Structure of radiation shielding body

Purpose: To attain a uniform shielding effect of lead powder added to silicon resin material irrespective of localized mixing state. Constitution: In a radiation shielding body for openings such as pipeways and ducts disposed within a nuclear power plant, silicon resin materials with a high hydrogen content capable of neutron shielding and lead powder capable of gamma-ray shielding are combined into a block form. Accordingly, when the silicon resin material and the lead powder are combined are injected alternately in a partitioned layer-like manner into a support frame for the shielding body, gamma-rays and neutrons can completely be shielded to attain shielding effects. Further, a fire proof performance can also be provided by covering the outside of the silicon resin materials. Furthermore, by incorporating the silicon resin material and the lead powder in the support frame for the shielding body, the material cost can be reduced. (Yoshihara, H.)