Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[ManuBZH]

If it was so trivial to make a big water-proof hole, they would have obviously done it.
As it takes weeks to make simple water/radiation-proof storage tanks, I highly doubt that's an easy task at all...

 

[zapperzero]

If it was so trivial to make a big water-proof hole, they would have obviously done it.
As it takes weeks to make simple water/radiation-proof storage tanks, I highly doubt that's an easy task at all...

Obviously nothing. It really is trivial. Dig, drop in pre-assembled metal section, weld to previous section, pour some concrete, cover with dirt, rinse, repeat. Three months of doing this would have produced quite a big water-proof hole.

It does not "take weeks to make simple water/radiation proof storage tanks". It's irrelevant either way. The tanks installed on-site have been bought from inventory, not manufactured since the accident.

That being said, I understand why TEPCO would want to solve the issue and start recirculating water and so I understand why they have chosen to expend effort in other ways.

EDIT: if you wanted to go all Russian about it, you could even "store" it in an open trench somewhere.
http://en.wikipedia.org/wiki/Lake_Karachay

 

[MJRacer]

(snip)
This is something that I almost know a little about (I use a RO system to desalinate seawater which is one reason I'm concerned about all the radiation dumped into the Pacific.) We have a really tricky engineering problem here. They need a very efficient oil separator before Areva's reverse osmosis system or they will destroy the membrane. The percentage of oil allowed in has to be very close to zero at these volumes. I don't imagine that oil and Zeolite interact well together. They must not remove the oil separator tower from the system. They do not have time to clean a water treatment system of radioactive oil.

I would agree. Oil would foul both the ion-exchange towers and the RO membranes. By bypassing parts of the system, they risk rendering the entire system non-functional. I have seen that happen in a municipal water treatment facility, where there was an accumulation of errors followed by attempts to "fix" them by bypassing parts of the treatment. The result was great damage to the system with markedly reduced treatment effectiveness.

One of the things that puzzles me is why they have the ion-exchange towers ahead of the flocculation (they call it co-precipitation). All the water treatment systems I am familiar with (the ones I operated, the ones I helped design and those operated and designed by others that I became familiar with) always had the flocculation step before sand filters, carbon filters, ion-exchange or RO. The reason for this is that it reduces fouling of the downstream processes. The term "salad dressing" I would interpret as the formation of an emulsion of oil with hot particles. I would use flocculation followed by filtration before the ion-exchange step. The problem is that flocculation would create a floc bed that would probably become highly radioactive and so would create operating difficulties. Second, filtration of the floc with sand or anthracite filters (which are normally periodically back-washed) would be impractical when treating radioactively contaminated water. The filter beds would become hot and back-washing would create more highly concentrated water that would, in turn, then have to be treated again.

Unfortunately, the filtration step is an essential component of flocculation. There is no point to flocculation, unless one filters the effluent from the flocculation step. Filtration by disposable membrane or DE might be an alternative, but installing that capacity at Fukushima would take some time. However, dealing with the emulsion otherwise is not going to be easy and bypassing the oil separation towers is risky. Although I have compared flocculation with the co-precipitation step, as a caveat I want to say that they might not, in fact, be equivalent. In other words, doing the co-precipitation step before the ion-exchange may not be an option. Unfortunately, the amount of detailed information that has been released about the co-precipitation step is small. It is hard for me to tell exactly what they are doing in that step.

In summary, it would appear to me that they are throwing the proverbial "kitchen sink" at the problem. They appear to be using every means of treating water that is available, but, in general terms, the technology being used is fairly standard. What is special about the various steps is in the details. The only water treatment technology that seems to be missing is a flocculation followed by filtration step after oil separation and before ion-exchange, assuming that the co-precipitation step is significantly different that it would not be technically recommended to simply do that step before ion-exchange.

 

[Atomfritz]

If it was so trivial to make a big water-proof hole, they would have obviously done it.
As it takes weeks to make simple water/radiation-proof storage tanks, I highly doubt that's an easy task at all...

I doubt the local geology will allow for the installation of a second "Lake Karachay"...
(After Mayak stopped ducting its effluents into Techa River because of high Ob River contamination they used a local lake, Karachay, as nuclear effluent dump.
At the boundary of the lake the radiation is about 600 Roentgens/hr.)

P.S.L I see Zapperzero had the same thought about the same time...

Surprise: I am not linked to any industry, I am not working for any industry. And I find your accusations mildly insulting.

I also don't know how Quim comes to thinking that Borek is a nuclear industry professional.
He appears just to be neutral for me.
But, I prefer green hair. It just looks better. :)

 

[zapperzero]

The only water treatment technology that seems to be missing is a flocculation followed by filtration step after oil separation and before ion-exchange, assuming that the co-precipitation step is significantly different that it would not be technically recommended to simply do that step before ion-exchange.

Co-precipitation is just what it says on the tin - salts are formed and precipitated out of solution, in the hopes that the radioactive alkali will precipitate along with the normal ones. Not something you need to do with regular water .

I have wondered myself why no flocculation - perhaps they don't expect to see fine particulates or heavy metals in significant quantities? I understand those are the main targets for flocculation?

 

[zapperzero]

I doubt the local geology will allow for the installation of a second "Lake Karachay"...

It's awful to think about, but they already have a lake nearby. They are drawing water from it to cool the reactors, in fact. It would be possible, I'm afraid, to dump it back in. There's no emoticon for horror, or I would have used it :P. Although I'm not sure polluting the ocean is the better alternative.

 

[ManuBZH]

It's awful to think about, but they already have a lake nearby. They are drawing water from it to cool the reactors, in fact. It would be possible, I'm afraid, to dump it back in. There's no emoticon for horror, or I would have used it :P. Although I'm not sure polluting the ocean is the better alternative.

To be precise, they are taking water from Sakagarbagea dam, here:
http://metalwings05.fc2web.com/dam/07_fukushima/sakagarbagea/index.html

 

[MiceAndMen]

Adding to NUCENG's comment - I believe the water treatment system is based on current AREVA technology used in their waste treatment streams either in their reprocessing plants or remediation programs. What we don't know is what access AREVA has had to the TEPCO site, or what information has been provided by TEPCO to AREVA concerning the contaminated water.

No, we do know this. From AREVA themselves:

For three weeks, AREVA has sent radioactive effluent treatment specialists to Japan to participate in work groups with Tepco. Backed by large teams in France, Germany and the United States, they proposed a method based on a co-precipitation concept.

http://us.arevablog.com/2011/04/19/...contamination-process-for-the-fukushima-site/

They had hands-on access to the site for 3 weeks prior to making their proposal.

 

[MJRacer]

Co-precipitation is just what it says on the tin - salts are formed and precipitated out of solution, in the hopes that the radioactive alkali will precipitate along with the normal ones. Not something you need to do with regular water .

I have wondered myself why no flocculation - perhaps they don't expect to see fine particulates or heavy metals in significant quantities? I understand those are the main targets for flocculation?

On co-precipitation, I would assume that the process shares some similarities chemically with flocculation. Some equate flocculation with coagulation/precipitation, while others distinguish between coagulation and flocculation. It can get to be very technical and, in my experience, has a lot of trial and error aspects to it (hence jar tests). In that regard, flocculation may interfere with their co-precipitation and/or the co-precipitation would be too specific to do before ion-exchange as it is not intended to remove oil emulsions. On flocculation, you are right that particulates and heavy metals are removed by it, but flocculation can be a pretty broadband treatment method. It is very effective and fairly cheap per liter, so it is also very cost effective. It makes the job of subsequent more expensive treatment methods more effective and cheaper (by reducing fouling). A further thought is that the "salad dressing" may be partially the result of the oil separation step using air flotation. In short, this is a mess that is compounded by lack of time and sheer scale.

 

[MiceAndMen]

In Japan, Germany etc there are many discussions about this interesting phenomenon of fraternalization of the nuke industry and the authorities.
People work for one side, then change their side at early retirement.
There is much money at work to which motivates people working at the regulatory to be "cooperative".
If they cooperate well they might be thanked with a well-paid leisure job.
They get much money without really have to work.
They just have to do lobby working at their former colleagues in the regulatory authority.
So these know well: "Cooperate and you'll have good income without having to work later.

This has been happening in Japan and the US as well. In the US it is known as the "revolving door", and people rotate between private industry and the agencies that are supposed to regulate them. One does not regulate too strongly lest he make enemies that would preclude a nice paycheck in the future.

To be fair, it is not just a problem in the nuclear power industry. It also exists in the financial industry where "regulatory capture" is pervasive and results in watered-down regulation at best and policy disaster at worst.

The problem exists in just about every industry where lobbyists ply their trade.

 

[Orcas George]

IMO it would be better to flood the Fukushima site and have the Japanese pay the cost of their series of blunders, rather than trashing the Pacific.

I agree that trashing the Pacific is a very serious matter and that the media and industry are too nonchalant about it. I live on an island, my wife trained as a marine biologist, I understand bioaccumulation better than the media ("oh, the sea is so big!)", and will contend that the scope of this disaster to the ocean is far more severe with long term consequences to a wide range of species -- including humans -- from the contamination of the ocean alone. At the risk of getting too political, this incident proves to me that nuclear power is not a solution to other very serious environmental and resource issues that we face. Imagine the consequences if this had happened to one of the reactors on Lake Erie or on top of the Ogallala Aquifier. We can live without electricity, we can't live without safe water and we are seeing how difficult it is to get radiation out of water.

Now for the "however."

First off, the people should not be punished for anything. If the Indian Point reactor went south on us I wouldn't be in favor of dumping the waste on the streets of New York just because New Yorkers happen to be citizens of the country that built the reactor. I don't even think that TEPCO officials should be punished; the problem is with the design and not the people. I have not seen any evidence that this incident is anything other than what you expect to happen when a nuclear plant melts down (or "partially melts down" or "has an oopsie" or whatever the politically correct term is.)

But, back to technical issues, the conseqences of flooding the plant grounds are that it will become nearly impossible to mitigate this problem. We have to get the rods in the spent fuel pools into safe, long term storage and that won't happen if the grounds are contaminated with the highly radioactive stuff they are trying to deal with. We can't just hope that there are no large aftershocks for the next 30 years, or that a roofless building that exploded will be able to handle typhoon-force winds.

So it is not even a matter of trade offs; but if push comes to shove the choice that leaves us with any options at all is to dump it into the sea. I hope there are options before that, like "load up a supertanker" but eventually that probably means "radioactive supertanker at the bottom of the sea." If we let the grounds flood and have to abandon the plant it will all go to the sea anyway.

But again, it is a horrible choice. Nobody really wants to think about what has already happened; when they pick up heavily contaminated seawater 30 kilometers from the plant site you are in a place that we should never have had the slightest odds of getting to. (IAEA report March 24).

It is true that it is difficult to discuss such choices. It is like deciding to amputate somebody's leg after a screw up in the hospital has sickened them. You need to discuss the option without forgetting how horrible the consequences are for the person and absolving the hospital from blame.

 

[NUCENG]

I remember only one action of this kind where NRC ordered a plant to shut down.
It was when a whistleblower revealed that the operators in the control room were sleeping, playing video games etc, but not caring for the reactor.

N: Obviously you haven't done your homework.

You read this between the lines.

N: Now there's a great citation. Clearly that carries the argument.

In Japan, Germany etc there are many discussions about this interesting phenomenon of fraternalization of the nuke industry and the authorities.
People work for one side, then change their side at early retirement.
There is much money at work to which motivates people working at the regulatory to be "cooperative".
If they cooperate well they might be thanked with a well-paid leisure job.
They get much money without really have to work.
They just have to do lobby working at their former colleagues in the regulatory authority.
So these know well: "Cooperate and you'll have good income without having to work later."

N: So Japan and Germany have a problem. And yet you hold up Chairman Jaczko as a hero. How did he get there?

In fact, I doubt that it is always for this reason.
In fact, the comments of some Commissioners regarding the extension of the discretion period from three to eight years remind me of a typical soviet style communist party sycophancy.

N: No evidence, no sense, but call it a communist plot. That always works.

As most national nuclear laws around the world are similar to the masterprint of the american system, I suspect it is like here in Germany.

N: Suspicion, another great source citation.

In the wake of the final shutdown of many German reactors it came at light that thousands of safety improvements etc, not only regarding flammable insulation foam, have been delayed by reactor operators for up to 17 years after having been ordered by the authorities.

N: Proving a Geman problem, if it is even true.

Just an example, the Brunsbüttel BWR at the Northern Sea.
It has been offline for some years now.
There had been a hydrogen explosion ripping open some tubes of the primary circuit and spraying radioactive steam.
But the reactor operator didn't consider this an important thing and insisted to operate the reactor until next planned shutdown about half a year later while just letting the leaking water flow into the sump (wetwell).

The nuclear authorities had to battle for three months until, with the help of the federal government, they finally got the reactor operator company agree to shut down the reactor.

In the aftermath of this accident it was revealed that this accident easily could have mutated into an uncontrollable LOCA if some piping cracked by the explosion would have severed the main cooling water circuit.

But the real reason why the authority was unable to allow to restarting the plant was the public pressure in sight of the fact that the NPP piled up more than 400 unremedied violations in a dozen years.

N: And that applies to a US plant how? What part of prompt and effective corrective action program do you not understand?

Jaczko fruitlessly opposed the extension of the discretion period to eight years.
As there is not always the possibility of enforcement after the end of the discretion period, as Jaczko clearly indicates, there can be easily more than ten years from the finding of a violation to when the NRC can order the plant operators to do something about.

N: Your post belongs on the "Other Political Thread, there is not one citation, not one ounce of anything more than uninformed opinion masquerading as conclusions. Your anti-American ravings are getting tiresome. I have been trying to answer a legitimate question about what the term enforcement discretion. You chime in with nothing but hot air. Go away little boy, you bother me!

 

[Quim]

you could even "store" it in an open trench somewhere.

I find that idea far far preferable to dumping high level radioactive waste into the Pacific Ocean.

 

[Atomfritz]

To be precise, they are taking water from Sakagarbagea dam, here:
http://metalwings05.fc2web.com/dam/07_fukushima/sakagarbagea/index.html

Thank you for the information. This dam is about a dozen kilometers away from the plant.

One or two miles southwest of the reactors there are also a few dams. Northwest, in about 2-3 miles there also is a dam. Maybe agricultural only and not connected to the normal grid.

It's awful to think about, but they already have a lake nearby. They are drawing water from it to cool the reactors, in fact. It would be possible, I'm afraid, to dump it back in.

Dams shouldn't be used for radioactive water/sludge storage, as dams are prone to all possible damages like earthquakes. See the Bellona.org documentation about the Mayak complex and its problems with keeping the radioactive water halfway safe.
The only lake that is probably not a dam and appears possibly large enough to dissipate such quantities of radwaste water is directly at the plant area border.
See this picture:

It could be a very convenient last alternative to pump the water in there before contaminating the ocean.
And it could be implemented very quickly, just laying tubes along the red line.

So this could buy quite some time for mankind to save the oceans.

 

[jim hardy]

thanks to the poster who has reverse osmosis experience. Sorry i forgot to note your name...

that technology does a beautiful job of turning municipal water into ultra-pure boiler grade water, but it seems to me a bit on the sensitive side for handling sludge.

Wouldn't an old fashioned moonshine still scaled up to industrial size capture the oil and sludge and most of the contamination too before handing the water to your equipment ?

Perhaps a line of old fashioned package boilers, say surplus WW2 Liberty Ship power plants, should serve as sacrificial distillation pre-cleaners for your high tech stuff . When you can no longer get close to them pick 'em up with a long crane and cart them away.

old jim

 

[etudiant]

It would be truly stupid to allow the site to be flooded, if only because there are a couple of thousand tons of nuclear fuel in it even apart from the corium in the damaged reactors, thus making the accident that much worse.
It may however become necessary to dump at least some of the water into inadequate storage facilities, whether tanks, megafloats or available oil tankers,, because the treatment facility is late and the facility is one good storm away from overflowing.
That said, I'm puzzled by the Kurion columns. We have close to 300 Petabequerels of cesium in the water, as Clancy688s post above documented. Also, we need to change out the cesium cartridges when their activity exceeds 4 millisieverts, according to the TEPCO conference reported by tsutsuji.

The plan was for about a monthly cartridge change, so only a dozen cartridge sets over the expected 1 year cleanup. If the columns have the claimed effectiveness of cutting cesium to 0.1% of the original level or better, that means that dozen sets will together contain nearly 300PBqs of radioactivity, held in cartridges producing a 4 millisievert radiation level of exposure when briefly handled.
This seems wildly implausible. What am I missing?

 

[MJRacer]

http://www.new.ans.org/pubs/magazines/download/a_726

http://www.businesswire.com/news/ho...ion’s-Ion-Specific-Media-based-materials-Mile

A couple of interesting articles on Kurion's technology. Here are some quotes:

"A key aspect of the ISM (Ion Specific Media) is that they are inorganic as compared with conventional organic media."

"Because of strong molecular bonds, however, isotopes remain captured during thermal treatment, eliminating concerns over volatilization of isotopes such as cesium."

"The company’s development program includes the ability to manufacture its media using patent pending sorbent impregnated porous glass microspheres. As a result, during vitrification the media self-supplies the glass frit required for vitrification, ..."

"Kurion has developed an MVS (Modular Vitrification System) that is simple enough to allow generators to safely perform this process onsite. Granted eight patents, the MVS employs a mechanically passive, first-principles, single-use melter internally integral to the customer’s waste container and achieves high volume reduction ..."

"The self-contained system utilizes nonintrusive inductive energy as its heat source to avoid electrodes, thermocouples, and probes normally associated with vitrification processes and that create secondary wastes along with maintenance, safety, and cost concerns. In addition, because the MVS does not rely on high temperatures to ensure glass conductivity and heating as required of joule-heated melters, it is uniquely capable of utilizing low-temperature glass formations to stay below the volatilization temperatures of off-gassing isotopes such as cesium."

"Aside from a small footprint and negligible off-gas, the MVS has the ability to keep the stainless steel waste canister relatively cool while processing. Kurion’s unique proprietary process keeps the waste canister exterior more than 500°C cooler than does the interior process, plus it doubles as a secondary containment."

 

[MJRacer]

thanks to the poster who has reverse osmosis experience. Sorry i forgot to note your name...

that technology does a beautiful job of turning municipal water into ultra-pure boiler grade water, but it seems to me a bit on the sensitive side for handling sludge.

Wouldn't an old fashioned moonshine still scaled up to industrial size capture the oil and sludge and most of the contamination too before handing the water to your equipment ?

Perhaps a line of old fashioned package boilers, say surplus WW2 Liberty Ship power plants, should serve as sacrificial distillation pre-cleaners for your high tech stuff . When you can no longer get close to them pick 'em up with a long crane and cart them away.

old jim

They are planning on using distillation after RO. They call it vapor condensation. That's why I called it the "kitchen sink" approach (except for flocculation).

See http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110609e8.pdf

 

[GJBRKS]

The plan was for about a monthly cartridge change, so only a dozen cartridge sets over the expected 1 year cleanup. If the columns have the claimed effectiveness of cutting cesium to 0.1% of the original level or better, that means that dozen sets will together contain nearly 300PBqs of radioactivity, held in cartridges producing a 4 millisievert radiation level of exposure when briefly handled.
This seems wildly implausible. What am I missing?

The monthly change was named with regards to the oil separating part ,not the cesium filters

These oil filters are somehow accumulating radioactivity where they are not supposed to ,

but the oil needs to be filtered out to avoid damaging the cesium filters.

There are 4 parallel installed processing lines

 

[Orcas George]

TEPCO says it may have absorbed larger-than-expected amounts of radioactive materials along with oil. The utility is now working on measures to solve the issue.

TEPCO says the effort will require time. In addition, depending on the situation, it may have to reconsider the working of the entire system and examine the effect of radioactivity emitted from nearby pipes.

http://www3.nhk.or.jp/daily/english/19_03.html

They need to not panic; messing around with the system will wreck it. They should call in some other filtration professionals (Parker Racor) and brainstorm. Perhaps a big prefilter unit that they can remotely backflush with several in reserve. These things are sitting in warehouses; if it gets fried just bury it with the other radioactive junk. They won't get the GPH they desire but if they can keep the water level from rising while somebody works out plan 'B' that would be good.

RO systems are very finicky since you are pushing stuff at great pressure through rubber it can easily get plugged up or holed. Oil is fatal. The technology really isn't for handling mixed dirt and sludge and oil. They need to get that stuff out first which is a dilemma because the filter to do that will get the most radioactive stuff in it. However a radioactive filter that you can stack somewhere is probably better than radioactive water.

My diesels have filters that separate water from diesel using centerfuge action plus a hydrophrobic membrane. I would be shocked if they didn't have filters like that in the system somewhere.

They will get it fixed if they keep their cool. On the reverse situation diesels will be instantly wrecked if any water gets into the injectors, so the we have really good technology for separating oil and water and particles. I'm convinced there is a part number that will solve this problem, at least in the short term (they may have to change out a machine every day or so.) The important part for now is to get the water cleaned, if they fill up a junkyard with hot equipment we can yell at them later.

 

[etudiant]

The monthly change was named with regards to the oil separating part ,not the cesium filters

These oil filters are somehow accumulating radioactivity where they are not supposed to ,

but the oil needs to be filtered out to avoid damaging the cesium filters.

There are 4 parallel installed processing lines

Thank you for the extra insight on the filter changes.
The question remains for me, how do they plan to capture 300PBqs of cesium in cartridges that need to be manually changed. The cesium is about a million curies worth, unless I've dropped a decimal somewhere.

 

[clancy688]

The cesium is about a million curies worth, unless I've dropped a decimal somewhere.

You did. It's ten million. ;)

I'd be interested in how many becquerels one filter is supposed to capture until it's changed. Or does anybody know how to convert "4 mS/v" of C134 and C137 at a 1:1 ratio into becquerel?

 

[Atomfritz]

]Wouldn't an old fashioned moonshine still scaled up to industrial size capture the oil and sludge and most of the contamination too before handing the water to your equipment ?

Perhaps a big prefilter unit...

Hmm, could a lake serve as temporary storage, oil and particle separator all-in-one?

Thank you for the extra insight on the filter changes.
The question remains for me, how do they plan to capture 300PBqs of cesium in cartridges that need to be manually changed. The cesium is about a million curies worth, unless I've dropped a decimal somewhere.

I also don't understand this. Formerly in https://www.physicsforums.com/showpost.php?p=3333806&postcount=8633" I calculated the mass of a megacurie Cs-134 as 773 grams and of Cs-137 as 11.55 kg.
So alone the cesium contamination in the water could be in the magnitude of a hundred kilograms up.

By the way, the Kurion steel/glass things appear to be designed to be handled remotely and instantly vitrified after getting satiated.
But I miss any statements that there a vitrification plant is projected.

Irradiation sources containing only milligrams of Cs are being transported in heavy lead shielding.
And there have been several detailed IAEA reports on the dire medical outcomes of people touching or approaching such very small sources unshielded.
Other uncanny reports tell about the fate of workers in the irradiation business.

So this is maybe just a calculation mistake?
It would not be the first one, and worse even would be the fact that Tepco, Areva and the other parties involved all overlooked that mistake.

 

[jlduh]

Thank you for the extra insight on the filter changes.
The question remains for me, how do they plan to capture 300PBqs of cesium in cartridges that need to be manually changed. The cesium is about a million curies worth, unless I've dropped a decimal somewhere.

Well, again, this is my main question: how can so much radioactivity which is normally contained inside a so big containment system (a reactor building) be contained in cartridges that have to be handled and stored? What kind of shielding in a cartridge can replace the one from a complete reactor? Contamination will be concentrated in these cartridges but how can this all system be run without huge radiation around pipes, cartridges and so on, making it almost unmanageable with the kind of volumes per day we are talking about?

This is a complete mystery for me...

But maybe this sentence from NHK is a beginning of the answer:

TEPCO says the effort will require time. In addition, depending on the situation, it may have to reconsider the working of the entire system and examine the effect of radioactivity emitted from nearby pipes.

By the way, i checked weather forecast and more than 70mm of rain are anticipated in the area in the next week... so new thousands of tons of water from this "natural cooling" will add soon to the current amount contained in the site. The situation is getting critical this time.

http://www.weather-forecast.com/locations/Fukushima/forecasts/latest

 

[razzz]

Grime, oil and don't forget salt all radioactive. Grime can be settled out in a holding pond, oil need detergent to separate it, and salt needs an acid bath.

Passive filtering would be pumping it to the top and let gravity pull it down through filters and trickle out the bottom for further processing.

All these things and mechanical separation like centrifuges besides heat distillation need added materials that become contaminated. Looks like they picked pressure filtering as the main theme which is working, the pre-clean problems can be overcome but has to be done on a massive scale. They should probably irradiate an empty oil tanker while waiting to figure out what to do. Buy some time storing it elsewhere.

 

[clancy688]

And there have been several detailed IAEA reports on the dire medical outcomes of people touching or approaching such very small sources unshielded.

The Goiana accident would be a very great example (INES 5, 1987, 93 grams, 50 TBq). The orphan source consisted of C137.

So this is maybe just a calculation mistake?
It would not be the first one, and worse even would be the fact that Tepco, Areva and the other parties involved all overlooked that mistake.

If so, then it would rather be a measuring mistake than a calculation mistake. They got the 720 PBq number by measuring each basement / turbine building / etc. alone and adding up the numbers.
I got the 2 * 140 PBq number for C134 and C137 by taking TEPCOs measurements of each basement / turbine building / etc. and adding up the numbers for each single isotope.

The pdf in question: http://www.tepco.co.jp/cc/press/betu11_j/images/110603a.pdf (page 8)

 

[Atomfritz]

Or does anybody know how to convert "4 mS/v" of C134 and C137 at a 1:1 ratio into becquerel?

Important and difficult question.
This http://www.aristatek.com/Newsletter/05%2002%20February/The%20First%20Responder%20Technically%20Speaking.htm" has a description of how this can be calculated and provides various examples.

Quotes:
"For example, the flux of gamma photons from 1 gram of Cesium 137 at a distance of 10 meters in air is 2.7543 (10)9 photons/m2-s. This converts to a dose of 0.402 rem/hr. There is only one gamma energy level to consider (0.66 MeV) and no neutron emissions."
"At 100 meters away, the rem dose for the cesium 137 example would probably be on the order of 0.004 rem/hour."

(See my last post for conversion becquerel->gram. For other isotopes FAS has a list also http://www.fas.org/programs/ssp/nukes/armscontrol/uraniumdirtybombs.html".)
Hope this helps to convert to Sieverts.

 

[clancy688]

Quotes:
"For example, the flux of gamma photons from 1 gram of Cesium 137 at a distance of 10 meters in air is 2.7543 (10)9 photons/m2-s. This converts to a dose of 0.402 rem/hr. There is only one gamma energy level to consider (0.66 MeV) and no neutron emissions."

That would be about 200 Sv/h at 10 meters for all basement water C137 collected in a bucket. Nice. Or rather... "ouch".

 

[MJRacer]

The monthly change was named with regards to the oil separating part ,not the cesium filters

These oil filters are somehow accumulating radioactivity where they are not supposed to ,

but the oil needs to be filtered out to avoid damaging the cesium filters.

There are 4 parallel installed processing lines

If I am not hallucinating, here is what may be happening:

Interesting things happen at interfaces. They tend to collect impurities. Consequently, one way to purify/refine/decontaminate something is to play with interfaces. Sugar is refined by crystallization. After crystals are grown, many if not most of the impurities will be on the surface of each crystal. By controlling the size of each crystal, it is possible to grow crystals of fairly uniform size that are larger than a given size wire mesh. After growing them, the crystal surfaces can be washed off, thus removing a huge amount of impurities in a single step. 2 crystallization steps suffice to produce almost perfectly pure sugar, by exploiting a liquid/crystal interface. Similarly, IIRC silicon is refined by pushing melt zones through a crystal. The impurities collect at the liquid/crystal interface and are pushed out with the melt zone. Beer can be concentrated by lowering its temperature slowly until water crystals form, which are then removed. The result is Eisbock. These are just some examples.

One would have to ask the NEs, but I suspect that highly radioactive water has, until now, almost never been contaminated with hydrocarbons. At Fukushima, several very large fuel tanks for the diesel generators were displaced by the tsunami. I would suspect that the thousands of gallons of fuel inside of them were also spread around the plant site. In designing the water treatment system, it appears to me that a rather conventional approach was taken by removing each contaminant in a separate step. There was no time for test runs.

They chose to remove oil via "dissolved air flotation," thus creating an air/oil/water emulsion with three interfaces: oil/water, air/oil and air/water. Furthermore, there is another interface involving the different viscosities of oil and water. As I said before, impurities tend to collect at interfaces. In this case, after concentrating impurities at the three interfaces, I would suggest that the impurities were trapped within the oil due to the large difference in viscosity between oil and water. Consequently, when the first Kurion ISM (oil and technetium) trapped the remaining oil droplets, it may also have trapped a good bit of all radioactive particulates and not just technetium. Hence, the large and rapid rise in radioactivity of the first cartridge.

They may have just discovered a novel way to remove large amounts of radioactive contamination from water in just three steps: (1) pour bucket of diesel fuel into contaminated water, (2) form air/oil/water emulsion, (3) filter through Kurion oil+technetium cartridge and Bob's your uncle! By trapping the oil droplets in the Kurion cartridge, the hot particles are also trapped. If this is happening, then one should be able to take a sample of what was collected in the first oil+technetium cartridge and see if large quantities of cesium and perhaps iodine are being trapped. They shouldn't be, as the next two cartridges are where the cesium and iodine, respectivelly, are supposed to be trapped.

If my theory is shown to be valid, then no flocculation step is necessary. The system will have shown itself to be effective at trapping hot particles in only 3 steps. However, the operational difficulties of dealing with hot cartridges may be very challenging.

Either that or I am totally wrong.

 

[joewein]

They got the 720 PBq number by measuring each basement / turbine building / etc. alone and adding up the numbers.
I got the 2 * 140 PBq number for C134 and C137 by taking TEPCOs measurements of each basement / turbine building / etc. and adding up the numbers for each single isotope.

The pdf in question: http://www.tepco.co.jp/cc/press/betu11_j/images/110603a.pdf (page 8)

I can confirm your calculations.

From the same data I also get a total of 3 kg of Cs-134 and 44 kg of Cs-137 in 105,100 t of water in units 1-4 and the central rad waste building.