Core Design of 100MWe Advanced Nitride-fueled Simplified Liquid Metal Cooled Fast Reactor

Abstract

A preliminary core design of 100MWe Advanced Nitride-fueled Simplified (ANTS) Lead-bismuth cooled Fast Reactor (LFR) for civilian multi-cycle nuclear power plant has been investigated. The prime design constraint is on the core size with the active core diameter and height equal to 2.4 m and 1.0 m, respectively. The core is composed of 144 hexagonal fuel assemblies enclosed with 15-15Ti steel duct. The core adopts the onion zoning with the two zones of low-enriched uranium for a better breeding capability to maximize the core lifetime for long cycle operation. Neutronics calculation is performed by the fast reactor analysis code system Argonne Reactor Computation (ARC) and the UNIST in-house Monte Carlo code MCS. It is confirmed that the cycle length of more than 12 years with a small burnup reactivity swing of less than 1,000 pcm is feasible. Power profiles generated by MCS are employed for thermal-hydraulic (TH) analysis with three different mass flow rates depending on the core power to flatten to the fuel temperature distribution. The research designs a reactor that is capable of natural circulation at an inlet temperature of 300°C. The total mass flow rate of 13,700 kg/s produces an outlet temperature of 450°C. TH analysis also demonstrates that the fuel and cladding temperatures are within normal operating range. Furthermore, several reactivity feedback coefficients have been computed by MCS to confirm the initial safety features of the suggested LFR.