The prospect of gas cooled fast reactors for long life reactors with natural uranium as fuel cycle input

Gas cooled fast reactors are among the Generation 4 nuclear power plants (NPPs) with hard neutron spectrum characteristics which can be utilized to create power reactors with high breeding/conversion ratio capability. In this study the gas cooled reactor system is combined with modified CANDLE burn-up scheme to create long life fast reactors with natural uranium as fuel cycle input. Such a system can utilize natural uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. Therefore, by using this type of nuclear power plants optimum nuclear energy utilization, including in developing countries, can be easily obtained without the problem of nuclear proliferation. In this paper, a design study of 800 MWt long-life gas cooled fast reactors with natural uranium as fuel cycle input has been performed. Due to the thermal hydraulic constraints, the average power density of the proposed design is limited to 70 W/cc. The system has excellent performance and is at least comparable to that of Pb–Bi cooled system. The average discharge burn-up is about 258 GWd/ton HM.

► A gas cooled fast reactor with natural uranium as fuel cycle input is discussed.
► Such a system can eliminate the necessity of uranium enrichment plant.
► In addition, this reactor can burn natural uranium up to 25.8% HM.
► Such a system will facilitate effective utilization of natural uranium resource.
► Long life of 10 years of refueling interval is also good for system availability.