Monday, April 8, 2013

Latest on Ever-Changing #Fukushima I Nuke Plant In-The-Ground Water Storage Leak: Now the Pond No.1 Is Also Leaking

(For the latest on April 10, 2013, see my latest post with continuous update.)

(For more information, see the previous post on the leak, including photos of the "pond" construction.)

While the Nuclear Regulatory Authority has said there is no other choice but to continue using the in-the-ground water storage (as they themselves are partly responsible for the current mess because of their insistence on ALPS vessel safety, which has significantly delayed the deployment of the system), a blame game is starting between TEPCO and the construction company who built these storage facilities in the ground.

TEPCO, after having speced out the in-the-ground water storage for Fukushima I Nuclear Power Plant, contracted Maeda Construction, a second-tier general construction firm. TEPCO is blaming Maeda Construction for the faulty construction, and Maeda Construction is blaming TEPCO for sloppy specs.

Or both, is my guess. And some more.

Latest information from Mainichi Shinbun (4/9/2013):

Liners used for the in-the-ground storage construction:

  • 1st and 2nd layers: Polyethylene (HDPE) sheet, 1.5 millimeter thick

  • 3rd and the bottom layer: Bentonite sheet, 6.4 millimeter thick

Leak detection pipes were installed through the 1st and 2nd layers

TEPCO's claim:

"Similar specifications have been used for constructing agricultural ponds. There is no problem if the leak detection pipes pierce through the layers, as long as the location is above the water."

Maeda Construction's claim:

"In water storage ponds, if such pipes are used that pierce through the liner sheets, the sheets may get pulled by the weight of the water, creating the gap through which the water could leak. Therefore, you don't spec these pipes to pierce through the sheets. As to the sheets themselves, we have used them for the storage facilities for solid objects, but never water."

TEPCO's spokesman Mr. Ono claimed in the press conference that the bentonite sheet must have absorbed a large chunk of radioactive strontium, and that justified TEPCO's announcing 710 billion becquerels of all beta in the leaked 120 tonnes of waste water.

But wait... This is no ordinary waste water. It is extremely saline.

Another Mainichi article (4/7/2013) quotes Professor Hideo Komine of Ibaraki University (civil engineering and geotechnology), who says:


[There is a possibility that] because of the high salt content in the waste water, bentonite did not expand, and didn't function as waterproof material.


The thicker the bentonite sheet, the more waterproof. The sheet used at Fukushima I Nuke Plant may not be thick enough.

Oops. But wait, there's yet some more. It's not just salt in the water. There are also cation (or positive ion). There are people who thinks the effect of radioactive materials, salt, and cation in the waste water on the bentonite sheet must be studied.

On a comical note, TEPCO has sent out the email notice No.20 to the press (which these days they post on their websites, a slight improvement) saying the company has resumed transportation of waste water from the pond No.2 (the one found with 120-tonne leak) to the pond No.1.

Resumed? Yes, resumed. It was stopped. Why was it stopped? Well, it was stopped when they noticed that some of the water they had transported to the pond No.1 was coming back into the pond No.2.

Why? you ask? TEPCO says it must have been a siphon effect.

OH WAIT... TEPCO just published the email notice No.21, and it says:


We conducted the analysis of water taken this morning from the in-the-ground water storage No.1 drains (2 locations) and from the leak detection pipes (2 locations).


According to the result, chloride concentration of the water taken from the leak detection pipe (northeast) rose to 910ppm from 4ppm yesterday.


Transfer of water from the in-the-ground water storage No.2 to No.1 using the temporary pumps was halted at 12:47PM.

So the pond No.1 is leaking. First it was just No.2, then No.3. If they cannot use No.1 and No.3 (they continue to use No.3 despite the leak, which they claim very minor), 27,000-tonne capacity is removed from the total 58,000 tonnes from 7 ponds.

When I saw him yesterday via the vid, Mr. Ono, TEPCO's spokesman, was rather confident that the water leak may not be that bad, because the layers may have effectively absorbed the water.

And the biggest problem: radiation levels. Even though most of gamma nuclides have been removed, the water contains 290,000 becquerels/cubic centimeter of all betas (mostly strontium). The radiation level on the surface of the waste water may be as high as 2 sievert/hour (beta radiation only), says independent journalist Kino, citing the leak from a tank storing the same waste water that happened on February 3, 2012. (Here's TEPCO's document, in Japanese; see pages 2 and 3.)

Let's check in to their latest presser (2:30PM local time) and hear what he has to say.

(Independent journalist Ryuichi Kino just tweeted that he is hurrying to the press conference, but says he got the email notice at 1:35PM, and sighs, "This is so like two years ago...")


(UPDATE) TEPCO press conference is still going on, nearly two hours after the start. My take is that TEPCO are in big trouble, trying to find any empty storage that can take 400 tonnes/day of the waste water after RO... Mr. Ono is very subdued today. A lot of reporters, and the room is almost full.


Anonymous said...

Now is time to act:
1) Turn on ALPS
2) Treat the water (and release the essentially harmless tritium)
3) Stabilize the resulting concentrated waste into solid blocks

Liquid waste is ALWAYS a problem, as numerous examples in the chemical and nuclear (e.g. legacy stuff at Hanford, Sellafield) industries attest.
Especially strontium is easy to include in concrete (in replacement of some of the calcium). If you cast the concrete into a "clean" concrete outer casing, the resulting blocks are very safe to handle, and may even be usefully recycled, e.g. as tsunami barriers for nuclear plants :-)

Concerning the bentonite sheets, you normally encase them in mechanically stable terrain - typically behind a sufficiently reinforced concrete layer. Did TEPCO / Maeda do this?
Otherwise, it's a well-known issue that in the case the ground moves a little (especially due to the additional weight of the water and low stability of freshly-excavated earth), the waterproofing sheets may rip, even without penetrations…

Anonymous said...

ALPS has already been turned on. It was started on 30 March 2013. See

Anonymous said...

ALPS is on the hot test run that will take months. The original start date for the actual water treatment was September last year, after a few weeks of hot test.

Atomfritz said...

1.5mm – this is less than the PE foil John Doe uses for his backyard Koi pond.

@anon 12:31

The drawing on the last page on Tepco document [*] indicates that possibly there was another small bentonite layer between concrete and the PE foil.


It also indicates that the PE foils were pierced twice, in contrast to the Maeda statement.
Did Tepco people walk around in the delicate tank to install the piercing probe, damaging the brittle PE foil and the bentonite?

@anon 11:45

The link you provide only tells that stage A of Alps has been put into hot testing.
It will take a while to complete tests, and then stages B and C will have to solve the same bureaucratic challenges, too, before Alps can go into full operation.

Anonymous said...

@ Atomfritz

Hot testing means cleaning contaminated water for real. If the test goes well, perhaps the amount of water that gets cleaned is not much smaller than the amount that gets cleaned under normal operation.

Atomfritz said...

Tepco now also released other isotope measurements, including ruthenium in quite high quantities.
The measurements Tepco publishes, however are just that what remains from the bentonite absorption from the leak spot to the sampling spot, potentially through dozens of meters.
The bentonite will be well-soaked with undesirable isotopes, releasing quite a few sieverts of beta on the surface. This alone should qualify for an INES 4 incident.

But, the true problem is: where does the main part of the water go to? The bentonite shell is only 6.4 mm thick. This means, it will be washed out quickly. The large grouted area is invariably full of cracks in the concrete, given the haste it was done and the least optimal season (winter). Water probably will flow out into the sandy underground without much resistance. With some bad luck, the "beta-enhanced" water will even wash out sands and undermine foundations.

And, then there are other bad things. Just one of them: HDPE foil is lighter than water. If pierced, it will swim up, opening up even more and more leak paths.
Tepco spokesman is not in a comfortable situation...

Yosaku said...

Hi Atomfritz,

Good comments. Just a few thoughts:

This HDPE material is very different than what John Doe would use for his backyard koi pond. Typical koi pond HDPE is about 20 mils (or 0.5 mm) (see, whereas the HDPE liner they’re using here is 60 mils. Trust me, you would not want to build a koi pond out of this stuff. It’s not nearly flexible enough and would result in an incredibly large koi pond that looks just like a storage pond—all straight edges and even grades.

For what it’s worth, 1.5 to 2 mm thickness in multiple layers is standard for all sorts of containment situations, including RCRA Subtitle C (hazardous waste) landfills.

Also, one of the advantages of the GCL over the CCL is that the GCL should not wash out. The bentonite is the "geo" part of the geosynthetic clay liner. The "synthetic" part is designed to ease application and keep the clay together. That being said, something has clearly gone wrong with the liner here, so maybe the bonding agent, whether needle-punching, stitching or chemical adhesive, has failed.

In addition, the HDPE liner is held down by concrete, rip rap, and the plastic inserts (see page 3 of the link you provided). I'm not worried about the fact that HDPE is slightly less dense than water here.

Atomfritz said...

Hi Yosaku,

0.5mm PE foil would be quite low-end imho, only suitable if supported with a CCL. Gardeners here (Germany) commonly use 1.5+mm foils for their biotopes to avoid these annoying leak hassles.

And I just have difficulties to understand why a 1/4 inch GCL shouldn't wash out when being pierced. I mean, when there is a hole, there is a hole. A 0.25 inch bentonite layer still is different than three feet of clay which you cannot pierce with a walking stick, worker shoes and the like.

I guess this is just advertising like "nuclear power is safe".

And, even if some part of the "tank liner" was hold down by inserts etc as shown in the pics, gravity will have helped the 100s of cubic meters strontiated water making its way into freedom by washing out the thin GCL and escaping through the concrete cracks, eased by swimming-up PE foils.

BTW, useful Wiki link:

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