Operational characteristics of LWR core fuelled with thorium-based fuel

The characteristics of a Pressurised Water Reactor (PWR), considered representative Light Water reactor (LWR), operating on thorium-based fuel has been analysed. An equilibrium cycle of PWR consisting of 151 fuel as-semblies and having three-batch fuel management has been considered for the analysis. The two types of thorium-based fuels resulting from mixing LEU and plutonium with ThO2 and representative UO2 have been taken for the core loading and fuel cycle study. The reactivity coefficients, kinetic parameters over the equi-librium cycle have similar trend for three fuel types considered. The control inventory with the natural boron in B4C and in dissolved boric acid is sufficient for the safe operational reactivity control and shutdown in all three alternatives. We find that enriched UO2 based fuel in conventional PWRs can be successfully replaced with ThO2 with Plutonium or LEU as fissile feed. Such approach is useful in initiating thorium as nuclear fuel which will support other diverse approaches requiring design and dimension changes for the utilization of thorium.