Preliminary Assessment of the Loss of Flow Accident for PGSFR

TRACE code have being considered as a candidate tool for SFR audit calculation for licensing review since 2012. On the basis of modeling and precalculation experience for the Demonstration Sodium cooled Fast Reactor (DSFR-600), TRACE code model for PGSFR was developed this year. In this paper, one of representing Design Base Event (DBE), Loss of Flow (LOF) accident was pre-calculated and Locked Rotor (LR) case was compared with LOF case since it could be a possible limiting case for LOF representing DBE. Sensitivity calculation for the LR case was implemented for identifying major parameters for the scenario. For the preparation of the review of licensing application for PGSFR, TRACE model for the PGSFR was developed and the loss of flow accident was precalculated. The locked pump rotor case was also calculated as a possible bounding case for the loss of flow scenario. Pre-calculation showed that the locked rotor case was similar or worst case to the loss of flow accident. Therefore, the locked rotor case should take into account in design base accident assessment of PGSFR. Sensitivity calculations for the rocked rotor case also studied for identification of unfixed design parameters influencing to estimation of inner surface temperature. Sensitivity result showed that the first temperature peak was largely influenced by reactor trip delay and second peak mostly influenced by pump coast down characteristic