A government-backed plan for a frozen underground wall to limit water contamination at the wrecked Fukushima atomic station needs further vetting for potential risks to the environment, an adviser to the plant’s operator said.
The plan, which is intended to keep groundwater from seeping into the basements of the plant’s damaged reactor buildings, may not function as intended because it’s based on untested assumptions about the site’s hydrology, said Dale Klein, who chairs Tokyo Electric Power Co.’s Nuclear Reform Monitoring Committee.
“Are there any unintended consequences?” Klein asked at a press conference today in Tokyo. “We’re concerned about safety and environmental protection.”
Japan’s government said in September that it would pay 32 billion yen ($313 million) to construct the 1.4 kilometer (0.9 mile) rectangular subterranean wall by pumping coolant through pipes sunk into the ground at the Fukushima Dai-Ichi plant.
The ice wall is part of efforts by Tepco, as the plant’s operator is known, to reduce radioactive water at the site. Levels of toxic water at the plant are rising at a rate of 400 tons a day as groundwater seeping into basements mixes with cooling water that has been in contact with highly radioactive melted reactor cores.
The wall is scheduled to be completed by the end of March 2015 and will remain in operation through 2020, Mayumi Yoshida, a Tepco spokeswoman, said by phone.
“We will take Dr. Klein’s words sincerely and work steadily with the government on the ice wall project,” Yoshida said.
A separate plan to divert groundwater from nearby hills away from reactors and into the sea would cut contaminated water being stored by 100 tons a day, Tepco has said.
Tepco and Kajima Corp., the ice wall project’s primary contractor, are now conducting tests on the system ahead of its actual deployment, Yoshida said.
“From those tests, if Tepco finds technical information that indicates the frozen wall is not the best, they need to communicate that to the government,” Klein said. “I know the government has said that they will put in the frozen wall, but I hope that science will trump political policy.”