2011 Japanese Earthquake and Tsunami - News and Analysis

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Lalmohan
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

amber-ji, its been snowing in the region, and the sea water temperature is likely to be below 5C
so its close to ice
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Bade »

The idea by AmberG in Heli-dropping crushed ice (to reduce impact damage and increase target hit rate) would be better than water from high up in the air in any case as a stop gap measure before more effective cooling with adequate power access begins. Transport is still involved from ice factories and not so readily available due to infrastructure damage in surrounding areas.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

Lalmohan wrote:amber-ji, its been snowing in the region, and the sea water temperature is likely to be below 5C
so its close to ice
Melting ice to water even at 0 C requires 334 KJ per kg. So heatwise its preferable to dump ice.


This makes me think there is a whole emergency handling equipment that needs to be invented for nuclear power plants. And this should be added to their cost.
Last edited by vnadendla on 18 Mar 2011 21:34, edited 2 times in total.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

shiv wrote:The fuel cannot explode like a nuke bomb. You need some serious enrichment for that.

This is not correct. The fuel can explode though it is more like a 'dirty bomb' than a proper nuclear bomb.


:eek: Really? I didn't know that.
Shivji - No, fuel can not explode like a nuke bomb (actually, when all said and done, it is still pretty hard to make a nuke .. remember all the discussion about fizzle vs sizzle.. :) )..
Fire, other explosions, earthquakes, etc..can disperse quite a bit of radioactivity which is serious.. (perspective - 3000 tons of material!)...Sea water rusts Zr coating, ..(I am being told that it (sea water) also effects concrete (seeping property - though experts are saying that it takes weeks or months for that))

On the side remark, you (and others) may enjoy Physics and Technology for Future Presidents ..(Or just google Richard A. Muller who has taught the course) .. many topics there may be of interest :)
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

whilst it is clearly better to use ice, or even supercooled ice, practically - the best available coolant in abundant quantity is sea water, and it is at between 3-5C, and is easily handleable with the equipment available
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Klaus »

Lalmohan wrote:amber-ji, its been snowing in the region, and the sea water temperature is likely to be below 5C
so its close to ice
Sea water does not freeze at 0 C, only pure water does. Added to that is the point about Latent heat (melting) which vnadendla has pointed out.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by shiv »

Amber G. wrote: Shivji - No, fuel can not explode like a nuke bomb (actually, when all said and done, it is still pretty hard to make a nuke .. remember all the discussion about fizzle vs sizzle..
Well this is what I thought. I do actually recall reading (some years ago) about the effects of a melt down. But then again I can't claim to be privy to all gyan on this.

If fission energy from say 20% of the fuel mass is released in 20 milliseconds you get a nuke bomb with temperatures in the millions of deg C at the core. If that same fission energy is allowed to gradually heat up the fuel and build up in the area - you get all those "melt-down" temperatures - one of the links said that Zircalloy melts at 1200 deg C and something else glows at 2400 deg C. These are "cool" temperatures and a very slow release of energy compared to a bomb. And with 20% enrichment at best I fail to see how a reaction leading to a fission explosion can be sustained. Any "explosion" has to be local effects - like throwing a bucket of water into a molten mass at 1000 deg C will cause a steam explosion that will carry steam and parts of the molten metal.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

er guys... i am not arguing against ice, i am just saying that you cant get enough of it into the plant very easily. on the other hand, you have the next best thing, i.e. sea water at low temperature and easily pumped to the reactor (if you have power)
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by shiv »

I'm no fizzicist or injinyaar but ice can never enter the crevices between tubes unless it is powdered and injected as a slurry (use snow?) Once in contact with a hot surface isn't ice per-se a useless conductor of heat. The part in contact with a hot tube will explode into steam and create a layer of superheated steam between zircalloy tube and ice. Same thing with water that is not pumped away quickly I guess.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Singha »

what would happen if instead of water they start spraying concrete slurry mixed with lead granules into all of this?
would the concrete harden into a new encasement layer and the lead contain most of the radiation...permitting a more permanent tomb to be rolled into place around the reactor buildings?
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

shiv wrote:I'm no fizzicist or injinyaar but ice can never enter the crevices between tubes unless it is powdered and injected as a slurry (use snow?) Once in contact with a hot surface isn't ice per-se a useless conductor of heat. The part in contact with a hot tube will explode into steam and create a layer of superheated steam between zircalloy tube and ice. Same thing with water that is not pumped away quickly I guess.
Shiv. No one is talking of boulder sized ice. Something smaller - big enough to retain integrity as it falls to ground and in a predictable trajectory but small enough to melt fast enough - maybe not slurry. Again consider both convection and conduction. In the first place remember the reactor is using water for heat transfer.
Singha wrote:what would happen if instead of water they start spraying concrete slurry mixed with lead granules into all of this?
would the concrete harden into a new encasement layer and the lead contain most of the radiation...permitting a more permanent tomb to be rolled into place around the reactor buildings?
Interesting idea. I am worried about structural integrity. You are more or less looking at making a solid tomb. Not a shell. But given the circumstances maybe only option. Again you need equipment that can deliver huge quantities of lead laced concrete slurry to build a solid mountain around the reactor.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by SureshP »

Fukushima – 18 March morning updates, radiation and tsunamis

There have been further developments at Fukushima overnight that have, according to the IAEA, made the situation ‘reasonably stable‘ (although it is still serious). Given the state of play over the last week, I’ll take any positive sign I can get.

Other points to note, as of the morning of Friday 18 March:

1. FEPC says the following:

Through visual surveys from the helicopter flying above the Unit 4 reactor secondary containment building on March 16, it was observed that water remained in the spent fuel pool. The helicopter was measuring radiation levels above Unit 4 reactor secondary containment building in preparation for water drops. This report has not been officially confirmed.

2. WNN says:

The Ministry of Economy Trade and Industry said at 8.38pm that a cable was being laid to bring external power from transmission lines owned by Tohoku Electric Power Company. This was to be connected when radiation levels had died down after a planned venting operation at unit 2. In addition, one of the emergency diesel units can now be operated and will be used to supply unit 5 and 6 alternately to inject water to their used fuel pools. Later, the power will be used to top up water in the reactor vessels…

After clearing heavy explosion debris from tsunami and the various explosions across the site over the last six days, eleven high pressure fire trucks showered unit 3. World Nuclear News understands that 30 tonnes of water “was delivered” in an attempt to shoot water through the holes in the side of the building, which appear to be very close to the fuel ponds themselves

Despite high levels of radiation close to the units, levels detected at the edge of the power plant site have been steadily decreasing [the below is given in reverse chronological order].

17 March, 4.00pm: 0.64 millisieverts per hour

17 March, 9.00am: 1.47 millisieverts per hour

16 March, 7.00pm: 1.93 millisieverts per hour

16 March, 12.30pm: 3.39 millisieverts per hour

3. The two statements above are supported by the updates from the NEI:

In Japan, engineers have laid a power line that can connect reactor 2 of the Daiichi facility to the off-site power grid, the International Atomic Energy Agency reported. Workers are working to reconnect the power to reactor 2 after they complete spraying water into the reactor 3 complex to provide additional cooling to the used fuel pool. Reconnecting to the power grid is expected to enhance efforts to prevent further damage at the plant.

Japan’s Nuclear and Industrial Safety Agency reported on Thursday that the backup diesel generator for reactor 6 is working and supplying electricity to reactors 5 and 6. TEPCO is preparing to add water to the storage pools that house used nuclear fuel rods at those two reactors.

Radiation readings at the Fukushima Daiichi site boundary were measured today at a lower level, between 2 and 3 millirem per hour.

Fukushima Daiichi site status

The reactors at the Fukushima Daiichi plant are in stable condition and are being cooled with seawater, but workers at the plant continue efforts to add cooling water to fuel pools at reactors 3 and 4. The status of the reactors at the site is as follows:

Reactor 1’s primary containment is believed to be intact and the reactor is in a stable condition. Seawater injection into the reactor is continuing.

Reactor 2 is in stable condition with seawater injection continuing. The reactor’s primary containment may not have been breached, Tokyo Electric Power Co. and World Association of Nuclear Operators officials said on Thursday. Containment pressure is at 65 psig, an indication that containment has not been breached.

Access problems at the site have delayed connection of a temporary cable to restore offsite electricity. The connection will provide power to the control rod drive pump, instrumentation, batteries, and power to the control room. Power has not been available at the site since the earthquake on March 11.

Reactor 3 is in stable condition with seawater injection continuing. The primary containment is believed to be intact. Pressure in the containment has fluctuated due to venting of the reactor containment structure, but has been as high as 83 psig.

TEPCO officials say that although one side of the concrete wall of the fuel pool structure has collapsed, the steel liner of the pool remains intact, based on aerial photos of the reactor taken on March 17. The pool still has water providing some cooling for the fuel, however helicopters dropped water on the reactor four times during the morning (Japan time) on March 17. Water also was sprayed at reactor 4 using high pressure water cannons.

Reactors 5 and 6 were both shut down before the quake occurred. Primary and secondary containments are intact at both reactors. Temperature instruments in the spent fuel pools at reactors 5 and 6 are operational, and temperatures are being maintained at about 62 degrees Celsius. TEPCO is continuing efforts to restore power at reactor 5.

If all of this is successful, the plant will be able to take over from the workers in cooling the fuel in the reactor.

I’ll provide a further update at the end of today. Meanwhile, you can track the comments on this post (Note: I suggest we switch to this thread for the rest of today), which are once again doing a great job at providing a minute-by-minute feed of the latest developments.



Below I reproduce a short essay by Ted Rockwell. Dr Rockwell is a member of the National Academy of Engineering. His classical 1956 handbook, The Reactor Shielding Design Manual, was recently made available on-line and as a DVD, by the U.S. Department of Energy. Back in 2002 he was co-author on an article in Science journal, “Nuclear Power Plants and Their Fuel as Terrorist Targets“. It’s definitely worth reading as it’s highly relevant to the current situation — if you bear in mind that the ‘terrorist’ in this context was Mother Nature — and a brutal one at that.

Ted’s short essay (Rod Adams has also reproduced this), given below, explains well what I meant by my earlier statement:

What has this earthquake taught us? That it’s much, much riskier to choose to live next to the ocean than it is to live next to a nuclear power station.

—————————-

Fukushima: it’s not about radiation, it’s about tsunamis

A lot of wrong lessons are being pushed on us, about the tragedy now unfolding in Japan. All the scare-talk about radiation is irrelevant. There will be no radiation public health catastrophe, regardless of how much reactor melting may occur. Radiation? Yes. Catastrophe? No.

Life evolved on, and adapted to, a much more radioactive planet, Our current natural radiation levels—worldwide—are below optimum. Statements that there is no safe level of radiation are an affront to science and to common sense. The radiation situation should be no worse than from the Three Mile Island (TMI) incident, where ten to twenty tons of the nuclear reactor melted down, slumped to the bottom of the reactor vessel, and initiated the dreaded China Syndrome, where the reactor core melts and burns its way into the earth. On the computers and movie screens of people who make a living “predicting” disasters, TMI is an unprecedented catastrophe. In the real world, the molten mass froze when it hit the colder reactor vessel, and stopped its downward journey at five-eights of an inch through the five-inch thick vessel wall.

And there was no harm to people or the environment. None.

Yet in Japan, you have radiation zealots threatening to order people out of their homes, to wander, homeless and panic-stricken, through the battered countryside, to do what? All to avoid a radiation dose lower than what they would get from a ski trip.

The important point for nuclear power is that some of the nuclear plants were swept with a wall of seawater that may have instantly converted a multi-billion dollar asset into a multi-billion dollar problem. That’s bad news. But it’s not unique to nuclear power. If Fukushima were a computer chip factory, would we consider abandoning the electronic industry because it was not tsunami-proof? It would be ironic if American nuclear power were phased out as unsafe, without having ever killed or injured a single member of the public, to be replaced by coal, gas and oil, proven killers of tens of thousands each year.

Moreover, the extent and nature of the damage from seawater may be less than first implied. Rod Adams, a former nuclear submarine officer, who operated a nuclear power plant at sea for many years, says that inadvertent flooding of certain equipment with seawater was not uncommon. He includes electronics-laden missile tubes. “We flushed them out with fresh water,” he said. “Sometimes we had to replace insulation and other parts. But we could ultimately bring them back on line, working satisfactorily.”

The lessons from Japan involve tsunamis, not radiation.

———————–

Footnote – Some additional comments from Ted Rockwell, by email correspondence:

I must admit that our Science articles did not give much attention attention to the small-volume containment plants, and we should do so after the information on Fukushima has come in. Our focus was on getting past the proving that scenarios that led to intolerable situations were tolerably improbable. This traditional approach is an essential but not sufficient part of plant design.

My approach was to come in from the other side: To assume that the worst situation was one that led to some molten fuel, coupled with loss of containment integrity, and ask: what then? Does radioactivity get out in great enough quantities, into enough lungs? That’s essentially the TMI situation, and I concluded that it led to the TMI outcome: a disaster for the plant owner, but a wholly tolerable situation radiologically. We’re going to have to go back and apply a wider range of conditions to that analysis.

But radiation must still be treated like any other variable, and not the ultimate injury. It should not outrank death by inhalation of coal particles, for example. The obsessive fascination with radiation as the worst possible danger leads to mass evacuation as the most conservative response. I don’t know any experienced disaster manager who agrees that mass evacuation is always a conservative response.
http://theenergycollective.com/barrybro ... d-tsunamis
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Reason: Added bold. Ramana
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Purush »

Folks, thanks for all the explanations and links. Much appreciated.

Looks like the situation is bad, but not really the doomsday scenario projected in the media.

Worst case: if a massive explosion that can eject/disperse a large tonnage of radioactive debris into the atmosphere seems imminent, is it not better instead to actively induce/hasten a meltdown and let the molten fuel sink into the concrete catchment block beneath the reactor vessel (if it burns through even the steel containment) and cool/solidify gradually?

Definitely not a good option by itself, but undeniably the lesser of the two evils..entrapping in concrete vs spreading it in the atmosphere(?).
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by pgbhat »

Lalmohan wrote:er guys... i am not arguing against ice, i am just saying that you cant get enough of it into the plant very easily. on the other hand, you have the next best thing, i.e. sea water at low temperature and easily pumped to the reactor (if you have power)
Simple onlee...it is a matter of logistics.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

pgbhat wrote:
Lalmohan wrote:er guys... i am not arguing against ice, i am just saying that you cant get enough of it into the plant very easily. on the other hand, you have the next best thing, i.e. sea water at low temperature and easily pumped to the reactor (if you have power)
Simple onlee...it is a matter of logistics.
Agreed. The point is when you cannot pump it but you throw it or spray it ice maybe better because I have better control over the trajectory. Again there could be practical difficulties. ie logistics. But I assume in this situation cost is not an issue. Make ice and take them closer in military air craft. Probably there are some industry scale ice making factories already in Japan. No point spraying sea water if most of it lands outside the small target zone.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

cheaper and faster to grab an iceberg off sakhalin and bring it offshore... ;-)
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by suryag »

^^^ that is under short supply due to to global warming sirjee. :)
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by ramana »

Purush, From the report posted by SureshP, there is no chance of any meltdown from the reactor fuel in any of the reactors. And per that expert the fuel in TMI (a PWR) melted only 5/8 inch of five inch steel vessel wall.
In this case there is no meltdown as the reactor had coolant pumped to it.

All damage to date is to the secondary containment due to hydrogen explosions.

The situation is bad for the spent fuel where there is lack of coolant. And they are working to take care of it.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

Shivji - As we have said many times before, there is no chance of fission for the spent fuel.

The energy (that comes off as heat) is due to radioactivity..the amount is of the order of 10KW per TON of the material... simple calculation shows, that heat produced by it for the whole day per TON is still about a MILLION time less than a nuke using just a few Kg of Pu. .. so while the thread of Fuel rods igniting is serious it is no where near a 'nuke bomb'.

Wrt to ice /water - as people have pointed out, latent heat of water (it takes about 320000 joule of energy to convert (aka melt) 1Kg of ice (at 0C) to 1Kg of water (at 0C).. but there is no practical way that running water (or things immersed in water) can be replaced by ice for routine cooling purpose. The suggestion of ice, (IMO) is emergency (temporary) measure for these fuel rods. The dumping of ice has merit if a) the ice is easily available and b) one can deliver it (Eg Bade said, if Helicopters can dump it) by dropping it in the existing pool of water. Helicopters would need less number of trips before they restore the pumping of water.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

i am waiting for one of the mullahs on this thread to calculate the tonnage of ice required to take away the ongoing heat production from one reactor
and then
calculating the production capacity from industrial units for said ice
and then
calculating logistical cost of doing so
and then

meanwhile, i'll be checking out my back catalogue of lalchix pictures
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

Lalmohan wrote:cheaper and faster to grab an iceberg off sakhalin and bring it offshore... ;-)
Or crush it and fly it.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

^^^ actually those type of calculations has been done (sort of routine) ..
The estimate for that is about a hundred tons .Helis can carry about 7.5 tons/trip . .. every small bit may help.. (point was you may cut down on Heli trips by about half)..
But you are right.. it is logistics..hopefully fire hoses and other method would make this unnecessary..
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

Purush wrote:^ The point about the fuel leaving the containment vessel ... What is the size of the containment vessel, ....
Perhaps some mech/thermal engg member could run the numbers?
...
Purush: I posted a link (look through my previous messages) which has all these details from the last inspection they run (Nov 2010).. Also IAEA site had current numbers.. level.. temperature(s) .
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

Amber G. wrote:^^^ actually those type of calculations has been done (sort of routine) ..
The estimate for that is about a hundred tons .Helis can carry about 7.5 tons/trip . .. every small bit may help.. (point was you may cut down on Heli trips by about half)..
But you are right.. it is logistics..hopefully fire hoses and other method would make this unnecessary..
Maximum payload of the C-17 is 170,900 lb (77,500 kg), and its Maximum Takeoff Weight is 585,000 lb (265,350 kg). With a payload of 160,000 lb (72,600 kg) and an initial cruise altitude of 28,000 ft (8,500 m), the C-17 has an unrefueled range of about 2,400 nautical miles (4,400 km) on the first 71 aircraft, and 2,800 nautical miles (5,200 km) on all subsequent extended-range models that include sealed center wing bay as a fuel tank. The C-17 is designed to airdrop 102 paratroopers and their equipment.

--http://en.wikipedia.org/wiki/Boeing_C-1 ... master_III
iceberg off sakhalin
Crushed by TBD
Loaded on C17.
Dropped on reactor
Just 2-3 trips per day.
Does it work?
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by pgbhat »

^ Helis have better control no? V-22 Osprey?? :-? Just trying to think out of the box onlee.
If I was in the middle of it I would be shivering in my wet and browned dhoti onlee. :oops:
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by vnadendla »

pgbhat wrote:^ Helis have better control no? V-22 Osprey?? :-? Just trying to think out of the box onlee.
If I was in the middle of it I would be shivering in my wet and browned dhoti onlee. :oops:
Reason is the range, speed and logistics. Transport aircraft are good for some things. Helis for others.

iceberg off sakhalin
Crushed by TBD
Loaded on C17. Just 2-3 trips per day.
Delivered nearby
Picked up by helis
Dropped on reactor. 50-100 trips a day

Does it work?

I am also expecting that c 17 is radiation hardened. If not there should be some other aircraft - note second strike capability.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Singha »

firefighting tugboats also have powerful pumps and diesel engines. from seaward side these could establish a new beachead and keep pumping water, getting resupplies of diesel as needed via a plastic pipe laid to a small tanker moored in deeper water.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by ramana »

ramana wrote:Suppiah this is what is called a "system accident". Prof Charles Perrow wrote a book on "Theory of normal accidents". Try to google and buy the book. A medical doctor has distilled the lessons and made i simple to understand. will locate my cache and post it.

A system accident needs a complex system
It needs a closely coupled system that is a fault at one place shows its effects some where else.
Third and most important log periods of no issues leads to complacency.

In this case no one postulated a tsunami wiping out the emergency power systems and subsequent loss of coolant and potential meltdown.

I don't think multiple incidents are mostly postulated with single event probability. I mean prob of a 9.0 eqk is very low. Probability of a major tsunami from that is even lower. And the probability of both occurring simultaneously is extremely low. Yet it happened.

That is why in modern risk management the likelihood is coupled with consequences. So high consequence events with even with very low probability are mitigated. In olden days only likelihood was considered.

----------
....
----------
How Complex systems fail

The author R.I. Cook MD, is an aerospace engineer who became a physician specailizng in anesthesia. He studied and distilled for common folks why systems fail.

pdf file.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by rsingh »

Imagin if this accident occured in Russia instead of Japan.......
Press would go ga ga over how bad is situation, how bad is Russian technology and rating agency would have brought rating as par with Mali. But this is Japan....not Russia. Sophesticated Japanese are pouring sea water from helicopters on overheated nuclear core :shock: :shock: :shock: but that is not danderous :?:.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Jayram »

Hope Admins are ok with me posting this here
http://www.youtube.com/watch?v=0wYiNnHE ... r_embedded

Check out this video for a closup view taken when the water comes pouring over due to the tsunami.. The situation goes from bystandar like to scary.
The house and the people seen at @39 secs and see the same at 2.14 .. I cant tell for sure but looks like the house and the people are gone...
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Lalmohan »

sigh... merger of C17 dhaga with this one... where are my lalchix when i need them most?
anyway... (breathing in very deeply and putting the .45 down)

been strangely quiet today - no news of any thing from the reactors apart from rad levels are dropping
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

Few Items, Sorry if they have already been posted ..
From NY times:

Greater Danger Lies in Spent Fuel Than in Reactors
Technical details and analysis is similar to what I have posted here a few days ago.

Also, sorry if this has been posted, but it is quite nicely written:
Introduction to Radiation Health Effects and Radiation Status at Fukushima
(All units here are in mSV of mRem - For reference, 1mSv = 100 mRem
1mSV = 10,000 bed ( banana equivalent of dose) for perspective -
Chest xray = 800 bed)

More understanding about why spent fuel can not become nuke bomb etc..(similar to what I have posted):
What is criticality?

And some thoughts on worst case scenario:
On prediction of “worst case” scenarios


Here is some radiation data:
Readings at Monitoring Post out of 20 Km Zone of Fukushima Dai-ichi NPP

(Sorry again if they have been posted before)
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

FWIW - (From various sources - Primary US news sources (CBS news, NYtimes) and official/semiofficial sites)

The International Nuclear Event Scale (0 to 7) for this disaster has been raised to from level 4 to level 5 ( "Accident With Wider Consequences" ) For reference same as Three Mile. Chernoybyl was 7 ("major accident" )
(Ref :
http://en.wikipedia.org/wiki/Internatio ... vent_Scale

(Note that there were no fatalities (or significant health issues for population in general) in TMI.



Unit 2 and 3 are more of a concern now then unit 4 (They are having some success in pumping - there might be some leak )

Power has been restored (Power lines have been laid etc)..
(But it may still take some time to start up all the pumps etc.. as wiring and windings may be burned out etc... (it is not easy to put new wiring for example, one has to do drilling in thick concrete walls while one has to wear bulky protective suits)

Radiation level(s) (outside immediate areas) fairly low and falling.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by SureshP »

Japan raises nuclear alert level

By Richard Black
Environment correspondent, BBC News

As it was almost bound to do at some point, Japan's nuclear safety agency has uprated its assessment of the Fukushima power station incident from a level four to a level five.

These are categories on the International Nuclear and Radiological Events Scale (INES), which runs from zero (nothing happened, essentially) to seven, a "major accident".

So far, Chernobyl is the only seven-rated incident in nuclear history.

Level five is defined as an "accident with wider consequences".

So what is the worst-case scenario for those "wider consequences" at Fukushima?
What clues are there either from that level five rating, or from the situation on the ground, as to how things might transpire - whether it will in the end prove to have been a disaster or a distraction from the serious and widespread impact of the tsunami?

"The worst-case scenario would be where you have the fission products in stored canisters or in the reactors being released," said Professor Malcolm Sperrin, director of medical physics and clinical engineering at Royal Berkshire Hospital, UK.

"Radiation levels would then be very high around the plant, which is not to say they'd reach the general public.

"And we're definitely not in the situation where we're going to see another Chernobyl - that possibility has long gone."
Distant advice


The level five rating applies specifically to the nuclear reactors in buildings 2 and 3 at Fukushima, rather than to the spent fuel cooling ponds that have lost water and where the stored fuel is heating up.

That implies that the regulators believe the main source of radioactivity coming from the plant has been the reactors.

Certainly, one of the the spikes in readings earlier in the week appeared to co-incide with damage to reactor number 2, believed to be a crack in the containment system - the symptoms being a sharp release of steam and an abrupt drop in pressure.

On Thursday and Friday, radiation levels around the plant appeared much more stable.

And although elevated readings have been noted in some locations 30km from Fukushima, there has been nothing outside the 30km protection zone that has appeared to pose a danger to health.

Despite this, a number of governments have advised their citizens to stay much further away - or in the case of the UK, to consider doing so.

However, when the UK's chief scientific adviser explained the reasoning to BBC News on Thursday, he was still painting a worst-case scenario that appeared some way short of apocalyptic.

"The worst-case scenario would see the ponds starting to emit serious amounts of radiation, with some of the reactors going into a meltdown phase," he said.

"We put that together with [a possible scenario of] extremely unfavourable weather conditions - wind in the direction of Tokyo, for example.

"Even in that situation, the radiation that we believe could come into the Tokyo area is such that you could mitigate it with relatively straightforward measures, for example staying indoors and keeping the windows closed."

Local issue

Fukushima now becomes the third level five incident in half a century of nuclear power.

The first was the Windscale reactor fire in the UK in 1957 - the second, the partial meltdown of a reactor at Three Mile Island in the US in 1979.

Richard Wakeford from the Dalton Nuclear Institute, a visiting professor in epidemiology at the University of Manchester, recently re-assessed the effect of radiation released at Windscale.

Using data and computer models, his scientific paper concluded that the release could have caused about 240 cases of cancer, half of them fatal.

However, inquiries into Three Mile Island concluded it probably caused no deaths.

That raises the question of why both are in the same INES category, given that Three Mile Island did not, in the end, have more than a local impact.

"The reason why Three Mile Island was rated a five is that there was major damage to the reactor core and there was potential for a widespread release of radioactive material - it didn't happen, but that potential is built into the event scale," said Professor Wakeford.

In terms of material released, he said: "Fukushima is somewhere between the two - clearly there have been releases, and you have a possible breach of the containment system - no-one really knows."

Slow down

As time passes, the reactors should in principle become less dangerous.

The rate at which they pump out heat decreases quickly, and by now the rate should be down to about one-thousandth of what it was a week ago, just before the Tohoku earthquake triggered a shutdown.

Prospects of exposure to perhaps the most dangerous radioactive substance, iodine-131, also diminish rapidly.

It decays quickly through radioactivity - after eight days, half the atoms present initially will already have decayed away.

There should be very little left in fuel rods that have been in storage ponds since November.

In addition, the continuing efforts to keep seawater flowing into reactors 1, 2 and 3 appear to have been relatively successful on Thursday and Friday.

If the reactors have been cooled, fuel rods will have been degrading at a slower rate, again curbing the release of radioactive substances.

On Friday afternoon, radioactivity readings had reportedly declined to less than 500 microsieverts per hour on site - below the level at which operators have to sound the alarm.
Nevertheless, computer simulations by the French Institute for Radiation Protection and Nuclear Safety (IRSN) indicate that harmful levels of radioactivity could have been experienced close to Fukushima but outside the 30km protection zone - though not further afield.


Greenpeace, with a long history of opposition to nuclear power, is not convinced that the time has come to declare that the risk of a major accident has subsided.

The group's nuclear campaigner Jan Beranek outlined a scenario where radioactive material was dispersed through fires or gas explosions of the type we saw earlier in the week.

"The mechanism could be destruction of the cladding around the fuel rods and fire - leading not only to the relase of radioactive iodine and caesium, but also opening fuel rods to the air," he told BBC News.

"With the fuel ponds, there is no barrier to further release.

"With the reactors, you could have a steam or hydrogen explosion if they try to pour water too quickly, and another explosion could give the final blow to the containment."
Hooking up

The cure for the plant's immediate problems could be the restoration of electrical power.

A grid connection was hooked up on Friday, although technicians were clearly struggling to power up systems around the site given that some of the plant's internal circuitry had been damaged by the tsunami or the gas explosions.


The nuclear safety authority outlined a timescale that would see power restored in reactor buildings 1-4 by Sunday.

If this all works, the prospects of the Greenpeace scenario should recede.

Then it will be time to take stock. And it may turn out, said Richard Wakeford, that no deaths at all will be attributable to the Fukushima incident.


"If you take one of the workers who's been exposed to 100 milliSieverts (mSv), that's not going to have any serious short-term effects," he said - "certainly nothing like the situation facing the Chernobyl emergency workers that killed 28 of them.

"The risk of a serious cancer arising from that kind of dose would be less than 1% in a lifetime - and you have to consider that the normal chance of dying from cancer is 20-25% anyway.


"As for people outside the plant - I can't see any chance of picking out the effect of the Fukushima releases against the general background of cancers."

World's worst nuclear incidents
Level 7: Chernobyl, Ukraine, 1986 - explosion and fire in operational reactor, fallout over thousands of square kilometres, possible 4,000 cancer cases
Level 6: Kyshtym, Russia, 1957 - explosion in waste tank leading to hundreds of cancer cases, contamination over hundreds of square kilometres
Level 5: Windscale, UK, 1957 - fire in operating reactor, release of contamination in local area, possible 240 cancer cases
Level 5: Three Mile Island, US, 1986 - instrument fault leading to large-scale meltdown, severe damage to reactor core
Level 5: Fukushima, 2011 - tsunami and possibly earthquake damage from seismic activity beyond plant design, leading to...?
http://www.bbc.co.uk/news/science-environment-12789749
Amber G.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

Singha wrote:firefighting tugboats also have powerful pumps and diesel engines. from seaward side these could establish a new beachead and keep pumping water, getting resupplies of diesel as needed via a plastic pipe laid to a small tanker moored in deeper water.
GD and others ... might of interest - actual amount as reported/approximated ... (from various sources - Obviously I can't vouch for accuracy but figures look right, and I believe are correct as guides..)
Helicopters runs (4 runs) 7.5 tons each.
Army fire truck s (Japan's) Six tons each (about 5 operations).
US Force ("high pressure spray) 2 tons.
There are fire trucks which delivered 6 to 40 tons (per spray) .. Tokyo fire department's "Hyper team" (which recently arrived has much more powerful hoses)

Actually for now they are more concentrating on unit 2 and 3. Visual inspection of Unit 4 confirms there is some water in the pool .. ( May be CNN etc will show this as news in coming hours/days /smile/ )_
Tohoku Electric Power has confirmed working transmission lines up to the plant.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Klaus »

For the uninitiated, a short guide to understanding the theory of accidents.

Link here
Amber G.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

In case you are curious about
As it was almost bound to do at some point, Japan's nuclear safety agency has uprated its assessment of the Fukushima power station incident from a level four to a level five.
The details of their assessment: (Per Japanese Govt)

Core damage at the Fukushima Daiichi 1, 2 and 3 reactor Units: 5 (on the INES scale).

The situation at Unit 4 (lack of water at the spent fuel pool) : is rated 3

Fukushima Daini nuclear power plant, : 3

(More technical details, for the curious):
Technical Briefing of nuclear safety aspects of the situation in Japan, March 18
Summary of Reactor Status March 18
Radiation Levels update.
Klaus
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Klaus »

A short piece on the importance of normal accident theory.
Also, a concise review of the Charles Perrow book can be found here, for those that may be interested in purchasing the book or otherwise.
Amber G.
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by Amber G. »

Xpost .
Nuclear power: Why the panic?
Suppose that a giant hydro dam had crumbled under the impact of the biggest earthquake in a century and sent a wave of water racing down some valley in northern Japan. Imagine that whole villages and towns had been swept away, and that ten thousand people were killed — an even worse death toll than that caused by the tsunami that hit the coastal towns.

Would there be a great outcry worldwide, demanding that reservoirs be drained and hydro dams shut down? Of course not. ..
<snip>
Okay, another thought experiment. Suppose that three big nuclear power reactors were damaged in that same monster earthquake, leading to concerns about a meltdown and a massive release of radiation — a new Chernobyl. Everybody within a 20-kilometre radius of the plant was evacuated, but in the end there were only minor leakages of radiation, and nobody was killed....
<snip>
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Re: 2011 Japanese Earthquake and Tsunami - News and Analysis

Post by abhishek_sharma »

Meltdowns and Misinformation: What do we actually know about Japan's nuclear crisis?

http://www.foreignpolicy.com/articles/2 ... nformation
To state the obvious, the nuclear crisis in Japan is bad and will get worse.

...

The latest available data shows that water levels inside reactors 1, 2, and 3 have fallen to cover only about half then length the fuel rods, allowing them to overheat and begin to crack. Reactor 4 does not have fuel in its core.

...

These three reactors contain about 200 metric tons of lightly enriched uranium; reactor 3 also contains plutonium fuel. The cores are beginning to melt. In a full meltdown, this molten fuel could drip down, burning through the steel reactor vessel and possibly breaching the concrete containment vessel --

...

Photos of the plant show that a series of hydrogen gas explosions has blown off the sides and roofs and compromised the integrity of several structures. The containment walls at reactors 2 and 3 were damaged and may have been breached. Primary and backup cooling systems are not working at reactors 1, 2, and 3. Radioactive steam appears to be leaking from these buildings. These reactor buildings also store spent fuel rods in large pools -- containing several times as much radioactive material as the reactors themselves. Two of these pools have been damaged, and the vital water that was cooling the spent fuel has drained. Without water, these fuel rods will begin to overheat, and the rods' coverings could catch fire. There are 1,760 metric tons of spent fuel in these ponds (with an additional 1,000 tons in the nearby reactor 5 and 6 complex).

The ponds contain many billions of curies of radiation that could easily exceed those associated with the reactor cores by a factor of five to 10. They have no containment structures, and radioactive smoke from these fires would spew directly into the atmosphere. Efforts by Japanese military and police to refill the ponds with water dropped from helicopters or by water cannons appear to have failed.

The biggest worry is that a spent fuel fire could contaminate the immediate area so badly that reactor workers would no longer be able to keep working to cool the overheating reactors. Then two scenarios will unfold, both far worse than authorities imagined just seven days ago.

The best worst-case scenario is that only two spent fuel ponds -- at reactors 3 and 4 -- catch fire and that the meltdowns at reactors 1, 2, and 3 are largely contained by the concrete walls surrounding the reactors. Toxic smoke would still spread massive amounts of radioactive contamination over the surrounding environment.

The worst worst-case scenario is that all three reactors with fuel in their core and all four fuel pools overheat and two or more reactors breach the concrete containment structures, burning through into the broader environment.

In either case, severe amounts of radioactive contamination will spread over tens, hundreds, or even thousands of square miles. In either case, radioactive contamination will spread over land and water, posing serious health hazards to life within 50 miles of the complex.

...

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