ALPS: An advanced loading pattern search program

In-core fuel management continues to be affected by trends toward longer cycles, increased discharge burnup, increasingly complex fuel assembly features such as axial blankets and reduced-length burnable absorbers. Obtaining efficient core loading patterns which meet several, often conflicting, design criteria is becoming difficult to perform manually. To address this need, Westingouse has developed the Advanced Loading Pattern Search program, ALPS, a self-contained fuel management tool. The computer program establishes a variety of loading pattern candidates, based on the existing fuel inventory of spent and fresh fuel assemblies, and burnable absorber configurations defined by the user. The possible loading pattern candidates are established based on a reactivity distribution target and an appropriate matching of available fuel and burnable absorber configurations. An extensive search algorithm evaluates thousands of alternatives, and selects the candidates that meet specific design criteria. This search approach offers several advantages over conventional methods, as no specific knowledge and/or constraints are fixed in the algorithm. ALPS includes an innovative approach to take into account the reactivity effects of three-dimensional features. Such an approach permits accurate and fast representation of 3D features, using a two-dimensional core physics model. The software is now operational on a workstation computer, with an advanced graphical user interface of streamline input setup and output review. (author). 2 refs, 2 figs, 1 tab