ORNL-1816 - the Molten Salt Energy Technologies Web Site

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ANP QUARTERLY PROGRESS REPORT
have developed a suitable composition by using
Sic as the bonding material. However, specific
details and samples of the material have yet to be
received.
Tubular Fuel Elements
Twelve fuel plates have been prepared for forming
into tubes, and eight more are being prepared.
These tubes are to be drawn at Superior Tube Co.
by the plug-drawing technique with low (10%)
reductions. Other techniques such as hot drawing
or hot swaging may be used.
Control Rods
Thirty-five control ro eing prepared for
the GE-ANP project. They were received as
specially straightened tubes, 0.504 in. ID, 0.625
in. OD, 35 in. long, with one end plugged. The
being filled with a mixture of 50% alumi-
er and 50% B,C, both supplied by the
General Electric Company. The B,C is a special
grade containing 81% boron. The mixture is pre-
pared with 2% paraffin as a binder and is being
packed tightly into the tubes with a pneumatic
hammer. Very small increments are used to obtain
a high density. Twenty tubes have been filled
with average boron concentrations of about 0.8
g/cm3, that is, somewhat in excess of the 0.7
g/cm3 required. After filling is completed, the
. tubes will be heated and evacuated to remove
the paraffin and then cold swaged to final size.
AI-UO, Elements for Shielding Experiment
Fuel plates 28 in. long and 23/4 or 2% in. wide
are being prepared for an experiment to determine
the shielding necessary for delayed neutrons.
These plates are to be mounted on a belt and
rotated at speeds up to 22 fps. The fuel concen-
tration of 0.25 g/cm3 required for these plates is
quite high compared with that usually specified
for fuel plates, and therefore new fabrication
problems must be resolved.
Several plates have been fabricated by using
UO, and aluminum powder cores roll clad with
aluminum. Three plates having 0.040-in. core
ith 62 wt % UO, had the required fuel
ation. Both high-fired and steam-oxidized
UO, were used with good results. The edges of
the core were quite clean and straight, and the
UO, was distributed fairly uniformly, as shown by
radiograph examination. Because of the high
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percentage of UO,, it was necessary to hot roll
the plates with the covers on at all stages to
prevent oxidation. Plates with lower percentages
of UO, may be protected with thin aluminum foil
pressed on the core compact during cold pressing.
The finished plates, as-clad with 2s aluminum,
were judged to be too weak for the high stresses
involved in the rapid cycling. Several more ele-
ments are being assembled by using 52s aluminum
as frame and cladding in the hope that work harden-
ing obtained in finish cold rolling will yield plates
of sufficient strength.
BRAZING ALLOY DEVELOPMENT
P. Patriarca K. W. Reber
R. E. Clausing G. M. Slaughter
Meta I I urgy D iv i si on
J. M. Cisar
Aircraft Reactor Engineering Division
R. L. Heestand
Pratt & Whitney Aircraft
The resistance to oxidation of a number of high-
temperature brazing alloys when used in con-
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junction with lnconel as a base material was , -
described in a previous report., This study has
been extended to include tests of several additional
brazing alloys. These tests have been conducted
in accordance with the experimental procedures 1
used in the previous studies. The results of
metallographic examination of inverted T-joint
specimens after exposure to static air at 15OOOF
for periods of 200 and 500 hr are summarized in
Table 7.6. It appears that the majority of these
alloys are suitable for service within the limits of
this investigation. The periods of exposure currently
being studied extend to 1000 hr. Tests are.
also being conducted at 170OOF in static air.
It is recognized that the test results obtained to
date may not be applicable except under isothermal
conditions. Therefore a duplicate set of experiments
will be conducted to determine the effect
of thermal cycling on the adherence of protective
oxide films. Included in these tests will be a
determination of the effect of the presence of water
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vapor on the nature of the scale formation and the
resistance of this scale to spalling under con- ..
ditions characterized by temperature fluctuations.
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