Detectability of pump/diagrid link rupture in pool-type sodium-cooled fast reactor

小野田 雄一; 内田 昌人*; 時崎 美奈子*; 岡崎 仁*

Nuclear Technology, 20 Pages, 2025/00

https://doi.org/10.1080/00295450.2025.2462367

The safety analyses were carried out to confirm the sufficiency of the function of the safety protection system against the pump/diagrid link rupture. The target plant is a pool-type sodium-cooled fast reactor (SFR) of about 600 MWe class equipped with an axially heterogeneous core currently under development in Japan. In the pool-type SFR, the primary system piping connects the primary pump and the high-pressure sodium plenum located at the inlet of fuel sub-assemblies and is called "pump/diagrid link." In order to confirm the detectability of the pump/diagrid link rupture by safety protection system signals, a series of analyses of the guillotine break for a pump/diagrid link was carried out. The sufficiency of the function of the safety protection system against the pump/diagrid link rupture was confirmed by whether or not the development target of the system in a pool-type SFR in Japan is satisfied. The target is that at least two kinds of signals are transmitted for the detection of the event.