Japan Plans Ice Wall To Surround Damaged Nuclear Plant
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The clean up operation for Japan's Fukushima Daiichi Nuclear Plant is costing hundreds of millions of dollars. The plant's power and cooling systems were knocked out in the earthquake and tsunami that hit the area in 2011. And today, the Japanese government committed $470 million toward building an underground ice wall around the plant, among other things.
The wall could stop radioactivity from flowing into the nearby ocean. NPR's Geoff Brumfiel explains.
GEOFF BRUMFIEL, BYLINE: The ruined Fukushima Daiichi nuclear plant sits right on the Pacific Coast. The surrounding environment is wet. Groundwater is constantly flowing through the basement of the plant, carrying radioactivity from melted reactor cores out to sea. Today, the Japanese government said it would spend nearly half-a-billion dollars to try and stop the groundwater by building a underground wall of frozen soil around the plant. Sound crazy?
LARRY APPLEGATE: It will work.
BRUMFIEL: That's Larry Applegate. He's president of SoilFreeze, a Seattle-based firm that has created frozen walls and tunnels for everyone from Boeing Corporation to the Port of Los Angeles. Wherever you have wet soil, or a lot of ground water, soil freezing is an option. Engineers start by sinking hollow pipes into the ground about five feet apart. Then they circulate a coolant.
APPLEGATE: We use just calcium chloride, which is saltwater.
BRUMFIEL: Over the course of days, the cool pipes cause the ground around them to freeze into a wall of solid ice and dirt.
APPLEGATE: When you feel, you know, the wall - of course it's cold and it's frosty - and you feel it and it is very, very hard.
BRUMFIEL: These walls can be eight feet thick. Water can't get through because it freezes before it reaches the other side. Applegate says an ice wall could be just the thing for keeping radioactivity inside the plant and ground water out. The technology has already been used in the U.S. to stop a nuclear leak at Oak Ridge National Laboratory in the 1990s.
But not everyone thinks the ice wall is a surefire solution. Ken Buesseler is a senior scientist at Woods Hole Oceanographic Institute in Massachusetts. He studies the ocean around Fukushima.
KEN BUESSELER: It's almost impossible to stop ground water. You know, you put a damn in a river and it'll go over and around or under.
BRUMFIEL: And Buesseler says, even if it does work, it might not be a good thing. The Fukushima plant is right by the ocean, so if you reduce the amount of groundwater in the area, seawater will fill in its place.
BUESSELER: Cities have this when they pump out too much ground water, they get saltwater coming in.
BRUMFIEL: That saltwater could actually soak up radioactive contamination in the soil even better than the ground water does.
BUESSELER: When you start changing ground water, you can have unintended consequences.
BRUMFIEL: Trying to get ahead of unintended consequences may be one reason why the Japanese government isn't providing just money for the wall. Along with today's announcement of financial support, the government is establishing a committee of senior cabinet officials to oversee the clean up.
Geoff Brumfiel, NPR News.
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