Sodium experiment on fully natural circulation systems for decay heat removal in Japan sodium-cooled fast reactor

Kamide, Hideki ; Kobayashi, Jun ; Ono, Ayako ; Kimura, Nobuyuki; Watanabe, Osamu*

Fully natural circulation system is adopted in a decay heat removal system (DHRS) of Japan sodium cooled fast reactor (JSFR). Sodium experiments were carried out for heat transfer characteristics of a sodium-sodium heat exchanger of PRACS and start-up transient of the DHRS loop with parameters of pressure loss coefficients in the loops. Influences of the pressure loss coefficient in the primary loop and the DHRS loop were limited on the core temperature and also heat removal of PRACS due to recovery of natural circulation head via the increase of temperature difference in each loop.