Evaluation of source terms using the BESNA code for reference spent fuels for future underground disposal system of South Korea

In this work, the source-terms such as nuclide inventories, radioactivities, neutron and gamma spectra, and decay heats were evaluated using new code BESNA in which the burnup dependent one-group cross sections were evaluated based on MCNP6. This work started with the selection of the reference spent fuels through a statistical analysis of all the accumulated PWR spent fuels in South Korea for safety analysis of a geological repository, which led to the two reference spent fuels for each of 16x16 and 17x17 fuel assembly types considering representative low and high burnups. Finally, the source terms were evaluated using our inhouse code BESNA for the reference spent fuels, and they were compared with those from ORIGEN in SCALE6.2 for validation purposes. The results of the comparison showed that BESNA gives good agreements with ORIGEN for all the considered source terms.