Criticality risk lies in the nuclear facilities and transport packaging since significant quantities of fissile materials are implemented during operations of manufacture, storage, transport or reprocessing. Prevention of this risk first relies on the evaluation of the under-criticality margins of any equipment containing fissile material in casual and accidental conditions. Within this framework, the purpose of the computer codes for qualification (or experimental validation) is to determine skews of calculations associated with a particular configuration.

The qualification relies on the comparison between computation results and experimental values. The variations observed are interpreted and then transposed to the real configurations to study. Thus, the experimental base used for the qualification of the computer codes, must be the most representative of all the situations met during the fuel cycle.

Qualification base Design

Experiments retained for the qualification base result from a methodical analysis of available benchmarks in the literature. The main criteria is to select representative experiments. Indeed, the goal is to obtain a very extent qualification base covering a maximum fuel cycle configurations. Thus, influence of various parameters such as the isotopic composition, the moderation ratio, the heart geometry, the presence or not of various types of reflectors or various poisons will be studied,... Experiments to qualify specificities of a material or a precise nuclide could also be retained.

The table below presents the experiments retained for CRISTAL V1 qualification and sums up the V1 CRISTAL calculation chain qualification state.

Update on May, the 20^th of 2005.