Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[rmattila]

NEI: UPDATE AS OF 1:30 P.M. EDT, MONDAY, MARCH 28:
Tokyo Electric Power Co. has detected isolated, low concentrations of plutonium in the soil at the Fukushima Daiichi nuclear power station. The density of plutonium is equivalent to the fallout that reached Japan from nuclear weapons testing during the Cold War, the company said.

TEPCO conducted analysis of plutonium contained in the soil collected on March 21 and 22 at five locations at the Fukushima Daiichi plant. Plutonium 238, 239 and 240 were detected, however just two of the samples may be the direct result of the recent incident, considering the ratio of the plutonium isotopes.

"The density detected in the plutonium is equivalent to the density in the soil under normal environmental conditions and therefore poses no major impact on human health," TEPCO said. The company said it plans to strengthen environmental monitoring inside the station and surrounding areas.

The results can be found on the TEPCO report:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110328e14.pdf

At sampling spots 1 and 5 the ratio of Pu-238 to total Pu activity is of the order of 1..2, which means the Pu originates from fuel with burnups > 10 MWd/kgU, i.e. reactor fuel. So, even though the absolute value of the Pu activity is not significantly higher than that resulting from the atmospheric nuclear testing, its composition implies that some fuel damages have occurred in such a way that small amounts of fuel have been dispersed to the vicinity of the plant.

The locations of the sampling spots are shown there:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110328e15.pdf

 

[Paul F.]

I've been wondering about the backup generators that were flown in that had "plugs which could not be used"...

I wonder if, since part of Japan uses 50hz power, and another part uses 60hz, if it was actually a mis-match of equipment phase, rather than the physical "plug" that was mismatched?
A poor translation, perhaps?


Paul F.

 

[PietKuip]

Pietkuip, you said: "30 sievert/hour"

Ouchhhhhh...

thanks for the clarification!

But I see in many articles written that the radiation is 1 Sievert/h in turbine building 2, which i interpret then as a mistake from a misleading info if I understand well: is it that difficult to have instruments measuring more than 1 sievert/h? Again that's unbelievable so see how information is biased because of inaccuracies and again misleading infos from TEPCO... Saying it's "more than 1 Sievert/h" when it's probably 30 Sievert/h is a misleading way (as a minimum!) of saying things, don't you think?

This failure in reporting is the incompetence of journalists and "experts", at NHK and other places. Some of them get it right, though. For example this guy: http://yokosonews.com/live/ He reported accurately that the true dose rate might be several times higher. And he seems to be mainly a culture and entertainment reporter. It seems that he had his info straight from watching a Tepco press conference.

No, it is not difficult to measure higher dose rates, see a previous posting. But the workers do not carry such instruments.

I must modify my estimate a bit with a caveat: I was tacitly assuming equal depths of the water in buildings 2 and 3. Dose rates will be higher if the water is deeper, up to the screening length for gammas.

 

[Reno Deano]

A properly designed radiation measuring instrument can easily measure 30 Sieverts per hour with little saturation or nonlinearity.

1 Sievert = 1 joule (of energy deposition) per Kg = 0.001 joules per gram

1 Sv/hr = 280 x 10^-9 joules per gram-sec

Because it takes about 35 eV to create an electron-ion pair in nitrogen (for example), the current in an ionization chamber would be about

1 Sv/hr = 7.9 nanoamps per gram of nitrogen gas (or air). 1 liter of air at STP is about 1.29 grams.

So 30 Sv/hr = 310 nanoamps per liter of gas in the ionization chamber.

For high dose rates, the ion chamber must be properly designed to minimize the effects of space charge (in the gas) on the electric fields in the chamber, which can affect the charge collection efficiency.

Radiation levels of this order are often seen around particle accelerators. The radiation detectors are designed to measure over 1 Sv/second. See

http://ab-div-bdi-bl-blm.web.cern.c...ectors/Literature/schaefer_biw02_tutorial.pdf

Bob S

-----------------------------

Areas around particle accelerators are enviornmentally stable. Only post TMI reactor compartment (dry well and reactor building) gamma detectors are designed and hardened for ultra-high dose rate measurements (10^5 Sv/hr) in a degraded environment. The equipment I am referring to is off the shelf laboratory type detectors.

 

[liamdavis]

Here are a couple of radiation mapping sites for Japan. The last one is the organization that makes them possible. They are probably more of interest from an academic standpoint of examining spontaneous self-help networks since the calibration would be difficult to establish. But since they monitor radiation I thought they might be of interest, if not use, here.
Liam

http://japan.failedrobot.com/

http://www.rdtn.org/

http://community.pachube.com/node/611

 

[Demidrol]

The results can be found on the TEPCO report:
At sampling spots 1 and 5 the ratio of Pu-238 to total Pu activity is of the order of 1..2, which means the Pu originates from fuel with burnups > 10 MWd/kgU,

That is the core of the reactor?

 

[britinjapan]

Could someone comment on the existence of Plutonium that has now been confirmed in the soil - does this make the current radius around the plant likely to change? What is the possibility of Plutonium spreading through the air and water to destinations further out of the zone (80km US has deliniated?)?

I`ve read that Plutonium is heavy and does not penetrate paper, but is exteeme if inhaled. Thanks

 

[Passionflower]

According to the same article those 20 to 50% might as well be 10% when the French do the math. (assuming it's math they are doing)

Any how , make your mind by your self !
I'll leave it to you to judge of the merit of the claim (speculation really) from the Austrian Weather channel http://www.zamg.ac.at (that's the expert)
(and may be blame the journalist...)

This data is not from the 'weather channel', are you intentionally trying to discredit the report?

The New Scientists reports on the same information:
http://www.newscientist.com/article...dioactive-fallout-nears-chernobyl-levels.html

 

[M. Bachmeier]

My Nephew, who was living in Tokyo and is now coming home:

http://www.chugai-pharm.co.jp/hc/Satellite?c=CrpCorner_C&cid=1259593215924&pagename=Chugai%2FCrpClassification

Just thought I'd try to remind people that this is also a human issue. It affects all of us. Our judgment, our empirical approach, our perceived knowledge and our humanity. I guess there are some things we can't be empirical about.

 

[|Fred]

I would be more interested in the How that in the from where, and would appreciate if someone could speculate on how Pu could make his way to the location it was found?

 

[TCups]

I would be more interested in the How that in the from where, and would appreciate if someone could speculate on how Pu could make his way to the location it was found?

From a "dirty boom" at unit 3?

 

[Passionflower]

From a "dirty boom" at unit 3?

It is possible.

The longer this is going on the less I am trusting TEPCO. It appears that they have a history of lying and fudging data. And the Japanese government is asking them to provide more information. Well at least it is not begging.

See for instance:

http://online.wsj.com/article/SB10001424052748703363904576200533746195522.html

"In 2007, an earthquake heavily damaged Tepco's Kashiwazaki-Kariwa plant. The company initially said there was no release of radiation, but admitted later that the quake released radiation and spilled radioactive water into the Sea of Japan."

"In Japan in 1999, an uncontrolled nuclear chain reaction at a uranium-reprocessing plant killed two employees and spewed radioactive neutrons over the countryside. Government officials later said safety equipment at the plant was missing and the people involved lacked training, adding that their assessment of the accident's seriousness was "inadequate.""

"..The scandal was the latest in a string of nuclear safety records cover-ups by Tepco, including the revelation that the company's doctoring of safety records concerning reactor shrouds, a part of the reactors themselves, in the 1980s through the early 1990s. Five top executives resigned after the company admitted to having falsified safety."

"In 2003, Tepco shut down all of its nuclear reactors for inspections, acknowledging the systematic cover-up of inspection data showing cracks in reactors. "

"The Fukushima Daiichi plant has a black mark on its record from earlier in the last decade, when a scandal involving falsified safety records led to parent company Tepco briefly shutting down its entire nuclear fleet in Japan. In 2002, Tepco admitted to the Nuclear and Industrial Safety Agency that it had falsified the results of safety tests on the containment vessel of the No. 1 reactor, which is now one of three reactors that workers are struggling to keep from overheating. The test took place in 1991-1992. "

http://nuclear-news.net/2011/03/22/tokyo-electric-power-company-tepco-faked-nuclear-safety-records/

"The operator of the Fukushima No. 1 plant submitted a report to the country’s nuclear watchdog 10 days before the quake hit on March 11, admitting it had failed to inspect 33 pieces of equipment in its six reactors."

"A power board distributing electricity to a reactor’s temperature control valves was not examined for 11 years, and inspectors faked records, pretending to make thorough inspections when in fact they were only cursory, Tepco said."

 

[liamdavis]

Not news but an interesting article on electronics in a radioactive environment. It may address some questions some of us new folks have on the reliability of data from electronic devices in an environment such as at Fukushima.
liam

http://spectrum.ieee.org/tech-talk/semiconductors/design/radiationhardening-101

 

[Soafcom]

If the fuel grains wash out, they go with the flow. If there is no flow, then they would settle toward the bottom of the core, or down through the plenum under the core plate.

Now, with the seawater, I have to wonder if some of the fuel particles will actually dissolve, in which one then has a solution, e.g., uranyl chloride. I don't know of any research into the chemical behavior of spent fuel in seawater.

The best source I could find for seawater interactions of fission products was related to the dissolution of Plutonium Dioxide in radioisotope power generators used in space exploration:
http://www.osti.gov/bridge/servlets/purl/4839392-lrKndC/4839392.pdf

Basically, the microspheres they tested did not dissolve very well into sea water (about 0.012 - 0.016 μg/mg/day - p19) and (this isn't relevant yet, but if PuO₂ were released into the open ocean it's a good thing) if they are encrusted with marine growth their dissolution rates go down by about half (about 0.0048 - 0.0076 μg/mg/day - p19.)

This obviously doesn't take into account the presence of other compounds in close proximity that might chemically interact with the Pu.

 

[razzz]

How many pounds or tons of fuel rods in 1 of these types of working reactors then *3/50% (conservatively speaking) for a possible amount of radioactive lava?

 

[fusefiz]

This may well be a naive reaction, but it seems to me that the obvious thing to do with the radioactively contaminated water in the turbine buildings is to pump it back into the reactors. Is there something wrong with that action? If/when they are able to re-establish core cooling, perhaps they could then work on dealing with the water contamination (salt, radioactive elements, etc) and leaks. But until then, why not reuse this water for the evaporative cooling?

 

[jensjakob]

Trench dimensions:
3x4x76 meters.
Source: http://www3.nhk.or.jp/daily/english/28_h37.html

3x4x76 = 912 m3.

Lets say 70% is full of water = 638 m3 of water. That is a lot of water...

I would like to learn:
1. Did it fill up from the Tsunami wave? Plausible.
2. When did last time inspect it - i.e. has it been dry after the Tsunami hit?
3. The article above talks about "a poodle of water" - which is VERY different from other stories of "filled to the brim".

Bottomline:
1. We don't know how much water is in the trenches
2. It would be good to learn how water rthere is
3. And if the trenches has been reported dry since the tsunami

and
4: Has these trenches been regularly checked for water seeping out of the containment?

 

[Joe Neubarth]

This may well be a naive reaction, but it seems to me that the obvious thing to do with the radioactively contaminated water in the turbine buildings is to pump it back into the reactors. Is there something wrong with that action? If/when they are able to re-establish core cooling, perhaps they could then work on dealing with the water contamination (salt, radioactive elements, etc) and leaks. But until then, why not reuse this water for the evaporative cooling?

Pump highly radioactive water to an area where it can be heated and release more radioactive delayed neutron precursors or accelerate gamma or Beta emitting dispersal?

Not a good idea.

 

[Bodge]

This failure in reporting is the incompetence of journalists and "experts", at NHK and other places. Some of them get it right, though. For example this guy: http://yokosonews.com/live/ He reported accurately that the true dose rate might be several times higher. And he seems to be mainly a culture and entertainment reporter. It seems that he had his info straight from watching a Tepco press conference...

Katz from Yokoso News is a legend! He has been broadcasting, whilst monitoring and translating several Japanese sources simultaneously. 10 hours a day since the crisis started, all with great professionalism and humour.

 

[rogerl]

Guys. If radioactive water keeps leaking and outside to the Pacific Ocean. How many miles off shore will the danger remain? I only eat fish and concerned about this.

 

[|Fred]

This data is not from the 'weather channel', are you intentionally trying to discredit the report?

ZAMG is the state meteorological and geophysical services in Austria (link provided in my original post), in mundane terms it's the Austrian weather channel.
I quoted the actual report rather than a press mixed version (press did not even bothered linking there source).
In the initial paper produced by the Zamg Dr. Gerhard Wotawa explains that they only feed 2 measuring points to there mathematical model extrapolating from data from the first few days.
This model gave result that are up to 40 points different from an other model based on similar data.

It does raise the question of reliability on what is presented as hard fact, in my opinion.

 

[M. Bachmeier]

I'm sorry, but does this discussion need to be a post apocalyptic (re: Joe Neubarth type of speculative fiction) or a valuable resource toward possible solutions?

Sorry Joe, you see the negative 10E* potential outcome in your fiction, but that is the nature of fiction. And with respect you help make my point clear.

I suggest something different.

There are thousands of people who could contribute toward amortization of this issue. The first step is (in a situation like this) a forensic analysis of what went wrong. This is missing (with respect to time). A very top down kind of analysis has been occurring. Who's asking what happened in the first hour.. minutes, 2hrs. + 24hrs.

The young minds who regularly contribute to this forum could be a sounding board + all others toward a bottom up analysis (which in this case needs to happen faster than normal) in order to participate in potential solutions with regard to substantive input.

What happened in the first hr. after main power loss? (not just a summary)?

What happened in the first 12 Hr. Re: after main power loss and backup failure?

What decisions were made based on 'then' expectations and loss of data?

I think this is a case where forensic analysis would be better served as a balance between speculation and hypothesis WRT initial conditions leading outward where possible. Followed by the active post-forensic approach that is seemingly dominant.

 

[|Fred]

From a "dirty boom" at unit 3?

so we are talking about the rods in the pool

M. Bachmeier,
Tepco did not provide data for the first 12h or so.. Mitsuhiko Tanaka pointed just like you did that the first 12h are crucial to understand what could have happen.. from the initial data he does figure a few thing
Reactor 1 Core vessel at t+12 is at 0.80Mpa donw from 7MPa , First reading of Containment Vessel is at 0.8Mpa (twice the design spec) up from 0.1MPA normal operating pressure.

 

[dave2004]

Guys. If radioactive water keeps leaking and outside to the Pacific Ocean. How many miles off shore will the danger remain? I only eat fish and concerned about this.

A very quick and dirty back of the envelope:
length of beach, let's say 500m on both sides of the factory, makes 1000m
area up to 500m from shore
average depth between beach and 500m distance: 100m
makes a volume of 5x10^7 m3

If you consider dumping for example 5000m3 of highly contaminated waste, you would dilute it by a factor 10'000.
(if uniformly distributed, not considering fish living close to the pipes leading into the sea, those I would avoid)
In my opinion, sea pollution is less of a problem than land pollution because of its 3 dimensions (on land Cs will stick to a certain limited depth where the plants have roots).

 

[georgiworld]

My Nephew, who was living in Tokyo and is now coming home:

http://www.chugai-pharm.co.jp/hc/Satellite?c=CrpCorner_C&cid=1259593215924&pagename=Chugai%2FCrpClassification

Just thought I'd try to remind people that this is also a human issue. It affects all of us. Our judgment, our empirical approach, our perceived knowledge and our humanity. I guess there are some things we can't be empirical about.

How do you explain this?

Goldman Sachs Employees Told Not to Leave Japan
http://www.cnbc.com/id/42304574

 

[trinon]

According to the same article those 20 to 50% might as well be 10% when the French do the math. (assuming it's math they are doing)

What french calculation are you quoting?

Anyway, is there another dispersion model calibrated with CTBTO data available? The ZAMG model (the national authority to analyse CTBTO data in Austria) does a good job on the prediction of radioactive emission according to their recent http://zamg.ac.at/display.php?imgPa...urce=©+ZAMG&imgWidth=1199&imgHeight=740"

They also made a nice animation of the model available to the public:http://zamg.ac.at/pict/aktuell/20110325_Reanalyse-I131-Period1.gif"

 

[M. Bachmeier]

How do you explain this?

Goldman Sachs Employees Told Not to Leave Japan
http://www.cnbc.com/id/42304574

My nephew is the taller guy asking questions in English.

 

[Astronuc]

The best source I could find for seawater interactions of fission products was related to the dissolution of Plutonium Dioxide in radioisotope power generators used in space exploration:
http://www.osti.gov/bridge/servlets/purl/4839392-lrKndC/4839392.pdf

Basically, the microspheres they tested did not dissolve very well into sea water (about 0.012 - 0.016 μg/mg/day - p19) and (this isn't relevant yet, but if PuO₂ were released into the open ocean it's a good thing) if they are encrusted with marine growth their dissolution rates go down by about half (about 0.0048 - 0.0076 μg/mg/day - p19.)

This obviously doesn't take into account the presence of other compounds in close proximity that might chemically interact with the Pu.

From the OSTI report - the ambient temperature was 15°C. I expect the temperatures in core are much high - ~ 200°C or higher, especially if proper cooling is not obtained.

The PuO₂ microspheres were also stoichiometric oxide, as opposed to irradiated fuel with a spectrum of fission products, so of which, e.g., I, Cs, Br, Rb are readily soluble in water.

 

[ExecNight]

I have been following this thread out of curiousity. And after such a long time, people still talking about possibilities just tells me something is wrong.

What i think is even if there is a catastrophic radiactivity, it will be held confidential for various reasons. And people will start talking about Fukushima again when cancer rates around the region increases ten times..

 

[TCups]

so we are talking about the rods in the pool

Well, speaking about what happened early on, Unit 1 blew up immediately after venting. That might make operators reluctant to go ahead and immediately vent Units 2 and 3. So pressure builds until Unit 2 and 3 explode. Unit 2 blows through the torus suppression pool without a lot of external damage to the building. Plutonium doesn't get on the ground that way. But Unit 3 was, as Ed Sullivan might have said, a "big, big, really big" explosion. My best analysis of the photos says it blew up and out of the south end of the top floor of Bldg. 3. If the source were from inside the primary containment and it didn't blow out of the torus pool, then it blew the drywell cap, came out the side of the primary containment, through the chute, and into the SFP.

That, to me, seems the most likely route to get Pu out, up, and back down on the ground.

Correct me if I am wrong, but there was no Plutonium in the SFP at Unit 4, right?