ORNL-2106 - the Molten Salt Energy Technologies Web Site

ANP PROJECT PROGRESS REPORT
Ta,O, was fused with potassium pyrosulfate, and
the tantalum-pyrogal lo1 color was developed, as
described in the earlier rep0rt.j
The coefficient of variation was 5% for the de-
termination of tantalum in NaF-ZrF,-UF,. In the
separation of tantalum from uranium and zirconium,
a sample which contained at least 0.5 mg of tanta-
lum was taken.
DETECTION OF TRACES OF NoK IN AIR
A. S. Meyer, Jr, J. P. Young
The design of an instrument for the photometric
detection of NaK in air was completed. A func-
tional description and the operational requirements
of the apparatus were given previously.6 The
electronic components of the instrument have been
assembled, and the optical system is now being
fabricated.
Preliminary engineering drawings of the instru-
ment for the detection of submicrogram quantities
of NaK in air by observation of the sodium reso-
nance radiation have been prepared. Experiments
are being carried out to devise a method for the
introduction of reproducible concentrations of alkali
metal oxides into air streams in order to provide
synthetic samples for testing these instruments.
The alkali metal is injected into the air stream
in a jet of helium which is saturated with alkali
metal by contact with the molten alkali metal.
The temperature dependence of the vapor pressure
of the molten metals provides the method for the
control of the concentration of the metal in the
helium. An apparatus has been assembled to test
the stability of sodium aerosols that have been
prepared at various mixing temperatures and various
flow ratios of helium to air and to determine a
quantitative method for transferring the samples
of air to the detection instruments.
DETERMINATION OF OXYGEN IN NaK
A. S. Meyer, Jr. G. Goldberg
Since it has been established that reasonable
precision can be obtained in making the determi-
nation of oxygen in alkali metals with the modified
Argonne distillation sampler, the sampler was
connected to a loop in which NaK was being cir-
culated. The loop operates at a temperature of
6A. S. Meyer et al.. ANP Qwr. Prog. Rep. March 10,
1956, ORNL-2061, p 207.
128
P
1200°F, with a cold trap differential of about
600OF. Since no inherent difficulties were en-
countered in the operation of the sampler in the
loop, a detailed, step-wise procedure' was written
which covers the use of the sampler with both
sodium and NaK loops. The analyses made over
a five-day period while the cold trap was in oper-
ation gave the following concentrations of oxygen,
in ppm: 1330, 1265, 575, 310, 265.
Since the results obtained with the sampler
appear to be satisfactory, additional tests will
be conducted in which the results from a plugging
indicator will be compared with the results from
the sampler. Plans are also being formulated to
add a known amount of oxygen to the NaK to make
further comparisons of the sampler and the plugging
indicator. In the sampler now being constructed a
sight tube is being placed in the distillation cham-
ber so that the operations of sampling and distilla-
tion may be observed.
EXAMINATION OF COLD TRAPS FROM
ALK AL I-META L SY ST EMS
A. S. Meyer, Jr. G. Goldberg
A program was initiated to carry out the chemical
examination of cold traps removed from systems
circulating alkali metals, such as heat-exchanger
test stands and corrosion-testing loops containing
sodium or NaK. A typical request for analysis
calls for the determination of oxygen, iron, chro-
mium, nickel, and, in the case of NaK, a sodium-
potassium ratio. Other constituents which are
sometimes requested are uranium, zirconium, and
beryllium. The cold traps range from 3 to 5 in.
in diameter and from 2 to 6 ft in length.
In order to carry out the determination of oxygen
successfully, the trap is drained as completely
as possible. The residual sodium, or NaK, on the
Demister packing within the trap is then reacted
with butyl bromide to form the neutral bromide
salts of sodium and potassium; oxides of these
elements do not react with butyl bromide. When
the reaction is completed, the organic material
is drained, and the trap is cut into two parts.
Until the trap is cut open, a blanket of helium is
maintained in it.
7J. C. White, Procedure for the Determination of Oxy-
gen in Sodium and NaK by tbe Distillation Method,
ORNL CF-56-4-31 (April 5, 1956).
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