Development and application of methodologies for source term analysis

Maruyama, Yu ; Ishikawa, Jun ; Zheng, X. ; Kido, Kentaro ; Matsumoto, Toshinori ; Shiotsu, Hiroyuki  ; Ito, Hiroto; Tamaki, Hitoshi 

An integral code system for severe accident analysis in light water reactors, THALES2/KICHE, has been developed at Japan Atomic Energy Agency (JAEA). The core melt progression and the transportation of radioactive materials within reactor coolant system (RCS) and containment vessel (CV) are analyzed with THALES2 code in conjunction with KICHE code for the iodine reaction kinetics in aqueous phase. The applications of THALES2/KICHE code have been made in various analytical studies for severe accident progression, including analyses for the accident at the Fukushima Daiichi Nuclear Power Plant (1F) in order to obtain technical knowledge on the source term into the environment and the core damage state.