Concept design and neutronics analysis of a heat pipe cooled nuclear reactor with CERMET fuel

Special off-grid power generations require the energy system to be reliable and compact. The heat pipe cooled reactor (HPR) is passively safe and highly modular, and is well suitable for energy demands ranging from a few kW to several MW. This study proposes a compact HPR design in which the ceramic metal composite (CERMET) fuel is used (HPR-CF). The CERMET fuel has advantages such as high temperature resistance and thermal conductivity. The fuel assembly using the CERMET fuel contains 6 heat pipes and fuel blocks with the hexagonal prism shape. The HPR-CF consists of 36 CERMET fuel assemblies containing 216 lithium heat pipes, 12 control drums, 1 safety control rod and peripheral beryllium dioxide reflector, all of which are mounted in a reactor vessel. The Monte Carlo code RMC is used to calculate the neutronics characteristics. The excess reactivity of the HPR-CF reactor is sufficient for operating at high temperature and 3 MWt for over 3000 days. The power distribution and the criticality safety are calculated and discussed. The results show the neutronics availability of the HPR-CF design.