| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for reducing an amount of radioactive substances from gravel or the like deposited with radioactive substances.SOLUTION: Gravel or the like deposited with radioactive substances is immersed in water for a certain period. The material deposited with radioactive substances and cloth such as cotton are then placed in newly prepared water so as to be agitated and rotated. This reduces the amount of radiation. The water for use may be passed through ion-exchange resin in a first step, and the water may be then passed through any one of tourmaline and igneous rock containing 65 to 76% silicon dioxide in first and then passed through the other one. |
