The Supercritical CO2 Heat Removal System - Status and Outlook

Abstract

The supercritical CO2 heat removal system is a very innovative reactor heat removal concept as it improves the safety of both currently operating and future BWRs and PWRs through a self-propellant, self-sustaining and self-launching, highly compact cooling system powered by an integrated Brayton-cycle using supercritical carbon dioxide (sCO2) as its working fluid. Since this system is powered by the decay heat itself, it provides new ways to deal with beyond design accidents. The turbine of a Brayton-cycle provides more energy than necessary to drive the compressor, which means that the sCO2-HeRo system provides electricity in addition. Therefore, this system can be an excellent backup cooling system for the reactor core in case of a Fukushima-like scenario, with a combined station blackout (SBO), loss of ultimate heat sink (LUHS) and loss of emergency cooling. In addition, this system might also be used as a heat removal system for the reactor in hot stand-by condition, removing the decay heat by keeping the reactor pressure vessel at operation temperature and pressure. The system is developed within a EU funded project called Supercritical CO2 Heat Removal System, sCO2-HeRo. The objective of this project is to build a small-size demonstrator and install it at the PWR glass model at GfS in Essen, Germany. By means of this down-scaled demonstration unit, important operational data will be gained to demonstrate the feasibility of this heat removal system.