The plutonium produced during the operation of commercial power plants and made available from the dismantlement of nuclear weapons needs to be properly managed. One important contribution to the management process consists in validating the calculation methods and nuclear data used for the prediction of power in MOX-fuelled systems. A series of theoretical physics benchmarks and multiple recycling issues of various MOX-fuelled systems have been studied by the NEA. This led to many improvements and clarifications in nuclear data libraries and calculation methods. The final validation requires linking those findings to data from experiments. Hence, the first experiment-based benchmark using the two-dimensional VENUS-2 MOX core measurement data was launched in May 1999.
This report provides an analysis of the results supplied by 12 participants from 10 countries. The comparison of the latest nuclear data libraries and of different calculation methods - including stochastic Monte Carlo and deterministic transport/diffusion methods - is presented. The report will be of particular interest to reactor physicists and designers as well as to nuclear power plant utilities.