Sensitivity analysis of the recycling process at the second stage of the PWR-ADS fuel cycle

A two-stage PWR-ADS fuel cycle is proposed as an option to transmute the minor actinides (MAs) from the PWR spent fuel in the ADS system. At the second stage, the spent fuel from ADS is reprocessed by the pyro-chemical process and the recovered actinides are mixed with the MAs from the PWR spent fuel to fabricate the new fuels used in ADS. The impacts of the cooling time before reprocessing the ADS spent fuel, the reprocessing loss during the pyro-chemical process and the source of MAs from spent UOX fuels with different discharge burnup or mixed MOX and UOX spent fuels on the system performance of ADS at equilibrium cycle are analyzed in this study. The numerical results indicate that longer cooling time leads to higher actinide inventory to achieve the same multiplication factor at the beginning of the equilibrium cycle but has little effect on the long term decay heat and radiotoxicity of fission products and non-recovered actinides sent to disposal; the reprocessing loss has neglectable impact on the core performance of ADS but determines the long term decay heat and radiotoxicity of fission products and non-recovered actinides sent to disposal; the discharge burnup of the spent PWR UOX fuel has small effect on the system performance of ADS, and ADS is flexible to transmute the MAs from the spent UOX fuels with different discharge burnup; the introduction of the MAs from the spent MOX fuels leads to higher reactivity swing and higher power peaking of the ADS system.