Mesures de laplaciens par la methode du remplacement progressif

The quest for competitive power from nuclear reactors requires an accurate knowledge of neutron balance with varying geometrical and physical lattice parameters. A great number of critical experiments with good relative accuracy are therefore needed.

The progressive replacement method described hereafter is particularly well suited to this objective, as it is a differential method. It is much cheaper and quicker than the usual critical experiment, but has comparable accuracy.

It is shown in the first part of the paper how this method has been applied to heavy water lattices in the critical facility ‘Aquilon’ and in the second part to graphite lattices during start-up experiments of the G1 and G2 reactors in Marcoule.