Officials from the Japanese nuclear power plant devastated by a 2011 earthquake and tsunami reported 300 tons of highly radioactive water has leaked from a storage tank.
A spokesman at Fukushima Daiichi's plant operator, Tokyo Electric Power Company, told reporters that much of the contaminated water had seeped into the soil and could eventually reach the ocean. Workers were placing sandbags around the leak site to prevent the spread of water, made more urgent by the forecast for heavy rain in the Fukushima region.
"We believe it is still leaking at this moment," TEPCO General Manager Masayuji Ono said at a news conference Tuesday.
The leak is the worst incident at the plant since the 2011 disaster.
Ono added that workers were pumping water out of the ground and transferring it to a storage container to reduce the risk of contaminants seeping into the ocean. The Associated Press reported they had only captured about four tons of contaminated water by Tuesday afternoon.
Russia Today reported the contaminated water contains 80 million becquerels of radiation per liter, more than 500,000 times the norm of 150 becquerels per liter.
Workers discovered puddles of radioactive water near one of the site's 1,000 tanks on Monday. A further investigation revealed the 1,000-ton capacity tank, thought to be nearly full, was only about 700 tons full, reported the New York Times.
Japan's nuclear regulator has suggested constructing an underground ice wall around the plant to prevent further seawater contamination. TEPCO's plans to use an elaborate filtration system to slowly leak low-level contaminated water into the ocean have been delayed by technical difficulties and protests by local fishermen, according to the Times.
Fukushima Daiichi is no stranger to problems following the 2011 disaster. On April 5, an effort to put up nets to keep rats out of the plant caused a cooling system failure for the second time in a month. The next day, officials reported about 120 tons of radioactive water may have leaked from a storage tank.
On Aug. 7, Reuters reported an estimated 300 tons of contaminated water was leaking into the ocean daily from Fukushima Daiichi.
Japan's Nuclear Regulation Authority classified the leak as a level one incident, the second lowest on the International Nuclear Event Scale.
The massive earthquake and tsunami that struck Japan in March 2011, causing a series of nuclear meltdowns, equipment failures and radioactive release, was rated at level seven, on par with the 1986 Chernobyl accident. The severity of an event increases by about 10 times for each rating, according to the INES. They are the only two incidents to reach the INES' maximum rating.