処理水放出の影響「極めて軽微」　福島第１、環境評価を公表―東電

　東京電力福島第１原発から出る放射性物質トリチウムを含んだ処理水について、東電は１７日、海洋放出した場合の環境や人への影響について「極めて軽微」とする評価結果をまとめた。今後、国際原子力機関（ＩＡＥＡ）の専門家や一般から意見を募り、内容を踏まえ評価を見直していくとしている。
　評価では、海水で１００倍以上に希釈した処理水を、トンネルを通じて発電所の沖合約１キロの海底から放出する計画を想定。ＩＡＥＡなどが定める手法を使って人への影響などをシミュレーションした。
　年間１２０日漁業に従事する人が海水などから受ける放射線量を調べた結果、厳しい条件を設定した場合でも、一般人の被ばく限度である年間１ミリシーベルトの２０００分の１から５００分の１程度にとどまるとした。
　放出した処理水の拡散状況も分析。年間を通じてみると、発電所の周囲２～３キロの海域で濃度が高いが、それ以外では通常の海水に含まれるトリチウム濃度とほぼ同じになったという。（2021/11/17-18:58）

Tokyo Electric Power Company Holdings Inc. has said that treated radioactive water planned to be released from its crippled Fukushima No. 1 nuclear plant into the sea would have "minimal" impacts on the environment and human health.
   The assessment was announced Wednesday. TEPCO simulated the impacts by employing a method adopted by organizations including the International Atomic Energy Agency, on the assumption that the treated water, which still contains tritium, a radioactive material, is released from the seabed about 1 kilometer from the plant in Fukushima Prefecture, northeastern Japan, through a tunnel after being diluted by seawater at least 100 times.
   The company said that it will review the assessment if needed after soliciting opinions from IAEA experts and members of the public. The Fukushima No. 1 power station was heavily damaged in the March 2011 earthquake and tsunami.
   After the water is released into the ocean, the amount of radiation exposure for a fisher going out to sea for 120 days a year would be limited at one-2,000th to one-500th of 1 millisievert even when the dosage is measured under strict conditions, TEPCO said. An annual dose of 1 millisievert is considered to be an acceptable limit for a person.
   TEPCO also studied how the treated water will spread in the ocean, finding that annual tritium levels would be higher in areas 2 to 3 kilometers from the plant but would be normal in other areas.