Tuesday, August 22, 2017

The Ice Wall Update-eth

Another bit of PR from the ice wall people; they've been coming about one a day for several days now.

This one has a nice video, which I hope you will be able to access for some time; NHK has recently added the ability to share their news posts with several social media.  I'm hoping that means their links will last more than one day.

The video has good diagrams, and even real footage of the ice wall apparatus; good to help understand.  Take a look-

Typically for NHK, the printed text is almost exactly the same as what the newsreader presents, quoted below, then I have a couple comments on the hydraulics/physics after that:

"Fukushima ice wall's last section being frozen

Final procedures have begun to complete an ice wall to prevent groundwater from entering the contaminated Fukushima Daiichi nuclear power plant.  Tokyo Electric Power Company workers started the process to freeze the remaining 7-meter section of the ice wall on Tuesday.  They opened 11 valves to allow coolant at a temperature of minus 30 degrees Celsius to circulate in the underground pipes.

TEPCO began freezing the 1.5 kilometer long wall in March of last year. The last section on the mountain side of the facility had been left unfrozen as officials said the move could cause a sudden drop in groundwater levels around the reactor buildings.  But the Nuclear Regulation Authority said safety measures were in place and gave permission for the procedure earlier this month.

TEPCO says it could take longer than the 2 months projected based on past records for the section to freeze, because the groundwater is flowing at a rapid rate.

They say once the wall is completed, the volume of groundwater flowing into the reactor buildings will be reduced to less than 100 tons a day, from the current 140 tons.  The nuclear regulators say they will carefully monitor the effectiveness of the wall.

In good PR fashion, they are setting the stage for it to - not work.  "It could take longer..."

And; the physics: so, the ground water is flowing - IN - at a rapid rate?  That does mean - it has to be also flowing OUT - somewhere, somehow - at a rapid rate.  Which means if/when you shut the flow off, there WILL be increased pressure on the 'up' side - and decreased pressure on the 'down' side; which means the pressure gradient will be increased.

The pressure on the upside is the easiest to understand, but actually the entire gradient is a better predictor of the likelihood of new leaks.  Think of it as more "incentive" for the water to find a new way to move.

Other Japanese news sources include more definite doubts:

"But some experts have cast doubt on the ice wall, and the country's Nuclear Regulation Authority said it has not yet done an independent analysis.

" 'We doubt the ice wall is going to be as effective as TEPCO claims it will be," said an NRA official who spoke on condition of anonymity. 'We're going to monitor its progress after it is finished to check the impact. ' "

"In June, the NRA's acting chief Toyoshi Fuketa publicly accused TEPCO of lying about the wall's effectiveness."

Ice wall cost so far admitted to: ~ $320 million; paid by the "government"; i.e. Japanese taxpayers.


Jason and Michelle said...

It's too bad more people are picking up the lies the company is giving, such as circulation while something is frozen.

Steve Carrow said...

And let's say it does work. Going from 140 tons a day to ~100 tons a day is not a very good fix.

Anonymous said...

Remediation is a very profitable business model. Who has the monopoly? Who has a motive for ending this model?

Anonymous said...

Looking at the illustration and numbers for the underground water flow & dam area, I fear the hydrostatic dam pressure, with no mention of the sheer strength of the substructure, will fail catastrophically, possibly sliding the entire 'containment' structure into the sea. Irretrievable failure will end the project, but not the permanent health threat in the sea water.

Greenpa said...

Anon 1 - there has already been an international complaint from non-Japanese contractors that they are being excluded from bidding on a bunch of remediation. No surprise.

Anon 2 - there is a LOT of water flowing in that aquifer, with lots of potential for hydrostatic pressures to keep rising. So many ways for it to squirt out somewhere unexpected and undesirable.