Japan earthquake - contamination & consequences outside Fukushima NPP

[zapperzero]

There are different degrees of "hard". The report will give you a good idea how hard it was at TMI-2.

Well, it has. Now what?

 

[nikkkom]

Well, it has. Now what?

Now you have more information to base your opinions on.

You, for example, now know that in a relatively benign accident at TMI-2, containment basement was flooded "merely" by reactor coolant, and it proved to be impossible to clean that basement up. Its concrete was flushed, it was scrubbed, its outer surface was scarified away by robots. Nothing of the above made the basement clean enough to allow human entry. Thirty-three years after that accident, it is still not fully cleaned up.

Fukushima basements will be *much* worse than that.

 

[zapperzero]

Fukushima basements will be *much* worse than that.

Yes. And?

 

[nikkkom]

Yes. And?

Okay. You are in charge of the cleanup. What is your plan? How do you propose to clean up containment and torus?

 

[zapperzero]

Okay. You are in charge of the cleanup. What is your plan? How do you propose to clean up containment and torus?

Nonono. It doesn't go like this. Show your hand. You have been insinuating and implying and suggesting for far too long and I have no more patience. What do YOU propose?

 

[nikkkom]

Nonono. It doesn't go like this. Show your hand. You have been insinuating and implying and suggesting for far too long and I have no more patience. What do YOU propose?

Wait until decay heat is low enough for corium to not overheat when isolated (it may already be low enough). While waiting, install air filtration, water filtration system and evaporator. Prepare storage for spent filtration vessels (likely to be high-activity).
Prepare dry waste storage for evaporator scale (low-activity waste).

Pump out torus room and drywell and vacuum dry both. Completely fill torus room with concrete. (None of these operations require personnel ingress. In particular, no sediment or corium removal from torus room is done.) If simulations deem it necessary for heat removal, embed heat pipes into this concrete and route them into rooms above torus.

This leaves reactor buildings' basements sealed and their radioactivity immobilized under several meters of concrete, all below ground level, protected against weathering and with no active measures necessary.

Your plan is ... ?

 

[zapperzero]

Wait until decay heat is low enough for corium to not overheat when isolated (it may already be low enough).

It will continue decaying and thus making heat for a very very long time. We don't even know how dense it is.

While waiting, install air filtration, water filtration system and evaporator. Prepare storage for spent filtration vessels (likely to be high-activity).
Prepare dry waste storage for evaporator scale (low-activity waste).

This is already MORE than has been done at Fukushima so far.

Pump out torus room and drywell and vacuum dry both.

I am now left dealing with several hundred tons of slurry which the pumps can't get at, comprised variously of bits of equipment, fuel debris and water. Better pray for no fission excursions!

Completely fill torus room with concrete. (None of these operations require personnel ingress. In particular, no sediment or corium removal from torus room is done.) If simulations deem it necessary for heat removal, embed heat pipes into this concrete and route them into rooms above torus.

How long do these pipes need to last? And again, what about reactivity control?

This leaves reactor buildings' basements sealed and their radioactivity immobilized under several meters of concrete, all below ground level, protected against weathering and with no active measures necessary.

This leaves the fuel in an unknown state, with no means to check on it and no means to get it out easily, or indeed at all. There is still underground water flowing around (and probably in) the basements. How long until water, earthquakes and the action of the fuel itself (heating, alphas, fast betas and neutrons) cracks the new concrete and starts leaching stuff away to who knows where, dispersing and re-accumulating at random?

Your plan is ... ?

I don't have a plan. I look at TEPCO's plan and I think it's decent in its intent, if overly optimistic and too reliant on the TMI experience. Generally speaking, the entire thing (reactor buildings and their environs) needs to be crunched into small bits, the low- and medium- level waste can be stored on site containerized, in bunkers, while the highly radioactive material needs to be concentrated as much as safely possible and dumped into long-term storage.

Fuel in the pools should go to reprocessing. Fuel in the reactors should probably be just stored.

Only, I have no answers for secure long-term storage of nuclear waste, but that doesn't make me an idiot because no-one else has either.

 

[nikkkom]

I don't have a plan.

My point.

Generally speaking, the entire thing (reactor buildings and their environs) needs to be crunched into small bits,

Could not be done even on TMI-2.

 

[nikkkom]

I am now left dealing with several hundred tons of slurry which the pumps can't get at, comprised variously of bits of equipment, fuel debris and water. Better pray for no fission excursions!

You missed "vacuum dry it" part. There wouldn't be much water.

As to reactivity excursions, the fuel in torus and torus room (if any) is lying on the floor. It can't magically roll up into a ball. Not to mention that more detailed plans, naturally, would include neutron poison materials in the concrete.

How long do these pipes need to last?

About 10 years, until decay heat falls to really low levels.

This leaves the fuel in an unknown state,

Look like well-known state to me: "encased in concrete". Most spent fuel on this planet so far is in LESS secure state than this one.

with no means to check on it and no means to get it out easily, or indeed at all. There is still underground water flowing around (and probably in) the basements.

Not more than there is water flowing inside Hoover dam. Stands for 80 years already.

How long until water, earthquakes and the action of the fuel itself (heating, alphas, fast betas and neutrons) cracks the new concrete and starts leaching stuff away to who knows where, dispersing and re-accumulating at random?

With proper design, after thousands of years. More likely outcome is that it will be dismantled before then.

 

[zapperzero]

The news site that will not be named posted a link to an article regarding contamination on the grounds of the Canadian embassy in Tokyo.
http://link.springer.com/article/10.1007/s10967-012-2040-3

In this study, soil samples were collected at Canadian embassy in Tokyo (about 300 km from Fukushima) on 23 March and 23 May of 2011 for purposes of estimating concentrations of radionuclides in fallout, the total fallout inventory, the depth distribution of radionuclide of interest and the elevated ambient gamma dose-rate at this limited location [...] The total fallout inventory was thus calculated as 225 kBq/m2 on March sampling date and 25 kBq/m2 on May sampling date.

For reference, the zone of permanent control around Chernobyl was defined as > 555 kBq/m^2 while the zone of periodical control starts at 185 kBq/m^2.
http://fukuleaks.files.wordpress.com/2011/10/591px-tchernobyl_radiation_1996-de-svg.png

 

[zapperzero]

You missed "vacuum dry it" part. There wouldn't be much water.

How much is too much? How much is just enough for moderation purposes in a bed of fuel particles? What little I've read suggests 50%

As to reactivity excursions, the fuel in torus and torus room (if any) is lying on the floor.

You don't know that.

Look like well-known state to me: "encased in concrete". Most spent fuel on this planet so far is in LESS secure state than this one.

Obviously this is not the case...

Not more than there is water flowing inside Hoover dam. Stands for 80 years already.

Hoover Dam is filled with natural rock. It is not a concrete dam. And no, if water was flowing through cracks in it, it would not have resisted for 80 years.

With proper design, after thousands of years. More likely outcome is that it will be dismantled before then.

Proper design of what? Dismantled how? You are just advocating that TEPCO should dump concrete in the reactors. Do you think that maybe someone can go in first and waterproof everything?

Your sole preoccupation seems to be with the costs incurred by TEPCO. I wonder why? Perhaps you are a shareholder? Because a responsible citizen of Earth you are certainly not.

 

[LabratSR]

Saw this today. Not sure where to put it.

http://www.newscientist.com/article/dn23307-us-soldiers-sue-over-fukushima-radiation-exposure.html

 

[nikkkom]

You are just advocating that TEPCO should dump concrete in the reactors.

No, I propose that rooms *around and under* drywell and reactor should be filled with concrete without attempting to competely clean them up.

Then drywell can be reflooded, reactor cap can be opened. Most likely, the vast majority of the corium will be in this volume, not elsewhere.

 

[zapperzero]

No, I propose that rooms *around and under* drywell and reactor should be filled with concrete without attempting to competely clean them up.

Then drywell can be reflooded, reactor cap can be opened. Most likely, the vast majority of the corium will be in this volume, not elsewhere.

What you are proposing is, among other things, illegal. There are laws in Japan (mandated at least to some extent by international treaties) about nuclear fuel accountability.

You can't just say "oh, it's in there somewhere".

 

[nikkkom]

Hoover Dam is filled with natural rock. It is not a concrete dam. And no, if water was flowing through cracks in it, it would not have resisted for 80 years.

Exactly my point. Water isn't flowing through Hoover Dam, despite being under pressure of more than 20 atm at the bottom. We know how to make concrete which is impermeable for water. We know it for at least 100 years already.

 

[nikkkom]

What you are proposing is, among other things, illegal. There are laws in Japan (mandated at least to some extent by international treaties) about nuclear fuel accountability.

You can't just say "oh, it's in there somewhere".

Why it can't be said? It *is* the truth - the corium is there. Would anyone honestly suspect that "evil TEPCO" clandestinely removed some corium from the torus room before pouring concrete? That would be just idiotic and pointless thing to do, not to mention technically hard.

What nuclear fuel accountability rules say about accounting for a few hundreds of kilograms of Caesium from spent fuel which is already dispersed far and wide by now? About a few kilograms of tritium lost? About Kr-85? Looks like TEPCO is in breach already :/

 

[cockpitvisit]

a few hundreds of kilograms of Caesium from spent fuel

I think it is just 4 kg of Caesium. The total Cs-137 release was estimated at 13,600 TBq, and one kg of Cs-137 has 3,215 TBq.

And I thought Kr-85 and tritium are always being released into the atmosphere by reprocessing plants, or am I wrong here?

 

[clancy688]

I think it is just 4 kg of Caesium. The total Cs-137 release was estimated at 13,600 TBq, and one kg of Cs-137 has 3,215 TBq.

That's only what went into the atmosphere. According to IRSN, at least double that number again went into the ocean.

 

[zapperzero]

I wonder if someone here could confirm or infirm this? http://ex-skf.blogspot.ro/2013/03/radioactive-japan-50-millisieverts.html
There's crazy talk in there about commuting to work being allowed in 50 mSv/y areas.

 

[Sorai]

I wonder if someone here could confirm or infirm this? http://ex-skf.blogspot.ro/2013/03/radioactive-japan-50-millisieverts.html
There's crazy talk in there about commuting to work being allowed in 50 mSv/y areas.

I don't think residents are supposed to commute and work regularly in those areas, at least on paper. You can read a definition of the three zones in this document from December 2011: http://www.meti.go.jp/english/earthquake/nuclear/roadmap/pdf/20111226_01.pdf

In relation to areas between 20 and 50 mSv/year ("Areas in which the residents are not permitted to live"):

"In this case, residents are ordered to remain evacuated in the areas, but people concerned can temporarily return home in the areas (but staying overnight is prohibited), pass through the areas along main roads, and enter the areas for purposes beneficial to the public interest, such as repairing the infrastructure and conducting disaster prevention-related work." [p. 10]​

Based on more recent Japanese documents, it does not seem like the definition has changed, though I guess residents would be able to commute daily as long as they can justify that their work is related to repairing basic infrastructure. Even in that case, they would only be exposed to part of the annual dose, since they are not allowed to stay overnight.

However, I've read of at least one farmer, Naoko Matsumura, who went back to the exclusion zone very early on after the accident and lives there taking care of his animals, so it seems the police is not forcing people to evacuate if they decide to stay: http://www.dailymail.co.uk/news/art...led-Fukushima-nuclear-plant-care-animals.html

 

[zapperzero]

I don't think residents are supposed to commute and work regularly in those areas, at least on paper. You can read a definition of the three zones in this document from December 2011: http://www.meti.go.jp/english/earthquake/nuclear/roadmap/pdf/20111226_01.pdf

In relation to areas between 20 and 50 mSv/year ("Areas in which the residents are not permitted to live"):

"In this case, residents are ordered to remain evacuated in the areas, but people concerned can temporarily return home in the areas (but staying overnight is prohibited), pass through the areas along main roads, and enter the areas for purposes beneficial to the public interest, such as repairing the infrastructure and conducting disaster prevention-related work." [p. 10]​

Based on more recent Japanese documents, it does not seem like the definition has changed, though I guess residents would be able to commute daily as long as they can justify that their work is related to repairing basic infrastructure. Even in that case, they would only be exposed to part of the annual dose, since they are not allowed to stay overnight.

However, I've read of at least one farmer, Naoko Matsumura, who went back to the exclusion zone very early on after the accident and lives there taking care of his animals, so it seems the police is not forcing people to evacuate if they decide to stay: http://www.dailymail.co.uk/news/art...led-Fukushima-nuclear-plant-care-animals.html

Thank you very much for your explanation.

 

[gmax137]

I wonder if someone here could confirm or infirm this? http://ex-skf.blogspot.ro/2013/03/radioactive-japan-50-millisieverts.html
There's crazy talk in there about commuting to work being allowed in 50 mSv/y areas.

I wouldn't let 50 mSv/year keep me from moving back into my home. But that's just me I guess.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130328/index.html Google started on 28 March to display "Google street view" on the internet for the streets of Namie town, as requested by the municipality. Buildings knocked down by the earthquake have not been removed, more than 2 years after the earthquake. Hardly any person or car can be seen. Google said it plans to cover more areas affected by the nuclear accident.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130315/index.html [15 March 2013] Among the fish samples taken in Fukushima Daiichi harbour between February 19 and 21, whose analysis results were released on March 15, the most highly contaminated fish until now has been found, with 740,000 Bq/kg of radioactive cesium (134 + 137 added together). As countermeasures, Tepco plans to exterminate the fish in the harbour and to install a net between the harbour and the open sea.

http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2013/images/fish_130315-e.pdf page 9/13: "Greenling (Muscle) No.5 In the Port of Fukushima Daiichi NPS (Around the Water Intake Open Conduit at Unit 1-4) February 21, 2013 260000 480000 740000" ; page 12/13: "<Reference> Outline Process (Draft) of the Countermeasures for Fish in the Port at Fukushima Daiichi NPS
① Preventing fish from moving out
② Sampling (extermination) of fish
②-1: Basket fishing ②-2: Gill net in the port entrance
③ Improving environment of the marine soil in the port (dredging)

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130315/0600_osensui.html [15 March 2013] As the cesium concentration in Fukushima Daiichi harbour is almost not declining, a Tokyo university research group calculated an estimate suggesting that it is possible that a quantity of radioactive cesium up to 73 times the yearly regulatory limit has been poured into the Fukushima Daiichi harbour even after the main leak was stopped in June 2011. Since last spring, the Cs 137 concentration has stopped declining, and remains stable around 100 Bq/litre. Based on the assumption that 44% of the harbour water is changed everyday by currents and tides, it was found that a Cs-137 source from 8 to 93 billion Bq/day is necessary. This has almost no consequence on the fish in the open sea, but it is feared that the fish in the harbour might accumulate the radioactive substances in their body. According to Tokyo University professor Jota Kanda, "it is difficult to imagine that contaminated Earth is washed out by rain and poured into the harbour, but it is possible that contaminated water pours into the harbour from ground water or broken pipes. A detailed investigation and a research of the cause is necessary". In response to this, Tepco said "we don't think that radioactive substances are pouring into the sea from the plant premises. However, as we don't know the reason why the harbour concentrations are not declining, we shall continue to investigate".

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130305/0910_80km.html [5 March 2013] A ministry of Education and Science survey performed in November 2012 in the 80 km range around the plant collected radiation data in 140000 locations onland and by helicopter. The average radiation at 1 m above ground is 40% lower than the value found one year earlier. Nuclear decay accounts for a 21% decline. The remainder of the decline is presumably due to the radioactive substances being washed by rain and poured into rivers and sea.

http://radioactivity.nsr.go.jp/ja/contents/7000/6749/24/191_258_0301_18.pdf The 6th aerial monitoring campaign (helicopter maps)

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130301/index.html [1 March 2013] The Joban expressway decontamination work has been started on a 17 km stretch between Hirono and Tomioka which is planned to reopen in fiscal 2013. The decontamination is done with high pressure washers and hoses that suck up the spent water. The radiation is reduced by more than one half. Cut branches and leaves are compressed to one fourth of their original volume before storage.

 

[zapperzero]

Another excellent article from ex-skf - the decontamination of detector sites continues apace, and the new lower numbers are being presented as improvements in the overall situation, which of course they are not. Disgusting.

http://www.ex-skf.blogspot.ro/2013/04/fukushima-prefecture-installs-fixed.html

FNN Local News reported on April 2, 2013 that radiation levels as measured in Koriyama City got significantly lower in one day. Its reporter spoke with the government official, and found out that, in addition to installing the fixed monitoring posts in locations that just got decontaminated, they also changed the unit of measurement from microsievert/hour to microgray/hour, shaving off 20% in numbers

EDIT: looking at the video now... the location of the old monitoring post is ridiculous.

 

[nikkkom]

The Joban expressway decontamination work has been started on a 17 km stretch between Hirono and Tomioka which is planned to reopen in fiscal 2013. The decontamination is done with high pressure washers and hoses that suck up the spent water. The radiation is reduced by more than one half. Cut branches and leaves are compressed to one fourth of their original volume before storage.

Got to love government at work. It took only two years to start washing down the roads.

 

[tsutsuji]

Got to love government at work. It took only two years to start washing down the roads.

If there is no prospect that many cars are going to use that motorway, it could be meaningless, or not a useful way of spending public money and not worth risking the decontaminating workers' health. I guess very few cars are going to use that stretch as long as the next stretch which runs just behind Fukushima Daiichi is sufficiently decontaminated and car drivers are confident enough to risk driving that close from Fukushima Daiichi.

 

[nikkkom]

If there is no prospect that many cars are going to use that motorway, it could be meaningless, or not a useful way of spending public money and not worth risking the decontaminating workers' health.

Letting Cs-137 contamination sit on the roads for years allowed it to soak into the road surface.

Considering how little washdowns cost and how little exposure workers get, it should have been done a few months after the disaster, not years.

I mean, come on. Bring standard spraying cars already owned by nearby cities, and make them drive around washing roads, when they aren't needed elsewhere and would alternatively sit in their garages doing nothing. The most expensive part of such effort may be not the usage of these cars per se, but the chemicals added to the water which promote washing out of caesium salts.

 

[zapperzero]

I mean, come on. Bring standard spraying cars already owned by nearby cities, and make them drive around washing roads, when they aren't needed elsewhere

Please, please for the love of Freya, start thinking before you write. The washing trucks themselves would become contaminated for sure, from wind and back-spray if nothing else. You would want them used somewhere else, after? Really?

 

[nikkkom]

Please, please for the love of Freya, start thinking before you write. The washing trucks themselves would become contaminated for sure, from wind and back-spray if nothing else. You would want them used somewhere else, after? Really?

"Oh no, we are all going to die!1111eleven!"

Contaminated to what level?

 

[tsutsuji]

http://josen.env.go.jp/material/pdf/jissyou_jikkenn.pdf Leaflet (released in February 2013) explaining decontamination tests. (26 pages, Japanese)

http://josen-plaza.env.go.jp/materials_links/pdf/kamishibai_omote.pdf Radiations explained to children (nuclear accident depiction on page 14/46) (the yellow dots figure the radiations) (released on 26 March 2013)

http://josen-plaza.env.go.jp/materials_links/pdf/kamishibai_ura.pdf Dialogues providing explanations to the pictures (nuclear accident dialogue on page 13-14/46)

http://josen-plaza.env.go.jp/materials_links/pdf/kamishibai_fukudokuhon.pdf?20130405 Supplementary reader (for children, 26 pages)

http://josen-plaza.env.go.jp/materi...130a.html?TB_iframe=true&width=600&height=400 Video on temporary storage design

http://josen-plaza.env.go.jp/materi...130b.html?TB_iframe=true&width=600&height=400 Slideshow on temporary storage (real photographs)

http://josen-plaza.env.go.jp/materi...405a.html?TB_iframe=true&width=600&height=400 Temporary storage safety video (distances)

http://josen-plaza.env.go.jp/materi...405c.html?TB_iframe=true&width=600&height=400 Temporary storage safety video (shielding)

http://josen-plaza.env.go.jp/materi...405e.html?TB_iframe=true&width=600&height=400 Decontamination basic principles video (removal)

http://josen-plaza.env.go.jp/materi...405b.html?TB_iframe=true&width=600&height=400 Decontamination basic principles video (farming fields, deep plowing)

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130423/0415_josen.html A ministry of environment specialist committee meeting was started on 22 April, examining a revision of the decontamination guidelines. The proposed revision includes new technologies such as real time recovery of the waste water, solutions for the disposal of waste water, etc. Diagrams and photographs provide easy to understand explanations.

http://www.yomiuri.co.jp/science/news/20130422-OYT1T01248.htm The new guidelines are expected to be released before or after the Golden Week (late April - early May).

 

[zapperzero]

"Oh no, we are all going to die!1111eleven!"

Contaminated to what level?

Contaminated enough to become radwaste themselves perhaps. Generally speaking, I'm tired of your constant drone of "oh this is too costly" "oh sure there needs to be some corner-cutting over there" "oh poor TEPCO is going to go into receivership if they are to pay for the cleanup". I don't really care. There are well known and universally accepted standards for cleanup and you are advocating that everyone should just ignore them... for the love of money.

 

[nikkkom]

Contaminated enough to become radwaste themselves perhaps. Generally speaking, I'm tired of your constant drone of "oh this is too costly" "oh sure there needs to be some corner-cutting over there" "oh poor TEPCO is going to go into receivership if they are to pay for the cleanup". I don't really care. There are well known and universally accepted standards for cleanup and you are advocating that everyone should just ignore them... for the love of money.

You are distorting my position.

In particular, in this thread I am expressing my dismay at the fact that road cleanup WAS NOT DONE. If I would be caring only about saving money, would I be unhappy about that? Doing nothing is the cheapest "solution".

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20130423/0415_josen.html A ministry of environment specialist committee meeting was started on 22 April, examining a revision of the decontamination guidelines. The proposed revision includes new technologies such as real time recovery of the waste water, solutions for the disposal of waste water, etc. Diagrams and photographs provide easy to understand explanations.

http://www.yomiuri.co.jp/science/news/20130422-OYT1T01248.htm The new guidelines are expected to be released before or after the Golden Week (late April - early May).

The new guidelines are available now :
http://www.env.go.jp/jishin/rmp/attach/josen-gl-full_ver2.pdf (256 pages, Japanese)

http://josen-plaza.env.go.jp/info/rebirth/pdf/rebirth_43.pdf Rebirth magazine, vol. 43, 30 May 2013. The lower right picture shows the JA (Central Union of Agricultural Cooperatives) direct sale shop with rice and vegetables grown in Tamura, Fukushima prefecture (Evacuation Directive Lift Prepared Area). Farming tests with rice and 10 vegetables performed in that town produced products well below the legal radiation limits. The decontamination work necessary to lift the evacuation order has been almost completed.

http://josen-plaza.env.go.jp/info/weekly/pdf/week_process_kawauchi.pdf?20130528 "Week process Kawauchi" map showing with red circles the decontamination work areas in Kawauchi city from 27 May to 1 June 2013.

http://josen-plaza.env.go.jp/info/weekly/pdf/week_process.pdf?20130528 "Week process Naraha" map showing with red circles the decontamination work areas in Naraha city from 27 May to 1 June 2013.

http://josen-plaza.env.go.jp/info/weekly/pdf/weekly_130531b.pdf Countermeasure area waste treatment weekly report, 31 May 2013