VIP, an international programme of benchmark experiments for the study of Mixed oxides-fuelled cores

In the frame of two international programmes, in which Belgian Japanese and UK contractors were involved, a series of benchmarks experiments have been conducted in Venus, a pool-type critical facility built and operated by Belgian nuclear centre. Typical PWR and BWR assembly configurations were modelled, with and without mixed oxides fuel, and with a moderator density reduced to 73% or 51% of its nominal value. Axial buckling and detailed (pin-to-pin) fission density distributions were measured, and a few other parameters were investigated (spectral indices, reactivity effects of water level variations, ...). These experimental results are the reference for calibration of theoretical analyses performed by each partner in order to validate, and possibly improve, their theoretical predictions and studies for the power reactors. This paper includes the comparison of a few Belgian computational results with the corresponding experimental result. (authors). 5 figs., 1 tab