As they inspected an underground storage pool near the crippled Fukushima Daiichi nuclear power plant earlier this month, Tokyo Electric Power Co. President Naomi Hirose (4th from left) and other officials wore protective suits and masks. Radioactive water stored in some of the pits has leaked. Tokyo Electric Power Co./Reuters /Landov hide caption

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Care managers tend elderly people in March 2012 in Minamisoma, Japan. The home's residents were evacuated eight days after the Fukushima Dai-ichi nuclear power station was crippled by the March 11, 2011 tsunami. Koji Sasahara/AP hide caption

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Smoke rises from Unit No. 3 of the stricken Fukushima Dai-ichi nuclear plant after the March 11, 2011 earthquake and tsunami. Anonymous/AP hide caption

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This photo, taken by a remote-controlled endoscope and released by Tokyo Electric Power Co., shows structures assumed to be small size piping or cable conduit inside the beaker-shaped containment vessel of No. 2 reactor at the damaged Fukushima Dai-ichi nuclear power plant. Tepco/AP hide caption

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Workers in protective suits and masks wait to enter the emergency operation center at the crippled Fukushima Dai-ichi nuclear power station on Nov. 12, 2011. David Guttenfelder /AFP/Getty Images hide caption

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Japan's Parliamentary Secretary for the Cabinet Office Yasuhiro Sonoda drinks a glass of decontaminated water taken from puddles inside the buildings housing reactors 5 and 6 at the Fukushima No. 1 plant.

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The tsunami flows over sea walls towards TEPCO's Fukushima Daiichi nuclear power plant on March 11, 2011. This photo was taken by Tokyo Electric Power Company. TEPCO/AFP/Getty Images hide caption

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A levee protects a home surrounded by floodwater from the Yazoo River near Vicksburg, Mississippi on May 18, 2011. Scott Olson/Getty Images hide caption

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