Thermal-hydraulic analysis of the thermoelectric space reactor power system with a potassium heat pipe radiator

The thermoelectric space reactor power system conceptual design incorporates fast reactor, liquid-lithium primary coolant loops that transfer heat to potassium-filled high temperature heat pipes and thermoelectric generators. An integrated system analysis model was developed to study the operating characteristics of the space power system, which consisted of reactor thermal-hydraulic model, neutron kinetics model, thermoelectric energy conversion assembly (ECA) model, heat pipe radiator model etc. One-dimensional thermal-hydraulic model was applied to model the coolant circuit. Quasi two-dimensional analysis models for heat transfer of fuel element, ECA and the heat pipe fin were established. Considering the thermoelectric conversion phenomena, an equivalent electric efficiency model was inserted in the ECA model. Both finite element method and thermal resistance network were applied to simulate the potassium heat pipe system. The normal operation condition and two demonstration accident scenarios (unprotected inadvertent movement of a sliding reflector and loss of heat pipes) were calculated to prove the capabilities of the new system model.