Comparative Assessment of Thermal and Radiation Characteristics of Fresh and Spent REMIX Fuel of Different Designs

The existing structure of the Russian (and world) nuclear power system is based on reactors with the thermal spectrum of neutrons. It is sufficiently provided with resources and fuel fabrication facilities and focused on the operation in the open nuclear fuel cycle. However, the development of nuclear energy industry on such a basis leads to exhaustion of natural uranium resources and accumulation of spent nuclear fuel which in its term leads to economic burden for utilities. In this situation the development of technologies of spent nuclear fuel management and radioactive waste treatment is the key factor for sustainable development of the entire energy system. The aim of this work is to estimate thermal and radiation characteristics of fresh and spent REMIX fuel of different designs. Authors selected technological scenarios and developed physical models to analyse options of application of REMIX fuel for closing nuclear fuel cycle in a nuclear power system based on LWRs. Thermal and radiation characteristics were estimated in terms of recycling of regenerated nuclear materials after SNF reprocessing: activity, heat release, intensity and spectrum of neutron and gamma radiation, dose rates. Selection of the limits (content of even uranium isotopes, spent fuel heat release) of applicability of the REMIX technology in the context of current transport and technological opportunities is carried out.