TOKYO, June 19 (Xinhua) -- Very high radioactivity levels were detected in groundwater from an observation well at the crippled Fukushima Daiichi nuclear plant, said the plant operator Tokyo Electric Power Co. (TEPCO) Wednesday.
The level of strontium 90 in the water sampled on May 24 stood at 1,000 becquerels per liter, about 30 times as high as the maximum allowable standard, while the tritium level was at 500,000 becquerels, about eight times higher, said TEPCO.
The observation well was set up on the Pacific side of the plant's No. 2 reactor turbine building last December to find out the reasons why radioactivity levels in seawater near the plant remained high.
The company said the sampled water could be from the contaminated water that seeped into the ground.
TEPCO now plans to dig four more wells around the observation well to check the spread of radioactive contaminated water and improve the seawall to keep the dirty water from flowing into the sea, according to a local report.