Neutronics design study of an advanced lead-cooled modular nuclear reactor (ALMANAR)

Abstract

A design of an advanced small modular reactor with long-life core is being studied in this paper. The core is designed to produce 45 MWth power with a lifetime of 20 years without refuelling. In order to achieve a compact design and have a good neutron economy, lead is considered as the coolant due to its excellent neutronics and thermo-physical properties. However, the lead coolant speed in the core is limited to 2 m/s to minimise the corrosion and erosion of the structural materials. On the other hand, U15N is used as the fuel which reflects excellent thermophysical properties and compatibility with lead. In this study, the neutronics properties of the core including the reactivity evolution during its lifetime, the control rod worth, and the fuel and coolant reactivity feedbacks are evaluated. It was found that ALMANAR could achieve a long-life core of about 22 effective full power years with very excellent inherent safety features. Monte Carlo Serpent code is used to perform the calculations in conjunction with the latest nuclear data library ENDF/B-VIII.0.