Study for 228Th reduction in thermal reactor with Th-U fuel cycls

By using computercode WIMS/CENDL, the effects of some parameters, core configuration such as fuel element structure, neutron flux and burn-up, are discussed in thispaper. It is shown that high neutron flux, small fuel rod diameter,large volume ratio of coolant to fuel, seed-blank heterogeneous corearrangement and ²³¹Pa chemical separation are necessary for reducing ²²⁸Th production in reactor.