Thermal-hydraulics and safety analyses of the Solid Core-Sectored Compact Reactor (SC-SCoRe) and power system

Highlights: • Performed safety and thermal hydraulics analyses of nuclear reactor for lunar surface power. • Integrated power system nominally supplies 38 kWe to lunar outpost. • Sectored core design and power system integration avoid single point failures. • Power system supplies 4 kWe to outpost, following a loss of coolant or cooling in a core sector. - Abstract: The paper presents results of thermal-hydraulics and safety analyses of the Solid Core-Sectored Compact Reactor (SC-SCoRe) and the power system that could nominally provide 38 kW_e continuously for ∼ 21 years to a lunar outpost. The power system employs static components and has no single point failures in reactor cooling and energy conversion. The monolithic-core reactor operates nominally at a thermal power of 1.0 MW_th and comprises six sectors cooled with circulating liquid NaK-56 at inlet and exit temperatures of 850 K and 900 K. The sectors that are neutronically and thermally coupled each has a separate pair of primary and secondary loops with thermoelectric (TE) powered electromagnetic pumps, a TE power conversion assembly, and heat-pipes radiator panels. Performed are 3-D thermal-hydraulics and safety analyses of the SC-SCoRe during nominal operation and following the unlikely event of a loss of coolant (LOC) or a loss of cooling (LOCo) in one of the reactor core sectors. Calculated results include the flow velocity and temperature fields in the core sectors, inlet and exit ducts and upper and lower plenums. Results demonstrate that with a core sector experiencing a LOC or a LOCo, the power system could continue to operate safely at a reduced reactor power of 323 kW_th, and generate four kW_e for critical life support functions at the lunar outpost.