Experience with Keneur, a Monte Carlo perturbation program

The perturbation Monte Carlo method is now an established tool for the estimation of reactivity effects resulting from small changes to a reactor configuration. In this article we report results of small parameter changes such as the withdrawal of fuel elements or control rods in real 3-D geometries as they were proposed in a recent international benchmark exercice. Furthermore we compare a series of calculations of small reactivity changes for a D2O system with the corresponding measurements. Both types of comparison aim at illustrating the potential of the method in real design studies