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Nuclear Energy Rendering of Fukushima ice wall (nucleotidings.com)

Published on June 6th, 2014 | by Sandy Dechert

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TEPCO Starts Fukushima Ice Wall Construction

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June 6th, 2014 by
 
Tokyo Electric Power Company started building something new and very cold at the ruined Fukushima nuclear power plant complex on Monday. It’s basically a big underground cooler meant to freeze the soil into a rectangular wall around TEPCO’s four nonfunctioning but still highly radioactive reactors. The frozen ground of the Fukushima ice wall should prevent the steady flow of clean groundwater from nearby hillsides mixing with irradiated cooling water under the reactors and turning a huge water contamination problem (400 tons per day) into an insurmountable one.

Fukushima ice wall (TEPCO)Demonstration of ice wall to freeze subsoil at Fukushima Daiichi I reactor units 1-4 and effect a 7-year groundwater block (photo: TEPCO).

By “new,” we mean that no one has ever tried to install such a structure this big or this permanent. Not at Fukushima, in Japan, or anywhere else in the world. Buried ice walls have been used for sinking mine shafts, protecting Arctic permafrost, and tunnel building near water bodies, but never on such a large scale. TEPCO cites construction of a Tokyo metropolitan government subway line as having involved more than half the amount of soil to be frozen as at Fukushima. However, that freeze, like most others conducted to date, was only a temporary measure. MIT Technology Review magazine cites a six-year ice wall 20% the size of the Fukushima one built at a plutonium-containing US Department of Energy site near Oak Ridge, Tennessee.

TEPCO has installed more than a thousand large aboveground tanks over the past three years to contain contaminated water. The company is running out of space for more tanks and has had problems with both leaks and potential ground subsidence. These difficulties prompted TEPCO to look for other solutions. Japan’s Nuclear Regulation Authority approved the Fukushima ice wall plan last week.

Rendering of Fukushima ice wall (nucleotidings.com)

Workers from Kajioma Corp., TEPCO’s subcontractor, have started installing 1,500 thin pipes one meter apart. They’re sinking the tubes up to 30 meters underground in a 1.5-kilometer rectangle enclosing the four reactors. The tubes will carry refrigerant at -30° C and are expected to create an impervious wall of frozen soil about two meters thick. The wall has a projected seven-year lifetime, which should allow TEPCO time to repair cracks in reactor and turbine buildings and block the structural influx of groundwater.

Fukushima ice wall and groundwater bypass  (japan news.com)A water bypass system put in use last month can divert up to 80 tons per day of fresh, treated, and only slightly polluted water into the Pacific Ocean. Unfortunately, the Advanced Liquid Processing System, which removes dozens of radioactive contaminants from cooling water, has not been working up to expectations so far. This has slowed bypass use.

The Fukushima ice wall is expected to reduce the flow of groundwater under the plant to a third of its current volume, say most sources. Kajioma tested the method last October and built a working small scale model onsite two weeks ago. The Japan Daily Press reports that TEPCO anticipates finishing the wall in March 2015, about twice as quickly as originally estimated. It will take several months after that to complete the freezing process.

However, plenty of people have predicted that the $313 million project (construction costs only) may fail or not work well enough. They include former US Nuclear Regulatory Commission Chairman Dale Klein, who told Kyodo News early in May that “No one has built a freeze wall this long for this period of time. Typically, you build a freeze wall for a few months.”

At the same time, former British Atomic Energy Authority Chairwoman Barbara Judge also expressed doubts. Both experts are part of an oversight panel for TEPCO’s nuclear safety efforts. Klein urged TEPCO to seek advice from experts in the US and Britain who have managed water and decontamination efforts at former military sites.

The Japan News reports this comment from Masashi Kamon, a professor emeritus at Kyoto University who is familiar with the soil-freezing construction method:

“There is a mountain of challenges, such as possible corrosion of frozen pipes and costs of electricity. They should discuss measures that would combine other methods, such as one using clay.”

Other experts have also raised concerns that the wall “may damage existing pipes underground,” and whether the “necessary work can be carried out properly at a place where the amount of radiation remains high.” Finally, operating costs and electric power needed to keep the ice wall frozen are expected to be colossal.

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About the Author

covers environmental, health, renewable and conventional energy, and climate change news. She's worked for groundbreaking environmental consultants and a Fortune 100 health care firm, writes two top-level blogs on Examiner.com, ranked #2 on ONPP's 2011 Top 50 blogs on Women's Health, and attributes her modest success to an "indelible habit of poking around to satisfy my own curiosity."



  • shecky vegas

    Two questions – 1) How is this ice wall going to be powered? and 2) Are these people nuts?

    • driveby

      1) electricity?
      2) desperate, not nuts.. :-)

  • Barry

    That ice wall is a bad joke
    and it will never operate properly to hold back the millions and millions of
    gallons of poisoned radioactive waste that has been and still is pumping into
    the Pacific Ocean to contaminate the fish, sea life, animals and humans that
    eat from the Pacific Ocean. Cancers and DNA changes will occur to affect and
    mutate the future generations of multiple life forms on this planet! Entire
    families can and will be affected from this radiation! Anyone that has been
    eating Pacific fish and seafood should consider doing a radiation detox with
    the natural mineral called Zeolite that has been proven to safely remove both
    radiation and heavy metals from the human body! For more information on this
    radiation detox do a search for the single word Zeolite.

  • Offgridmanpolktn

    This is a big and risky project but Japan is dealing with a big and risky mess there at the plants. At least let’s appreciate them for trying to do something to slow the spread of the contamination.
    And while I have heard that Russia is finally doing something about trying to seal up Chernobyl (? spelling), it is a very long term project. Japan just doesn’t have the extra space like them to walk away and get back to it later, and fortunately there seems to be more of a social conscience to care for their environment.

    • Offgridmanpolktn

      Also to address the concerns about the power draw for this freezer, haven’t there been built or plans made for some decent size solar farms in this area.

      • spec9

        They should fill all that radioactive Fukushima area with wind turbines and solar PV. The wind turbines and solar PV don’t mind the radioactivity.

        • driveby

          Wouldn’t be so sure about that. Radiation will mess with materials and especially semiconductors…

  • JamesWimberley

    This $313 million project is only one small component of the cleanup costs for Fukushima. There’s a reason why nuclear reactors are uninsurable on the open market.

    • spec9

      Yep. We have the Price-Anderson act in the USA which provides a massive subsidy in the form of limited liability . . . but Wall Street is still quite skeptical about nuclear power. I think we need to build some nuclear as a back-stop for 24/7 carbon-free electricity generation (except for refueling periods). But it must be done very cautiously and only in areas with low seismic activity.

      • Bob_Wallace

        Nuclear is worthless as backup. It can’t be started quickly and the cost of using new nuclear only from time to time would be astronomical.

        Better, IMO, to build some large reservoir pump-up hydro with extra turbines. The system could be used for normal daily storage cycles and be available for larger volume output if needed.

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