90% frozen

September 13, 2016

Fukushima ice wall is 90% frozen, more work needed

http://www3.nhk.or.jp/nhkworld/en/news/20160913_18/

The operator of the Fukushima Daiichi nuclear power plant made public on Monday a facility to monitor the condition of an ice wall built to keep groundwater from entering the reactor buildings.

Tokyo Electric Power Company is using a 1.5 kilometer-long underground barrier of frozen earth to prevent water from flowing through the damaged reactors and becoming contaminated.

The freezing process started at the end of March.
Monitors show frozen areas of the wall in blue and sections with high temperatures in red.

Government officials say 99 percent of the wall closest to the ocean has been frozen, but the ratio remains at 92 percent on the landward side.

The officials say it is difficult to freeze further as there is a risk of contaminated water leaking out from the reactor buildings if groundwater levels are not kept constant.

Additional work is underway to step up the freezing of some areas where the temperature doesn't drop so easily.

TEPCO also has to deal with the aftermath of recent heavy rains, which have raised temperatures in some sections of the wall.