Development of ex-vessel phenomena analysis model for multi-scenario simulation system, spectra

Uchibori, Akihiro ; Aoyagi, Mitsuhiro ; Takata, Takashi  ; Ohshima, Hiroyuki

The multi-scenario simulation system named SPECTRA has been developed for integrated analysis of in- and ex-vessel phenomena during a severe accident in sodium-cooled fast reactors. The base module computing ex-vessel compressible gas behavior by a lumped mass model and a sodium-concrete interaction module were verified through the basic analyses individually. A validity of the system including the base module and the individual physical module such as the sodium-concrete interaction module was confirmed through the analysis assuming sodium leakage from a reactor vessel and a primary cooling loop.