THE SOVIET JOURNAL OF ATOMIC ENERGY VOLUME 10, NO.2

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• Document Creation Date: December 27, 2016
• Document Release Date: March 1, 2013
• Sequence Number: 1
• Publication Date: November 1, 1961
• Content Type: REPORT

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Yolumte 10, No. 2
November, 1961
THE SOVIET JOURNAL OF
OMIC ENEIUiJY-
TRANSLATED FROM RUSSIAN
CONSULTANTS- BUREAUw
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VOLUME I
VACUUM, MICROBALANCE TECHNIQUES
Proceedings of the 1960 Conference, Sponsored by
The Institute for Exploratory Research
U. S. Army Signal Research and Development Laboratory,
Edited by`
M. J. K AT Z
U. S. Army Signal Research and Development Laboratory
Fort Monmouth, New Jersey
Introduction by
Thor N. Rhodin
Cornell University
The proceedings of this conference provide
an authoritative introduction to the ~ rapidly
widening scope of microbalance methods
which is not available elsewhere in a single
publication. -
The usefulness of microbalance techniques in
the study of the properties of materials lies
in their extreme sensitivity and versatility.
This renders them particularly important in
studies of properties of condensed systems.
In addition to the historical use of microbal-
ance techniques as a tool of microchemistry,
they have, in recent years, found-extensive ap-
plication in the fields of metallurgy, physics,
and chemistry. The uniqueness of the method
results from the facility it provides in making
a series of precise measurements of high sen-
sitivity under carefully controlled conditions
over, a wide range of temperature and,
pressure.
This significant new volume contains.papers
in three major categories. The first group of
reports deals with the general structural
features and measuring capabilities of micro-
balances. In the second group, a sophisti-
cated consideration and much needed evalua-
tion of sources of , spurious mass changes
associated with microbalances is presented.
The third group describes some of the most
recent extensions in microbalance work-to
new research areas such as semiconductors,
ultra-high vacuum, and high temperatures.
These papers provide an interesting- account
of advances in the application of the micro-
gravimetric method to three new and impor-
-tan( fields of research on the behavior of
materials.
170 pages , $6.50
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EDITORIAL BOARD OF
ATOMNAYA ),`NERGIYA
A. I. Alikhanov
A. A. Bochvar
N. A. Dollezhal'
D. V. Efremov
V. S. Emel'yanov
V. S. Fursov
V. F. Kalinin
A. K. Krasin
A. V. Lebedinskii
A. I. Leipunskii
I. I. Novikov
(Editor-in-Chief)
B. V. Semenov
V. I. Veksler
A. P. Vinogradov
N. A. Vlasov
(Assistant Editor)
A. P. Zefirov
THE SOVIET JOURNAL OF
ATONIC ENERGY
A translation of ATOMNAYA ENERGIYA,
a publication of the Academy of Sciences of the USSR
(Russian original dated February, 1961)
Vol. 10, No. 2
November, 1961
CONTENTS
RUSS.
PAGE PAGE
Using the Method of Moments to Calculate the Space-Energy Distribution of Neutron
Density from Flat and Point Sources in an Infinite Medium. A . R. P t i t s y n ........
109
117
The Creation of a Magnetic Field with an Azimuthal Variation. R. A. M e s h c h e r o v
and E. S. Mironov ........................ ..................
122
127
The Thermoelastic Stresses in the Walls of a Reactor Housing with Internal Sources of Heat
in Nonstationary States. B. I. Maksimenko, K. N. Nikitin, and
L. I. Bashkirov .......... ............... ..... ...........
126
131
The Reaction between Solid U02 and MnO2 in a Sulfuric Acid Solution.
E. A. Kanevskii and V. A. Pchelkin ................. . .....
133
138
A Study of the Properties of Uranium Hexafluoride in Organic Solvents. N. P. G a l k i n ,
B. N. Sudarikov, V. A.-Zaitsev, D. A. Vlasov, and V. G. Kosarev .
138
143
Methods of Reducing Uranium Hexafluoride. N. P. Gal kin, B. N. Sudarikov, and
V. A. Zaitsev ...............................................143
149
LETTERS TO THE EDITOR
The Mechanism of Reaction of Fast Nucleons with Nuclei. V. S. B a rash e n k o v ,
V. M. Mal'tsev, and E. K. Mikhul..............................
150
156
Measuring the Radiation Capture Cross Sections of Fast Neutrons of 127.
Yu. Ya. Stavisskii, V. A. Toistikov, and V. N. Kononov, .........
153
158
A Beta-Source Based on Au198 for the Investigation of Physical Properties of Substances during
Irradiation. M. A. Mokul'skii and Yu. S. Lazurkin .................
156
160
A Generator Producing a High Flux of 14 or 2.5 Mev Neutrons. V. 1. Petrov .. . . . . . . . . .
159
163
The Effect of Radiation on the Electrochemical Behavior of 1Kh18N9T Steel.
V. V. Gerasimov and V. N. Aleksandrova .......................
161
164
A Method of Investigating Processes of Retardation of Fission Fragments in Metals and Alloys."
N. A. Protopopov, Yu. B. Shishkin, V. M. Kul'gavchuk, and
V. I. Sobolev.. . ............................... ? ........
The M
lti
P
i
d O
e
164
166
e
ng
o
nt an
th
r Properties of the Lower Oxides of Niobium. O. P. Kolchin 11 and N. V. Sumarokova .......................................
167
168
The Hardness of Some Niobium-Base Alloys at High Temperatures. I . I . K o r n i l o v a n d
R. S. Polyakova .............................................
170
170
The Characteristics of Irradiated Glasses. Z d e n e k Spurn y ......................
172
172
The Build -Up Factors for Heterogeneous Shielding. L. R. K i m e l ..................
174
173
Annual subscription $ 75.00
? 1961 Consultants Bureau Enterprises, Inc., 227 West 17th St., New York 11
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Single issue
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Note: The sale of photostatic copies of any portion of this copyright translation is expressly
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CONTENTS (continued)
RUSS.
PAGE PAGE
Solution of the Kinetic Equation for a Medium with a Point Monodirectional Source.
E. B. Breshenkova and V. V. Orlov
176
175
The Effect of Inelastic Scatter of Neutrons in Uranium on the Moderation Length in Water.
B. A. Levin, E. V. Marchenko, and D. V. Timoshuk............
179
177
NEWS OF SCIENCE AND TECHNOLOGY
International Conference on Radioisotope Applications in the Physical Sciences and in
Industry. V. V. Bochkarev and A. S. Shtan' ...
182
180
[Third Conference on Training Reactors, USA .. .......... ................
185]
[Nuclear Power Development Program in the USA.................... ........
187]
[The Present State and the Outlook for Nuclear Steam Superheat
Source: Nucl. Engng. 5, No. 52, 355 (1960) ..........................:.
189]
Brief Communications .... .............................. ...... .
189
190
BIBLIOGRAPHY
New Literature ....................................................
190
192
The Table of Contents lists all materials that appears in.Atomnaya Energiya. Those items that
originated in the English language are not included in the translation and are shown enclosed in. brackets.
Whenever possible, the English-language source containing the omitted reports will be given.
Consultants Bureau Enterprises, Inc.
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USING THE METHOD OF. MOMENTS TO CALCULATE
THE SPACE-ENERGY DISTRIBUTION OF NEUTRON DENSITY
FROM FLAT AND POINT SOURCES IN AN INFINITE MEDIUM
Translated from Atomnaya Energiya, Vol. 10,.No. 2, pp. 117-126, February, 1961
Original article submitted April 6, 1959
A method is given for calculating the space-energy distribution of neutron densities from. flat and point
sources in an infinite medium.
N
The neutron density $ (x, E) is sought in the form (0, E) Za1 (E) K Lbi (E)x].. To a large
=f
degree the form of the function K (x) is'arbitrary; its selection is based on physical principles. From
the 2N space moments of the function 0 (x, E), 2N parameters at, bi are found. The neutron density
distribution is found in hydrogen and water. The calculations for water are compared with experi-
mental data. A comparison with the accurate solution of Wick [1] in the case of retardation of
neutrons by hydrogen shows that from four moments the suggested method can, with sufficient ac-
curacy, find the spatial distribution of neutrons at distances up to 20 free path lengths.
In [1-4] in principle the problem was solved of finding the space-energy distribution of photons and neutrons in
an infinite medium. In [1,2] a study was made of the asymptotic form of the solution for very large distances from
the source.
An analytical solution was found in [1] for the case of a constant free path length for strongly retarding neutrons.
For cross sections depending on energy, in [3] a semianalytical method was developed to calculate the distribution at
very large distances from the source.
For comparatively small distances the method of polynomial expansions can be used for the calculation [4]. It
is precisely these distances (-15-20 free path lengths) which are of interest to us. The idea of the polynomial method
consists of expanding the required function into a series in terms of known polynomials Ui(x):
i, (x, E) =.e-Hx1Ai (E) Ui (Px),
where the coefficients Ai(E) are found from a system of integral equations. This method was developed in application
to photons,and at distances of 15-20 path lengths it can find the photon density by means of four polynomials, which
amounts to finding four space moments.
In the case of weakly retarding media this method is also suitable for determining neutron density; however,
with strong retardation, especially when the free path length decreases weakly with decrease in energy, the series in,
terms of polynomials converges poorly. Here the use of four terms of the series [1] at distances equal to 5-6 paths leads .
to negative values of neutron density. This is presumably due to the unsuitably of the polynomial expansion method
for these problems, although a knowledge of the four space moments 0 n (E) is in itself sufficient to find the neutron
density at the given distances for any values of E*.
As is known, neutron density mainly depends exponentially on the distance x; however.the exponent is not al-
ways a linear function. Thus, in the case of a monoenerg source S(E-ED) the neutron density, where there is not a
single collision, at all values of x is proportional to e-xf>. Being retarded, these primary particles will give at any
distances a neutron spectrum proportional to e-x/ X . The accumulation of neutrons, as shown in [1,2], leads to a
? The author of [5] showed that a value of the parameter a can be chosen in the polynomial expansion (1) for which
the series in terms of polynomials converges well.
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still slower reduction in density at large distances. On the other hand, at small distances x< in EEO/ Faccording to
the theory of age,the density of neutrons retarded to an energy E(E> d . RC 2n --a)>> d,
Fig. 1. Shape of plane-parallel poles used to where R is the radius; a is the angle of the sector; n is the number
calculate the distribution of magnetic field of sectors.
intensity.
Figure 2 gives regions on complex planes which are converted
into one another by means of the formula
nz nz
d Ile d+x?-x a d+1
W_ In-- z
en d -}- x2-{- x I~ en d -I-1
D l.n Ilend-}-1- Ile A W + X2
Ilend+I+ Ilend+x2
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VI = as I`_0 = - H,, (r, (p).
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Fig. 4. Dependence of the magnetic field intensity,
averaged with respect to cp, on the radius.
x
0
Fig. 2. Regions on complex planes wand z.
H1(u,o)/Hmax
Hz-Ho
Ho '
Fig. 5. Shape of sector covers
and boundary of equivalent
magnetic field (dotted lines).
From the theory of the complex potential it follows that the
magnetic field between stepped poles (see Fig. 1) is equal to
~ and.
H(w)=H.+iH iHmaxx e +f (5)
2 d d e a+xz
Fig. 3. A comparison of the calculated and experi-
mental data. The continuous curve represents the
where Hmax is the field intensity on moving an infinite distance
to the left.
calculated data; the points show the results of the Using formulas (4) and (5) a calculation was made of the
measurements at different radii (in millimeters): distribution of intensity Hv=f (u) in the middle plane between
?-50; X-70; 0-90; A-110; 0-130; 4-145. the stepped poles of infinite length. The results of the calcula-
type
tion are given in the form of a curve in Fig. 3.
In many cases, especially when studying the movement of ions in an idealized magnetic field of the sector
[4], Hv = f (u) is best represented in the form of an equivalent stepped field (see Fig. 2). A characteristic value
of this field is the parameter A-the difference in coordinates of the steps of the pole surface and the equivalent
magnetic field:
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H max(1- x) t ,l H?(u) du - Hmax du - ` xH maxdu
00 _C0 0
Preliminary Experiments
The experiments were carried out with an electromagnet with pole pieces of diameter 370 mm and 90 mm
between them. Between the cylindrical poles there were two steel discs of diameter 370 mm and thickness 16 mm
with sectors fastened to them at an angle of 52.5? and thickness 5 mm. The gap between the sectors was 40 mm, con-
sequently d = 20 mm, D = 25 mm and x = 0.8. The measurements were carried out with a magnetic field intensity in
the center Ho=6000 oe. The points of Fig. 3 show the values of the function Hz(R,(P/Hz max obtained from experi-
mental data, Hzmax being the greatest of all values of magnetic field intensity near the middle of the sector. As
should be expected, the best coincidence is observed at large distances from the center. At R= 50 mm the experi-
mental data differ considerably from the calculated data.
In the range of radii 50 U02SO4 + MnSO4 + 2H2O
U02 + Mn02 + 4H' ---> U02+ + Mn2` + 2H2O.
Our experimental check of the correctness of this equation confirmed that the ratio of the number OfUO2 moles
tothenumber of Mn02 moles taking part in the reaction is equal to unity. For this reason in later work when consider-
ing possible mechanisms we used this equation.
It might be assumed that in an acid medium at first one of the oxides is dissolved and then there is a hetero-
geneous oxidation-reduction process. In this case the reaction of U02 and Mn02 in acid medium is expressed by one
of the following schemes:
(I) UO2(3) 4I3iaqr - U(aq) -{- 2H2O(1); (a) U02(+aq> + Mn2+ -I- 2H2O(1)
{ U(aa) + Mn02(,r) UOZaq) + Mn(aq) (b)
Mn02(s)-}-4H(+aq) Mn(4q)-}-2H2O(1); (a)
U02(s) + Mn02(s) + 4H(aq) > (I I) {` b9n(aq) + U02(s) > Mn~aq> {- U02(av). (b)
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It can also be asumed that at first there is solution of U02 and MnO2 and then homogeneous reaction of the tetra-
valent and hexavalent uranium in the solution:
U02(s) + 4H(aq) U~oq) + 2H.20(1); (a)
(III) MnO2(s)+4H(aq) --> Mfl(aq)+2H20(1); :b)
U(aq) + Mn(4aq) + 2H2O(1) ->UO2(aq) + D1n(aq) + 4H(aq)? (c)
It should be emphasized that in the suggested schemes the separate stages are not shown, but only the successive
reactions. The possibility is not ruled out therefore that, for example, one of the stages of the reaction (II, b) or (III, c)
is the formation of trivalent manganese. However, this problem will not be discussed here.
A common feature of the schemes (I) and (II) is the fact that in not one of the successive reactions do the U02
and Mn02 take part simultaneously. Because of this the rate of the total process should be in a linear relationship to
the size of the U02 surface, if the (I, a) reaction is limiting. The size of the Mn02 surface should not have any effect
on the rate of the process. On the other hand, if reaction (II, a) limits the process, then its rate should be in a linear
relationship only to the size of the Mn02 surface.
.To check the correctness of these conclusions a determination was made of the dependence of the rate of reac -
tion for a constant amount of U02 on the excess of Mn02 with respect to the stoichiometric calculation (figure, MnO2/
/U02) and then the dependence of the rate of the process on the excess of U02 (see figure, U02/MnO2)" . An appropriate
correction was introduced because the "pure" grade of manganese dioxide contains MnO impurity.
However, the experimental data (see figure) show that the rate of the processes is affected by the size of both
the U02 and Mn02 surfaces. It should also be emphasized that the dependence of the rate of the process on the size of
the U02 or Mn02 surfaces is not linear. A similar shape of the curve presumably indicates that the U02 and Mn02 play
the same part in the reaction, i.e. they take part simultaneously in it.
stages c;aii uc UUl1JJUGleU iuuuiiig iii auy case. rULLLLGIU1ULe, Ill LUC 1LguL
of obtained experimental data the possibility cannot be excluded that
25 the process could take place according to the following scheme, as-
suming "solid phase" reaction of the oxides:
20
0
Mn02/U02 U02(s)+MnO2(s) --> UO3(s)+MnO(s); (a)
0 95
U~l (IV) UO3($)+2H(aq)->U02+aq)+H2O(1); (b)
U
Mn0(s) 12H(aq) -> Mn(aq) + H20(1) (c)
~ "I I I I I I I in neutral organic oxidizing agents at room temperature [7] apparently
Ratio of components, M
Rate of solution of U02 and Mn02.
supports this assumption.
It is obvious that in aqueous solutions the reaction between U02
and Mn02, i.e.,stage (IV, a), is not a solid phase, reactionin the sense
in which it is understood in [8-10]. In a number of other papers it is
assumed that the so-called solid phase reactions in most cases proceed
with the decisive participation of gases or liquids or the same and others simultaneously [11]. When considering stage
(IV, a) it should be remembered that MnO2 in aqueous solution is undoubtedly hydrated [7],and on the surface of U02
in acid solutions a hydroxide forms [12]. Consequently, the solid phase process, shown schematically in the form of
equation (IV, a), in practice is much more complex. It is important that according to this scheme for the reaction
between U02 and Mn02 in acid solution, not containing foreign ions, it is essential to have contact between the solid
phases.
It is well known that UO3 and Mn02 in acid solutions dissolve rapidly; therefore all kinetic features of the total.
reaction, if the scheme (IV) is correct, are bound up with the reaction of U02 and Mn02; more accurately with processes
occurring at the points of contact of the hydrated layers of these components.
The observed dependence of the rate of the process on the size of the surface of U02 or Mn02 will not be under-
" The method for determining the rate of reaction was described in detail by the authors in an article submitted to the
journal "Neorganicheskaya Khimiya."
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standable if the reaction proceeded according to schemes (I), (II) or (III)?on the whole surface of U02 and Mn02, since
the rate of solution of solids in liquids is in a linear relationship to the size of the solid phase surface (for example see
[13,14]). If the reaction occurs not on the whole surface of the U02 and Mno2 particles, but only in a layer formed at
the point of contact, it is obvious that the dependence of the rate of the process on the size of the surface of the react-
ing components should not be linear.
If the rate of the process is limited by the reaction (IV, a) then it should be expected that the concentration of
hydrogen ions, not taking direct part in this stage of the process, should not affect the degree of reaction of U02 and
Mn02 in acid medium over a fixed length of time of the experiment. For a comparatively wide region of change in
concentrations of sulfuric acid with an equimolar ratio of U02 and Mno2 and 100 ml solution,this is confirmed by experi-
mental data. The absence of an effect of sulfuric acid concentration on the degree of reaction of U02 and Mn02 is
difficult to reconcile with schemes (I), (II) or (III), since each of them includes the reaction of solution of oxides with
the participation of hydrogen ions, these reactions depending to a large extent on the concentration of hydrogen ions
[15,16].
The given experimental data agree most completely with scheme (IV). However, on their basis the possibility
cannotbe excluded of the process occurring according to other schemes if the rate of the process can be effected in
the same way by U02 and Mn02 and the hydrogen ion concentration has no effect.
Some Features of the Process
We will consider at first the effect of preliminary grinding of U02 and Mn02. Samples of U02 (1.0 g) and MnO2
(0.37 g) were ground for an hour in a mechanical SMB mortar. After this for 4 hr at 20?C in 50 ml of 0.5 N H2S04,
oxides were dissolved, separately or ground together ,and, in parallel, oxides were dissolved which ha *d not been subjec-
ted to additional grinding. The grain size of the initial U02 and Mn02 was 0.074 mm, their degree of.reaction was
determined from the concentration of uranium in the solution after the end of the experiment. The data on the reac-
tion of U02 and Mn02 are as follows:
Conditions for preparing speci- Degree of reaction, 16
mens
U02 (initial) 0.3
U02+ Mn02 (initial) 12
U02 + Mn02 (ground separately) 45
U02 + Mn02 (ground together) 83
These data show that the grinding of U02 and Mn02 especially when they are ground together, has a very favor-
able effect on the reaction of these substances in sulfuric acid solution, which confirms the correctness of scheme (N).
However, an x-ray study showed that the solid -phase reaction during the grinding of dry oxide for several hours only
occurs to a very small extent -less than 0.1%. Consequently, the role of grinding is mainly to facilitate the formation
of pairs of U02 and Mn02 particles in close contact.
Other assumptions can also be put, forward for the mechanism of reaction of U02 and Mn02 in sulfuric acid med-
ium. For example, we will asume that the reaction occurs at the moment of fast impact of free particles of these di-
oxides and then these particles diverge. In this case the completeness of the reaction should depend on the number of
impacts of particles and, consequently, should increase with decrease in the ratio S:L. The effect of this factor should
therefore be studied.
Experiments were carried out at room temperature in glass test tubes fastened on a disc rotating at a speed of
60 rpm. The weight of U02 was 0.5 g, that of Mn02 was 0.185 g. The oxides were ground together for an hour in a
mortar. The H2S04 concentration was 5 N, time of the experiments,30 min. When calculating the ratio S:L the weight
of the solid was taken as the total weight of U02 and Mn02. The degree of reaction of U02 and Mn02 in sulfuric acid
solution in this case was determined by the concentration of uranium. The following data were obtained for the effect
of the ratio S:L on the reaction of U02 and Mn02:
S:L
Degree of reaction
1:1
22.6
1:2
21.0
1:3
21.5
1:4
21.5
1:5
23.8
1:10
21.2
1:15
21.2
1:20
21.0
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The lack of dependence of the degree of reaction of components on the ratio S:L indicates that the reaction
between U02 and MnO2 in sulfuric acid solutions occurs not as a result of rapid reaction of the particles in brief con-
tact with one another but probably occurs in the boundary layer which is strongly hydrated, forming at points of close
and constant contact of U02 and Mn02 particles.
The relative strength of these pairs of particles is also confirmed by results of experiments in which a study was
made of the effect of the intensity of mixing. On changing the speed of the four-blade mixer from 50 to 500 rpm the
degree of reaction of UO2 and Mn02 in 1 N or 5 N H2SO4 remains practically unchanged both in the stoichiometric
ratio of these oxides and with a large excess of Mn02.
From the combination of all experimental data it can therefore be assumed that the reaction of U02 and Mno2
in sulfuric acid solution proceeds according to the scheme (IV) in the absence of foreign ions. At first there is reaction
in the surface hydrated layers of the UO2 and Mno2 particles in close contact; then the reaction products are rapidly
dissolved, reaction again occurs on the fresh surface of the particles, etc. However, it must not be assumed that the
process cannot occur according to schemes (I), (II) or (III) if at separate stages of successive reactions,unstable, rapidly
decomposed substances are formed. In this case, as when the process occurs according to scheme (IV)- if there is not
sufficient contact between the reacting substances the rate of the process is limited by steric hindrances.
The experimental data obtained in the present work throw more light on the role of iron ions during the sulfuric
acid leaching of uranium from ores using pyrolusite. The assumption that iron is a direct oxidant and the process occurs
according to t1e scheme A
U02(s) + 2Fe(q) -~ UOz~as) + 2Fe(aq); (a)
(V)
2Fe(aq) { Mn02(s) 14H(a9) - 2Fe(aq) -{- Mn(a9) + 2H20(l) (b)
b
at first glance is in contradiction to the higher oxidation-reduction potential of Mnz+/Mno2 compared with Fe2?/Fes+:
Fe('aQ) Fe(ag)+e (E?=0,77v);
Mn(aq) -{- 2H20(1) Mn02(s) -I-- 4H(aQ) -}- 2e- (E? =1,22x).
Further, if we consider the necessity for contact between the two solid phases for oxidation of UO2 by means of
Mn02 in pure solution and the absence of necessity for such contact in the presence of iron ions in the solution, then
it becomes understandable why the sulfuric acid leaching of primary uranium mineral from ores, which almost always
contain iron, occurs according to scheme (V).
1. A study has been made of the effect of the intensity of mixing, the ratio UO2:MnO2, the H2S04 concentration
preliminary grinding of oxides and other factors on the reaction between UO2 and Mn02 in sulfuric acid solution.
2. On the basis of the obtained experimental data, possible schemes have been discussed.
3. It has been found that the occurrence of this reaction in which two solid phases take part is effected to a
large extent by steric factors. In connection with this the problem was considered of the occurrence of the process
with the presence in the solution of Fee' and Fes+ ions, eliminating these steric hindrances.
In conclusion we would like to thank V. G.Romanova for taking part in the work and L. V. Zverev for his useful
comments.
LITERATURE CITED
1. B. V. Nevskii, Atomnaya Energiya q, 1, 5 (1959).?
2. G. E. Kaplan, B. V. Nevskii,and B. N. Laskorin, Atomnaya Energiya. 6, 2, 113 (1959).?
3. J. Clegg and D. Foley, Uranium Ore Processing. Addison-Wesley Publ. Co., Reading, 1958.
4. A. Godin, Reports of the International Conference on the Peaceful Use of Atomic Energy (Geneva, 1955), Vol.
8, [in Russian] (Moscow, Metallurgy Press, 1958), p. 17.
'Original Russian pagination. See C. B. translation.
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 Declassified and Approved For Release 2013/03/04: CIA-RDP10-02196R000600060001-2
5. A. I. Ponomarev, Methods for the Chemical Analysis of Minerals and Rocks. Vol. 1, [in Russian] (Moscow, Acad.
Sci. USSR Press, 1951), p. 158.
6. P. N. Paley, Reports of the International Conference on the Peaceful Use of Atomic Energy (Geneva, 1955),
Vol. 8 (in Russian) (Moscow, Metallurgy Press, 1958), p. 268, 271.
7. R. Evans. Quart. Revs, 13, No. 1, 61 (1959).
8. W. Jost. Diffusion and chemische Reaktion in festen Stoffe, 1937.
9. J. Hedvall. Reaktionsfahigkeit der festers Stoffe, 1938.
10. J. Hedvall, and H. Jagitsch. Z. anorgan. and allgem. Chem. 262, 49 (1950).
11. A. M. Ginstling, Studies of the Mechanism and Kinetics of Reactions in Mixtures of Solids. Thesis [in Russian]
(Leningrad, 1952).
12. J. MacKay and M. Wadsworth. Trans. ASME 212, 597 (1958).
13. D. A. Frank-Kamenetskii, Diffusion and Heat Transfer in Chemical Kinetics [in Russian] (Moscow Acad. Sci.
USSR Press, 1947).
14. A. B. Zdanovskii, The Kinetics of Solution of Natural Salts under Conditions of Forced Convection [in Russian]
(Leningrad State Chemistry Press, 1956).
15. E. Ya. Rode, Oxygen Compounds of Manganese [in Russian] (Moscow, Acad. Sci. USSR Press, 1952) p. 131.
16. V. I. Spitsyn, G. M. Nesmeyanova,and E. A. Kanevskii, Zhur. Neorg. Khim. 5, 9, 1938' (1960).
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 Declassified and Approved For Release 2013/03/04: CIA-RDP10-02196R000600060001-2
A STUDY OF THE PROPERTIES OF URANIUM HEXAFLUORIDE
IN ORGANIC SOLVENTS
N. P. Galkin, B. N. Sudarikov, V. A. Zaitsev,
D. A. Vlasov,and V. G. Kosarev
Translated from Atomnaya Energiya, Vol. 10, No. 2, pp. 143-148, February, 1961
Original article submitted April 14, 1960
Studies have been made of the solubility and kinetics of solution of uranium hexafluoride in carbon
tetrachloride, chloroform, dichloromethane, asymmetricaldichloroethane,symmetrical tetrachloro-
ethane, pentachloroethane, trifluorotrichloroethane, symmetrical trichloropropane,and tetrachloro-
propane. It has been shown that solutions of uranium hexafluoride in carbon tetrachloride, tetrachloro-
ethane, pentachloroethane,and trifluorotrichloroethane are completely stable for two weeks at 20?C;
at this temperature solutions of uranium hexafluoride in chloroform, dichloroethane,and dichloro-
methane are unstable. It has been shown that reactions of uranium hexafluoride with these studied
organic solvents at 60-100?C occur in the following way: at first uranium pentafluoride is formed
which is reduced at first to the intermediate uranium. fluorides, containing a large amount of tetra-
valent uranium,and then to uranium tetrafluoride.
It is known that uranium hexafluoride is soluble in carbon tetrachloride, chloroform, symmetrical tetrachloro-
ethane.and other halogenated hydrocarbons [1,2]. In [3] the solubility of uranium hexafluoride was studied in carbon
tetrachloride in the 'temperature range 5-35?C.
Solutions of uranium hexafluoride and chlorinated and fluorinated hydrocarbons have varying stability. For
example, uranium hexafluoride forms a stable solution in symmetrical tetrachloroethane. The yellow solution loses
its color on boiling; on cooling, the yellow color is restored. This change in color is explained by the formation of
complex compounds of uranium hexafluoride with tetrachloroethane which becomes colorless on boiling. Solutions
of uranium hexafluoride in pentachloroethane have a stability which is still greater than in symmetrical tetrachloro-
ethane.
In addition to this uranium hexafluoride reacts with some organic solvents. For example, 1,2-difluoro-1,1,2,2-
tetrachloroethane reacts fairly rapidly with uranium hexafluoride. Gases are liberated and as a result the whole of the
uranium hexafluoride is reduced to uranium tetrafluoride [1]. Some organic solvents can be used to reduce uranium.
hexafluoride to the tetrafluoride at fairly low temperatures. The reduction of uranium hexafluoride by liquid trichloro-
ethylene at -.80?C was described in [4].
On heating solutions of uranium hexafluoride in carbon tetrachloride up to temperatures of 150?C in an auto-
clave a reaction takes place, accompanied by an increase in pressure and temperature. The reaction products are
uranium tetrafluoride, chlorine and a mixture of freons CC13F and CFCI3. The equation of the reaction will have the
following form:
UFs + 2CC14 --~- UF4 + C12 + 2CC13F.
The aim of the present work is to determine the solubility of uranium hexafluoride in halogenated hydrocarbons
which are the most stable to uranium hexafluoride, and to study the stability of the obtained solutions. Most of the
selected solvents are readily available and cheap.
The solubility of uranium hexafluoride was determined in a quartz vessel with a seal. The sealing liquid was a
mixture of completely fluorinated hydrocarbons with a boiling point of -?140?C. A fixed volume of the organic solvent
was added to the vessel and solid uranium hexafluoride in an amount needed to form a saturated solution at the parti-
cular temperature. When mixing was complete and the liquid had been allowed to stand, a fixed volume of solution
was removed for analysis. The uranium content in the organic phase was determined volumetrically. All the organic
solvents used in the work were subjected to careful chemical purification and repeated fractional distillation. -
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 Declassified and Approved For Release 2013/03/04: CIA-RDP10-02196R000600060001-2
1 I I I I I I 1 I 1
07' i I 1 '-L
' ?30 50 90 120 150 180 210 240
Time of contact, min
Fig. 1. The effect of time of mixing on the
solubility of uranium hexafluoride at 25?C
in halogenated hydrocarbons: 1) CH2C12; 2)
C2C13F3; 3) CHC13; 4) CC14.
30 60 90 120 150 180 210
Time of contact, min
The kinetics of solution of uranium hexafluoride in all organic
solvents was studied at 25?C; experiments with dichloroethane were
carried out at 10?C. Figures 1 and 2 give the solubilities of uranium
hexafluoride in halogenated hydrocarbons for different times of mix-
ing.
As can be seen from these data, equilibrium in the solution of
uranium hexafluoride in most organic solvents is established in 1 hr.
Only in chloroform and trichloropropane is the equilibrium established
in 3 hr. The values are given below for the solubility of uranium hexa-
fluoride in the investigated halogenated hydrocarbons at 25?C:
Organic solvent Solubility of UF6, g/ml
CH2Cl2 0.983
CHC13 1.095
CC14 0.799
C2H4C12
C2H2C14
C2HC15
C2C13F3
C3H5C13
C3H4C14
0.626
0.520
0.490
0.983
0.415
0.600
When studying the dependence of uranium hexafluoride solu-
bility on temperature the time of mixing was 1 hr for all organic sol-
vents; only for chloroform and trichloropropane was the time of mix-
ing 3 hr. Figures 3 and 4 give the solubilities of uranium hexafluoride
in halogenated hydrocarbons at different temperatures. In the investi-
gated temperature range the solubility of uranium hexafluoride in all
halogenated hydrocarbons increased with temperature.. Chlorine deri-
vatives of methane had greater dissolving capacity than the chlorine
derivatives of ethane and propane.
A study was also made of uranium tetrafluoride solubility and
that of uranyl fluoride in carbon tetrachloride and chloroform at 25?C.
These studies were of interest because these compounds can be present
in uranium hexafluoride in small amounts. A determination was also
made of the solubility of the double salt 3NaF?UF6 at 25?C. The results
Fig. 2. Effect of time of mixing on the solubility of the experiments are given in Table 1.
of uranium hexafluoride at 25?C in halogenated As can be seen from the data, the solubility of uranium tetra-
hydrocarbons: 1) C3H4C14; 2) C2H2CI4; 3) C2HC15; fluoride and uranyl fluoride in carbon tetrachloride and chloroform
4) C3H5C13; 5) C2H4C12 (at 10?C). is very low (it is presumably of the same order in the other investi-
gated solvents), the solubility of the double salt 3NaF?UF6 is some=
what higher, which is possibly due to the presence in it of hexafluoride which was partially absorbed during the pre-
paration of the salt.
Solutions of uranium hexafluoride in the studied halogenated hydrocarbons had different colors: green-in
carbon tetrachloride, orange-in chloroform, yellow-in tetrachloroethane and pentachloroethane, cherry red-in di-
chloroethane, dichloromethane, tetrachloropropane and trichloropropane. An exception is the colorless solution of
uranium hexafluoride in trifluorotrichloroethane. The intensity of the color of the solutions increases with the con-
centration of uranium hexafluoride. The formation of colored solutions is probably due to the formation of complex
compounds of uranium hexafluoride with the organic solvents.
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2,?
I's
00
71
0, 8
0,4 10 20 30 40 50
Temperature, ?C
Fig. 3. The temperature dependence of the solubility
of uranium hexafluoride in halogenated hydrocarbons:
1) CHC13; 2) C2C13F3; 3) CH2C12; 4) CC14.
1, 6
1,4
1, 2
qW 1,0 2
w 3
4 5
w n8
l
0 A
l
0,6
0
(/) -1 -I
11, 2 -
?11 30 40
Temperature, ?C
Fig. 4. The temperature dependence of the solubility
of uranium hexafluoride in halogenated hydrocarbons:
1) C3H4C14; 2) C2H4C12; 3) C2H2C14; 4) C2HC15; 5)
TABLE 1. The Solubility of Uranium Tetrafluoride,
Uranyl Fluoride and the Double Salt 3NaF?UF6 in
Carbon Tetrachloride and Chloroform at 25?C
Solubility mg/liter U
Compound
in cc14 in citcls
UF4