SPECTRAL DRIFT REACTOR COMPRISING ELEMENTS OF MOVEMENT OF WATER IN MATERIALS ABSORBING SLOW AND INTERMEDIATE NEUTRONS, FOR SELECTIVELY CHANGING THE VOLUME OF THE WATER-MODERATOR MIXTURE IN THE HEART OF THE REACTOR

摘要

The pressurized and spectral drift water reactor according to the present invention comprises an apparatus 38 for introducing and removing water displacement elements 40, 82 having different neutron absorption capacities to modify the reactivity of the core. The displacement elements 40, 82 comprise substantially cylindrical and hollow bars 40 absorbing slow neutrons and substantially cylindrical and hollow bars 82 made of thick-walled stainless steel. Because the stainless steel displacement bars have a higher neutron absorption capacity, each bar produces a greater change in reactivity. However, by having fewer stainless steel displacement bars 82 in a cluster, it is possible to obtain that the reactivity value of the cluster of stainless steel displacement bars is lower than that of a cluster of neutron absorbing displacement bars. slow.