Design Feasible Area on Water Cooled Thorium Breeder Reactor in Equilibrium States

Thorium as supplied fuel has good candidate for fuel material if it is converted into fissile material 233U which shows superior characteristics in the thermal region. The Shippingport reactor used 233U-Th fuel system, and the molten salt breeder reactor (MSBR) project showed that breeding is possible in a thermal spectrum. In the present study, feasibility of water cooled thorium breeder reactor is investigated. The key properties such as flux, η value, criticality and breeding performances are evaluated for different moderator to fuel ratios (MFR) and burn-ups. The results show the feasibility of breeding for different MFR and burn-ups. The required 233U enrichment is about 2% - 9% as charge fuel. The lower MFR and the higher enrichment of 233U are preferable to improve the average burn-up; however the design feasible window is shrunk. This core shows the design feasible window especially in relation to MFR with negative void reactivity coefficient. (authors)