Regulators OK underground ice wall around Fukushima plant
In this March 10, 2014 file photo, workers wearing protective gears install a trial model of the underground frozen wall at the Fukushima Daiichi nuclear power plant in Okuma, Fukushima Prefecture, in their attempt to stop the leakage of radioactive water that has accumulated at the crippled nuclear power plant. Japanese regulators on Wednesday, March 30, 2016, approved the use of a giant refrigeration system to create an unprecedented underground frozen barrier around buildings at the Fukushima nuclear plant in an attempt to contain leaking radioactive water.
AP Photo/Koji Sasahara, Pool, File
TOKYO —
Japanese regulators on Wednesday approved the use of a giant refrigeration system to create an unprecedented underground frozen barrier around buildings at the wrecked Fukushima nuclear plant in an attempt to contain leaking radioactive water.
The Nuclear Regulation Authority said the structure, which was completed last month, can now be activated.
The plant’s operator, Tokyo Electric Power Co (TEPCO), said it plans to turn on the ice wall on Thursday, starting with the portion near the sea to minimize the risk of contaminated water escaping into the Pacific Ocean. The system will be started up in phases to allow close monitoring and adjustment.
Nearly 800,000 tons of radioactive water that is already stored in 1,000 industrial tanks at the plant has been hampering the decontamination and decommissioning of the nuclear facility, which was damaged by a massive earthquake and tsunami in 2011.
The success of the ice wall is believed to be key to resolving the plant’s water woes.
The project, proposed by construction giant Kajima Corp, is more than a year behind schedule because of technical uncertainties. Some experts are still skeptical of the technology and question whether it’s worth the huge cost.
The 35 billion yen government-funded project consists of refrigeration pipes dug 30 meters underground that are designed to freeze the soil around them. They are supposed to form a 1.5-kilometer wall around the reactor and turbine buildings to contain radioactive water and keep out groundwater.
At a meeting Wednesday of the nuclear agency, Chairman Shunichi Tanaka cautioned against high expectations because the success of the project depends in part on nature. “It would be best to think that natural phenomena don’t work the way you would expect,” he later told reporters.
Similar methods have been used to block water from parts of tunnels and subways, but a structure large enough to surround four buildings and related facilities is untested. A smaller wall was used to isolate radioactive waste at an U.S. Department of Energy laboratory in Tennessee but only for six years. The decommissioning of the Fukushima plant is expected to take decades.
Three damaged reactors at the plant must be continually cooled with water to keep their melted cores from overheating. The water, which becomes radioactive, leaks out through cracks and other damaged areas into the reactor basements, where it mixes with groundwater, increasing the volume of contaminated water.
Many experts including Tanaka say a “controlled release” of treated water is the only solution to the water woes, but concerns about ocean health make it a contentious subject.
A test of part of the ice wall successfully froze the ground around it, and officials hope the entire wall can be formed within several months, according to Shinichi Nakakuki, a spokesman for TEPCO.
TEPCO officials say they hope the ice wall will stop most of the flow of groundwater into the area and allow the turbine basements to be dried by 2020, confining the contamination to the three melted reactors.
Asked at the meeting if the ice wall is worth the cost, TEPCO accident response official Toshihiro Imai replied, “Its effect is still unknown, because the expected outcome is based on simulations.”
Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
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25 Comments
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2
Yubaru
It's taken over two years to finish this wall, and according to the news last night it is supposed to not "stop" the flow totally, just cut it down to about 50 tons a day.
0
SenseNotSoCommon
Was anyone expecting the NRA not to? Not a baited breath on these islands, me thinks.
-1
Utrack
Entomb the Fukushima Daiichi Nuclear Power Plant.. The ice wall did not work for Chernobyl and I for one am not expecting it to work at the Fukushima Daiichi NPP either. ....... Wasting time and money must be Politically Acceptable..... But the cost to the citizenry of Japan and the environment is Not Acceptable to any sane person...
3
sangetsu03
An unprecedented taxpayer-funded boondoggle that was approved years too late, and will be far more expensive and less effective than promised.
3
NZ2011
Anyone ever involved in any large Japanese business, especially ones with public "accountability", would know that this was going to go forward the moment they first talked about it. trust me its infuriating.
Someone makes a plan, possibly entirely arbitrarily, people approve it, and no matter if new evidence, better ways come to light, going to cost 100 times much more money, now totally redundant and a complete waste of time, it doesn't matter.. it will go ahead, because following "the plan" is all thats acceptable.
1
shonanbb
Chernobyl had an ice wall? I thought it just had giant cement walls.
3
garymalmgren
Ok, It is easy to knock the engineers who are trying to deal with the explosion and meltdown in the Fukushima nuclear plant. They are not idiots and they are dealing with something that no one has ever had to tackle before. These are not just Japanese engineers but a collection of the most knowledgeable people in the fields concerned.
Do some of you JT contributers really WANT them to fail?
There are a multitude of extremely complex, expensive and dangerous steps to be taken over a very long time span before this disaster can be called over. This article deals with the problem of underground water coming in contact with highly radioactive substances and then running into the sea.
The original step was to drill wells , pump up the contaminated water , store it and then decontaminate it.
However the amount of water soon made that plan unviable.
The current plan is to build a frozen wall on the western side of the plant. The wall will hopefully divert underground flow so it will transit to the north and south around the contaminated area and flow into the ocean. When the flow is controlled they can then move to the next step of excavating a trench and building a more permanent water diversion system.
The engineering behind a frozen wall is sound and is used in deep underground mines to control water ingress. However the length and depth of the wall that has been constucted at Fukushima is unprecedented.
Knock it if you want , but it would be more helpful if we came up with better engineering solutions to the current problem at hand. As for burying the whole plant under concrete: how does that solve the current pressing problem of contaminated water flowing into the ocean?
I am open to any ideas.
-1
papigiulio
Yet, turning on reactors that are located above fault lines is no problem right??? what the...
1
Freddie Krug
Lets not scare the public
0
Citizen2012
Won't be a waste of money for TEPCO and all the middle men, and that is the only reason why it has been approved.
-1
Utrack
Yes, lets not scare the public by telling them the truth... Nuclear Reactor Exploding = Nuclear Explosions... 2 nuclear explosions mind you....... Entomb Fukushima Daiichi NPP because this ice wall is not going to happen... Since the water flowing into the reactor building basements is Radioactive ergo to hot to freeze this is just like in Chernobyl trying a ice wall. The water was to radioactive hot to freeze it did not work so they entombed the reactor
1
sangetsu03
The engineers are not idiots, but those holding their leashes are. Japan has the worst record of problems at nuclear power plants than any other country, and this is the reason that they now have such a problem to tackle.
1
garymalmgren
**Since the water flowing into the reactor building basements is Radioactive ergo to hot to freeze **
The idea is to freeze the ground upstream of the underground water flow, thereby diverting the water before it becomes radioactive.
this ice wall is not going to happen...
To quote the article above The Nuclear Regulation Authority said the structure, which was completed last month, can now be activated.
This ice wall is happening at this moment, as to its success , only time will tell.
1
nandakandamanda
garymalmgren is the first commentator to come out and ask for some understanding of the nature of the problem that Tepco is facing. There is no joy in being right if or when this ice wall fails, but most of us can clearly see the potential problems in our mind's eye.
NZ2011 has expressed what we have all sensed here in Japan, that once a proposal has been made, everyone will get behind and push it through to the bloody end, even if it is a case of the Emperor's new clothes.
Will it freeze totally throughout? I really hope it works as designed, or if not that it changes the game plan in a positive way, despite the costs of construction and the massive amount of power to run it.
In the meantime let's get a couple more of those giant filtration systems so we can return the stored water to the ocean.
1
Citizen2012
People, Nuclear Industry is not about knowledge or being idiot or not, otherwise, there won't be any nuclear plants on active fault lines, it is only about money and greed and that is why they will stay here. A nuclear disaster is only a disasters for the locals (who will never get compensated), for the others, the ones running the show, it means more public money to funnel in cleaning cost and vain promises, certainly one of the most important reason why the govt took over TEPCO I presume, they saw the benefit.
-2
Utrack
garymalmgren
Why is not the water upstream radioactive???? The Whole area is radioactive ...... 2 Nuclear Explosions does not stay confined to one small area.... Upstream must be contaminated if the water flowing into the reactor basements are already contaminated...
radioactive contaminated water is hot...... too hot to freeze
-1
bullfighter
Do you have a hard data source for your claim or are you just engaging in Japan/Japanese bashing?
Sounds like you are talking about Pentagon arms procurement.
-1
Disillusioned
They hope? The great Japanese ice wall saga continues! This is a big gamble using unproven technology that failed miserably the first time they tried it. Why should anybody believe it will work this time, especially as we are coming into the hot summer months. Furthermore, I'm wondering if the motors and electrics for this system will be tsunami safe or just placed on the ground next to the flooded back up generators? They say that, lightening never strikes twice in the same place, but history has proven that tsunamis do. Let's 'hope' there isn't another tsunami, shall we?
1
wanderlust
utrack - upstream water is natural ground water, that cannot be diverted. It is not radioactive. The whole area is not radioactive. They were no nuclear explosions, but meltdowns; the explosions were from the build up of hydrogen gas, that led to atmospheric dispersal of radioactive materials. The concentration of uranium in a reactor pile is not high enough to cause an explosion like a nuclear bomb.
It is only when the groundwater has passed through the reactor building area that it becomes radioactive, as it mixes with cooling water, which is deliberately injected into the building to keep the corium (wherever that maybe) in a cool state.
The freezing plan is to try to reduce the amount of groundwater that passes through and then mixes with cooling water, thereby reducing the load on the filtration systems.
0
CH3CHO
Now, those self-claimed experts are saying that releasing the CONTAMINATED water is the solution. They should know the meaning of solution.
UtrackMAR. 31, 2016 - 07:25AM JST
How? Covering the building like Chernobyl does not work because the problem is under the earth.
0
Reckless
the horse done left the barn my friends,,,
-1
Stuart hayward
Does anyone know why the wall has to be an "ice wall", rather than a permanent fixed wall, that doesn't require to be so expensively maintained?
-1
Mike O'Brien
Chernobyl didn't attempt an ice wall because they don't have a ground water issue and entombing won't do anything for Fukushima's ground water situation.
What? How can water be 'to hot to freeze'? Boiling water (which this water obviously isn't) can be cooled down enough to freeze.
No it isn't.
It is proven technology and has been used for decades, just not on this scale. And they haven't used it here before, the trenches was a different situation with different issues NOT an ice wall.
0
Stuart hayward
Mike O'Brian: I simply asked a question, can you answer it or can you only give a down vote?
0
wanderlust
@stuart - they tried pouring concrete as an initial attempt, but it could not flow down far enough, it could not get into the small spaces, and the water flow pushed against it. By freezing all of that water, they hope to alleviate that problem.
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