Optimized core design of high converting pressure-tube type LWR

An optimization of conceptual nuclear design was done for a high-converting pressure-tube type light water cooled reactor (HCPLWR) with an once-through thorium cycle. Thorium blanket fuel bundle are designed to stay about 10 years within a light water cooled pressure tube, whereas uranium driver fuel bundles are to be refueled by on-power refueling mode with about 780 EFPD discharge burnup rate. Fuel rod bundles are configured in hexagonal lattice array in a similar size of those of CANDU. Fuel pin size is the same with conventional PWR rod, however but the radius of blanket rod is a little lager than that of conventional PWR. Sixteen core design options were tested and the optimum design option was sought for. The optimized core design has 1 to 3 volume ratio of driver channel and blanket channel, which shows a higher conversion ratio than conventional LWR. Driver channels are loaded with U-10%Zr alloy fuels (enriched with 15 w/o U-235) and blanket channels are loaded with new fuels, which consist of pyrocarbon-coated UCO particles (enriched with 5 w/o U-235) and pyrocarbon-coated ThO2 particles in a graphite matrix