Tokyo Electric Power Co (TEPCO), the All Japan newsese company that operates Fukushima nuclear power plant, said on Tuesday that the density of radioactive cesium in groundwater by the sea at the plant is around 90 times higher compared to three days ago.
The groundwater sample collected from an observation well located close to the Pacific Ocean contained 9,000 becquerels of cesium-134 per liter and 18,000 becquerels of cesium-137 per liter, TEPCO’s officials say. The reason for the sudden rise in toxicity is unknown.
“Mud that has absorbed radioactive cesium may have got mixed with the water. We will measure the (contamination level of the) water again,” a TEPCO official said according to Kyodo news agency.
TEPCO announced last month that it has detected radioactive cesium in groundwater samples taken from the premises of the crippled nuclear complex.
At that time the company’s officials changed their mind, reversing a previous statement that any contamination was negligible.
The company has tried to make an understanding with the local fishermen over the dumping in the Pacific Ocean of groundwater that has been pumped out from wells at the site. TEPCO previously announced that concentrations of radioactive substances are low enough for the groundwater to be dumped into the ocean.