Closed Thorium Cycles in the Pebble Bed HTR

摘要

For the pebble bed high temperature reactor an uranium/thorium closed fuel cycle Th/U is introduced which achieves the conversion ratio of 0.82 averaged over 30 years lifetime, and the fissile inventory of only 1270 kg/GW/sub e/. It allows minimum uranium ore requirement for some 2 generations. Secondly, a Th/U-prebreeder is introduced which produces U-233 for the installation of HTR-netbreeder fuel cycle inventories. The U-233 production per required U sub 3 O sub 8 is by a factor of 2.3 higher than the Pu production of a LWR for plutonium cycles. Thirdly, an alternative of the closed thorium cycle is introduced which meets the demands of non-proliferation. No weapons grade uranium appears anywhere in the cycle. The plutonium content of the reprocessed elements is strongly denatured by the even isotopes Pu-240 and Pu-242 and its quantity is extremely low. All three cycles are economic. The technological feasibility of the fuel elements is largely ensured by the THTR element test experience. The detailed features of the cycles are outlined as far as relevant for their assessment. 14 refs., 11 figs., 16 tabs. (ERA citation 11:029775)