Patent ID: 6931090

Claim:
A method of establishing a nuclear reactor core loading pattern for loading fuel assemblies into a nuclear reactor, comprising the steps of: a. determining the reactivity of each fuel assembly; b. dividing the fuel assemblies into multiple batches of fuel assemblies of like coarse levels of reactivity; c. generating a plurality of parent loading patterns utilizing selected core load position constraints considering all fuel assemblies in each batch of fuel assemblies as having the same coarse level of reactivity; d. selecting from the plurality of parent loading patterns, selected parent loading patterns; e. dividing the multiple batches of fuel assemblies into a number of refined batches of fuel assemblies according to finer levels of reactivity; f. for each selected parent loading pattern, determining whether any daughter loading patterns of the refined batches of fuel assemblies meeting the specified core load position constraints satisfy specified engineering requirements, and if so, selecting an optimal daughter loading pattern optimally meeting the specified engineering requirements; g. eliminating any selected parent loading patterns for which no daughter loading pattern meets the specified engineering requirements; h. for each parent loading pattern with an optimal daughter loading pattern, updating the parent loading pattern with the optimal daughter loading pattern; i. repeating steps e-h with ever finer levels of reactivity until each batch of fuel assemblies comprises a single fuel assembly; and j. selecting from loading patterns remaining, a final loading pattern.