Optimization of nuclear reactor reloading patterns

The loading pattern of fuel bundles in a reactor core determines the characteristics of the reloading cycle. The problem of maximizing fuel utilization during a cycle may be formulated as a nonlinear mixed integer programming problem, but has until now mostly been treated by heuristic optimization methods like simulated annealing. This paper evaluates the performance of state-of-the-art nonlinear programming routines on a simplified model of this problem, and compares results with available heuristic solutions.