(UPDATE 8/12/2013) Plan B (ice/dry ice) seems to have failed. See my latest post.
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(UPDATE) According to @jaikoman who follows and tweets on every single TEPCO and NRA press conferences, TEPCO poured ice and dry ice, thinking ice would float, cooling the top layer of water, and dry ice would sink, cooling the bottom layer of water.
Well they need a Plan C. Dry ice pieces they pour were apparently too small, and they all floated. Water remain unfrozen, and TEPCO says they will know by mid August whether the operation will work.
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TEPCO says by dumping ice and dry ice they can lower the temperature of the contaminated water in the trench to about 5 degrees Celsius, then they will be able to form a continuous ice plug.
Here I thought that water freezes at zero degree Celsius. As the whole world is seemingly going crazy afresh this July, maybe TEPCO is correct that water does freeze at 5 degrees Celsius.
From TEPCO's photos and videos library, 7/24/2014:
On July 24, 2014, TEPCO started the experiment of dumping ice into the Reactor 2 turbine building trench, trying to freeze highly contaminated water which has refused to freeze despite 3 months of freezing effort. Workers dumped only 2 tonnes of ice, or 4 bags with 500 kilograms of ice each.
Workers seem to be wearing vests, probably to shield ambient radiation. The location is the oceanside (east side) of the turbine building, where, according to the latest survey map by TEPCO as of July 8, 2014 (which I had a very hard time locating in TEPCO's updated site) the radiation level looks to be about 0.20 millisieverts (or 200 microsieverts) per hour. According to TEPCO, workers spent two and a half hours dumping 2 tonnes of ice using shovels.
Locations of the trenches filled with highly contaminated water (most likely from April/May 2011), and the locations in blue squares TEPCO wants to create ice plugs so that no water from the turbine buildings enters the trenches, from TEPCO's presentation to Nuclear Regulation Authority on 7/7/2014, when TEPCO disclosed that after three months of attempt, the water was still not frozen (English labels are by me):
Part of TEPCO's survey map (7/8/2014) showing ambient radiation levels, with "Shaft A" marked (by me) in red square:
So why isn't the water freezing? According to TEPCO's convoluted explanation to NRA on 7/7/2014, it is because of the fluctuation of water levels in the turbine building which creates water flow through the gaps created by the pipes that go through the turbine building walls. The flow was strong enough to disturb the freezing process, which TEPCO hadn't anticipated from the mock-up.
I do remember from January, I believe, a meeting at Nuclear Regulation Authority in which TEPCO and NRA commissioners discussed these ice plugs. Commissioner Fuketa openly questioned the efficacy of the scheme, asking TEPCO why they were planning to create a plug right outside the turbine building where lots of pipes are going through in a narrow space, as you can see even in TEPCO's simplified presentation to NRA on 7/7/2014 (English labels are by me) below.
The red rectangle right outside the turbine building is the ice plug to be created. The purple pipe in the diagram going down to the red rectangle is where workers were dumping ice.
Commissioner Fuketa also expressed doubt that it would ever freeze. I think he even asked what TEPCO's "Plan B" was, in case it would not freeze. TEPCO's answer was that it would freeze. (Watching this futile exchange live, I kept thinking, "Why can't they just pour concrete?")
Well the water didn't freeze. Nowhere close. TEPCO's measurement shows the temperature of part of the water which should have frozen is as high as 15 degrees Celsius, after 3 months of freezing.
So dumping ice and dry ice, then, is TEPCO's "Plan B". And ask the god of physics to look the other way and make water freeze at 5 degrees Celsius at sea level.
Ahhh good (bad) old days are back... when TEPCO used diaper polymers, saw dusts, shredded newspaper to try to stop the same highly contaminated water in the same set of trenches from pouring into the plant harbor.
It feels it was only yesterday.
Well...
ReplyDeleteAs I recall, in the report about the 'it's not freezing' it was not exactly clear if the flow they are referring is real flow or convection.
- if it's a real flow then this kind of effort is really pointless.
- if it's a convection, then it can work. The cold water created by the freezing goes down, to the bottom of the trench and some water at ambient temperature (maybe around 10C degree) comes up instead of it. The stronger the cooling, the stronger is this convection -> fail.
If the water on the bottom of the trench can be cooled to 4C degree (check the significance of this temperature of water somewhere!) then the convection stops and the freezing can become effective.
Pleased to read you again.
ReplyDeleteGood to have you back.
ReplyDelete*mscharisma*
Is the water affected by tidal flow? Is it brackish..either would mean a really HARD time to freeze the liquid. And if water freezes at 5 degrees C as TEPCO says..what is mixed with it to allow that to happen?
ReplyDeleteIs it naive to think that because every radioactive decay generates a little bit of heat, that the water is going to be warmer than if it were not radioactive?
ReplyDeleteSincerely,
Captain Obvious
Interesting watching the clowns in a circus, pure entertainment.
ReplyDeleteEither the water in the tunnel is flowing like a river or rich in saltwater, maybe both. Saltwater requires -2C degrees (28.4F) to freeze.
If TEPCO can't even get the top of to ice over then they have bigger problems to deal with. Maybe they should wait for winter to set in. So much for 'cold' shutdown.
I cannot read this. Can die while reading of stupid but powerful people doing bad theatre on nuclear dump?
ReplyDelete"Either the water in the tunnel is flowing like a river .. "
ReplyDeleteDid Tepco have groundwater problems before the quake?
These guys can't seem to catch a break.
"Did Tepco have groundwater problems before the quake?
ReplyDeleteThese guys can't seem to catch a break."
Before the Great Quake, TEPCO had sump pumps to pickup any nuisance water at various spots around the site plus to monitor for radioactive water (leaks).
During the Great Quake, ground fissures were opening up on site and knocked over a transmission line nearby thus causing the station blackout. Most of the coastline in that area was subsiding (sinking) about 2 1/2 feet and sliding east 5 feet during the Great Quake. TEPCO caught a break between the time the plant site was being built until the Great Quake struck, then there luck ran out.
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"...Portions of northeastern Japan shifted by as much as 2.4 m (7.9 ft) closer to North America,[19][20] making some sections of Japan's landmass wider than before.[20] Those areas of Japan closest to the epicenter experienced the largest shifts.[20] A 400 km (250 mi) stretch of coastline dropped vertically by 0.6 m (2.0 ft), allowing the tsunami to travel farther and faster onto land..."
https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami
As pointed on the comments, because water gets its maximum weight at 4 degrees maybe they are trying to fill in first with 4 degree water, from bottom to top, and then move on to lower the temperature below 0.
ReplyDeleteWhat I dont get, maybe a bit naive, is why they are trying to do it in summer.It is true that rains are not so strong but temperature of water flows, soil and environment does not seem to help... also working in those suits must be hell..
A few weeks ago NHK tv newscaster visited the headquarters in Fukushima and was talking with some of the staff.First time in prime-time, AFAIR. Felt kind of a Tepco infomercial to calm the masses but better than nothing.. I hope these people get more recognition..
"If TEPCO can't even get the top ..to ice over then they have bigger problems to deal with."
ReplyDeleteThey should try partitioning the water with baffles to break its flow as a body.
Ha ha ha, "defies (the) laws of physics", there's a good writer there, with a Marx brothers-like sense of humour. In French we would say it just the same : défie les lois de la physique. Lol, Phiphi.
ReplyDeleteDo we need greater evidence than this:
ReplyDelete"Nowhere close. .. after 3 months of freezing.
Ahhh good (bad) old days are back... when TEPCO used diaper polymers, saw dusts, shredded newspaper .. "
Flawed TEPCO narrative +
TEPCO must have been using the outlier measures of temperature to get those results these last few years.
And those tepcam videos of heat rising above the reactors? There 'ya go ..
To Anonymous at July 31, 2014 at 9:16 PM : it's true that summer is not the best for some freezing ops, but if they do it in winter and the can't keep it up during the next summer then it would not be much help anyway...
ReplyDeleteBut actually the real reason is simply that they got the permissions and finished the preparations. So they moved.
Uht oh, Obokata's boss offed himself!
ReplyDelete"As deputy director of Riken’s Center for Developmental Biology, Sasai supervised the work of lead author Haruko Obokata .. "
"Sasai left five suicide notes ..
.. recently had trouble communicating due to side effects of medical treatments he was undergoing .. "
http://www.theglobeandmail.com/life/health-and-fitness/health/researcher-dies-by-suicide-after-japans-stem-cell-research-scandal/article19911278/
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ReplyDelete