Grant: Alliance Grants

There are about 600 SMR projects being developed around the world. Ontario Power Generation and SaskPower decided to select GE-Hitachi BWRX-300, for construction. This reactor will use very traditional Urania based fuel. ARC Clean Energy, Saint John, NB is currently developing a SMR with U-10Zr metallic fuel. Fuel selection and understanding of fuel performance is critical for safe operation of SMR nuclear reactors and there is already significant knowledge of Uranium based fuel in power generation nuclear plants. However, the operational conditions and fuel enrichment of new SMR reactor systems are different and there is a need for better understanding of the fuel performance in the SMR reactors that were selected to be built in Canada. The objective of this program is to understand what is a role of the operational conditions of both reactors on the fuel performance. In particular we plan to examine changes in structure, thermal conductivity, mechanical properties under different temperature and evaluate how fission products and irradiation damage will affect the thermo-mechanical properties. Overall objective of the project is to identify benefit of the replacement of the present fuels by ATF fuels to improve the safety and economy of operation of investigated SMR reactors. Calculations will be done using ub-initio codes based on density functional theory (DFT). However, due to the complexity of first principles-based methods for investigations of actinides we will also develop new machine-learning based interatomic potential to study the thermo-physical, interfacial, and radiation related properties of actinide systems. We will propose self-organization of structural defects as a tool for controlling materials degradation which has implications for understanding the migration of defects, ions, and fission gases. This part of the project is focused on understanding the superstructure-properties relationship to inform about the design of failure tolerant materials. Our theoretical investigation aims at predicting most relevant thermomechanical, physical and mechanical properties of the fuels used in Hitachi and ARC SMRs and compare these predictions with simulated characteristics of several accident tolerant fuels. The prediction will be verified by experiments we made for UO2 10%Mo and possibly the results obtained by our collaborator in INL Safety of the SMRs operation is of paramount importance and information obtained in our research might be used by the designer in the selection of the ATF fuels for next generation of SMRs.