Analysis of reusability of ThO2 and spent UO2 fuels enriched with ads in a CANDU reactor

Abstract

The study presents the analysis of the reusability of ThO2 and spent UO2 fuels enriched in two different ADS reactors fuelled with Minor Actinide. The spent UO2 fuels are taken out from pressurized water reactor and CANDU spent fuels. For this analysis, the CANDU-37 reactor having a total fission thermal power of 2156 MW is considered and 14 different cases of enriched fuels taken from the previous enrichment processes are analysed by burning in this reactor. The 3-D and time-dependent critical burnup calculations are carried out by using the MCNP 2.7 code. To determine the effective burn time of each case, these calculations are performed until the values of kinf decrease to about the criticality threshold of 1.05 for all investigated cases. The percent ages of the 239Pu and 233U fissile isotopes appear to be below weapons-grade plutonium and uranium, respectively, in all enriched fuel cases. At the end of effective burn times, the burnup values can reach the values varying in the range of 26.770 and 33.540 GWd/MTU which are a mean of 3.5-4.5 times the burnup value of the CANDU-37 reactor fed with the NatUO2 fuel. The results of this study bring out that in terms of energy production, the CANDU-37 reactor fuelled with the ThO2 and spent UO2 fuels enriched in ADS designs demonstrates higher neutronic performance than the conventional CANDU-37 reactor.