The tank leaked more than 300 tons of contaminated water in August. Some of it is believed to have poured into the sea via a ditch.Officials of the Tokyo Electric Power Company say that they detected 400,000 becquerels per liter of beta ray-emitting radioactive substances, including strontium, at the well on Thursday.
The level is 6500 times higher than the readings on the previous day.The well was dug to monitor the impact of the leakage and is located at about 10 meters from the tank.High levels of radioactive tritium, which tends to be transferred easily in water, had been already detected.TEPCO officials believe Thursday's findings show that radioactive substances such as strontium, which are transferred relatively slowly, have reached the ground water.
There is another well about 100 meters from the tank near the seaside. It's for pumping up groundwater before it seeps into the reactor building and vicinity so as to contain the increase of contaminated water.
TEPCO will remove the contaminated soil around the tank and continue to closely watch radioactivity levels of the groundwater at the monitoring well. Oct. 18, 2013 - Updated 00:48