By Peter Fairley: How the Fukushima Ice Barrier Will Block Radioactive Groundwater!
Japanese officials desperate to contain an ever-growing crisis at the Fukushima with an underground wall of ice. Here's how it how it would works. Japanese officials desperate to contain an ever-growing crisis at the Fukushima nuclear power station are looking to use artificial permafrost to stop radioactive water from leaking. The idea is to build a mile-long wall of frozen earth around Fukushima's toxic reactor buildings to stem the groundwater contamination, the most experienced specialists in the field say the plan should work. The Japanese firms involved appear to be taking a go-it-alone approach. Two weeks ago, a top official at Tokyo Electric Power (TEPCO) signaled that the utility behind the Fukushima disaster would seek international assistance with the Fukushima disaster would seek international assistance with the Fukushima water contamination crisis. But experts at the U.S.-based firms and national labs behind the world's largest freeze-wall systems, and the only one proven in containing engineering and construction firms and national labs behind the world's largest freeze-wall systems, and the only one proven in containing nuclear contamination -have not been contacted by either Tepco or its contractor, Japanese engineering and construction firm Kajima Corp. One of these experts is Elizabeth Phillips, who managed the installation of a 300-foot-long, 80-foot deep freeze wall to isolate radioactive waste at the U.S. Department of Energy's Oak Ridge National Laboratory in Tennessee in 1996 and 1997. While freeze walls are commonly used to hold back groundwater to facilitate evacuations at constructing sites and mines, this case calls for specialized expertise, she says. "You should go with someone who has done it before." Every day roughly 400 tons of groundwater flowing down from the nearby mountain enters cracks in the reactor buildings damaged by the meltdowns and explosions at Fukushima in 2011, according to an April 2013 Tepco briefing document. Water that escapes from the buildings pollutes the groundwater downstream and ultimately spills into the sea. The contaminant levels are dangerously high. Last month were orders of magnitude higher than the levels deemed safe by the Japanese Nuclear Regulation Authority. Tepco's efforts to prevent that spread so far have been ineffective, risky, and ultimately unsustainable. It's primary response has been to pump contaminated groundwater into holding tanks, adding to the more than 300,000 tons of radioactive water already stored at Fukushima in hastily assembled tanks that are vulnerable to future earthquakes. Some have already leaked. Last week Japan's Nuclear Authority recorded one recent 300-ton leak as a level-3 incident, the first incident at Fukushima that it has rated on the international nuclear event scale since 2011. The freeze wall would be a more definitive approach to managing groundwater. As proposed by Kajima in April and endorsed in May by a Nuclear Regulation Authority expert panel, it would run 1.4 kilometers and encircle the site's four destroyed reactors. Vertical pipes are to be drilled or driven into the ground at one-meter intervals, creating what looks like an array of sub-soil fence posts. Fourteen 400-kilowatt refrigeration plants would pump -20-C coolant down each pipe to absorb heat from the ground, producing an expanding cylinder of frozen earth.