Sept. 29 (UPI) -- Radioactive contamination may have been leaking from Japan's paralyzed nuclear plant in Fukushima, and the water could have been seeping out for months.
The Asahi Shimbun reported Tokyo Electric Power confirmed Thursday nuclear reactors 1 to 4 at the Fukushima site have been leaking contaminated water, owing to erroneous settings on water gauges.
The error caused groundwater levels to sink at nearby wells to 3 feet below required safety levels, Sky News reported Friday.
The drop in groundwater levels then may have caused radioactive water to leak into the surrounding soil in May, and the leak was discovered this week, according to Tepco.
Tepco spokesman Shinichi Nakakuki said soil samples did not register abnormal levels of radioactivity and "leaks to the outside are unlikely," according to Sky News.
Tepco has struggled to contain the growing volume of contaminated water at the damaged Fukushima plant.
About 100 to 400 tons of contaminated water is being generated daily because of continued flow of groundwater from outside the site.
Tepco's solution has been to use wells, 40 in total, to pump the groundwater away from the reactor's basements.
The report of radiation leaks come at a time residents in Iwaki, Fukushima Prefecture, are holding radiation inspections of local seafood products in a bid to assure the public the food is safe for consumption.
Japanese magazine Nikkei Business reported the seafood sampled at the inspection site is "safe" and fish caught in an area about 6 miles from the nuclear plant contained radioactive Cesium-137, at an activity of 6.3 becquerels per kilogram.
The level of radioactive substance did not exceed the standard, the magazine reported.
Cesium-137 has a half-life of 30 years and was released during the Chernobyl disaster in 1986.