Nuke watchdog gives okay to Fukushima ice wall

Underground barrier of frozen soil designed to divert groundwater around reactors

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      Japan’s Nuclear Regulation Authority (NRA) has given the go-ahead to the operator of the crippled Fukushima nuclear power plant to build a so-called ice wall around four reactors to prevent incoming groundwater from becoming severely contaminated.

      The NRA, Japan’s nuclear watchdog agency, had been considering the plan by Tokyo Electric Power Co. (TEPCO), which runs the Fukushima Daiichi plant, since last fall.

      TEPCO, which announced the idea in May 2013, conducted limited tests of the relatively unproven technological fix in October 2013 and, most recently, two weeks ago.

      According to Asahi Shimbun news on May 17, a spokesperson for Kajioma Corp., the construction company building the ice wall, declared the latest test a success.

      The Japanese government has pledged $313 million to fund the project.

      Project will take almost a year

      TEPCO is expected to commence construction of the underground ice-wall—which, along with a recently implemented groundwater-bypass scheme, is part of TEPCO’s approach to reduce the amount of radioactive groundwater now being stored and treated in temporary tank farms on the site—in June and finish the project sometime in March 2015, according to the Japan Daily Press on May 27.

      The wall is designed to operate for about seven years.

      The ice-wall project involves sinking tubes carrying coolant, one metre apart, up to 30 metres underground and in a roughly 1.5-kilometre rectangular shape around four reactors. The piped refrigerant, at minus-30 ° C, would freeze groundwater and create an impervious two-metre-thick soil wall.

      Up to 400 tons of water per day flows underground from nearby hillsides into the site, often mixing with contaminated water used to cool reactors that were severely damaged in the March 2011 earthquake and tsunami.

      More than 1,000 storage tanks already built

      The groundwater-bypass plan—which is expected to lessen this volume of water by piping up to 80 tons per day of diverted (as well as treated and moderately contaminated) water into the Pacific Ocean—was designed to reduce the need to build additional water storage tanks at the site. More than 1,000 tanks have been installed in the past three years.

      TEPCO has said that if all goes according to plan, with both the bypass and the ice wall in operation, the outside-groundwater inflow will be reduced to 130 tons per day.

      The ice-wall technique has been used previously in tunnel construction near watercourses, but not on such a large scale.

      Contaminated-soil storage plan moves ahead

      Meanwhile, the Japan Daily Press reported on May 28 that the Japanese government is putting the finishing touches on a plan to store the Fukushima Daiichi site’s contaminated soil prior to disposal outside of the prefecture.

      The decontamination process is expected to take upwards of 30 years.

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      spartikus

      May 30, 2014 at 8:11am

      And let me guess - the guards will be known as "The Night's Watch"

      7 13Rating: -6

      josh

      May 30, 2014 at 1:52pm

      The NRA is a newly formed group of nuclear experts, at least they said they are experts. So them ok ing anything is suspect. That they continue to withhold info about fukushima from the public is criminal.

      9 15Rating: -6

      me

      May 30, 2014 at 3:35pm

      Why do they keep using the "before" picture? It looks nothing like that now.

      Martin Dunphy

      May 30, 2014 at 4:04pm

      me:

      Thanks for the post. Pictures of the Fukushima Daiichi plant post-disaster are, for the most part, proprietary.

      The international news agencies don't generally grant permission to use them, and TEPCO, the operator, restricts its own photos that it permits to be used.

      Generally, we use a photo like the above (which is accompanied, by the way, with a current photo from the construction site) in order to demonstrate just how close the reactor site is to both the Pacific Ocean and built-up areas.

      Miki

      May 30, 2014 at 4:16pm

      So in other words ; we're going to be glowing ,. Sterilants for the foreseeable decades to come

      8 17Rating: -9

      DAW

      May 30, 2014 at 6:22pm

      This is a very unfortunate decision. They know it will displace the entire sight into the ocean. Any attempt to erect a wall of anything other than porous material will push the land into the sea... but that's what is happen for the last 3 years and no one has stopped the behavior. Oh and but the way the energy needed to freeze the wall will require a new nuclear plant. We are sheep.

      9 16Rating: -7

      kimberly davis

      May 31, 2014 at 5:11am

      Martin, thanks for your prompt response re: the pre-2011 picture. Can't the cutline at least be precise? E.g., "Japan's Fukushima Daiichi nuclear-reactor [plant], April 2010."

      It is still stunning to me what you say about restriction on freedom of the press to use current photos - or even better, ones from the week of March 18, after the explosions, so people understand what they're dealing with in terms of groundwater.

      Go here for the Geology of Fukushima published in 2010. Scroll down for a view in section: http://www.fukushima-blog.com/article-the-geology-of-fukushima-88575278....

      They don't need nuclear experts any more; they can stand down, their job is done.
      The need hydrogeologists, experts in soils in construction projects, and marine chemists and biologists.

      6 10Rating: -4

      Dr. RH Bennett

      May 31, 2014 at 10:16am

      The new NRA is anything but a watchdog. Its more like a lap dog. The idea of a frozen wall has been roundly critiqued by geotechnical experts. The Vancouver papers article make a misleading case that TEPCO et. al. know what they are doing. Rather its more of a case, we need to look good and do something, anything.
      Three nuclear cores melted and burned releasing extremely radioactive microfine ash into the air. Japan, TEPCO, and the UN have ignored this fact in hopes that no one will notice. The US Navy noticed after it blundered and sailed into the ash ridden snow storm that contaminated the ship. It took months to decontaminate this carrier.

      Thus my Canadian friends all is not well, ice wall or not... Question authority especially the nuclear types.

      3 13Rating: -10

      Martin Dunphy

      May 31, 2014 at 12:28pm

      kimberly davis:

      You are welcome, and, yes, we will in future make an indication as to whether or not the photo is pre- or post-2011.
      Although media freedom in Japan is a growing concern in the past year or two (see http://www.straight.com/news/655491/japan-halts-criminal-contempt-case-a...),the legal restrictions against violating copyright are, more or less, buainess as usual.
      Sometimes it is a question of having the time to be able to search for non-copyright images. Established news agencies often don't bother going after bloggers, but we can't count on such largesse.

      7 10Rating: -3
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