Conceptual design of a mobile nuclear-electric hybrid energy storage system based on the heat pipe-cooled reactor.

• Combining the compactness and mobility of heat pipe reactors, a mobile nuclear-electric hybrid energy storage system based on the heat pipe-cooled reactor has been proposed for the first time. • The safety of the core under different reactor accident conditions is analysed based on a neutronics-thermal coupling analysis approach. • The design values of the energy storage system were systematically analysed for the target parameters. To achieve the goals of carbon emission peak and carbon neutrality, it is necessary to expand support for non-fossil energy sources. Heat pipe reactor (HPR) is a new reactor design concept that uses the efficient, passive thermal conductivity of heat pipes to cool nuclear fuel, which makes solid state HPR very suitable as a power source for mobile transport vehicles. However, it is also faced with the problem of frequent start-stop and variable output. In this paper, a conceptual design of nuclear power and energy storage coupled power system was proposed, using uranium nitride as fuel placed in a solid metal matrix, with the sodium heat pipe as the heat conduction device to remove heat from the core. The condenser of the heat pipe is connected to a dual-mode power generation system, comprising a thermoelectric generator and a Stirling generator. Additionally, a hybrid energy storage system, consisting of power battery packs and supercapacitors, is integrated to facilitate power output adjustment and energy storage. This comprehensive configuration enables the realization of a peak power output of 350 kW. Finally, the neutronics and thermal characteristics of the design were analyzed. Calculations showed that the radial power peak factor was 1.2396 and 1.4924 for the axial direction, it also showed the maximum core temperature to be 1269.6 K under steady state conditions with neutronics and thermal coupling, which is 16.54 % higher than before coupling. [ABSTRACT FROM AUTHOR]