neutronic calculations of boron carbide coated nuclear fuels

A comparative study was performed on the behaviour of boron carbide and boron nitride coated low enriched fuel in a pressurized water reactor. A fuel element containing one burnable poison fuel pin per ten ordinary fuel pins was modeled with the computer code WIMS,and burnup dependent criticality, fissile isotope inventory and two dimensional power distribution were obtained. Calculations were performed for burnable poison fuels coated with 1μ and 5μ of boron carbide. Boron carbide coating gives the same performance as boron nitride coating at smaller thicknesses due to its higher density. No difference were observed in fissile isotope behaviour nor the value of power peaking