Wednesday, July 31, 2013

#Fukushima I Nuke Plant Groundwater Contamination: High Contamination Confirmed in Water in Shaft B Connected to Reactor 3 Turbine Building

But the level of contamination is less than water in Shaft C that connects to Reactor 2 turbine building.

TEPCO announced the results of nuclide analysis of the water sample taken from the Shaft B (see the diagram below, from TEPCO's 7/26/2013 document, with added English labels) at different water levels in the shaft. Shaft B and the seawater intake pipe trench that connects to the shaft go to Reactor 3's turbine building.

In an effort perhaps to make the data more accessible to mere mortals, in addition to announcing the results in liter TEPCO also spelled out the numbers instead of using "x.xE+x" format. (I wish they just used Bq/cm3. Too many zeroes, and I couldn't grasp the numbers right away.)

From TEPCO's 8/1/2013 handout for the press in Japanese (English labels are by me):

Comparing Shaft B for Reactor 3 and Shaft C for Reactor 2, you will note:

  • Chloride content is one order of magnitude bigger in Shaft B than in Shaft C.

  • Cesium content is one order of magnitude smaller in Shaft B than in Shaft C.

  • All-beta content is one order of magnitude smaller in Shaft B than in Shaft

Therefore, unlike the water in Shaft C and seawater pipe trench for Reactor 2, the water in Shaft B for Reactor 3 is not likely to be the highly contaminated water that leaked to the ocean in April 2011. Rather, the density is in the same order of magnitude as in the water that is currently in the Reactor 3 turbine building basement.

According to the most recent analyses of the contaminated water inside the turbine buildings,

Water in the Reactor 3 turbine building basement (as of 6/13/2013) has:

  • Cs-134: 1.5E+04 Bq/cm3, or 15,000 Bq/cm3

  • Cs-137: 3.1E+04 Bq/cm3, or 31,000 Bq/cm3

For reference, water in the Reactor 2 turbine building basement (as of 7/22/2013) has:

  • Cs-134: 1.1E+04 Bq/cm3, or 11,000 Bq/cm3

  • Cs-137: 2.5E+04 Bq/cm3, or 25,000 Bq/cm3

The numbers are comparable to water in the Reactor 3 turbine building basement but one order of magnitude smaller than the water sitting in the Shaft C and trenches connected to it.

Put the information yet another way for easier comparison, the numbers in Bq/cm3 instead of Bq/liter, except for chloride (click to enlarge):


Anonymous said...

Or, Unit 3 leaks like a sieve and is being cleansed by groundwater or radioactive contaminated waters are flowing away in different directions compared to Unit 2's melted core that found different avenues to flow to solidify and is better able to contaminate trapped water.

Just possibilities.

Anonymous said...

How is it possible that in rector 2 shaft C at 13m the reported values are (in Bq/cm3):
134Cs 300000
137Cs 650000
all beta 520000

Should not all beta exceed or be close to the sum of 134Cs and 137Cs at least?

Anonymous said...

Anon 7:46AM: Cs are the easiest to detect. The heavier, longer lasting elements take more time to test for and identify, usually are not in Tepco's reports beside the 100+ cocktail of all other decaying man made radioactive isotopes with their alpha, beta, gamma, xrays and probably neutrons flying around.

M. Simon said...

You are my goto guy for all things Tepco. So I'm back.

Since you like technical stuff I should let you know that I now blog regularly for:

netudiant said...

The reality of Fukushima is still very bad, but we should not fail to recognize progress where appropriate.
Over the past 30 months, cumulatively, TEPCO has reprocessed about 500,000 tons of coolant water, of which 300,000 tons are in storage and 100,000 tons are flooding the site.
During that time, the radioactivity of the coolant has dropped by 99%, from millions to tens of thousands of bequerels/milliliter.

Imho, that is wonderful news, not so much because it shows that TEPCO's reprocessing has not been entirely futile, but rather because it proves that the much larger quantity of contaminants still in the reactor fuel remains in place and is not getting mobilized by the coolant water, even though the zirconium cladding has burned off.
That imho transforms the problem into a long term disaster, rather than an imminent threat.

Anonymous said...

netudiant: You read as a bit numb from 3 meltdowns. Another major quake will roll through the plant again, it is only a matter of time.

If the melted cores were contained, I might agree with you but they are exposed to the elements and will leak long past your lifetime.

Like Chinese water torture, one drip at a time.

Anonymous said...

"exposed to the elements"?

Do you have a link to that information? Thanks.

Anonymous said...

Anonymous said...

"exposed to the elements"?

Do you have a link to that information? Thanks.
August 2, 2013 at 7:39 PM
I'm going to refrain from calling you fuk'in moron because I think you can 't comprehend what you are reading, it's the only possible explanation.

This EX-SKF site has posting after posting of higher than normal radioactive readings, pictures of radioactive steam (condensation), dead robots frozen in time, remote construction removal work of 'hot' debris, workers and visitors in Tyvek suits. Why would they use robots and remote machinery? Could it be cause everything is radioactive and to dangerous for humans to get near? Are the Units covered and secure from leeching of radioactivity to the air? Are high radioactive readings from wells and ocean water because the melted core are inside secure and watertight containments?

Exactly what hint do you need to clue you in that there is no containment and hasn't been any since at least after the explosions? The Great Quake dislocated the foundations and connecting tunnels and since have filled with radioactive water from contact with melted cores and now freely leak in every direction into groundwater then onward to the sea hence the high radioactive readings being reported by TEPCO.

TEPCO doesn't know where the melts cores are but everything is fine. Right?

netudiant said...

I think we should not talk past one another.
The current status is clear, 3 reactors with cores molten down and breached containments, in a facility that is invaded by ground water and extensively contaminated by the radioactive materials released during the meltdowns and explosions.
It is also clear that all the activity to date has been peripheral, trying to clean up the site sufficiently to allow some path forward to be determined. By analogy, we are at the stage where the patient is getting cleaned before the operation, nothing more. The actual job of finding and removing the nuclear fuel is still a long ways off.
Meanwhile, the fact that the radioactivity of the water on the site has fallen by 99% since the accident is a major positive.
First, it shows that the water decontamination is doing its job.
Second and more important, it shows the fuel is not contaminating the water seriously. If it were, the water would be getting more radioactive, not less, because there is still hundreds of times as much cesium in the fuel as the amounts released to date.
Because the fuel is already out and the site structures busted, another earthquake would simply make the rubble bounce, but not change things much, imho.

Anonymous said...

netudiant (Mr. Kool):

You can always go to work for TEPCO making optimistic unsubstantiated conclusions because they control the numbers being released.

Spent fuel pools have to be unloaded, that is the only thing in their power to control at the moment. Lost melted cores...well, there is no answer for that.

You won't live long enough to see the end result of Daiichi, Fukushima.

arevamirpal::laprimavera said...

(OT) I ask readers to be civil when leaving comments.

netudiant said...

Hi anonymous@12:30,
No argument that I won't live long enough to see the end result of this disaster.
Likewise no argument that TEPCO/Japanese Government controls the available information and spins it to the most optimistic perspective.
Finally, agreed that unloading the spent fuel pools is the next major step apart from dealing with the ground water issue.
That said, there is a real gap between spin and outright falsifying the numbers. While TEPCO has made selective omission of data a fine art, they have not afaik resorted to simply pulling numbers out of the air. So I go with what is in print on their web site, which is also endorsed by the various Japanese agencies that are involved, for what that is worth.
That data does show a 99% decline in the radioactivity burden of the 100,000 tons of water flooding the facility. Part of that is because 500,000 tons of water have been treated, with 300,000 still in tanks, the rest recycled. Another part is surely because the water under the plant does flow into the ocean, along with the rest of the ground water.

The key point imho is that while there is 300 times as much cesium still in the lost fuel under the plant as was emitted thus far, it is not getting mobilized, otherwise that plant water would be getting more radioactive, not less. I was surprised by that, because cesium is pretty reactive and I had expected it to get leached out of the lost fuel by the warm salty water in the plant. We can only be grateful that it is not happening, because there is no way, short of really large scale suicide missions, that this site will be cleaned up in less than 20 years. The lost fuel will stay exposed until then.

Post a Comment