Abstract

In this paper, the potential advantages of the thorium fuel cycle are assessed and discussed focusing on the neutronic parameters of the thorium fuelled-core during the irradiation and the consequences on the fuel cycle parameters after irradiation. Finally, an integration of thorium fuel based reactor to the actual Belgian nuclear fleet is analyzed. For the neutronic parameter assessment and the fuel cycle scenario study, typical Belgian PWRs are used with different thorium based fuels (Th-UOX, Th-MOX). The computational simulations are carried out with the JEFF-3.1.2 nuclear data and two SCK/CEN home developed computing codes: the ALEPH-2 code for burn-up calculations and the ANICCA code for fuel cycle analyses. For our study, we have compared 2 thorium fuel cycle scenarios against the reference UO2-MOX fuel cycle scenario. In the spent fuels, a decrease of plutonium (239Pu, 240Pu and 242Pu) production of and minor actinides (Am and Cm) generation is observed. Since the thorium fuel cycle generates more fissile nuclide (233U) during the operation, and so, a decrease of the reactivity loss per cycle is obtained, this phenomenon could be beneficial for the fuel cycle length in the sense that we could extend the time of fuel stay in the reactor to reach higher burn up. This leads to a reduction of the fuel required and also a reduction of the amount of plutonium at the end of cycle, however more minor actinides are generated