, Fluorocarbon (from chromatogram) Air, Ar CF 4 C2F4 c 2 F 6 o c 3 r 8 o 0.88 1.7 5.8 6.5 10.5 96.3 3.3 Trace 0.4

PAGE 174

Sample No, 160; Capsule size: 371 cc; Irradiatioo type: none Contents: Material Form Gram Moles CF 4 gas l.68X10 UF gas 2.03Xl0-3 6 Xe gas l.70Xl0 Pressure of Gas Sample Chromatographed: 80, 61 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -166Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) Xe 0.88 1.7 3,0 5.8 99.7 0.3

PAGE 175

-167Sample No. 161; Capsule size: 371 cc; Irradia ti on type : reactor Contents: Material Form Gram Moles CF 4 gas l.68Xl03 UF6 gas 2.03Xlo 3 Xe gas 1. 65Xlo 4 Irradiation time: 0,5 hour; Power: 100 kw 13 2 Integrated thermal flux: 5.13Xl0 n/cm Energy absorbed by: capsule CF 4 5.19Xl021 ev 0,970Xlo 21 ev Pressure of Gas Sample Chromatographed: 84 mm Hg Appearance Time Compound (minutes) %, gu phase, Fluorocarbon (from chromatogram) Air 0,88 CF4 1. 7 93.6 Xe 3,0 C2F4 5,8 6.4 C2F 6 0 6.5 Trace

PAGE 176

Sample No. 162; Capsule size: 365 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. 67Xlo 3 UF6 gas 1. 994Xlo 3 Xe gas 1.65Xlo 4 Irradiation time: 1 hour; Power: 100 kw 13.5Xl0 13 n/cm 2 Integrated thermal flux: Energy absorbed by: capsule 13.4X10 21 ev 2.54}tl0 21 ev Pressure of Gas Sample Chromatographed: 78 IIDD Hg -168type: reactor Appearance Time Compound (minutes) %, gaa phase, Fluorocarbon (from chromatogram) Air 0.88 CF 4 1.7 87.6 Xe 3.0 C2F4 5,8 12.4 c 3 F 8 0 10.5 Trace

PAGE 177

Sample No. 163; Capsule size: 371 cc; Irradiation Contents: Material Form Gram Moles CF4 gas l,64X10 UF6 gas 2,03Xl0 Xe gas 1.69Xl0 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux: 20,6Xlo 1 3 n/cm 2 Energy absorbed by : capsule 20.8X10 21 ev 3.82Xl0 21 ev -3 -3 -4 Pressure of Gas Sample Chromatographed: 79 mm Hg type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air CF4 Xe C2F4 c 2 F 6 o 0,88 1. 7 3,0 5.8 6.5 78.9 20.5 0.6

PAGE 178

Sample No. 164; Capsule size: 367 cc; Irradiation Contents: Material Gram Moles CF 4 gas 1. 82x10 3 UF6 gas 2.01x10 3 Xe gas 1. 69x10 4 Irradiation time: 2 hours; Power: 100 kw Integrated thermal flux; 29.2Xlol 3 n/cm2 Energy absorbed by: capsule CF 4 29,3Xl0 21 ev 5,87Xl0 21 ev Pressure of Gas Sample Chromatographed: 80 mm Hg -170type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air CF4 Xe C2F4 C2F 6 0 0,88 1.7 3.0 5.8 6.5 70.5 28.4 1.1

PAGE 179

-171Sample No 165; Capsule size : 372 cc; Irradiation type: reactor Contents: Material Form G r am Moles CF 4 gas l.53Xl03 UF6 gas 2.02x10 3 Xe gas l.68Xl0 4 Irradiation time: 3 hours; Power: 100 kw Integrated thermal flux: 44.3Xl o 13 n / cm2 Energy absorbed by: capsule CF 4 44.6Xto21 ev 7.74Xlo21 ev Pressure of Gas Sample Chromatographed: 88 mm Hg Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air 0.88 CF 4 1. 7 63.6 Xe 3.0 CzF4 5.8 36.4 c 2 F 6 o 6.5 Trace C3FsO 10.5 Trace

PAGE 180

Sample No, 166; Capsule size: 384 cc; Irradiation type: none Contents: Material Form Gram Moles CF 4 gas l,89Xlo 3 UF6 gas 2.11x10 3 SF 6 gas l.92Xl04 Pressure of Gas Sample Chromatographed: 85, 68 mm Hg Comments: Sample was chromatographed after 30 days and again after 60 days. -172Compound Air Appearance Time (minutes) 7., gas pha1e, Fluorocarbon (from chromatogram) 0,88 1. 7 5.1 100

PAGE 181

Sample No. 167; Capsule size: 368 cc; Irradiation Contents: Material 1.2!!!! Gram Moles CF 4 gas 1.89Xlo3 UF6 gas 2.02x10 3 SF 6 gas 2.21x10 4 Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal flux: 5. 50Xl013 n/cm2 Energy absorbed by: capsule CF 4 5.53Xl0 21 av 1. 13Xlo 21 ev Pressure of Gas Sample Chromatographed: 86 DID Hg type: reactor Appearance Time Compound (minutes) 1., gas phase, Fluorocarbon (from chromatogram) Air CF 4 SF 6 C2F4 c 3 F 8 0 0.88 1. 7 5.1 5.8 10.5 95.3 3.5 1.2

PAGE 182

Sample No. 168; Capsule size: 369 cc; Irradiation Contents: Material Form Gram Moles CF 4 gas 1. 93Xlo 3 UF6 gas 2.03Xlo 3 SF 6 gas 2.18x10 4 Irradiation time: 1 hour; Power: 100 kw 14 2 Integrated thermal flux: 13.0XlO n/cm Energy absorbed by: capsule 13. 1x10 21 ev 2.71Xlo 21 ev Pressure of Gas Sample Chromatographed: 90 mm Hg -174type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air CF 4 SF 6 C2F4 c 2 r 6 o : C 3 F 8 0 0.88 1.7 5.1 5.8 6.5 10,5 93.3 6.7 Trace Trace

PAGE 183

-175Sample No. 169; Capsule size: 369 cc; Irradiation type: reactor Contents: Material Form Gram Moles CF 4 gas l.84Xl03 UF6 gas 2.02X10 3 SF 6 gas 2.osx10 4 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux: 19. 7Xl0 13 n/cm 2 Energy absorbed by: capsule CF 4 17.8Xl0 21 ev 3.56x10 21 ev Pressure of Gas Sample Chromatographed: 150 mm Hg Comments: Capsule leaked air. Appearance Time Compound (minutes) Air 0.88 CF4 1.7 SF 6 5.1 C2F4 5.8 c 2 F 6 o 6.5 C 3 F 8 0 10.5 %, gas phase, Fluorocarbon (from chromatogram) 91. 9 3.5 Trace 4.6

PAGE 184

Sample No. 170; Capsule size: 369 cc; Irradiation Contents: Material Gram Moles CF 4 gas 1. 73Xlo 3 UF6 gas 2.03Xlo 3 SF 6 gas 1. 12x10 4 Irradiation time: 2 hou r s; Power: 100 kw Integrated thermal flux: -3 2 22.lXlO n/cm Energy Absorbed by : capsule 22.4Xl0 21 ev 21 4.25Xl0 ev Pressure of Gas Sample Chromatographed: 82 mm Hg -176type: reactor Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air 0.88 CF4 1.7 92.0 SF 6 5.1 C2F4 5.8 5.6 c 1 F 6 o 6.5 Trace C3F 8 0 10.5 2.4

PAGE 185

-177Sample No. 171; Capsule size: 365 cc; Irradiation type: reactor Contents: Material Form Gram Moles CF 4 gas 1.nx10 3 UF6 gas 2.01x10 3 SF 6 gas 2.01x10 4 Irradiation time: 3 hours; Power: 100 kw Integrated thermal flux : 47.8Xlol 3 n/cm2 Energy absorbed by: capsule CF 4 47. 9Xl0 13 ev 9.09Xl0 13 ev Pressure of Gas Sample Chromatographed: 77 mm Hg Appearance Time Compound (minutes) %, gas phase, Fluorocarbon (from chromatogram) Air 0,88 CF4 1,7 94.3 SF 6 5.1 C2F4 5.8 3,1 C2F 6 0 6.5 Trace C3F 8 0 10.5 2.6

PAGE 186

Sample No. 172; Capsule size: 12,1 cc; Irradiation Contents: Material Gram Moles CF 4 gas 1.1sx10 3 UF 4 solid 2. ssx10 2 C solid 2.sox10 1 Pressure of Gas Sample Chromatographed : 90, 71 mm Hg Comments: type: none Sample was chromatographed after 3 0 days and again after 60 days -178Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 100

PAGE 187

Sample No, 173; Capsule size: 12.2 cc; Irradiation Contents: Material Gram Moles CF4 gas 1. 74Xl0 UF4 solid 2,55Xl0 C solid 2,SOXlO Irradiation time: 0.5 hour; Power: 100 kw Integrated thermal flux: 4.19Xlo 13 n/cm 2 Energy absorbed by: capsule 4.12Xlo 20 ev 0. 622Xl0 19 ev -3 -2 -1 Pressure of Gas Sample Chromatographed: 89 mm Hg -179type: reactor Compound Air Appearance Time (minutes) %, gaa phase, Fluorocarbon (from chromatogram) 0.88 1.7 100

PAGE 188

Sample No. 174; Capsule size: 11.8 cc; Irradiation Contents: Material Gram Moles CF 4 gas 1. 12x10 3 UF4 solid 2.ssx10 2 C solid 2.sox10 1 Irradiation time: 1 hour; Power: 100 kw Integrated thermal flux: 10,47Xlol3 n/cm2 Energy absorbed by 1 : capsule CF 4 10.2x1020 ev 1.53Xlol9 ev Pressure of Gas Sample Chromatographed: 83 mm Hg type : reactor Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1.7 5.8 99.9 0.1

PAGE 189

Sample No. 175; Capsule size: 12.0 cc; Irradiation Contents: Material Gram Moles CF 4 gas 1.12x10 3 UF4 solid 2.55X10 2 C solid 2.sox10 1 Irradiation time: 1.5 hours; Power: 100 kw Integrated thermal flux : 11. 9Xl0 13 n/cm 2 Energy absorbed by: capsule CF 4 11. 1x10 20 ev 1. 74x10 19 ev Pressure of Gas Sample Chromatographed: 98 mm Hg -181type: reactor Appearance Time %, gas phase, Fluorocarbon Compound (minutes) (from chromatogram) Air 0.88 CF4 1. 7 99,7 C2F4 5.8 0,3

PAGE 190

Sample No. 176; Capsule size: 11. 7 cc; Irradiation type: Contents: Material Form Gram Moles CF 4 gas 1. 76Xlo 3 UF4 solid 2.ssx10 2 C solid 2.sox10 1 Irradiation time: 2 hours; Power: 100 kw Integrated thermal flux: 19.7Xlol3 n/cm2 Energy absorbed by: capsule CF 4 19,3Xlo20 ev 2,94Xlol9 ev Pressure of Gas Sample Chromatographed: 86 unn Hg -182reactor Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5,8 99.7 0.3

PAGE 191

Sample No. 177; Capsule size: 11.8 cc; Irradiation Contents: Material !2!!! Gram Moles CF 4 gas 1. 76Xl03 UF4 solid 2,55Xl0-z C solid 2.sox10 1 Irradiation time: 4 hours; Power: 100 kw Integrated thermal flux: 40.0Xlo 13 n/cm 2 Energy absorbed by : capsule 39. 3Xl0 2 0 ev 6.oox10 19 ev Pressure of Gas Sample Chromatographed: 72 mm Hg -183type: reactor Compound Air Appearance Time (minutes) %, gas phase, Fluorocarbon (from chromatogram) 0.88 1. 7 5.8 99.7 0.3

PAGE 192

LIST OF REFERENCES 1. Manowitz, B., Raseman, C., Steinberg, M., Stoller, s., Hogerton, J., and Geller, L., "A Chemonuclear Program for the United States Atomic Energy Commission," BNL 804, Upton, New York (July, 1963). 2. Wethington, John A., Jr., "Research Pertaining to a Uranium (VI) Fluoride-Fluorocarbon Reactor," Puerto Rico Nuclear Center, Mayaguez, Puerto Rico (April 26, 1962). 3. Askew, W. C., Ph. D. Dissertation, "Effects of Radiation on Mix tures Containing Fluorocarbons and the Identification of the Perfluoroheptane, C7F16, Isomers," University of Florida (April, 1966). 4. Osterholtz, Fred D. to Gurley, Richard N., Private Communica tion (July 7, 1966). 5. Manowitz, B., Steinberg, M., Sutherland, J. w., Harteck, P., Dondes, S., and Cusack, J. G., "The Development of Chemonuclear Processes," BNL 7993 (1964). 6. Steinberg, Meyer, "Chemonuclear and Radiation Chemical Process Research and Development," BNL 10020 (February, 1966). 7. Steinberg, Meyer, "Fission Recoil Synthesis," BNL 9985 (Febru ary, 1966) 8. Steinberg, Meyer, "Chemonuclear Reactors and Chemical Pro cessing," in Advances in Nuclear Science and Technology, E. J, Henley and H. Kouts, Editors, 247-333, Academic Press, New York (1962). 9. Steinberg, Meyer, "Progress in Chemonuclear and Radiation Chemical Process Development," BNL 8836 (January, 1965). 10. Beller, M. and Steinberg, M., "Chemonuclear Reactors for Water Treatment,'' BNL 9970 (February, 1966). 11. Beller, M. and Steinberg, M., Nuclear Applications, 1, 237238 (1966). -184

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-18512. Beller, M., Goellner, D., and Steinberg, M., Nuclear Applica tions, l, 322 (1965). 13. Steinberg, M., Beller, M., and Manowitz, B., "The Outlook for Chemonuclear Process Development," BNL 10000 (February, 1966). 14. Harteck, P. and Dondes, s., Nucleonics, 14, No. 3, 66-72 (1956). 15. Harteck, P. and Dondes, s., Journal of Physical Chemistry, 63, 956 (1959). 16. Dondes, s., Harteck, P., and von Wayssenhoff, H., Zeitsheit schrift fuer Naturforschung, ~, 13-18 (1964). 17. Harteck, P. and Dondes, S. Science, lli, 30-35 (1964). 18. Harteck, P., Dondes, S., and Thompson, B., Science, ill, 393-394 (1965) 0 19. Fueki, K. and Magee, J. L., Discussions Faraday Society, 36, 1~ (1963). 20. Dondes, S., Harteck, P., and Kunz, C., Radiation Research, !Z,, 174-210 (1966). 21. Dondes, Seymour to Gurley, Richard N., Private Communication (June, 1966). 22. Bush, D. E. to Gurley, Richard N., Private Communication (October, 1966). 23. Cusack, J. H. and King, P.A., "Fissiochemical Development Program, Semiannual Progress Report, July December, 1964," AGN 8132 (February, 1965). 24. Cusack, J. H. and King, P. A., "Fissiochemical Development Program, Semiannual Progress Report, January June, 1965," AGN 8156 (August, 1965). 25. Cusack, J. H. and King, P.A., "Fissiochemical Development Program, Semiannual Progress Report, July December, 1965," AGN 8178 (February, 1966).

PAGE 194

26. Cusack, J. H. and King, P.A., "Fissiochemical Development Program, Final Report," AGN 8196 (August, 1966). 27. Fritsch, C. P., Gustavson, M. R., Cusack, J. H., and Miller, R. I., Chemical Engineering Progress, ll, No. 3, 37 (1961). -18628. Miller, A. R., Tsukimura, R.R., and Velton; R., Science, ill, 688 (1967). 29. Miller, R. I., Transactions of American Nuclear Society, .!Q., No. 1, 46 (June, 1967). 30. Axtmann, R. c., Transactions of American Nuclear Society, .!.Q., No. l, 44 (June, 1967). 31. Elliott, D. M., '. Transactions of American Nuclear Society, lQ., No. 1, 45 (June, 1967). 32. White, E. R., International Journal of Applied Radiation and Isotopes,.!, 419-424 (1965). 33. Reed, T. M., Mailen, J. c., and Askew, W. C., "Experimental Effects of Pile Radiation on Pure Fluorocarbons," Final Report to the United States Atomic Energy Commission on contract No. AT-(40-1)-2846 (1965). 34. Reed, T. M., "A Proposal Submitted to the United States Atomic Energy Commission for a Contract to Study Radiolytically Induced Heterogenous Reactions with Perfluorocompounds," Department of Chemical Engineering, University of Florida, Gainesville, Florida (February, 1966). 35. Scott, T. H., Ph.D. Dissertation, "Fission Product Degrada tion and Neutron Moderating Propertie of Fluorocarbons," University of Florida (April, 1966). 36. Benedict, M. and Pigford, T. H., Nuclear Chemical Engineering, McGraw Hill Book Company, Inc., New York (1957). 37. Dewitt, R., "Uranium Hexafluoride: A Survey of the Physico Che~ical Properties," GAT 280 (August, 1966). 38. American Society for Testing Materials, "Tentative Method of Measuring Absorbed Gamma Radiation Dose by Fricke Dosi metry," ASTM Designation D 1671-598, Philadelphia, Penn sylvania (1959).

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39. Boyton, A. R., "Guide for Irradiation in the University of Florida Training Reactor," Leaflet No. 139, Vol. XV, No. 7, Florida Engineering and Industrial Experiment Station, Gainesville, Florida (July, 1961). 40. Horton, A. D., Nuclear Science and Engineering, Q, 103-109 (1962). -18741. Panek, Karel and Mudra, Karel, Jaderna Energie, 10, 214-216 (June, 1964). Abstracted in Nuclear Science Abstracts, 18, 35618 (1964). 42. Simons, J. H. to Gurley, Richard N., Private Communication (June, 1966). 43. Reed, T. M. to Gurley, Richard N., Private Communication (June, 1966). 44. Dacey, J. R. and Hodgins, J. W., Canadian Journal of Research, 1_, 173 (1950). 45. Purnell, H., Gas Chromatography, John Wiley and Sons, Inc., New York (1962). 46. Dmitrievskii, V. A. and Migachev, A. I., Atomnaya Energie, ._, 533 (1959). Translated by G. Rybeck, Journal of Nuclear Energy, Part A: Reactor Science, 12, 185 (1960) 47. Reed, T. M. to Gurley, Richard N., Private Communication,(May, 1967). 48. Simons, J. H., Fluorine Chemistry, Vol. V, 222-227, Academic Press, New York (1964). 49. Casson, Dr. H. to Gurley, Richard R., Private Communications (August and September, 1966). 50. Grant, L. G., "Guide for Activation Analysis at the University of Florida," Bulletin No. 124, Vol. XX, No. 6, Florida Engineering and Industrial Experiment Station, Gaines ville, Florida (June, 1966). 51. Hughes, D. J. and Schwartz, R. B., "Neutron Cross Sections," 2nd Edition, Supplement 1, BNL 325 (1959). 52. Molm, J. G., Selig, H., Jortner, J., and Rice, s. A., Chemicals Reviews, i:l., 199-236 (April, 1965).

PAGE 196

BIOGRAPHICAL SKETCH Richard Norwood Gurley was born November 24, 1935, in Columbia, South Carolina. He attended Newton-Conover High School in Newton, North Carolina. In 1958, he was awarded a Bachelor.of Chemical Engineering Degree, with High Honors, by North Carolina State Uni versity. He was awarded a Master of Science Degree in chemical engineering by North Carolina State University in 1959. Since 1963 he has attended the University of Florida. During this period he has held a Ford Fellowship and a Special Fellowship from the Oak Ridge Institute o~ Nuclear Studies. In 1964, he received the Master of Engineering Degree from the University of Florida. He is married to the former Mary Yoder. He is a member of Phi Kappa Phi, Tau Beta Pi, and the American Institute of Chemical Engineers. He is an associate member of Sigma Xi and a member of the University of Florida Student Chapter of the American Nuclear Society. -188

PAGE 197

This dissertation was prepared under the direction of the chairman of the candidate's supervisory committee and has been approved by all members of that committee. It was submitted to the Dean of the College of Engineering and to the Graduate Council, and was approved as partial fulfillment of the requirements for the degree of Doctor of Philosophy. August, 1967 Dean, Graduate School Supervisory Co11111ittee: