Japan plans to stop radioactive leaks from Fukushima with an ice wall

Japan has announced it will encircle the Fukushima nuclear plant with a mile-long “ice wall” to stop radioactive water from leaking out of the contaminated site.

An earthquake and tsunami destroyed the nuclear plant’s cooling systems in 2011, and three reactors melted down. Since the disaster, plant operator Tokyo Electric Power Company (Tepco) has pumped water in to cool the reactors, but storing the 400 tons of contaminated water that’s created every day has become a challenge as some tanks have sprung leaks.

Government spokesman Yoshihide Suga said the government would spend $473 million on the project, which would be completed by March 2015. He said leaks of radioactive water were getting worse, and the government "felt it was essential to become involved to the greatest extent possible.”

The government will create a wall of frozen earth below the soil surface that’s about 95 feet deep, using pipes filled with coolant.

The wall would remain frozen even during power outages lasting days or weeks. “It would take months or years to thaw the wall out,” Daniel Mageau, vice president and design engineer for Seattle-based contractor SoilFreeze, told MIT Technology Review.

The most experienced specialists in freeze-wall systems told MIT Technology Review that the plan should work.

One issue, however, is that frozen walls are typically considered a short-term containment solution, and it is expected to take 40 years to decommission the Fukushima plant. "We still need a few layers of safety backups in case it fails," Atsunao Marui, an underground water expert at the National Institute of Advanced Industrial Science and Technology, told the Associated Press. "Plus the frozen wall won't be ready for another two years, which means contaminated water would continue to leak out."

MIT Technology Review noted that international experts have not been contacted by either Tepco or its contractor, Japanese engineering and construction firm Kajima Corp., for assistance in constructing the wall.

"The world is closely watching whether we can dismantle the (Fukushima) plant, including the issue of contaminated water," Japanese Prime Minister Shinzo Abe said. "The government is determined to work hard to resolve the issue."