Tepco inspection shows no further radioactive leaks from tanks

Tokyo Electric Power Co. (9501), grappling with the worst radioactive spill since the March 2011 nuclear disaster, said an inspection of storage tanks at its wrecked Fukushima plant showed no further leaks of irradiated water.

The inspection of about 300 tanks similar in design to the unit that leaked contaminated water this week did reveal two separate radiation hotspots near adjacent tanks, which the company can’t yet explain.

“At the moment, we don’t know why radiation was detected,” said Hiroki Kawamata, a spokesman for the utility known as Tepco. He said there wasn’t any water found in the areas showing high radiation levels.

The inspection comes after Tepco said on Aug. 20 that 300 tons of contaminated water had leaked into the soil from a tank used to store water pumped from under the plant’s damaged reactors. Japan’s nuclear regulator yesterday rated the accident as a 3 on the 7-stage International Nuclear and Radiological Event Scale or INES, denoting a “serious incident.”

The absence of further leaks allays some of the fears surrounding the spill. Nuclear Regulation Authority Chairman Shunichi Tanaka called the possibility of other leaky tanks “the biggest concern” at a press conference yesterday.

Tepco stores about 400 tons of water a day at the plant after using it to cool the reactors that melted down as a result of the March 2011 earthquake and tsunami. There are more than 1,000 tanks on site holding 330,000 tons of water as of Aug. 13.