SELECTION OF OBJECTIVE FUNCTIONS IN THE MULTI-OBJECTIVE FUEL MANAGEMENT OPTIMIZATION

Abstract

One of the most important problems in the in core fuel management optimization is to select a proper objective function. This becomes harder when one needs to use a multi-objective cost function. The most well-known method for implementation of multi-objective cost function (MOCF) is to convert a MOCF into summation of objective functions which are related through weighting factors. In a nuclear reactor, there are so many parameters which can be selected as cost function. Among them, cycle length, Keff and power peaking factor are of the most important ones. In addition to weighting factors, the way we formulate the cost function will affect the final result. In this investigation, we analyzed these effects on the fuel management optimization of a typical pressurized water reactor. The results show that finding a loading pattern which gives better power peaking factor is harder than that of longer cycle length. Moreover, using proposed formulation (flatting function) instead of just minimizing PPF can result in better arrangements.