Official: Radioactive water leaking into sea through crack in concrete - 2nd Apr 2011

Power plant workers began filling a cracked concrete shaft with fresh cement to stop highly radioactive water from earthquake-damaged nuclear reactors from draining into the Pacific Ocean, Japanese regulators said Saturday.

Water from the 2-meter deep, concrete-lined basin could be seen escaping into the ocean through a roughly 20-cm (8-inch) crack, the Tokyo Electric Power Company told reporters Saturday afternoon. Electrical conduits run upward through the space, which lies behind the turbine plant of the No. 2 reactor at the Fukushima Daiichi nuclear plant.

Work to fill the shaft with concrete began Saturday, and it was only partly completed Saturday evening, said Hidehiko Nishiyama, a spokesman for Japan's Nuclear and Industrial Safety Agency.

Radiation levels in the shaft have been measured over 1,000 millisieverts per hour, which is more than 330 times the dose an average resident of an industrialized country naturally receives in a year. Radioactivity above the shaft was measured at 250 millisieverts per hour, said Tokyo Electric, the plant's owner. Read More