Pre-conceptual study of small modular PbBi-cooled nitride fuel reactor core characteristics

In this paper a pre-conceptual neutronics study on a small modular Pb-Bi cooled reactor with nitride fuel (SMoPN) is presented. The SMoPN is designed to meet the requirements for nuclear energy expansion in the next decades, by using the plutonium and thorium nitride fuel to increase the efficiency and performance of fuel. Based on the existing experiences of nuclear reactor, the primary design parameters were provided to match the design goals by the whole core three-dimensional calculation. The nitride fuel, stainless steel cladding and Pb-Bi coolant have a perfect compatibility with each other, as well as with excellent neutronics characteristics. High conversion ratios have been achieved to ensure 20 effective full power years (EFPYs) without refueling and shuffling. During the core lifetime, the burn-up swings slightly due to the perfect breeding capability. All of the important reactivity coefficients are negative to assure the SMoPN holding passive safety. The control system can provide enough shutdown margins in both normal and abnormal operational conditions. Therefore, the SMoPN concept satisfies completely the advanced design idea and the requirements of advanced nuclear reactor system.