ORNL-1771 - Oak Ridge National Laboratory

AM? QUARTERLY PROGRESS REPORT
at predetermined pressures to transfer the melt. A
prohe indicates when the desired liquid level is
reached in the second pot and activates a rejoy
which closes the helium inlet to the first pot and
opens a corresponding one in the second pot to
reverse the cycle.
Velocities obtained with the apparcstus have
reached 5 fps, which corresponds to a Reynolds
number of only about 1500. It is hoped that art
improved design now being assembled will make
possible turbulent flow. A 200°C gradient across
the cooling section was desired; however, it has
not yet been possible to achieve o differential of
more than hQ"C. The transfer cycle consists in
having the melt contained in either pot at 700"C,
being heated to 8W"C in the first section of the
transfer line, cooled in the iiiiddle section, brought
back to 700°C in the third section, momentarily
stored in the opposite pot cat 7QO"C, and then the
cycle is reversed. A complete cycle, that is, from
one pot to the other and back, required approxi-
mately 5 min. It is believed that this apparatus will
yield corrosion data under conditions not easily
obtainable by presai-at means.
Weactiom Between Graphite nad Fluoride Melt
F. A. Knox
Materials Chemistry Division
Graphite has been used extensively as n COR-
tainer material during preparations of fuel and
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coolant materials; therefore, an investigation WQS
made of possible reaction between it and a fluoride
melt. In the procedure used an lnconel reaction
tube was loaded with either NeF-ZrF,-UF, (53.5-
40-6.5 mole %) alone or with the fluoride mixture
plus graphite which had been treated under vacuum
for degassing. The reaction tube was connected
to a manometer and then held at 1000°C until the
gas pressure became constant.
It was found that the rather large gas pressures
obtained were due chiefly to SiF,. Analysis of
the graphite indicated the presence of nearly 1%
Si, The use of spectrographically pure graphite in
this apparatus has yielded pressures very nearly
the same as the pressure of the pure fluoride. No
HF or CF, was detected during these tests.
1- ithi urn Fi Mor ide Casti rigs
N. V. Smith F. Ksrtesz
Materia I S Chemis try Division
At the request of the Instrumentation and Controls
Division, high-density lithium fluoride cylinders
were cast from powdered material for use in an
x-ray spectrometer. These cy1 inders were pre-
pared by charging the powder to graphite crucibles
and heating in an inerf atmosphere to 900°C. The
graphite liner containing the melt was then re-
moved from the furnace and a strong air iet was
applied to its periphery, The resulting cylinders
were uniform and acceptable.