A Probabilistic Description of Overpower and Loss of Flow Events and Their Impact on Limiter Temperature

Abstract

A probabilistic description of limiter temperature following overpower and loss of flow events is presented. This description includes both the frequency of the event, and the resultant temperature rise before shutdown occurs. It is found that the LOCA, and overheating of a limiter sector due to flow cutoff, are the most severe transients. The total loss of flow transient also has the potential to be severe, and is dependent on the coolant loop design. Finally, the dominant contributor to transient frequency is found to be the partial loss of flow transient.