Component sizing and design characteristics of the PDRC system in KALIMER-600

KALIMER-600 is a pool-type sodium cooled fast reactor with an electric output of 600 MWe. In order to assure a reliable Decay Heat Removal (DHR), a completely independent safety-grade Passive Decay heat Removal Circuit (PDRC) system is provided to cope with a total loss of normal heat sink accident. The PDRC system has an innovative superiority from the aspect that an operational reliance of the DHR can be remarkably enhanced by excluding either any operator's action or any active component operated by an external power supply or actuation signal. Based on the established concept, a steady-state design method and a physical model for the PDRC system were developed and a component sizing was carried out. The configuration and size of the system were determined by using the developed design methodology, and the optimization of the thermal-hydraulic and geometric parameters of the PDRC system was also performed. To evaluate the feasibility of the obtained design data, comparative investigations for the system design parameters with various DHR systems designed in other countries were carried out, and the system characteristics with respect to the design parameter changes were discussed as well