Environmental monitoring techniques after Fukushima Accident

福島事故後の環境モニタリング技術

植頭 康裕; 江尻 明; 依田 朋之

Uezu, Yasuhiro; Ejiri, Akira; Yoda, Tomoyuki

東日本大震災を経験し、当時の環境モニタリングでの問題点(モニタリングカーの検出器の測定範囲が越えてしまったこと、Ge半導体検出器が汚染したこと、4歳未満の小児の内部被ばくができなかったこと)が生じたが、それらの改善点を報告し、新たな時代の環境モニタリング技術を提案する。

The Great East Japan Earthquake occurred on 11th March 2011. The Tsunami attacked the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co. As a result, electric power was lost, furthermore electronic power generators were broken. After failing to restore power, there was an explosion and a large amount of radionuclides were released to the atmosphere. Japan Atomic Energy Agency (JAEA) monitored air dose rates, radionuclides in the air and environmental samples. At that time, there were many problems in the environmental radiation monitoring. The dose was beyond the range of the air dose monitor in monitoring car. The Ge detector's iron and lead shields were contaminated by the air. No standard source as "the phantom" could be obtained for children under 4. The JAEA solved these problems by developing new monitoring techniques. In this presentation, these improvements are shown and proposed as a new generation environmental radiation monitoring technique.