The Korea 150 MWe Prototype GEN-IV Sodium cooled Fast Reactor (PGSFR) project has reached the middle of its preliminary safety analysis report (PSAR) design phase. Core design studies are being conducted by KAERI. Some design features for the core have been made to comply with the PGSFR objectives.

The multi-discipline considered reactor core shutdown system was carried out. There are many considerations to consider when designing a reactor core shutdown system, which are the reactor hydraulics, safety analysis, structural and neutronics design viewpoints. This paper describes the control rod for the PGSFR core at the end of the PSAR phase and studies performed to optimize the performances. Focus is placed on innovations and specificities in the design compared with the PGSFR.

To determine whether the previous reactor shutdown system, it satisfies each design requirement through analysis or experimental methods. To provide diversity, these core shutdown systems are considered two types of control rod drive mechanism (CRDM), which are the primary and secondary control rod assemblies (CRA).