Core Designs and Economic Analyses of Homogeneous Thoria-Urania Fuel in Light Water Reactors

The objective is to develop equilibrium fuel cycle designs for a typical pressurized water reactor (PWR) loaded with homogeneously mixed uranium-thorium dioxide (ThO₂-UO₂) fuel and compare those designs with more conventional UO₂ designs.

The fuel cycle analyses indicate that ThO₂-UO₂ fuel cycles are technically feasible in modern PWRs. Both power peaking and soluble boron concentrations tend to be lower than in conventional UO₂ fuel cycles, and the burnable poison requirements are less.

However, the additional costs associated with the use of homogeneous ThO₂-UO₂ fuel in a PWR are significant, and extrapolation of the results gives no indication that further increases in burnup will make thoria-urania fuel economically competitive with the current UO₂ fuel used in light water reactors.