New MHI Safety Analysis Code Package for DBA (1) Overview of New MHI DBA Code Package

摘要

At PWR license in Japan after Fukushima daiichi accident, MHI has introduced an improved code package of safety analysis for Beyond Design Basis Accident (BDBA). Regarding safety analysis for Design Basis Event (DBE), including normal operation. abnormal transient and DBA, Mitsubishi group has also finished to develop an upgraded code package and to prepare for licensing application. This upgraded code package involves all parts of DBE analysis, consisting of fuel behavior and design, core design and evaluation for nuclear and thermal-hydraulics and safety evaluation covering Loss Of Coolant Accident (LOCA), Reactivity Initiated Accident (RIA), Steam Line Break Accident (SLBA) and other transient events. Each code of the developed package has interface, as described in this paper. The code package is expected to calculate new safety issues and to be applied for introduction of advanced core and fuel.