RESEARCH ON THE UTILITY OF MAAP AT THE ACCIDENT TRANSIENTS

抄録

After Fukushima nuclear accident, there are higher demands and requests for the development of severe accident analysis software since the nuclear regulatory agencies set more stringent and specific rules of the nuclear power plant (NPP) in severe accident emergency and training. This research introduces an initialization and coupling method, which captures and continues an accident transient by MAAP5.03 code. Integrated with the existing full-scope simulator (FSS), the implementation of severe accident simulation can be extended through the method. Thus the FSS can perform more abundant and complete accident scenes in the personnel training and accident drills. Moreover this method provides us a predictive way to the NPP operating state or accident processes by limited parameters, together with the accident detection and diagnostic analysis procedures. To ensure MAAP’s calculation effectively recognizing and following the transient tendency, the architecture of MAAP was analyzed and a set of simulation parameters were selected. The comparative results of the steady state and a LBLOCA accident state for 3rd generation passive NPP were performed and some specific quantitative assessments was defined to verify the functionalities derived from the initialization and coupling method. We also examined the prediction and evaluation of accident management for the plant under the MSLB conditions. The results show MAAP can adequately capture and smoothly continue the accident transient state. And also it demonstrates the feasibility to externally revise the severe accident analysis programs for extensively simulating and analyzing demands for the NPPs.