39o: Thermoelectric Heat Exchangers for Nuclear Reactors

The domestic energy sector is preparing to begin deploying a new generation of nuclear power plants in the next decade. New technologies are needed to substantially improve the capabilities and performance costs of this fleet of small, modular nuclear reactors. These technologies should also decrease the operational or capital costs of employing nuclear energy while also being safe, simple, and adaptable to various systems or conditions. The development of an emerging thermoelectric heat exchanger technology is being proposed to meet these goals and objectives. The small, modular nuclear reactors are designed with a coolant loop that transfers thermal energy from the nuclear fuel to water vaporization, which generates electricity with a steam turbine. All of the contemporary reactor designs include several large, high temperature gradient heat transfers. A thermoelectric heat exchanger directly generates electricity from the transfer of heat from hot to cold sources. This collection of additional electricity from one or more steps as the heat is transferred from fuel to steam generation will significantly increase the overall plant power output and energy efficiency. The contemporary small, modular reactor designs have at least one point where a thermoelectric heat exchanger can be cost-effectively integrated without significantly affecting the overall design or capitol costs. The significant increases in efficiency and net electricity generated, however, will significantly decrease the costs of electricity generation. The proposed thermoelectric heat exchanger technology is based a recent, novel thermoelectric generator design that overcomes the conventional limitations in heat-to-electricity conversion efficiency as well as the ability to conduct heat. The semiconductor materials conventionally used in thermoelectric generators simply cannot conduct heat fast enough to be applied in compact heat exchangers, steam generators, or condensers. The proposed thermoelectric heat exchanger technology, however, is composed of highly conductive, standard metallic thermocouple materials. These standard thermocouple materials can achieve extraordinary energy conversion efficiencies when integrated with this unconventional thermoelectric module design. The proposed project will develop the innovative manufacturing approach required to achieve the unconventional design features as well as the modeling tools required for performance optimization. Since the standard metallic thermocouple materials are commercially available and rated for relevant operational conditions, no new materials are required for technology development and the thermoelectric heat exchangers will be ready for deployment before the year 2030.