A NEW MILP BASED LOADING PATTERN SEARCH TOOL

摘要

The Pearls? loading pattern search tool has generated reactor core loading patterns with significant fuel cycle cost benefits over the years. This mixed integer linear programming (MILP) based tool has worked well for so called standard loading pattern searches. A new tool (TNT) is under development at Westinghouse that will build on the success of Pearls and on the once through cross section capability of NEXUS but will remove the limitations of Pearls. This will again be a MILP based method. TNT will handle the full panoply of objective functions and constraints. All PWR currently used burnable absorbers will be included. One particularly difficult aspect of loading pattern search is the choosing of the feed pattern. Two very different feed patterns may yield near optimum loading patterns once all the other decisions are made. An unusual feature of this new tool is that it systematically and exhaustively analyzes all feed patterns within the MILP framework. The expectation is then that the final loading patterns will be global optima within the accuracy of the associated licensed reactor core neutron flux solver.