Monte Carlo calculations on transmutation of plutonium and minor actinides of pebble bed high temperature reactor

摘要

The paper aimed to maximize the fuel burnup performance of plutonium and minor actinides fueled pebble bed high temperature reactor (PBMR-400). The PBMR-400 was designed as a reference core. The neutronic calculations were performed by the code combination MCNP-ORIGEN-MONTEBURNS. In this study, neutronic performances of three different types of nuclear fuels (Reactor Grade Plutonium -RGPu; Weapon Grade Plutonium - WGPu and Minor Actinides - MAs) combined with natural uranium were conducted in a PBMR-400 full core. The neutronic performances were compared with the original uranium fuel designed for this reactor. Neutronic calculations showed that 9.6 wt % enriched uranium has a core effective multiplication factor (k_(eff)) of 1.2395. Corresponding to this k_(eff) values the natural UO_2/ RG-PuO_2; natural UO_2/WG-PuO_2 and natural UO_2/MAO_2 mixture were found 70%/30%, 76%/24% and 63%/ 37%, respectively. The operation times were computed as ～2000, ～2500 and 1400 days whereas, the corresponding burnup values were obtained as ～163 000, ～194 000 and ～116 000 MWD/T, respectively, for end of life k_(eff) set equal to 1.08.