Geometric Optimization of Nuclear Reactor Cores

Abstract

Traditional designs of nuclear reactor cores, both for power and research reactors, rely on expert judgment and good practices with sound theoretical and experimental backgrounds. There are, however, come cases in which the decision of which design is the best for a certain application that cannot be easily answered and an engineering design optimization scheme ought to be applied. This work addresses some simple problems in which geometric parameters should be chosen in such a way to optimize a certain objective function —for example the location of irradiation chambers or boron injection nozzles— in order to understand how the different minimization algorithms works. The objective function to optimize may refer to performance such as maximize the neutron flux at a certain location, to economics for example to reduce as much as possible the construction and/or operations costs, or to a certain combination of both aspects. In particular, only two-dimensional few-group core-level problems are described in this article, because they are simple enough to be well understood and analyzed yet at the same time they maintain the basic physics and some of the geometric complexities found in full three-dimensional cases. The methodology developed for optimizing the simple problems addressed in this work can be extended to handle real cases of interest for the nuclear industry.