Station blackout simulation model for a BWR plant

This paper presents the results of a station blackout transient analysis for the Hope Creek boiling water reactor (BWR). The analysis has been performed using the MOD2 version of the best-estimate code RELAP5 on a Cyber 932 under the NOS/VE operating system. Whereas the RELAP5 code is primary a pressurized water reactor simulation code, new modeling features introduced into the MOD2 version, particularly the jet-mixer model, has allowed the authors to effectively simulate the jet pumps in BWR systems. The station blackout transient, unless otherwise stated, assumes and takes credit for normal functioning of plant instrumentation and controls, plant protection, and reactor protection system. In their analysis, three cases with different plant states and protection availabilities have been considered: (1) reference case: no steam dump, three banks of S/R valves available, the reactor coolant inventory control (RCIC) and high pressure core injection (HPCI) systems not operative; (2) steam dump: 25% steam dump, three banks of S/R valves available, the RCIC and HPCI systems not operative; and (3) HPCI system on: no steam dump, three banks of S/R valves available, the HPCI and HPCS systems operative