Study on the accident characteristics of heat pipe reactors under reactivity insertion accident using different thermoelectric conversion systems

[Background]: The heat pipe reactor (HPR) is characterized by inherent safety and a compact structure, making it widely applicable. The thermoelectric conversion system (TEC) is a key system in the HPR that converts thermal energy to electrical energy. Its form and operational principles significantly impact the accident safety characteristics and dynamic response of the HPR.[Purpose]: Based on the self-developed analysis code TAPIRS-D for HPR systems, which has already incorporate stirling cycle and semiconductor thermoelectric conversion system, this paper developed a new dynamic thermoelectric conversion modules which is open Brayton cycle.[Methods]: Combined with the reactor design of SAIRS-C, this paper carried out research on the accident safety characteristics of different thermoelectric conversion systems for HPR systems.[Results]: The research results showed that, under the same accident conditions involving the introduction of reactivity, the calculation results indicated that the reactor using the Stirling conversion system had the smallest change in core power after an accident while the temperature rise of the Stirling machine's hot end was relatively high.[Conclusions]: On the aspect of output power, the output power of open Brayton cycle and thermoelectric conversion system had a similar variation change, which are both larger than that of stirling conversion system. On the aspect of cycle effieiceny change, heat pipe reactor system coupling with semiconductor thermoelectric conversion system has the largest cycle efficiency gain. However, special attention should be pay on the circuit load of semiconductor thermoelectric conversion systemu nder reactivity insertion accident.