Study on evaluation method of decay heat removal of pool-type sodium-cooled fast reactor

Ezure, Toshiki ; Kobayashi, Jun ; Matsuno, Keiko*; Tanaka, Masaaki 

In the design of the demonstration tank-type sodium-cooled fast reactor, an evaluation method for decay heat removal including under natural circulation conditions have developed as one of the key R&D issues in the conceptual design phase. For the demonstration reactor, installation of Intermediate Reactor Auxiliary Cooling System (IRACS) as one of decay removal system is considered as one of the diversified decay heat removal systems to enhance the safety. This paper focuses on thermal stratification in the hot plenum during the decay heat removal using IRACS and presents the results of PLANDTL-2 experiments conducted with consideration of similarity laws to the demonstration reactor.