Improved PWR Core Characteristics with Thorium-containing Fuel

摘要: Thorium is an element for possible use as nuclear fuel, because of the fertile property Th-232, which could convert into U-233 after neutron capture and beta decays. However, thorium based fuels have not been successfully implemented, high cost higher complexity compared with once-through uranium fuel. Therefore, focus this thesis on in traditional light water reactors improving core characteristics by: achieving a more homogenous power distribution to provide larger thermal margins, plutonium incineration efficiency reduce stockpile, improved load-following capacity. The chosen methodology similar one commonly used industry. The model Ringhals-3 PWR, Studsvik Scandpower Ltd. codes are calculate neutronics fuel reactor cores. The divided three parts. first part addresses absorber concept, achieved by adding small amounts pellets improve margins. benefits reduced need burnable absorbers, slower decrease reactivity function burnup. The second describes thorium-plutonium mixed oxide since barely generates any new uranium-plutonium cores alter behavior such stronger Doppler feedback lower fraction delayed neutrons, require boron (B-10) enrichment, increased number control rods efficiency. The third focusing capacity thorium-containing Th-232 has about times absorption cross section U-238, hardens spectrum. This leads less sensitivity spectrum changes, xenon poisoning, axial fluctuations upon load changes. capacity, be positive complement intermittent sources, solar or wind power.