Environment

Japan activates underground ice wall to seal away Fukushima's nuclear waste

Japan activates underground ic...
With 400 tons of groundwater flowing downhill into the reactor basements each day and some of that then spilling into the sea, there is a need for alternative solutions
With 400 tons of groundwater flowing downhill into the reactor basements each day and some of that then spilling into the sea, there is a need for alternative solutions
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Fukushima workers pour brine into the refrigerated pipes
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Fukushima workers pour brine into the refrigerated pipes
Fukushima workers pour brine into the refrigerated pipes
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Fukushima workers pour brine into the refrigerated pipes
Fukushima workers pour brine into the refrigerated pipes
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Fukushima workers pour brine into the refrigerated pipes
The ice wall might sound like something out of science fiction, but is actually an engineering technique that has been used for tunnel boring and mining, albeit on a smaller scale
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The ice wall might sound like something out of science fiction, but is actually an engineering technique that has been used for tunnel boring and mining, albeit on a smaller scale
With 400 tons of groundwater flowing downhill into the reactor basements each day and some of that then spilling into the sea, there is a need for alternative solutions
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With 400 tons of groundwater flowing downhill into the reactor basements each day and some of that then spilling into the sea, there is a need for alternative solutions

Among the many problems plaguing the cleanup at Fukushima is the threat of radioactive water spilling from the site. The Japanese government is now ramping up its efforts to contain this problem, by flicking the switch on an underground ice wall that will enclose the failed nuclear facility to slow the spread of contaminated material.

An ice wall might sound like something out of science fiction, but is actually an engineering technique that has been used for tunnel boring and mining, albeit on a smaller scale. Refrigerated brine cooled to -30 degrees Celsius (-22 ° F) will be pumped through pipes plunging 30 m (98.5 ft) into the ground, freezing the soil and eventually sealing the four reactors damaged in the 2011 earthquake and tsunami inside a 1,500 m (5,000 ft) barrier.

Scientists have recently detected elevated levels of radiation in seawater samples collected near the reactors, and even as far away as the US west coast, confirming that there is an ongoing release of toxic materials from the plant. Workers at Fukushima have already filled purpose-built steel tanks with tons of toxic water from the reactors, but there are some areas that they simply can't access as radiation levels remain dangerously high, so high in fact that even robots sent in to investigate are having their wiring fried.

So, with 400 tons of groundwater flowing downhill into the reactor basements each day and some of that then spilling into the sea, there is a need for alternative solutions.

Fukushima workers pour brine into the refrigerated pipes
Fukushima workers pour brine into the refrigerated pipes

Construction on the frozen soil wall began in 2014 and is now complete. Japan's nuclear regulator gave the green light for the wall to be activated on Wednesday, setting in motion a plan to surround the four damaged reactors with an impenetrable barrier. The wall will be turned on in stages, but the first will see around 95 percent of the barrier activated. Plant operator Tepco says that initially leaving a gap in the wall will keep groundwater levels within the perimeter at a higher level than that of the basement water, therefore preventing the latter from spilling over.

Once it has assessed the success of this first stage, which it expects to cut the flow of groundwater into the buildings by 50 percent, it will seek approval to switch on the remaining portion to form a solid boundary around the four reactors. There is no set timeline, but the process is expected to take place over a period of months.

Source: Tepco

5 comments
sutski123
Glibly repeating TEPCO's ill-informed wishes of "totally sealing in the plant" by freezing a bit of soil is just silly. This solution is temporary and only scratching the surface of the problem at best and a disasterous/extinction level event at worst. This situation is so serious it is being ignored by 99% of the planet!!! That "water samples off the west coast of the USA" are now contaminated, suggests the whole of the Pacific is contaminated no? If not, which bit is still OK?! Did anyone test all the dead sea-birds found on Alaska's beaches recently? This whole situation makes make seethe. Where the hell are all the world's Governments and scientists and why are they not making a joint-effort to try and come up with a solution to this awful, awful problem?
bfearn
Remarkable that this article did not say how long this 'wall' needs to be operating or the energy required for that length of time???
EzeFlyer
Doing something however ineffective makes people feel better. Now they can continue to push nuclear power on the people of the planet they are killing.
sk8dad
Since the ice enclosure is intended to prevent any ground water from coming or going, wouldn't it also be really good a trapping rain? How long before the enclosed area become "Lake Fukushima"?
christopher
"*Some* of that spilling into the ocean". ? 75% isn't my idea of "some"! Last estimates were "At least 300 tons of contaminated groundwater is flowing from the Fukushima nuclear plant into the sea every day - http://www.nace.org/CORROSION-FAILURES-Fukushima-Nuclear-Plant-Tank-Leak.aspx#sthash.TulCQZE2.dpuf "