EPA時事
福島第一原発では9月16日正午ごろ、台風18号の接近に伴う大雨の影響で汚染水タンク周辺の囲いにたまった水を、排水溝を通して海に放出した。放射性物質ストロンチウムの濃度が、海への排出基準を十分に下回っているというのが理由だ。急激な水位上昇を受けた「緊急措置」として、セシウムの濃度を測らず排水した。時事ドットコムでは「汚染水への懸念が高まる中、批判を招く可能性もある」と報じている。
NHKニュースの報道によると、台風18号の接近で雨や風が強まり、山側に設置された汚染水をためたタンクの囲いでは、中の水の量が急速に増え、周囲にあふれ出る恐れが出てきたという。
今回排水したのは300トンの汚染水が漏れたエリアの南側。時事ドットコムでは、エリア内にたまっていた水は、ストロンチウムなどのベータ線を出す放射性物質の濃度は、1リットル当たり9ベクレルだったと東電の発表を伝えている。この結果をもとに、同社ではエリア内での汚染水漏れはないと判断。ガンマ線を出すセシウムの濃度も十分低いと予想できるとして、測定せずに排水した。
東電はHPで以下のように説明している。
台風の接近に伴う降雨により、堰内に多量の雨水が溜まっている下記のエリアについて、放射能濃度（全ベータ）が、ストロンチウム90の告示濃度限度(30Bq/L）より低い値となっており、堰内の溜まり水は雨水であることを確認したことから、緊急措置として当該堰内に溜まった雨水を堰外に排水しています。
関連記事
台風18号が列島横断【2013年9月16日】
(01 of19)
epa03869480 Strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, damages a woman\'s umbrella in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and will bring heavy rains. Special warnings are issued in western and central Japan. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(02 of19)
epa03869481 Strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, damages a woman\'s umbrella in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and will bring heavy rains. Special warnings are issued in western and central Japan. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(03 of19)
epa03869482 Strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, damages a woman\'s umbrella in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and will bring heavy rains. Special warnings are issued in western and central Japan. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(04 of19)
epa03869483 A woman holding an umbrella broken by strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and will bring heavy rains. Special warnings are issued in western and central Japan. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(05 of19)
epa03869485 Strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, damages an umbrella in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and will bring heavy rains. Special warnings are issued in western and central Japan. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(06 of19)
epa03869491 Pedestrians hold umbrellas broken by strong wind caused by Typhoon Man-yi, which is approaching to Japanese capital of Tokyo, in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and bring many flood of rivers. Special warnings are issued in western and central Japan2 EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(07 of19)
epa03869500 People clean up after water left a flooded street of Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bullet-train services were temporarily suspended in centr \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(08 of19)
epa03869501 People walk through a flooded street of Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bullet-train services were temporarily suspended in central and wester \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(09 of19)
epa03869502 A police officer deploys a \'keep-out\' tape on the flooded riverbed of the Katsura river in Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bullet-train servic \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(10 of19)
epa03869504 A flooded playground is seen on the riverbed of the Katsura river in Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bullet-train services were temporarily su \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(11 of19)
epa03869505 A police officer and a city worker deploy a \'keep-out\' tape on the flooded riverbed of the Katsura river in Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bu \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(12 of19)
epa03869506 A \'keep-out\' tape is seen on the flooded riverbed of the Katsura river in Kyoto city\'s Arashiyama district, Kyoto Prefecture, western Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. Man-Yi made landfall in central Japan at around 8 am as the agency warned residents to expect flooding, mudslides and high waves in western, central and eastern Japan. Bullet-train services were temporari \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(13 of19)
epa03869507 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and bring many flood of rivers. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa Rivier EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(14 of19)
epa03869508 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon Man-yi, 18th typhoon of the season, is running from western through eastern Japan and bring many flood of rivers. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa Rivier EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(15 of19)
epa03869510 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa River. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(16 of19)
epa03869510 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa River. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(17 of19)
epa03869511 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa River. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(18 of19)
epa03869512 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa River. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
(19 of19)
epa03869513 Passengers are waiting for restart of Tokaido Shinkansen bullet train over Mishima Station at JR Tokyo shinkansen station in Tokyo, Japan, 16 September 2013. Typhoon \'Man-Yi\', the 18th typhoon of the season, is crossing Japan bringing heavy rains and strong winds to wide areas of the country. The Tokaido Sinkansen bullet train is suspending over Mishima station for Nagoya, central Japan and Osaka, western Japan for hours due to flood warning on Fujigawa River. EPA/KIMIMASA MAYAMA \n\n撮影日： 2013/09/16 (credit:EPA＝時事)
福島原発 地下汚染水の視察
福島原発・福島第１原発を茂木経産相が視察(01 of12)
1、2号機の海側で行われている、地下汚染水の対策現場を視察する茂木敏充経産相（中央）＝8月26日午後2時45分、福島県大熊町の東京電力福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・視察する廃炉安全監視協議会(02 of12)
放射能汚染水漏れを受け、東京電力福島第１原子力発電所を視察する廃炉安全監視協議会のメンバー＝4月24日午後、福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・福島第1原発を茂木経産相が視察(03 of12)
汚染水の漏えいが見つかったタンク（正面）周辺を視察する茂木敏充経済産業相（右）＝8月26日午後、福島県大熊町の東京電力福島第1原子力発電所［代表撮影］ (credit:時事通信社)
福島原発・説明を受ける廃炉安全監視協議会のメンバー(04 of12)
放射能汚染水漏れがあった東京電力福島第１原子力発電所の配管について、東電の担当者から説明を受ける廃炉安全監視協議会のメンバー＝4月24日午後、福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・福島第１原発を茂木経産相が視察 (05 of12)
1、2号機の海側で、地下汚染水の対策現場を視察する茂木敏充経産相（右手前）ら。中央の円柱状のものは遮水壁＝8月26日午後2時41分、福島県大熊町の東京電力福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・第１原発敷地内の汚染水タンク(06 of12)
東京電力福島第1原子力発電所の敷地内に立ち並ぶ汚染水タンク（手前）＝3月5日（時事通信社チャーター機より撮影） (credit:時事通信社)
福島原発・敷地内に並ぶ汚染水を貯蔵するタンク(07 of12)
敷地内に並ぶ汚染水を貯蔵するタンク＝3月1日午後0時6分、福島県大熊町［代表撮影］ (credit:時事通信社)
福島原発・敷地内に並ぶ汚染水を貯蔵する大型タンク(08 of12)
敷地内に並ぶ汚染水を貯蔵する大型タンク＝3月1日午後0時24分、福島県大熊町［代表撮影］ \n (credit:時事通信社)
福島原発・海側で行われている地下汚染水の対策(09 of12)
1、2号機の海側で行われている地下汚染水の対策。手前は地下水のくみ上げ設備。中央奥に遮水壁がある＝8月26日午後2時49分、福島県大熊町の東京電力福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・下汚染水の対策現場で地下水のくみ上げを行っている設備 (10 of12)
1・2号機の海側で行われている、地下汚染水の対策現場で、地下水のくみ上げを行っている設備＝8月26日午後2時48分、福島県大熊町の東京電力福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・汚染水を入れるＧ６タンク増設エリア(11 of12)
汚染水を入れるG6タンク増設エリア＝6月11日午前11時28分、福島県大熊町の福島第1原発［代表撮影］ (credit:時事通信社)
福島原発・汚染水流出防止の護岸工事 (12 of12)
汚染水の海洋流出防止のため、東京電力福島第1原発2号機の取水口付近で行われている護岸の地盤改良工事＝22日午後7時［代表撮影］ (credit:時事通信社)