Optimization of reload core designs for pressurized water reactors

In-core nuclear fuel management concerns the arrangement of fissile and control materials within the reactor core over an operating cycle such that the greatest economic benefit is derived while satisfying operational constraints. With the improvements in computer technology of recent years, there has been renewed interest in automating the solution of the reload core design problem. Through cooperation with member utilities and nuclear fuel vendors of the North Carolina State University Electric Power Research Center, the computational capability to determine fuel and BP LPs via mathematical optimization has been developed. The FORMOSA-P code employs the random search technique of Simulated Annealing in examining tens of thousands of candidate LPs. The optimization produces not a single result, but multiple solutions ranked according to varying LP characteristics, such as the margin to thermal operating limits. The engineer is therefore afforded a number of different candidate solutions, statistically validated to lie in the vicinity of the optimum for one several objective functions including minimization of fresh fuel enrichment, minimization of radial power peaking factor, maximization of cycle length (for a fixed fuel enrichment), and maximization of region average discharge burnup.