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

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