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 burn up 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 thresh old 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.