Officials scramble to contain, handle tainted water.
TOKYO – Tokyo Electric Power Company’s plan to manage radioactive water at its wrecked Fukushima plant might include a controlled discharge into the ocean once its toxicity is brought within legal limits, Japan’s nuclear regulator said Monday.
Nuclear Regulation Authority Chairman Shunichi Tanaka said the ocean dump could be necessary as the government prepares to present its plan for handling tainted water that’s increasing by 400 tons a day.
Managing the water used to cool melted fuel at the Fukushima plant’s reactors has become a fundamental challenge for the utility known as TEPCO, which has struggled to contain a series of leaks including the loss of about 300 tons of contaminated water it reported two weeks ago.
“It is important for us to understand the need to make difficult judgments in order to avoid larger problems in the future,” Tanaka said of the possible ocean discharge.
Contaminant levels must be brought below accepted limits through filtration or other treatments before the water is discharged, he said.
Japan’s Nuclear Emergency Response Headquarters might present its response to the water management crisis as early as today, Deputy Chief Cabinet Secretary Katsunobu Kato said Monday, relaying earlier comments from Chief Cabinet Secretary Yoshihide Suga to lawmakers.
The government wants to present a “complete package” of steps to tackle the water problem, Suga said.
TEPCO’s challenge was illustrated Sunday when the utility said it had found a new radioactive leak, capping its worst month since the March 2011 earthquake and tsunami caused reactors to melt down.
The company said it had halted the contaminated water leak from a pipe near an area of high radiation levels discovered on Saturday.
Of the hot spots found over the weekend, one recorded radiation of 1,800 millisieverts per hour around the bottom of a bolted-flange tank storing water used to cool melted reactor cores. That’s 18 times the level reported at the same spot on Aug. 22, TEPCO said.
The weekend findings probably reflect TEPCO’s beefed-up monitoring crews finding contamination that was missed earlier, former nuclear engineer Michael Friedlander said.
TEPCO boosted the number of tank-inspection patrols from twice to three times daily after last month’s 300-ton leak, said company spokesman Yoshikazu Nagai, and to four times a day on Monday, when the inspection staff grew from 10 members to 60.
The company also planned to install gauges on all tanks to monitor changes in water levels that suggest leaks, Nagai said. Those water level checks were being done by measuring the temperature of the tanks’ outer walls.
“They threw these tanks together, they’re exposed to the elements and now that they have more people looking at it with a higher degree of diligence, they’re finding leaks,” said Friedlander, who spent 13 years operating U.S. nuclear plants. “Those leaks have probably been around for quite some time, and they’ve probably been growing because until now they haven’t been doing any work on them.”