Preliminary Core Design for Long-life Small Modular LFR

Abstract

A preliminary design of a long-life Small Modular Liquid-metal Fast Reactor (SMLFR) cooled by Lead-Bismuth Eutectic (LBE) was developed for power reactors. The main design constraint on this reactor is a size constraint: the core should be small enough so that i) it can be carried on board of nuclear icebreakers and provide power to those vessels or ii) it can be transported in a Spent Nuclear Fuel (SNF) cask and meet the electricity demand in remote areas and off grid locations. The reactor was designed to achieve a thermal power of 37.5 MW with an assumption of 40% thermal efficiency. Uranium Nitride (UN) fuel is adopted for this reactor. It is confirmed through depletion calculations with the fast reactor analysis code system Argonne Reactor Computation (ARC) that the designed reactor can be operated for 27 years without refueling. Furthermore, core performance characteristics using the inhouse Monte Carlo code MCS were analyzed for criticality, isotopic inventory, and radial and axial power profiles. The SMLFR core is also evaluated in view of various significant safety parameters, including control rod worth, fuel temperature coefficient, and coolant void reactivity.