Thorium Based Fuel Performance Modelling and the Development of the Multi-pellet Material Fuel and Sheath Modelling Tool (MPM-FAST)

Abstract

A path for achieving greater sustainability in the nuclear power production industry would be to develop thorium based fuel cycles. The Canadian Super-Critical Water cooled Reactor (SCWR) concept is using this route to achieve the sustainability requirement of the Gen-IV Forum (GIF). However the study of Th-based fuel irradiation behaviour is less advanced than that of UO₂ fuel. With the majority of studies focused on (Th,U)O₂, and very limited work examining the (Th,Pu)O₂fuel type proposed in the SCWR project.

The Fuel and Sheath Modelling Tool (FAST), a fuel performance model for CANDU UO₂ fuel was developed at the Royal Military College of Canada (RMCC). Its capabilities could be extended to includeThO₂,(Th,U)O₂ and (Th,Pu)O₂ as fuel pellet materials and potentially be used as a tool to aid in the design and performance assessment of Th-based fuels, including the SCWR (Th,Pu)O₂ fuel.

The development of the (Th,U)O₂ and (Th,Pu)O₂ models that were added to FAST to produce the Multi-Pellet Material Fuel and Sheath Modelling Tool (MPM-FAST) was performed in co- operation with Canadian Nuclear Laboratories (CNL). Presented below is an outline of the (Th,U)O₂ and (Th,Pu)O₂ models as well as modelling results from MPM-FAST compared to the Post Irradiation Examination (PIE) data from two CANDU fuel like experimental irradiation tests (DME-221 and BDL-422) conducted at Chalk River Laboratories (CRL).