抄録
MAAP5(Modular Accident Analysis Program Rev. 5.0.0), developed by Fauske & Associates, Inc.'s (FAI) based on the MAAP4 code, is a severe accident analysis code. It is a computer program capable of simulating the response and mitigation actions of light water reactor nuclear power plants (NPPs), including advanced boiling water reactor (ABWR) during severe accident. The effectiveness of the execution of emergency operation procedures (EOPs) for an advanced boiling water reactor (ABWR) during postulated accident conditions using MAAP5 code is discuss in this paper. The simulation scenarios included the loss of feedwater pumps and turbine driven Core Isolation Cooling System (RCIC), the anticipated transient without scram (ATWS), and loss of reactor pressure vessel (RPV) water level indication. Based on the comparisons of responses on different parameters for cases with and without EOP actions, we concluded the RPV emergency depressurization (ED) in the EOP could effectively mitigate the consequences of the accident. The simulation clearly reveal that the execution of ED for the condition of RPV water level unknown could reduce primary containment pressure, suppression pool temperature, and avoid large fluctuation of RPV pressure, water level, and core power. For the RPV level unknown under ATWS condition, RPV ED can give the operator the easier way to control RPV pressure, and to assure adequate core cooling.
