ORNL-1771 - Oak Ridge National Laboratory

ANP QUARTERLY PROGRESS REPORT
approximately 1 /,6 in. It is concluded that no
problem will be encountered in the use of similarly
equipped motors in the ARE.
REACTOR SYSTEM COMPONENT TEST LOOP
Operation of Leap
W. 6. Cobb A. G. Grindell
Aircraft Reactor Engineering Division
D. 5. Trauger G. A. Kuipers
Technical Division, K-25
Operation of the reactor system component test
loop' Qt K-25 was temporarily halted after 1047 hr
of operation to remove one ARE core hairpin tube
for metallographic examination. Shutdown, tube
removal, tube replacement, and re-startup were
accomplished under a complete helium blanket to
prevent air from contaminating the fluoride mixture
or the inside of the lnconel system. An irradiated
V-belt that was installed, as described above,
after 875 hr of system operation ha5 operated for
more than 900 hr of the approximately 1800 hr
of system operation. Plugging of gas line con-
nections to the pump tank by ZrF4-vapor condensate
has occurred periodically. In some instances the
plugs have been removed by heating the gas line
involved and blowing the vaporized ZrF, back
into the pump tank. No completely satisfactory
solution to this problem has been found to date;
the use of a large-capacity vapor trap is being
studied as a possible solution.
8H. W. Savage ef al., ANP Qua. Prog. Rep. June 10,
1954, ORNL-1729, p 14.
16
Examination of Hairpin Tube
G. M. Adamson R. S. Crouse
Meta I I urgy Division
Metallographic examination of the hairpin tube
showed normal subsurface void attack. The maxi-
ilium penetration was to a depth of 5 mils. There-
fore it appears that corrosion from impurities will
not be a serious problem in the ARE. Since this
loop was not precleaned, the corrosive conditions
should have been worse than those in the ARE.
No information on the amount of corrosion that
may be expected from mass transfer could be
obtained because the loop is being operated iso-
thermally.
REACTOR PHYSICS
M. E. LaVerne
C. B. Mills
W. K. Ergen
R. R. Coveyou
Aircraft Reactor Engineering Division
R. Bate C. S. Burtnette
United States Air Force
The Eyewash code, developed by the ORNL
Mathematics Panel for use on the UNIVAC, yielded
the following results for the ARE: critical mass,
30 Ib of U235; UZ3' required to yield the 4% excess
reactivity needed for operation, 35 Ib; keff for
40 Ib of U235, 1.07; critical mass without controls,
safety, or instrument apparatus, 17 Ib (this emphasizes
the high cost of these materials); hk/(h~/~)=
0.232; temperature coefficient applicable to slow
temperature changes and due to expansion of the
whole reactor and to thermal base effects,
-4.3 x 10-5/0F; reactivity value of U235 in tube
bends at reactor ends, 0.006'in keff.