| 摘要 |
PROBLEM TO BE SOLVED: To prevent the risk of the radiation exposure for workers engaged in maintenance, inspections and the like of radiation emission sources because a radiation shield, where concrete whose unit water content is made higher than that of usual concrete by adopting ordinary portland cement for general purposes as a binder is generally used as a material for a shield against radiation, gets induced radioactivity when such a radiation shield is exposed to neutrons. SOLUTION: Concrete for the radiation shield is obtained by mixing high alumina cement, fine and coarse aggregate consisting of electrofused alumina, a compound containing boron like colemanite and a water reducing agent and the like as needed and kneading them. The concrete for the radiation shield is excellent in its radiation shielding effect and can hardly be activated even though it is irradiated with radiation such as neutrons. COPYRIGHT: (C)2008,JPO&INPIT
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