Tokyo Electric Power Co (9501). has found levels of radioactivity in groundwater at its crippled Fukushima nuclear station at levels 244 times those considered safe for an atomic plant.
The utility known as Tepco detected cesium 137 levels of 22,000 becquerels per liter at a monitoring well in its turbine complex at the Dai-Ichi plant yesterday, it said in a statement today. Japan’s nuclear safety guidelines require cesium 137 levels for waste liquids at nuclear plants to remain below 90 becquerels per liter.
The findings highlight the debate about the safety of Japan’s nuclear power plants just as the nation’s utilities push to restart stations idled for safety checks after the Fukushima disaster. Japan’s Nuclear Regulation Authority said that it strongly suspects contaminated water from underground leaks at the Tepco plant was seeping into the ocean, Kyodo News said today.
The cesium 137 levels had risen from 18,000 becquerels per liter a day earlier, while those of cesium 134 increased to 11,000 becquerels from 9,000, Tepco said. The nuclear safety guidelines require cesium 134 levels at plants to remain below 60 becquerels per liter. Japan’s safety limit for radioactive materials in drinking water is 10 becquerels per liter.
A separate monitoring well at the turbine complex showed cesium 137 levels stable at 0.74 becquerels per liter between yesterday and July 8, while cesium 134 increased to 0.50 becquerels from 0.49 becquerels.
The Tokyo-based company didn’t provide a reason for the spike in radiation levels nor did it explain why levels varied so much at different monitoring wells.
The higher levels of radioactivity were found in a well that Tepco began surveying on July 7 as part of its monitoring of strontium and tritium found in groundwater at the wrecked Fukushima site.
Tepco President Naomi Hirose said last week that the company would seek permission to start two reactors at its Kashiwazaki-Kariwa plant in Niigata prefecture as soon as possible.
The utility, which had a 685.3 billion yen ($6.8 billion) loss last fiscal year, said in May 2012 that it would return to profit this year if reactors at the plant are restarted.
Kansai Electric Power Co. and three other regional utilities have applied to Japan’s nuclear regulator for safety checks, a step toward restarting reactors idled after the Fukushima atomic disaster in March 2011.
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