Japan’s atomic regulator urged Tokyo Electric Power Co. (9501) to speed up completion of a seawall to protect the ocean from rising levels of contamination detected in the Fukushima nuclear plant’s groundwater.
The utility known as Tepco should try to finish building the wall earlier than the planned completion date of by March 2015 and should attempt to remove contaminated water collecting in trenches at the Fukushima Dai-Ichi plant, the Nuclear Regulation Authority said today in a statement.
“It is strongly suspected that highly contaminated water leaking underground may be seeping into the ocean,” the agency said in the statement.
The recommendations highlight safety concerns over nuclear power as the regulator considers requests by utilities to restart atomic plants idled for safety checks after the March 2011 meltdowns at the Dai-Ichi station.
They were also released after Tepco, which has struggled with the handling of contaminated water at Fukushima, announced that it found levels of cesium 137 in the plant’s groundwater at levels 244 times those considered safe for an atomic plant.
The utility found the radioactive isotope at 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. Japan’s nuclear safety guidelines require cesium 137 levels for waste liquids at nuclear plants to remain below 90 becquerels per liter.
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 July 8 and 9, 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.