A record 264,000 becquerels of radioactive cesium per liter has been detected in groundwater at the Fukushima No. 1 nuclear power station, Tokyo Electric Power Co. disclosed Saturday.
The sample was taken Thursday from an observation well near reactor 2 reactor of the plant, which was destroyed by the March 2011 quake and tsunami.
According to Tepco, recent heavy rains pushed up the levels of groundwater, causing it to reach soil containing highly radioactive water leaked earlier from the plant’s crippled reactors.
The per liter level of cesium-137 rose to 200,000 becquerels from 190,000 becquerels in groundwater sampled from the same well on Wednesday. The cesium-134 level was unchanged at 64,000 becquerels.
Tepco is dumping within the plant’s premises water containing less than 15 becquerels of cesium-134 and less than 25 becquerels of cesium-137.