An estimated 5.3 tons of water contaminated with radiation leaked from a pipe in a building housing cesium removal equipment at the stricken Fukushima No. 1 nuclear power plant, the facility's operator said.
The leaked water contained 383,000 becquerels of radioactive cesium per liter and 480,000 becquerels of beta ray-emitting radioactive substances per liter.
Tokyo Electric Power Co. said March 23 the water has not flowed outside the high temperature incinerator building. TEPCO said it was in the process of pumping up the water for storage.
The utility said workers doing remodeling work earlier in the day cut off a pipe inside the incinerator building. When workers subsequently operated radioactive material removal equipment in another building, contaminated water leaked from the cut section of the pipe to the floor of the incinerator building.
TEPCO said it is trying to determine the cause of the incident, adding that workers had confirmed that they closed a valve before cutting off the pipe to prevent water leakage.