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AR'P PROJECT QUARTERLY PWOGFWSS REPORT
static corrosion tests of stainless
steel, Inconel, and nickel in these
fluorides indicate little corrosion.)
The possibility of locating the
instrument beneath the Loop and
co~iipletely submerging the bellows in
a bath of molten lead with a temperature
gradient in the lead from 1100°F
at the top to just above the melting
point at the bellows is hcing investigated.
This would provide a
molten lead- molten fluoride interface
that would makc possible pressure
transmittal from a 1500°F fluoride
stream without exposing the bellows
to damaging temperatures. Static
tests have indicated that the fluoride
mixture w i l l remain on top of the
lead and w i l l not mix with the lead.
HANDLING OF FLUORIDES AND LIQUID HETALS
L. A. hlann D. R. Ward
J. M. Cisar P. W. 'Taylor
W. B. McDonald
ANP Division
NaK Distillatioa Test. The use of
eutectic NaK alloy (78 w t % K, 22
w t % Na) for cleaning the ARE fuel
circuit is planned. It is anticipated
that about 95%of the NaK in the entire
fuel circuit can be drained and the
remainder w i l l be removed by vacuum
distillation under heat. An experi-
mental unit has been constructed, and
the first test of vacuum distillation
of NaK has been conducted. in this
test, approximately 6 lb of eutectic
NaK at 1200°F was distilled from a
boiler by using a small vacuum pump
that pulled continuously from the
receiver and maintained a pressure of
less than 2 mm Hg. A steady flow of
approximately 3 scfm of helium was
maintained through the system. This
operztion continued intermi tten tly for
approximately three days; however,
there was some down t i m e on the system
because of gas leaks and other equipment
failures. 'This test indicated that
under attainable operating conditions,
this quantityof NaK could be distilled
32
from a boiler in somewhat less than
16 hours.
Gas-Lime Plugging, It was reported
previously( '1 that continued tests
were being conducted to determine the
extent of gas-line plugging from the
vapors of a bath of the fuel mixture
NaF-ZrF,-UF, (46-50-4 mole %) at
various elevated temp era tu res. A
summary of the results of the tests,
to date, follows:
I.. In operation at 1050"F, there
wasno gas-line plugging during 1488 hr
of testing.
2. In operation at 1300°F, all.
lines partly plugged after 666 hr of
operation. Upon examination, the
lines appeared to be totally plugged,
hut the plugs were sufficiently parous
to allow the passageof gas at approximately
one-tenth that of the initial
flow rate.
3. In operation at 1500"F, all
lines plugged solid in 100 hr of
opera ti on.
These tests indicate that gas
lines may be expected to operate
satisfactorily in a system containing
this fuel, providing the free surface
of the fuel adjacent to the entry gas
lines is at a temperature in the range
between 1050 and 1100°F. Above these
temperatures, some difficulty may
be expected.
ZrF, Vapor Condensation Test. ( 12)
In the absence of reliable vaporpressure
data for ZrF,, tests were
conducted to determine the minimum
c ont aine r-wa 11 t emperatur e needed to
minimize or prevent condensation of
ZrE', on the walls. Each of four
1-in.-IPS tubes 18 in. long was
charged with approximately 180 g of
the fuel mixture NaF-ZrF,-UF, (46-50-4
mole 7%). The fuel was maintained at
1500°F in each tube, and the portions
above the fuel tubes were maintained
at different temperatures, ranging
from 900 to . 1500"F, for each tube.
('''W. B. McDonald and P. W. Taylor, ANf Quar.
Prog. Rep. Sept. 10, 1952, ORNL-1375. p. 32.
(12)W. B. McDonald and J. W. Trurnmel,
frog. Rep. Sept. 10, 1952, ORNL-1375, p.
ANf Quar.
34.