Out-of-core fuel management optimization utilizing the integer linear programming technique

Nuclear fuel management decisions for light water reactors can be categorized as out-of-core and in-core decisions. Out-of-core decisions concern what fuel and burnable absorbers to place in the core and in-core decisions concern where to place them. This paper reports on an automated capability to determine the optimum values of out-of-core fuel management decisions. The objective is to determine the optimum cycling scheme so that the levelized fuel cycle cost over a planning horizon is minimized without violating any constraints. The cycle energy requirements are assumed known. By discharging the least reactive fuel at the end of each cycle, the burned assemblies to reinsert are determined. Selecting the number of fresh assemblies as the decision variables, the enrichments of these assemblies are uniquely specified by the cycle energy requirements. Constraints considered include maximum enrichment and discharge burnup limits. In addition, to assure quarter-core symmetry, the number of fresh assemblies is constrained to multiples of four