ORNL-1771 - Oak Ridge National Laboratory

ANP QUARTERLY PROGRESS REFORT
be simplified if simplification proves to be ex-
pedient. Large blowers coupled to banks of NaK-
to-air radiators will be used to provide heat dumps
that will be simpler, more reliable, and easier to
control than turbojet engines. While conventional
heat exchangers like those of the ARE might be
used, experience in fabricating and testing tube-
and-plate finned radiators5 indicates that aircraft-
type radiators should cost little more and that they
will make a much neater, more compact instel-
lotion. Further, they will effect a manyfold re-
duction in the NaK holdup in the system and will
give a thermal inertia and a NaK transit time es-
sentially the same as those for a full-scale aircraft
power plant. The fabricating and operating ex-
perience obtained should also prove to be quite
valuable. It appears that d-c motors will be the
most practical means for driving the various pumps
in the system, but the blowers will probably be
driven by a-c motors, with control being effected
by the use of air bypass valves and/or shutters.
Key data for the CFRE are presented in Tables 2.1
and 2.2, and a flow sheet for the system is given
in Fig. 2.1. The maior components are shown
approximately to scole on the flow sheet, although
their arrangement relative to each other is purely
schematic. The more important plumbing and
wiring connections expected to be mode through
the reactor chamber wall and to auxilirrryequipment
are listed in Tables 2.3 and 2.4.
CFRE COMPONENT QEVELOPMENT PROJECTS
The projected design effort for the CFRE has
been tied closely to a comprehensive series of
component development projects. A list of these
projects as currently conceived is given in Table
2.5. It is fully expected that the need for ad-
ditional projects will develop as the program
evolves, but those listed should provide the most
important information required.
The first project was completed recently, and
the results are presented below; work on some of
the other projects is well under way. The test
of beryllium in contact with sodium and lnconel
under thermal stress was given high priority be-
cause the results were needed in the determination
of the amount of poison to be expected in the
reflector. With the amount of poison in the re-
5W. s. Farmer et al., Preliminary Design and Per-
jonnance o/ Sodiuni-tu-Air Radiators, OBNL-1509 (Aug.
3, 1953),
18
flectar known, the reactor critical mass, the core
size, the fuel concentration, etc. could be de-
termined. In the second test, which is well under
way, the hydrodynamics of the pump-volute, ple-
num-chamber, and core system are being studied.
Work on the same basic problem is also being done
by the Heat Transfer and Physical Properties
Group and by *he Pratt & Whitney Aircraft Di-
vision. It is hoped that the different approaches
of the three groups will lead to a thoroughly sound
solution. I he objective of the third project is to
produce a plastic model of a pump and header-tank
arrangement that will remove xenon from the fuel.
Data on the solubility of xenon in the fuel and on
the rate of production of xenon in the fuel are
being obtained by the Fuel Chemistry end Radi-
ation Damage groups; the data thus obtained will
provide a measure of the efficiency of xenon re-
moval by the pump. An in-pile test of a full-scale
pump may be required eventually. Xenon removal
by the pump is very important, from the control
standpoint; in addition, if it can be effected as
plonned, the bulk of the other volatile fission
products will also be removed. This will dispose
of a maior potential hazard in the event of a
reactor failure and should simplify the reactor
installation design problem.
The infotmation given in Table 2.5 for most
of the other component development projects is
largely self-explanatory. To expedite the work,
some of the projects can be undertaken by other
organizations; for example, another organization
might undertake the entire job of designing, de-
veloping, arnd fubricating the fill-and-drain system,
the fuel addition equipment, the control rod drive
mechanism, or the sample heat exchanger tube
bundle.
-
The last project listed, the Zero Power Unit
(ZPU), deserves special mention. Experience with
the ARE has demonstrated that many problems will
arise in the fabrication of the CFRE ond that there
will be a number of doubtful items, especially
welds, that could hardly be trusted in a high-power
reactor. This seems particularly true of the re-
actor core, heat exchanger, and pressure shell
assembly. If it is accepted that the first attempt
at fabricating the unit will leave much to be de-
sired, planning to use it os a hot mockup seems
to be more sensible than spending much time and
money trying to rework and patch it. It can be
endurance-tested at tenip2rature without developing