ORNL-4191 - the Molten Salt Energy Technologies Web Site

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Fig. 1.10. East Side of Heat Exchanger Showing Heater Box HX-1 ond the Cocked Spacer on the Right.
thermocouple readings have been reliable, but
there have been a relatively few cases when there
have been shifts in thermocouple readings that
have resulted in calculation errors.
Temperature Disturbance in Reactor Cell. - Dur-
ing run 11, a shift upward of a reactor cell ambient
thermocouple was noted. This upward shift,
which occurred on only one of ten ambient couples,
took place the day after reaching maximum power.
A rather extensive inv tion revealed that
several other thermoco were affected at the
same time, all in the area between the fuel pump
and the heat exchanger.
Many tests were performed to determine the
cause of this temperature d urbance, but none
gave any conclusive answers. This area was
viewed with closed-circuit television during the
run 11 shutdown in May and June. The only ab-
normality noted which might have caused this in-
crease was a cocked heater spacer between
heaters HX-1 and HX-2 on the heat exchanger.
This spacer is shown in Fig. 1.10, a photograph
of the television screen. It was concluded that
cocked spacer, which was viewed only after
the fuel system was drained and cooled, was an
indication of an even larger opening which existed
during operation.
Fuel Salt Afterheat
At the conclusion of run 11 power operation, an
experiment was run to determine the amount of
fission product afterheat in the fuel salt. Power
operation of run 11 was terminated by a rod and
load scram from full power, and the temperature