Japan earthquake - contamination & consequences outside Fukushima NPP

[a.ua.]

I don't know, but some water levels are ... interesting. Disturbing. What's happening there??

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130823_04-e.pdf

Perhaps this is due to the full moon.
The strongest tides.?

 

[tonio]

I just looked at the data. I didn’t realize that the remediation efforts are focused at a very small area inbetween the reactor 1 and 2 inlets, possibly related to a ground water contamination caused by a spill in 2011? Three images:
- 01: general ground water quality data;
- 02: detail of area inbetween 1 and 2 inlet, with newly constructed barrier
- 03: ground water levels on 23 august 2013

Thus the ground water cleaunup works seem to be limited to the small area inbetween reactor 1 and 2 inlets. Due to the installation of the barrier in this area, the ground water level in this area significantly increased in the weeks before august 8. The ground water level in other areas (holes 2 and 3) didn't change much.

On august 8, the water level in hole 1 and the surrounding holes starts to decline. I assume that this is due to a ground water withdrawal somewhere near holes 1 /1-2. On august 17, the lowering started to accellerate, probably due to an increased withdrawal speed.

The level in hole 1-4 seems to be erratic, possibly due to a malfunction of the measurement device (electronic device).

The typical daily fluctuation of the water levels, expecially in hole 2, puzzles me. Ground water levels can show tidal variations comparable to the sea water tide, but with much smaller amplitudes, in the order of centimeters, as far as I know. Very strange!

 

[zapperzero]

Fukushima Voice version 2e: Twelfth Prefectural Oversight Committee Meeting: Thyroid Ultrasound Examination Results

 

[a.ua.]

tonio

Ground water levels can show tidal variations comparable to the sea water tide, but with much smaller amplitudes, in the order of centimeters, as far as I know.

But on Monday, Tepco said that data it collected showed the levels of the water in its test wells was rising and falling along with sea-water levels, according to the tides. That led the company to conclude that there could indeed be a link between the groundwater at the coastal side of the plant where the wells are, and sea wate

July 23, 2013,

Fukushima Watch: What's Different About the Latest Radioactive Leak Into the Sea - Japan Real Time - WSJ

 

[Rive]

I just looked at the data. I didn’t realize that the remediation efforts are focused at a very small area inbetween the reactor 1 and 2 inlets, possibly related to a ground water contamination caused by a spill in 2011?

They've just started the ground improvement work between Unit 3-4 some days ago.

The level in hole 1-4 seems to be erratic, possibly due to a malfunction of the measurement device (electronic device).

IMHO it's not likely. That data requires immediate checks. It would be really stupid from (somebody) to let it unchecked for so long.

Otherwise, it has a kind of fluctuation related to the tidal wave, but much greater scale than anything else there. Really strange. Maybe the hole was (Fortunately? Unfortunately?) drilled directly into a flow path between the trenches and the ocean?

 

[tonio]

Some observations about the ground water fluctuations:

- a.ua quotes Tepco concluding that "there could indeed be a link between the groundwater at the coastal side of the plant where the wells are, and sea water". It is difficult to believe that Tepco has made such a silly statement. Unless the site has been constructed in some sort of "bath tub" totally isolated from the surrounding ground water and sea water (which clearly is not the case), there will always be such a link.

- the ground water lever wil fluctuate together with the sea water tide with an amplitude that is equal to the tide at the contact between the seawater and the ground water (i.e. at the sea bed) and which will decrease with increasing (hydraulic) distance from the sea bed.

- the exact ground water fluctuation at any point of the site (x, y and z coordinates) could be predicted if you have a three dimensional geohydrological model of the site with the hydraulic permeability of the soil (including the backfilled materials), the just installed barrier and other possible barriers such als underground walls, quay walls, etc. I am quite certain that Tepco must have made such a model, which is absolutely required for the effective planning of ground water remediation measures.

- With respect to the fluctuation of the ground water level in hole 1-4, I would believe that a direct flow path between this hole and the sea as suggested by Rive could exist, but only if the water level in the hole would be (almost) equal to the sea level. But that is clearly not the case. Thus, it seems to me that there must be another explanation for it.

 

[zapperzero]

https://www.physicsforums.com/showpost.php?p=4486102&postcount=14130

 

[tonio]

translation...

 

[tonio]

Interesting report! Also available in English? I can't read it, but the figures more or less speak for themselves, I copied two of them.

P43 cross section geology shows the geology of the site, as far as I can see. I assume that the dark green layer is a relatively impermeable layer.

P53 cross section withdrawal shows the withdrawal wells and a map with the positions of these wells. I assume the dotted blue line gives the normal ground water table and the continuous blue lines the lowering of the ground water table as a result of the withdrawal. But what are these shallow holes left and right of the buildings?

What surprises me is that the withdrawal wells are relatively shallow, probably because of the presence of the (brown coloured) impermeable layer which prevents deeper emplacement of these wells. But it means that there will remain quite a significant ground water slope (and thus groundwater flow) towards the sea.

I don't known why Tepco emplaced these wells at the plateau and not at the foot of the steep slope, because that would have enabled a further reduction of the ground water slope and thus a further lowering of the ground water flow through the site.

 

[zapperzero]

err

the shallow holes should be piping trenches and such

 

[LabratSR]

Stumbled across this site.

Database on the Research of Radioactive Substances Distribution

http://radb.jaea.go.jp/mapdb/en/

 

[Greg Bernhardt]

How accurate is this video?

https://www.youtube.com/watch?v=3l8TT1dv-PM

 

[Rive]

How accurate is this video?

It would be good to know the released amount they used for the calculation. Anyway, it might be accurate.

But: please mind the scale! And the used color.
That part is the oldest trick in that book.

 

[russ_watters]

Looks reasonable to me, as a representation of how substances dissipate in water. Note the order of magnitude concentrations: after 1 year, the highest concentration (center of the plume) is 1/10,000th the initial concentration and it equalizes at 1/100,000th the initial concentration.

Here's some more detail:

Dilution due to swift horizontal and vertical dispersion in the vicinity of the energetic Kuroshio regime leads to a rapid decrease of radioactivity levels during the first 2 years, with a decline of near-surface peak concentrations to values around 10 Bq m−3 (based on a total input of 10 PBq). The strong lateral dispersion, related to the vigorous eddy fields in the mid-latitude western Pacific, appears significantly under-estimated in the non-eddying (0.5°) model version. (ii) The subsequent pace of dilution is strongly reduced, owing to the eastward advection of the main tracer cloud towards the much less energetic areas of the central and eastern North Pacific. (iii) The magnitude of additional peak radioactivity should drop to values comparable to the pre-Fukushima levels after 6–9 years (i.e. total peak concentrations would then have declined below twice pre-Fukushima levels).

http://www.washingtonsblog.com/2012...rica-could-be-10-times-higher-than-japan.html

 

[Azby]

Looks reasonable to me, as a representation of how substances dissipate in water. Note the order of magnitude concentrations: after 1 year, the highest concentration (center of the plume) is 1/10,000th the initial concentration and it equalizes at 1/100,000th the initial concentration.

Here's some more detail:

http://www.washingtonsblog.com/2012...rica-could-be-10-times-higher-than-japan.html

It's worth reading the original study; the HTML version includes a link to the entire video. Also, Fig.7 sums up their predicted changes pretty clearly:

Model simulations on the long-term dispersal of 137Cs released into the Pacific Ocean off Fukushima
http://iopscience.iop.org/1748-9326/7/3/034004/article?v_showaffiliations=yes

Pre-Fuku background in the Pacific was about 2 Bq/m3 (higher in the North Pacific; see attached map). The authors state:

"Tentatively assuming a value of 10 PBq for the net 137Cs input during the first weeks after the Fukushima incident, the simulation suggests a rapid dilution of peak radioactivity values to about 10 Bq/m3 during the first two years, followed by a gradual decline to 1–2 Bq/m3 over the next 4–7 years. The total peak radioactivity levels would then still be about twice the pre-Fukushima values."


Here's a more recent paper with slightly different estimates, but in the same general ballpark (within an order of magnitude or so).

Multi-decadal projections of surface and interior pathways of the Fukushima Cesium-137 radioactive plume
http://www.sciencedirect.com/science/article/pii/S096706371300112X

The attached map is from the Woods Hole website. I think it helps put the expected increases in the Pacific due to Fukushima in perspective.:

http://www.whoi.edu/page.do?pid=83397&tid=3622&cid=94989

The biggest take-away for me is that while the simulations by Behrens et al (peaks of about 3-4Bq/m3 total) and by Povinec, Aoyama et al (peaks of about 10-30Bq/m3 total), show much lower Cs137 levels in coming years near Hawaii and the West Coast than the Irish Sea, Baltic, or Black Sea in 1990, the extent of ocean affected will be vastly bigger than any of these. Along with the important caveat that these are simulations, and nature could surprise us unpleasantly.

 

[Rive]

... nature could surprise us unpleasantly.

Thanks for the simulations.

As I know Cs tends to stick in the mud, and only limited amount remains free for dilution.
For long term it would mean that:
- the measurable level in the ocean might be lower than expected
- but even with lower levels in the waters every fish from around Fukushima should be checked because sporadically there will be always some fish with high levels of Cs.

 

[Azby]

Thanks for the simulations.

As I know Cs tends to stick in the mud, and only limited amount remains free for dilution.
For long term it would mean that:
- the measurable level in the ocean might be lower than expected
- but even with lower levels in the waters every fish from around Fukushima should be checked because sporadically there will be always some fish with high levels of Cs.

Rive,

I definitely agree that monitoring of contamination in fish caught of Japan needs to be continued for the long term and improved. Maybe the least predictable aspect is what could happen in shallow water off coastlines like Hawaii, Aleutians, or the West Coast. Maybe nothing above the barely detectable level, but maybe we'll see some kind of "warm spots" (not enough to be called "hot spots").

 

[etudiant]

People eat fish from the 125 Bq/m**3 Baltic every day and in canned form it is offered for sale in the US.
Ditto the 55 Bq/m**3 Irish Sea, home of 'Organic Salmon'.
Why are these obvious targets not getting more intensive scrutiny? Better PR management than TEPCO?

 

[nikkkom]

Not to mention that K-40 contributes ~15 kBq/m3 (yes, that is "kilo"!) in seawater.

 

[Rive]

Why are these obvious targets not getting more intensive scrutiny? Better PR management than TEPCO?

I don't know about those.

But as long as I followed the sampling, there was always some fish with excess Cs values - mostly species which are:
- predators
- likes dead flesh
- living close to/on the seabed.

So I think that mud is still dangerous (or at least: what living on it can be above the limits) and it'll remain so in the next centuries even if the Cs in the seawater is low.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130925/index.html Rice was harvested for the first time since 2010 in Hirono, 30 km south of the plant, and 100% testing has started. It concerns 110 Ha or half of Hirono's rice fields.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130925/0637_ryo.html So-called test-fishing was started again (after the suspention due to the plant's contaminated water problem) in Fukushima prefecture, with 25 boats leaving Matsukawaura port, Soma city, early in the morning on 25 September. Fishing is restricted to 16 species and depths not exceeding 150 m, in locations farther than 50 km from the plant.

 

[zapperzero]

According to ex-skf blog, the so-called "trial" fishing is actual fishing, the fish will get sold.
http://ex-skf.blogspot.ro/2013/09/trial-fishing-in-iwaki-city-in.html

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131001/1520_zengyoren.html A representative of Japan Fisheries Cooperatives Zengyoren is visiting the South Korean embassador in Tokyo today to ask South Korea to lift its import ban of Japanese fish.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131001/index.html Decontamination work was started today for the first time inside the "hard to come back area", where the radiation is above 50 mSv/year. The work is started as a test in 5 locations in Namie and in Futaba. The test will be performed until the end of this year, with the aim of producing data covering efficiency, cost, and worker exposure management.

 

[a.ua.]

No decision yet on disposal sites for contaminated waste in 5 prefecture

A cattle farmer with contaminated rice straw he stores at his farm in Tome, Miyagi Prefecture, on Sept. 20

Why should it be stored?
You can mix the "dirty" with clean straw.
Furthermore, the straw is obviously contaminated mainly cesium.
It is necessary to feed the cattle 6 months of clean straw (after dirty)
In meat, the cesium will not.
* In the past (after Chernobyl) have done so.
Will radioactive manure.
This is an excellent fertilizer for sunflower and rapeseed

 

[nikkkom]

No decision yet on disposal sites for contaminated waste in 5 prefecture

Why should it be stored?
You can mix the "dirty" with clean straw.
Furthermore, the straw is obviously contaminated mainly cesium.
It is necessary to feed the cattle 6 months of clean straw (after dirty)
In meat, the cesium will not.

Because it is not the Soviet Union, where government can ignore its people opinion and health.

 

[Rive]

Why should it be stored?
You can mix the "dirty" with clean straw.

Is there a serious shortage of straw (or storage space) in the area?

Even that Cs is not all that dangerous, it should not be there. If there isn't a serious reason to let it back to the environment then it should be kept safe. Especially if it costs practically nothing.

 

[a.ua.]

Because it is not the Soviet Union, where government can ignore its people opinion and health.

I think you exaggerate somewhat.
It is a scientific fact does not correlate with the political system.
Rive

Is there a serious shortage of straw (or storage space) in the area?

And if there was a fire during the retention period?

 

[nikkkom]

Is there a serious shortage of straw (or storage space) in the area?

Even that Cs is not all that dangerous, it should not be there. If there isn't a serious reason to let it back to the environment then it should be kept safe. Especially if it costs practically nothing.

Looks like some unwarranted paranoia is at work.

It's *Japan*.

Japan IIRC is quite active in creating new land offshore (for airports and such). This requires LARGE amounts of material to be dumped.

I would imagine that all this moderately Cs-137-contaminated material, if properly immobilized, can safely be put into the lower layers of such artificial islands.

Yet, apparently it is not done. I guess because public gets hysterical every time words "contaminated" and "Fukushima" are uttered.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131005/index.html Japan is taking the Korean fish import ban (covering fish caught in eight Japanese prefectures) to the World Trade Organisation.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20131011/index.html Cesium was detected for the first time in the sea outside the port on 8 October 2013 with 1.4 Bq/l of Cs-137. This is below the World Health Organization's 10Bq/l limit for drinking water. On 10 October, the cesium concentration in the same location was below detection limit.

http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/2tb-east_13101002-e.pdf Detailed Analysis Results in the Port of Fukushima Daiichi NPS [8 October]
http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/2tb-east_13101003-e.pdf Detailed Analysis Results in the Port of Fukushima Daiichi NPS [10 October]