Work on frozen walls to start

January 28, 2014

TEPCO to create frozen walls to stop water leaks

http://www3.nhk.or.jp/nhkworld/english/news/20140129_01.html 

Tokyo Electric Power Company is to begin work at the Fukushima Daiichi nuclear plant to stop radioactive wastewater from flowing into the sea.

The task of creating underground frozen walls is due to start at the Number 2 and Number 3 reactors on Wednesday.

Massive amounts of water are being poured into the reactors to prevent melted nuclear fuel from overheating.

Some of the water is contaminated with radioactive substances, and is leaking from the damaged reactor containment vessels.

The water has accumulated in the reactor buildings, adjacent turbine buildings and underground tunnels. TEPCO believes the water is leaking from the tunnels, seeping into the ground and reaching the sea.

Engineers will begin their work by digging vertical holes where the tunnels meet the turbine buildings. Pipes will be installed in the holes to inject liquid coolant to create frozen walls to block the water.

But cables and other objects in the tunnels could hamper the work. Engineers cannot go there because of the radioactive water, so they have to rely on images sent from remote-controlled cameras.

TEPCO hopes to finish installing the pipes by late March and to start removing 11,000 tons of wastewater from the tunnels in May, after the frozen walls are completed.

TEPCO is also digging wells in the compound to see whether water is leaking directly from the buildings.