from the-japan-news.com / August 20, 2014 / Tokyo Electric Power Co. said Tuesday it had failed in an attempt to create an ice wall in an underground tunnel to block the flow of highly radioactive water from a damaged reactor at the Fukushima No. 1 nuclear power station.
Since last month, TEPCO has injected more than 400 tons of ice and dry ice to freeze radioactive water in a section that connects the tunnel, used to run cables, with the turbine building of the No. 2 reactor, one of three reactors that suffered core meltdowns in the March 2011 disaster.
By freezing the water, TEPCO hoped to create a wall of ice to block the flow of water between the turbine building and the tunnel. The process would have made it easier to pump out highly radioactive water from the tunnel.
But the temperature inside the section did not fall low enough despite the use of large amounts of coolants, officials said at a meeting with the Nuclear Regulation Authority.
TEPCO now plans to use a filler, probably from mid-September, to slow the flow of water in the unfrozen part of the section. The move is expected to help freeze the remaining section.
At Tuesday’s meeting, NRA members and experts questioned or even expressed doubt about the effectiveness of the measure.
TEPCO said it would continue using ice to cool the section.