Cj. Choi et H. Nakamura, RELAP5 MOD3 ANALYSIS OF A ROSA-IV/LSTF LOSS-OF-RHR EXPERIMENT WITH A 5-PERCENT COLD LEG BREAK/, Annals of nuclear energy, 24(4), 1997, pp. 275-285
An analysis was performed using the RELAPS/MOD3 version 3.1.2 code for
a loss of residual heat removal event during midloop operation after
reactor shutdown in a Westinghouse-type pressurized water reactor. An
event during a main coolant pump shaft seal removal operation was anal
yzed using the data of a ROSA-IV LSTF experiment that simulated the ev
ent with a 5% cold leg break. The predicted time when boiling started
in the core and the peak primary system pressure showed good agreement
s with the measured data. The late loop seal clearing, however, was ca
lculated because the steam condensation in the U-tubes started early.
A large mass error appeared in the transient calculations because of n
umerical truncation errors. The influence of the mass error was insign
ificant on the primary pressure prediction in this analysis. Copyright
(C) 1996 Elsevier Science Ltd