Application of the inverse generalized perturbation theory to the optimization of fuel assembly design

• The method is useful to determine optimal parameters in multi-objective problems.
• The perturbation equations are exact and need only one calculation of the adjoints.
• Examples as the determination of the water density maximizing k-eff are presented.

Many methods have been proposed to optimize fuel assembly design, most of them based on metaheuristic techniques. The method presented here is based on the inverse perturbation theory. Parameters to be optimized are some isotope densities, such as Gd, 235U, 239Pu. The optimization is constrained to some target values of relevant reactor observables, such as the breeding ratio, the reactivity loss rate during the fuel cycle, the maximum reactivity, the spectral index. The method is fit to solve multi-objective problems. In the examples, 2 or 3 simultaneous objectives are determined.