ORNL-1771 - Oak Ridge National Laboratory

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THERMGCOL!PLE WELL
must be accumulated before it will be certain that
sodium distillation is not taking place in sufficient
quantities to cause trouble.
In the apparatus a tubular Inconel specimen con-
taining 0.2 g of NaF-ZrF,-UF, (53.5-40.0-6.5 mole
5%) in the fuel chamber attached to the fixed base
is eccentrically loaded through a lever arm by a
weight. A stress pattern is produced across the
horizontal cross section which varies from a
maximum compressive stress. Surrounding the
specimen is a sodium coolant chamber with baffles
which reduce the magnitude of the thermal-con-
vection currents and allow closer control of the
specimen temperature. A furnace helps to marlatarn
the temperature at 1500°F throughout the test.
Two thermocouple wells prolect into the sodium
PERIOD ENDING SEPTEMBER 70, 7954
IJNCLASSIFIEO
ORNL-LR-DWG 3tn9
chamber to a position near the walls of the speci-
men at the neutral axis. A double-walled, con-
centric, sodium fill line, with only the outer tube
welded to the chamber, and a vacuum exhaust tube
complete the apparatus. All surfaces in contact
with the fuel and sodium ore made of Inconel.
The assembly is hydrogen fired for 1 hr at
1750"F, filled with fuel, and welded in a dry
box under purified helium. The other parts of
the container are welded into subassemblies, hy-
drogen fired, and then welded together, with helium
backing up the welds. The lever arm and weight
are adlusted and spot welded onto the specimen,
and the chamber covers ore welded into place.
Before the rig is filled with sodium, it IS filled
with NaK and heated to 1000°F to remove any
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