Fuel cycle scheme design and evaluation for thorium-uranium breeding recycle in CANDU reactors

摘要

This work is aimed to develop a fuel cycle scheme for thorium-uranium breeding recycle in CANDU reactors. According to the neutronics theory on the breeding of fissile nuclides in nuclear fuel system, the prerequisite of Th-232-U-233 breeding is revealed in CANDU fuel system and a roadmap of thorium-uranium breeding recycle in CANDU reactors is promoted. Following the roadmap, the thorium-based fuel cores were designed and the neutronics performance was evaluated. A CANDU-6 core with rated thermal power of 2061 MW was taken as the reference core. Based on the fuel management strategy, the spent-fuel characteristics for employed fuel types were assessed, including radiotoxicity, decay heat and gamma rays. Finally, the thorium-uranium breeding recycle schemes were established and evaluated in contrast with natural uranium once-through cycle, widely applied in operational CANDU reactors. The design and evaluation results indicated that the Th-U breeding recycle is technically feasible in current CANDU reactors. (C) 2016 Elsevier Ltd. All rights reserved.