21 Décembre 2013
December 20, 2013
Radioactive cesium detected in deeper groundwater
Tokyo Electric Power Company says radioactive substances have been detected in water samples taken from deep underground at the crippled Fukushima Daiichi nuclear power plant.
Highly radioactive substances had been detected in previous months in shallow groundwater that was found to be leaking into the ocean.
But for the first time in December, TEPCO investigators detected radioactivity in groundwater taken from a layer 25 meters beneath the No. 4 reactor's well facing the ocean.
In a water sample taken on Tuesday of last week, 6.7 becquerels per liter of Cesium 137 and 89 becquerels per liter of strontium and other beta ray-emitting radioactive substances were detected.
TEPCO officials say radioactive substances may have been mistakenly mixed during the process of getting the sample.
But they are concerned that if contamination of deeper layers of groundwater is confirmed, it could be another source that is leaking into the ocean. The inspectors plan a further examination.
Meanwhile, at the No. 2 reactor, the density of beta ray-emitting radioactivity in groundwater has been rising since November. On Thursday