Super-Deep-Burn with the FCM (Fully Ceramic Microencapsulated) TRU Fuel in CANDU

Abstract

For sustainable development of the nuclear energy, the spent fuel should be appropriately dealt with and one of the potential approaches is to transmute the TRUs (transuranics) in nuclear reactors. In this paper, transmutation of the PWR TRUs in the CANDU reactor has been studied from the reactor physics point of view. The extremely high neutron economy of the CANDU reactor results in a very high burnup of TRU fuels in CANDU and integrity of the highly burned fuel element is an open problem. In this work, a special nuclear fuel called FCM (Fully Ceramic Microencapsulated) is introduced to achieve a super-deep-burn of the TRUs. In the FCM fuel, the conventional TRISO particle fuels are randomly dispersed in a SiC matrix and it is expected that it can accommodate an extremely high burnup. The core performances and characteristics were analyzed with the fuel lattice analysis. The fuel depletion calculations were conducted by using the Monte Carlo method and the fuel discharge burnup was determined based on the non-linear reactivity theory. We evaluated the major safety parameters of the FCM-loaded core, which includes the fuel temperature coefficient, void reactivity, coolant temperature coefficient.