ORNL-1816 - the Molten Salt Energy Technologies Web Site

PERIOD ENDING DECEMBER 70, 7954
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10. ANALYTICAL STUDIES OF REACTOR MATERIALS
The research effort in analytical ch
concentrated primarily on NaF-KF-LiF-base reactor
fuel, and, in particular, on analysis after it had
been utilized as a solvent for the reduction of
UF, by Uo to UF,. Tentative methods for the
determination of Uo and UF, were developed.
Studies were continued on the determination of
oxygen as oxides in fluoride fuels. Development
work was completed on the determination of sulfur
in various reactor fuels and coolants and in off-
gases from the production of fluoride fuels. Be-
cause of the urgency of other activities, no further
workwas done onthe determination of alkali metals
in NaF-KF-LiF-base fuels.'
ANALYTICAL CHEMISTRY OF
REACTOR MATERIALS
J. C. White
Analytical Chemistry Division
Determination of Uranium Metal in
Fluoride Salt Mixtures
A. S. Meyer, Jr. B. L. McDowell
Analytical Chemistry Division
A method based on the measurement of the
hydrogen derived from the decomposition of UH,
was developed for the determination of Uo in
nronosed reortor fuels. In this determination Uo
is con lverted to UH, by heatina in
".
of hvdroaen , " at 250'C 'for 1 hr. - The . UH, is decomposed
by heating ina stream of Co, at 4OO0C,
m
C. D. Susano
Analytical Chemistry Division
xoduced by the reduc-
_ _ The CO is reduced at temper-
, L -- * .,.?-.
' )th Uo and UF,.
1,. ce Go Le McDowell, ANP
Quar. Prog. Rep. Sept. 10, 1954. ORNL-1771, p 152.
J. M. Warde
Metal I urgy D iv is ion
_.1
The volumes of gas derived from reactions 1 and
2 are reproducible; 1.5 moles of CO is formed for
each mole of UH, decomposed when the ignition
is carried out at temperatures between 500 and
6OO0C, and 0.5 mole of CO is formed per mole of
UF, under similar conditions. The CO must be
removed from the effluent gases before ttle meas-
urement of hydrogen is made. This is accornplished
by passing the gases through a tube packed with
I,O, and powdered pumice, which is maintained at
a temperature of 150°C. The CO is oxidized to
CO, in the following reaction:
5CO + I,O, + 5C0, + 1,
When the method was tested by analyzing samples
of pure uranium metal, the hydrogen evolved
corresponded to 97% of the theoretical value with
a coefficient of variation of 2%. Satisfactory
precision has also been obtained for the deter-
mination of Uo in NaF-KF-LiF-base fuels and in
UF,. The concentration limits of the methcds have
not been measured experimentally, but, on the
basis of the quantities measured, concentrcitions of
Uo as low as 0.05% may be determined when 1-9
samples are utilized.
Since the I,O, tubes may become inactivated
after only limited service, a more dependable
method of eliminating the CO is needed. In a
modified procedure that is being considered, UH,
will be decomposed in an atmosphere of iimmonia
and the hydrogen will be measured over a solution
A. S. Meyer, Jr.
D. L. Manning
in Fluoride Fuels
W. J. Ross
B. L. McDoweII
* I . , P I . . m. ..
d eve I o p i n rimetric metb
priate conditions, trivalent uranium is selectively
oxidized by cupric chloride, CuCI,, titanium tetra-