抄録
Research and development activities for two-phase analysis codes for nuclear reactor design and safety analyses have been reviewed focusing in recent twenty five years. For reactor safety evaluation, large-scale tests were performed to confirm effectiveness of ECCS in 1980’s and 1990’s. These test results were succeeded to so-called best-estimate codes such as RELAP5 , TRAC codes. Severe accident researches were performed in 1980’s and 1990’s and accident management methods were studied. Detailed simulation methods such as subchannel analysis, multi-dimensional analyses have been developed based on test results and computational technology enhancement in 1990’s and 2000’s. Future scope is summarized briefly.
