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ANP PRQJECT QUARTERLY PROGRESS REPORT
PART 1. REACTOR THEORY, COMPONENT
DEVELOPMENT, AND CONSTRUCTION
1. Circulating-Fuel Aircraft Reactor Experiment
The Aircraft Reactor Experiment was operated
successfully for over 100 Mw/hr. During this
time the maximum equilibrium outlet fuel tempera-
ture was 158OoF, and the maximum power level
was over 2.5 Mw. The temperature coefficient of
reactivity 2 min after the introduction of a pertur-
bation was -5.5 x although its instantaneous
value was considerably higher. As a result, the
reactor was extremely stable while operating at
power, and there were no control problems. The
ciitical mass was 32.5 Ib of U235 and thus was
in reasonable agreement. with the calculated
value of 30 Ib.
Operation of the process systems and their
instrumentation was exceptionally trouble-free
during the six days of operation*from the time the
equipment was sealed in the pits until the sodium
and the fuel were dumped.
It is believed that most of the fission-product
gases evolved from the liquid fuel. In a 25-hr run,
it was determined that no more than 1 part in 30 of
the xenon poison remained in the fuel.
An unexpectedly steep initial slope that was
observed in the usual plot of [l - (l/multiplication
constant)] was found to be due to the formation of
SUMMARY
rotary elements functioned satisfactorily.
Fuel samples were withdrawn from the ARE
during operation below criticality and at very low
power. As was anticipated, the chromium content
of the fuel increased after each addition of fuel
concentrate. Just before the first additions of fuel
concentrate were made, the chromium concentration
of the carrier material was 100 ppm and the carrier
had been circulated for 155 hr. Since the system
had been operating isothermally, the chromium
content of 100 ppm was considered to represent
0.5 mil of attack on the Inconel. By the time the
final sample was taken, after 13 total of 307 hr of
operation, the chromium content was 445 ppm,
which represents about 5 mils of attack. A plot
of the data obtained showed that the chromium
content of the fuel had started to level off. Since
it was not possible to sample the fuel during full
power operation, no information on mass transfer
can be obtained until the equipment can be sec-
tioned.
2. Reflector-Moderated Reactor
The reactor assembly and the installation for
the Aircraft Reactor Test (ART), formerly the
Circulat ing-Fue I Reactor Experiment (CF RE), have
been the subject of analytical layout and detailed
design studies. Component development tests are
proceeding as scheduled, and specifications have
ompleted for o be used as heat
in heat exc S. ork
has been done on the development of a hydraulic
I ,
ierature level of the
power runs
temperature to which ARE pumps have been An analysis has been made of the activation of
subiected, it was interesting to note that all the Inconel core shells that would come from two