A comparison of fission product behavior for typical PLWR and PHWR with FCVS operation

Highlights: • FP behaviors of SBO sequence were compared for OPR-1000 and CANDU6 NPP. • Case studies were conducted depending on the assumed operation condition of the FCVS. • MAAP and ISAAC codes were used for the OPR-100 and CANDU6 plants, respectively. - Abstract: Since the accident at the Fukushima Dai-ichi nuclear facility, a severe accident source term analysis has been recognized as a very important research area for accident management and emergency planning. In this paper, the fission product behaviors of a severe accident sequence were analyzed for a typical pressurized light water reactor (PLWR) and a pressurized heavy water reactor (PHWR). The OPR-1000 and CANDU6 were selected as the reference plants. A station blackout scenario, in which all off-site power is lost and the diesel generators fail, is simulated as the initiating event of a severe accident sequence. The results obtained are for (1) the fission product release from the reactor core, (2) the fission product distributions in the reactor coolant system, molten corium, reactor vessel, or containment building, (3) the fission product release from the containment building, and (4) the comparative characteristics of the fission product source term depending on the operation conditions of a filtered containment vent system.