A neutron moderating and absorbing slab

The slab for neutron moderation and capture is made of a resin filled with a neutron absorber and reinforced with a glass or metal fabric or with honeycomb elements. For increasing its resistance the slab can be jacketed with a protective corrosion-proof foil, and for increasing its moderating effect it can be coated with a layer of a neutron-moderating material. The resin is radiation-curable, and although it is partly destroyed by gamma radiation during its performance, 60-65 % of its mass remains in the system. The protective jacket, which also prevents the slab from disintegration during performance, must not be hermetic because the resin decomposition products are gaseous. As compared with conventional moderating slabs, this slab can contain neutron absorbers in higher quantities, and it is usable in corrosive media and in media with high gamma levels. (P.A.)