DECONTAMINATION TREATMENT METHOD OF RADIOACTIVE SUBSTANCE ADSORBENT, AND DECONTAMINATION TREATMENT APPARATUS FOR RADIOACTIVE CONTAMINATED WATER

• Main Authors: MAKITA NORIO, SHIOZAWA YASUSHI
• Format: Patent
• Language: English; Japanese
• Published: 12.03.2015
• Subjects: DECONTAMINATION ARRANGEMENTS THEREFOR; MEASUREMENT OF NUCLEAR OR X-RADIATION; MEASURING; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; PHYSICS; PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULARRADIATION OR PARTICLE BOMBARDMENT; TESTING; TREATING RADIOACTIVELY CONTAMINATED MATERIAL

PROBLEM TO BE SOLVED: To propose a new method for determining replacement time of a radioactive substance adsorbent, that is capable of properly determining replacement time of a radioactive substance adsorbent.SOLUTION: A method for determining replacement time of a radioactive substance adsorbent is provided for a decontamination treatment apparatus for radioactive contaminated water that includes: a radioactive substance adsorbent filling part which is filled with a radioactive substance adsorbent; and a configuration for allowing water conduction of treated water in a specified direction inside the radioactive substance adsorbent filling part in order to decontaminate the treated water. The method for determining replacement time of the radioactive substance adsorbent includes the steps of: measuring a radiation surface dose rate at a position at an appropriate interval in a water conduction direction of the treated water, in an outer peripheral part of the radioactive substance adsorbent filling part; and obtaining a value correlated to a radioactive substance concentration of treatment water or a value correlated to a radioactive substance concentration of the radioactive substance adsorbent filled into the radioactive substance adsorbent filling part, on the basis of the obtained radiation surface dose rate. In the method for determining replacement time of the radioactive substance adsorbent, these values are used as the basis for determining whether or not to replace the filled adsorbent. 【課題】放射性物質吸着剤の交換時期を的確に判断することができる、新たな放射性物質吸着剤の交換時期の判断方法を提案する。【解決手段】放射性物質吸着剤を充填した放射性物質吸着剤充填部を備え、当該放射性物質吸着剤充填部内に被処理水を一定方向に通水させて該被処理水を除染する構成を備えた放射能汚染水の除染処理装置における放射性物質吸着剤の交換時期の判断方法であって、放射性物質吸着剤充填部の外周部において、被処理水の通水方向に適宜間隔をおいた位置にて放射線表面線量率を測定し、得られた放射線表面線量率に基づいて処理水の放射性物質濃度と相関する値又は放射性物質吸着剤充填部に充填された放射性物質吸着剤の放射性物質濃度と相関する値を求め、これらの値に基づいて充填吸着剤を交換するか否かを判断することを提案する。【選択図】図１