Japan's nuclear situation

[Bertilak]

Here is an observation from MIT by way of Japan about the nuclear plant situation there. This is from a newsletter I subscribe to, http://jasonkelly.com/. (Reproduced with permission.)

The nuclear meltdown situation is hard to understand, with government saying it's under control but having also said that prior to the big explosion. The most dire warnings describe the worst-case scenario as being a hydrogen-bomb-like explosion that spreads radioactivity over a large area.

Scientists dismiss that out of hand, however. The most encouraging piece I've seen on this came from Dr. Josef Oehmen, a research scientist at MIT, who wrote (http://www.businessinsider.com/japan-reactors-pose-no-risk-2011-3) that "there was and will *not* be any significant release of radioactivity from the damaged Japanese reactors."

He's disappointed to find in media reports "blatant errors regarding physics and natural law, as well as gross misinterpretation of facts, due to an obvious lack of fundamental and basic understanding of the way nuclear reactors are build and operated." He offers the following reassurance:



The entire "hardware" of the nuclear reactor - the pressure vessel and all pipes, pumps, coolant (water) reserves, are then encased in the third containment. The third containment is a hermetically (air tight) sealed, very thick bubble of the strongest steel. The third containment is designed, built and tested for one single purpose: To contain, indefinitely, a complete core meltdown. For that purpose, a large and thick concrete basin is cast under the pressure vessel (the second containment), which is filled with graphite, all inside the third containment. This is the so-called "core catcher". If the core melts and the pressure vessel bursts (and eventually melts), it will catch the molten fuel and everything else. It is built in such a way that the nuclear fuel will be spread out, so it can cool down.

...

The [Fukushima] plant came close to a core meltdown. Here is the worst-case scenario that was avoided: If the seawater could not have been used for treatment, the operators would have continued to vent the water steam to avoid pressure buildup. The third containment would then have been completely sealed to allow the core meltdown to happen without releasing radioactive material. After the meltdown, there would have been a waiting period for the intermediate radioactive materials to decay inside the reactor, and all radioactive particles to settle on a surface inside the containment. The cooling system would have been restored eventually, and the molten core cooled to a manageable temperature. The containment would have been cleaned up on the inside. Then a messy job of removing the molten core from the containment would have begun, packing the (now solid again) fuel bit by bit into transportation containers to be shipped to processing plants. Depending on the damage, the block of the plant would then either be repaired or dismantled.

That's more encouraging than media and government reports!

Hat tip to Anne Groden, et al. for the article.

Jason


Jason Kelly & Co.
Plaza Kei 101
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Japan

[nav]

This is really great news! I have been reading the media articles and they are presenting a dooms day type scenario so this article really is great for the people of Japan!

[ImaWestie]

How does this explain the massive hydrogen explosions?

The fact is, what you describe may be easily implemented assuming roads are passable and (appropriately trained) staff are available to implement the prepared procedure. However, right now, both those things are reduced to "maybe's" or "somewhat's" rather than absolutely.

With the level of destruction they've already had, the last thing they need is Chernobyl part II, III and IV.

[danparker77]

Yet the Titanic still sank! :lol:

[Bertilak]

How does this explain the massive hydrogen explosions?

Read the linked article. It answers that and the rest of your concerns.

[Bertilak]

Yet the Titanic still sank! :lol:

So I guess it's a good think we stopped all cross-Atlantic shipping to avoid future incidents.

[The Nid Hog]

With all due respect to the OP and his good intentions, I wouldn't credit this report too much. You'd have to close one eye and squint to call Josef Oehmen a "research scientist at MIT." He works in the Lean Advancement Institute there and all his published work is about supply train management. It's unlikely that he knows any more about what's going on in the reactor than anybody else. That's not to say that you should prepare for the apocalypse. I just don't think it's productive to do anything more than wait and hope until the reality of the situation on the ground becomes clearer.

On the good news/bad news front, I'd say that I don't hear anything about a nuclear explosion on the TV news. I've had CNN on almost constantly in the background since this happened, and I'm following Japanese newspapers and broadcasts on line. The real fear (in a worst-case scenario) seems to be widespread broadcasting of radioactive material in the area and long-term contamination.

[danparker77]

So I guess it's a good think we stopped all cross-Atlantic shipping to avoid future incidents.

Not what I am saying at all. Just saying that no matter how "unsinkable" something is, it can still sink. Especially in a "perfect storm" scenario.

[ouch]

In 1945, the Manhattan Project engineers came to realize that one of their biggest problems was figuring out how to detonate the bomb.

[M80]

With all due respect to the OP and his good intentions, I wouldn't credit this report too much. You'd have to close one eye and squint to call Josef Oehmen a "research scientist at MIT." He works in the Lean Advancement Institute there and all his published work is about supply train management. It's unlikely that he knows any more about what's going on in the reactor than anybody else. That's not to say that you should prepare for the apocalypse. I just don't think it's productive to do anything more than wait and hope until the reality of the situation on the ground becomes clearer.

+1

Anyone who wants to read the full original blog posting, it is here:
http://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-worried-about-japans-nuclear-reactors/
Reading through the comments many people bring up very good points that make Oehmen's assertions very suspect.

[Seraphim]

In 1945, the Manhattan Project engineers came to realize that one of their biggest problems was figuring out how to detonate the bomb.

Correct. A nuclear plant meltdown can in no way create a nuclear explosion ala a atomic bomb. It can however quite easily still release a cloud of radioactive material if the containment structures are compromised.

[Blue Raccoon]

if one has to have a nuclear problem I'm glad it's the Japanese who are in charge correctly it.

[jansob]

I have a friend who actually operates a nuclear reactor in the US. He told me that this article is quite accurate and reflects his thinking as well.

http://online.wsj.com/article/SB10001424052748704893604576198421680697248.html

Guess we're about to find out...

[raisindot]

I'm no nuclear scientist (nor do I play one on TV), and I'm no defender of nuclear energy (mainly because the nuclear waste issue is far bigger threat to the environment than any other threat), but the situation is Japan is not comparable to Chernobyl and there is no chance of a nuclear exposion occurring.

First off, the reason by Chernobyl was such a disaster was because the plant had no containment field. When everything went to hell, there was nothing to stop the radiation from going everywhere.

The Japanese plants, on the other hand, do have containment fields, and, by their descriptions, these appear to be very thick concrete bunkers that have several layers of reinforcement. Should meltdown occur, it is unlikely that these materials will borrow through the bottom and into the center of the earth as all of the doomsday scenarios seem to be suggesting. There would certainly be a release of radiation, but it would not be as even a fraction as bad as Chernobyl.

Given that probably every nuclear expert in the world is gathered at these plants, it seems unlikely that such a total meltdown will occur and that some kind of makeshift cooling system will be restored.

The bad news is that those who have to clean up any of these materials will probably die in days or at the very least have their lives shortened by decades.

Second point: Nuclear explosions occur when the right proportions of fissionable materials are smashed together within a tighly enclosed, high pressure delivery medium--such as a bomb. Such as explosion won't happen in these reactors because the fuel rods are not bashed together in a tightly enclosed space. Even if one rod fell on top of another, this wouldn't be enough to cause a nuclear exposion (although it would very likely cause a complete meltdown of both rods).

In other words, the situation is serious, but this is no doomsday scenario. More people will end up dying from the tsunami than will ever die from anything happening at these plants.

[jansob]

Yep, should have added that there is truly zero danger of a "nuclear explosion"... the worst case is a dispersal of nuclear fuel through either steam explosions or it getting through the floor and into the soil/sea, which is probably not possible.

[insomniac]

+1

Anyone who wants to read the full original blog posting, it is here:
http://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-worried-about-japans-nuclear-reactors/
Reading through the comments many people bring up very good points that make Oehmen's assertions very suspect.

I'd not trust the blog comments; while I have no experience in nuclear plants, when I read tech blogs on an area I do understand, I always shake my head at the "insight" of the commentors.

There are a few exceptions but these tend to be highly specialized blogs that don't get a lot of press.

[Bertilak]

I have a friend who actually operates a nuclear reactor in the US. He told me that this article is quite accurate and reflects his thinking as well.

http://online.wsj.com/article/SB10001424052748704893604576198421680697248.html

Guess we're about to find out...

Thanks for the link. Says about the same thing as the link in my opening post, but a bit more concisely and by, perhaps, a more established source, or at least from a different, confirming, source.

[Seraphim]

Thanks for the link. Says about the same thing as the link in my opening post, but a bit more concisely and by, perhaps, a more established source, or at least from a different, confirming, source.

That was an informative articele. I will just highlight the fact it was written by a staunch nuclear advocate, FWIW.

[Greyfox]

I've been working in the commercial nuclear industry for 34 years. As long as they can continue to get water to that core and relieve the decay heat that situation will abate. Radiation levels are low. If you were to stand at the gate of that facility for 1 hour you would get a total dose equal to the amount of radiation that you would get just living everyday from background radiation. You would receive SIGNIFICANTLY more if you were to go to the dentist and get a set of bite wing X-Rays. The regulations and standard for release of radiation to the environment is extremely low. In addition the Japanese are handing out Potassium Iodine so that any radioactive Iodine released (IF ANY) will not be absorbed by the thyroid. Again if they keep the containment intact they will be no noticable effect on the general public.

The explosions are due to releases of Hydrogen. This has NOTHING to do with a potential for a Nuclear explosion. These cores do not contain enough pure enriched uranium to go supercritical and explode. Again the challenge is to keep the core covered and remove the decay heat, stop the hydrogen production and then establish some long term cooling plan. The fear that is being touted regarding potential core melt is a bit hysterical by the media. The core has in fact ALREADY experienced some damage as evidenced by the hydrogen production and the need to release it as it builds up. Again the radiation is contained in the Containment structure until they release and burn the hydrogen.

Fears of a Chernobyl type situation are complete fabrications by the media designed to get folks to watch their program. It can not and will not happen. There was no containment structure at Chernobyl and the reactors in Japan are totally different designs.

While the situation is bad from a nuclear engineering standpoint and these are challenges that no nuclear professional wants to deal with there are procedures and training to deal with contigencies like dumping seawater into the core to cool it. You can bet that the best nuclear minds in the world are assisting. Those reactors are destoyed but in a few days this crisis will be over as long as they keep enough water to remove the decay heat. Just remember the core at Three Mile Island was significantly melted and very little radiation was released. No one died.

Core melt DOES NOT mean Chernobyl level disaster. The strategy will continue to be to keep the core covered and keep the containment intact.

[Seraphim]

The hydrogen is being produced by the core, correct? Which means that it is present inside the containment vessel, correct? Which means that there is a chance, however unlikely that it could ignite within said containment vessel, and thereby compromise it?

Thanks to all for the very well informed posts! I'm learning quite a bit! I'm dubious o nuclear power, but by gaining a better understanding of it helps to broaden my mindsetand views in that regard.

[Greyfox]

The hydrogen is being produced by the core, correct? Which means that it is present inside the containment vessel, correct? Which means that there is a chance, however unlikely that it could ignite within said containment vessel, and thereby compromise it?

Thanks to all for the very well informed posts! I'm learning quite a bit! I'm dubious o nuclear power, but by gaining a better understanding of it helps to broaden my mindsetand views in that regard.

Yes the hydrogen is being produced by the core and is collecting inside the containment. That is why they are releasing it. As long as they can continue to do this and keep water on the core they can keep it from building up to explosive levels inside the containment. As the core cools and gets below about 2200 degrees F the rate of hydrogen production will fall off significantly. The entire success of this mitigation strategy is to keep the core covered as much as possible to keep the temperatures down. You can bet it is an intense situation but so far they are doing a good job. It just needs to continue. It took a cataclysmic event to put these plants in this situation. This is far beyond design basis. The event will be studied for years and plants will be modified to better deal with such situations. Nuclear is still a much safer, cleaner and greener source of energy than any of our coal and oil fired plants. We need it in our energy mix.

[Seraphim]

2200F?!

That article said 550F, didn't it? Was that guy lying?


EDIT:
Here is that guys platitudes:

The core of a nuclear reactor operates at about 550 degrees Fahrenheit, well below the temperature of a coal furnace and only slightly hotter than a kitchen oven.

So which is it?

And yes, so far everything, while being a challenge is OK, but if one more link in the chain fails (cooling water, ability to keep up with hydrogen venting, etc) things will go south quickly, no?

[Greyfox]

The 550 degrees or so is normal operating temperatures. The 2200 degrees or so they are experiencing now is due to fuel damage and overheating. No the guy was not lying. He was just stating what the normal operating temperature is. So I think you can see the importance of keeping cooling going until those temperatures return to normal.

[Obsessed]

It took a cataclysmic event to put these plants in this situation. This is far beyond design basis.

That's the part that scares me.

[Malaspina]

As distressed as I am at the situation in Japan I believe that they are the best prepared and trained in the world to handle a situation like this. If this had occurred almost anywhere else in the world I believe there would already have been far more disastrous results with regards to containment and melt-downs. The Japanese people are in so many ways one of the most conscientious societies by far. Look how well prepared the population was for when the Tsunami warnings went off - no-one tried to run to their car or grab all their valuables - they simply got to higher ground immediately, at least those that could did. There are so many things we can learn from them in the preparedness arena, especially those of us who live by the ocean....

I just wish so many didn't have to suffer the catastrophe the Japanese are currently experiencing.

[Greyfox]

I understand the concern but there are a lot of things in life that are dangerous that can not be planned for. The key is to learn the lessons when things happen. This event will be studied in detail and plant modifications and procedures will be developed to cope with similiar situations should they ever occur again. I am presently training a group of nuclear license operator candidates and the nuclear industry will require us to discuss and understand this event and mitigating strategies with them before they ever are able to get a license to operate. No technology is perfect and there is always some risk. The key is to make the risk acceptable. The risk of a nuclear plant is far less than many of the risks you accept everyday without even giving it a second thought. Things like driving, flying, fishing, hunting, snowmobiling, etc. The list goes on. Nuclear power, unfortunately got its start as a tremendously destructive force and the nuclear industry in its arrogrance thought that the general public's ability to understand the technology was not worth the effort required to educate them. As a result there is a general lack of knowledge by the general public regarding what is dangerous and what is not. This situation in Japan is serious and demands that the operators take the correct action at the correct time. They have been well trained to do so.

[Obsessed]

I understand the concern but there are a lot of things in life that are dangerous that can not be planned for. The key is to learn the lessons when things happen. This event will be studied in detail and plant modifications and procedures will be developed to cope with similiar situations should they ever occur again.

I understand what you are saying. I have my qualms about nuclear power, but I'm not a complete alarmist, either. (I did buy a house within ten miles of a nuclear plant.) Still, the lessons that will undoubtedly be learned here will not be learned in the abstract. There are potentially serious human and environmental costs.

I'm very gratified to hear your opinion that this situation will stay under control. It just seems to my untrained mind that we're in uncharted territory.

[Bertilak]

That's the part that scares me.

None of the rest of Japan's infrastructure was designed for this scenario either. Reports say thousands were killed*, but I don't think there were ANY deaths attributed to the nuclear plants. They seem to have done quite well compared to other major failures. If only that could be said of all of Japan's infrastructure. If the rest of the infrastructure weathered this storm as well there would have been very few casualties.

* I think I remember reading about two casualties at the nuclear plants, the worst being a broken arm. Might be more, but the larger point stands. Even in the worst earthquake ever recorded in Japan and the fifth worse anywhere, damage so far has been contained at the immediate facilities.

[Greyfox]

I understand what you are saying. I have my qualms about nuclear power, but I'm not a complete alarmist, either. (I did buy a house within ten miles of a nuclear plant.) Still, the lessons that will undoubtedly be learned here will not be learned in the abstract. There are potentially serious human and environmental costs.

I'm very gratified to hear your opinion that this situation will stay under control. It just seems to my untrained mind that we're in uncharted territory.

To some degree we are. Not in terms of what needs to be done but with all the damage they are having some difficulty getting the water to the site in enough quantities to get the situation turned. This is due to roads being out etc. I am sure that they are working on getting the water source there. Given the handicaps they are working with they are doing well. Hopefully they will park a ship off shore with enough pumping capacity to keep the core covered. It's tense right now I know. But if the official reports are correct from the agencies there they are doing the right things to get this under control. Keeping that containment intact is paramount so I expect them to be venting it (and releasing radiation) over the next few days.

[Obsessed]

None of the rest of Japan's infrastructure was designed for this scenario either. Reports say thousands were killed*, but I don't think there were ANY deaths attributed to the nuclear plants. They seem to have done quite well compared to other major failures. If only that could be said of all of Japan's infrastructure. If the rest of the infrastructure weathered this storm as well there would have been very few casualties.

Right, but nuclear plants should be built to much higher specifications than other infrastructure, because the magnitude of the possible harm from their failure is enormous, even if the probability is low.

Don't get me wrong. I'm not trying to argue with you, and the fact that the containment structures are as of this moment still holding through all this is a testament to how well they were built. As I said before, it just seems we're in a situation that no one has really faced, and that even the experts (which I most assuredly am not) can't be sure of how things will develop.

[Don Barbiere]

Just to be clear,the problem with Chernobyl was,that the regular folks were told that there is no cloud coming our way and nothing was broadcasted to us about it,while politicians were already hiding like rats,leaving the regular folks exposed to it.Media was controlled by the comunist and they reported whatever they were told! I lived through it, but grew 6 inches in 4 months!

[Geeno]

I heard on the news this morning that somebody feels a core was completely uncovered. The claim is that some of the contaminates they are measuring in the atmosphere can only be generated from an uncovered core.

I agree with folks here - this can not be as bad as Chernobyl, I know there is no way an "atomic bomb" type explosion can occur, and I think we need more reactors generating power - but this is a bit upsetting, if true.

*edit: Dave - I am pretty sure I know what part of TN you are in...one of my favorite areas in the state.

[Greyfox]

Just to be clear,the problem with Chernobyl was,that the regular folks were told that there is no cloud coming our way and nothing was broadcasted to us about it,while politicians were already hiding like rats,leaving the regular folks exposed to it.Media was controlled by the comunist and they reported whatever they were told! I lived through it, but grew 6 inches in 4 months!

:biggrin1: Yeah it seems that when it comes to nuclear issues the politicians get either very quite or try to explain something they don't understand. The media is even worse. They create sensational byte lines to get people to watch. BTW the statement regarding what well these plants should be built compared to other infrastructures is true. The fact is that plant IS built to a much higher standards than other infrastructures. The statement that the rest is holding up OK is just NOT TRUE. In fact the failure of that infrastructure is a major contributor to what's happening at the site. No electrical power, roads out, etc. The max credible earthquake in California according to scientists is about a 6.5 with a water surge of about 25 feet. The San Onefre nuclear plant is designed to withstand an earthquake of magnitude 7 and has a 30 foot surge wall. Again it gets back to how much over design do you want and are you willing to pay the $'s every month above the cost of production of electricity to pay for the increase margin to withstand above design basis natural events. Just like everything else there is no free lunch.

[Seraphim]

The 550 degrees or so is normal operating temperatures. The 2200 degrees or so they are experiencing now is due to fuel damage and overheating. No the guy was not lying. He was just stating what the normal operating temperature is. So I think you can see the importance of keeping cooling going until those temperatures return to normal.

What bothers me in this regard is the spin that guy put on his "reporting". By saying that the "normal" temp is only a bit hotter than your kitchen oven, he completely glossed over the actual accident temperature that is being dealt with, which is now four times that level.

He goes on to say that 550 is nowhere near the heat needed to melt steel (I.e. The containment vessel), but when you get Greyfox's "actual" emergency temp estimate of 2200, that gets much closer to what I found as a ballpark melting temperature for steel of 2500F

http://education.jlab.org/qa/meltingpoint_01.html

This kind of half truth presentation of information is exactly what makes me, and I'm sure many other exremely leery of the other info they are putting out.

On the one hand I agree, alot of the safety design stuff has worked (so far), which is remarkable given the EXTREME circumstances. But as much as there is alarmist possible misreporting of the danger levels, there is an equally high BS level saying everything is perfectly safe, as per that WSJ article slant on things.
Thank you, Greyfox for sharing your expertise. B&B is a remarkable collection of people in the know!

[The Nid Hog]

None of the rest of Japan's infrastructure was designed for this scenario either. Reports say thousands were killed*, but I don't think there were ANY deaths attributed to the nuclear plants. They seem to have done quite well compared to other major failures. If only that could be said of all of Japan's infrastructure. If the rest of the infrastructure weathered this storm as well there would have been very few casualties.

* I think I remember reading about two casualties at the nuclear plants, the worst being a broken arm. Might be more, but the larger point stands. Even in the worst earthquake ever recorded in Japan and the fifth worse anywhere, damage so far has been contained at the immediate facilities.

This seems like a strange point to be arguing now. The earthquake and the typhoon are over and the Japanese government and people are trying to deal with it's effects. On the other hand, the incidents at the nuclear power plants in the Sendai area are still unfolding. We don't know how that's going to end--that's why people are so concerned. Apart from recovering and burying the dead, treating the injured, caring for the homeless and restarting the Japanese economy, there's this crisis to deal with. The explosion of the second superstructure injured 11. Granted that's not much when we think about a death toll that will probably climb above ten thousand, but it points to a very dangerous problem that is still unresolved. Hopefully there won't be any more serious aftershocks to cause more destruction and the emergency management people on the scene will get things under control with the reactors without any further incidents. But until that all happens, I'll probably withhold my enthusiasm.

[Bertilak]

But until that all happens, I'll probably withhold my enthusiasm.

I don't recommend enthusiasm. I do recommend putting things into perspective. Heck, there are lots of catastrophic things that *might* happen and not all of them have anything to do with nuclear plants.

[Bertilak]

What bothers me in this regard is the spin that guy put on his "reporting". By saying that the "normal" temp is only a bit hotter than your kitchen oven, he completely glossed over the actual accident temperature that is being dealt with, which is now four times that level.

He goes on to say that 550 is nowhere near the heat needed to melt steel (I.e. The containment vessel), but when you get Greyfox's "actual" emergency temp estimate of 2200, that gets much closer to what I found as a ballpark melting temperature for steel of 2500F

Here is a quote from the link in my original post in this thread. "That guy" (Dr. Josef Oehmen) did not spin nor gloss over anything. Maybe you didn't read it to the end.

Once the rods start to be exposed at the top, the exposed parts will reach the critical temperature of 2200 °C after about 45 minutes. This is when the first containment, the Zircaloy tube, would fail. And this started to happen. The cooling could not be restored before there was some (very limited, but still) damage to the casing of some of the fuel. The nuclear material itself was still intact, but the surrounding Zircaloy shell had started melting.

[Seraphim]

Here is a quote from the link in my original post in this thread. "That guy" (Dr. Josef Oehmen) did not spin nor gloss over anything. Maybe you didn't read it to the end.

Aha! Thanks! I am reading this on my iPhone, and the second page didn't load or something. I was shocked at what appeared to be a rather glaring ommision! Thanks again!

EDIT:
I modify my apology. The WSJ article appears to only mention the 550 figure, and does not go any further than that, thus my outrage at the half truth being written about.
The other article that you linked to does go into much greater detail, thank you for that.
I'll therefore stick by my original assertion that the BS levels can be high on both sides. The guy writing the article for the WSJ certainly seems to have an agenda (read the footnote about the author), and seems to have only gone as far as was comfortable to support his views.


Mr. Tucker is author of "Terrestrial Energy: How Nuclear Power Will Lead the Green Revolution and End America's Energy Odyssey" (Bartleby Press, 2010).

[The Nid Hog]

I don't recommend enthusiasm. I do recommend putting things into perspective. Heck, there are lots of catastrophic things that *might* happen and not all of them have anything to do with nuclear plants.

Are you an industry spokesman?

[voerman]

The explosions are due to releases of Hydrogen. This has NOTHING to do with a potential for a Nuclear explosion. These cores do not contain enough pure enriched uranium to go supercritical and explode. Again the challenge is to keep the core covered and remove the decay heat, stop the hydrogen production and then establish some long term cooling plan. The fear that is being touted regarding potential core melt is a bit hysterical by the media. The core has in fact ALREADY experienced some damage as evidenced by the hydrogen production and the need to release it as it builds up. Again the radiation is contained in the Containment structure until they release and burn the hydrogen.



I will admit I am not an expert but I will question the buildup of hydrogen. I have no idea where the hydrogen is coming from. Is it a byproduct of the decay of the fuel or the superheating of the water?


Lou

[Bertilak]

Are you an industry spokesman?

In case that's a serious question, no. Just someone who pays attention.

[Greyfox]

I will admit I am not an expert but I will question the buildup of hydrogen. I have no idea where the hydrogen is coming from. Is it a byproduct of the decay of the fuel or the superheating of the water?


Lou

The fuel rods are clad with an alloy called Zirconium. When the fuel temperature gets around 2200 degrees or so the Zirconium starts reacting with water forming Zirconium oxide and hydrogen. This can only happen at these kinds of temperatures.

[VolpeVerde]

I lived through it, but grew 6 inches in 4 months!

Is that height, width, girth or length?

[ImaWestie]

They seem to have set a maximum safe working time for the onsite techs now?

[Nils]

2 years ago I had a talk with an industry representative. He told me that the things we're witnessing now "won't ever happen". He quoted Japanese nuclear power plants as THE example of the industry's safety.
Sorry, but I'm deeply sceptical about all those assurances that nothing really dangerous is going on.

[talibeard]

2 years ago I had a talk with an industry representative. He told me that the things we're witnessing now "won't ever happen". He quoted Japanese nuclear power plants as THE example of the industry's safety.
Sorry, but I'm deeply sceptical about all those assurances that nothing really dangerous is going on.


Well, at least we are safe from a carbondioxide point of view...:001_rolle

[Bertilak]

Here is the latest update from the source in my first post.

http://jasonkelly.com/2011/03/wednesday-japan-update/


http://jasonkelly.com/wp-content/uploads/2011/03/Operation-Tomodachi.png

America's quick, powerful response to Japan's crises has touched many hearts here, and the choice of name is charming: Operation Tomodachi, which means Operation Friend. Excellent touch, just the kind of goodwill everybody here needed. A neighbor woman not known for public displays of emotion hugged me with tears in her eyes, and said she wanted to express to all Americans her appreciation for what they're doing for Japan. I felt proud of my countrymen.

When the USS Ronald Reagan Carrier Strike Group arrived, people jumped for joy. What could inspire more confidence at a time when so many feel helpless and alone? The group flew 29 sorties yesterday, delivering 17 tons of supplies such as food, water, and blankets to the worst-hit of the disaster zone. So far, it's delivered 25 tons. The American presence (http://clicks.aweber.com/y/ct/?l=85ItB&m=i7so5PawWWQw&b=oWjuPjVBTd8cp_1wPPXTOw) is discussed widely, and warmly.

Trouble at the Fukushima nuclear power plant continues. With intense emotion involved, and a tendency toward hyperbole in media, I've begun focusing on raw data instead of interpretation. Taking that approach, let's examine the situation as of noon Wednesday, Japan time.

The following screen capture is from the Tochigi Prefecture radiation monitoring page. All of Japan's prefectures -- divisions akin to counties in California -- are now required to report radiation levels every hour. My town of Sano is in Tochigi Prefecture, hence its radiation readout is the one I'm monitoring most closely. Here's how it looked at noon today:

2011-03-16 12 PM Tochigi radiation

http://jasonkelly.com/wp-content/uploads/2011/03/2011-03-16-at-2.12.13-PM-Tochigi-radiation.png

The top bullet summarizes the area closest to me. The first line describes the location. The second shows that, as of March 16, 12 pm, radiation exposure was measured at 0.224 microsieverts per hour. The third line shows in parentheses that a typical X-ray scan exposes a person to 60 microsieverts. The next bullet group shows an area of Tochigi closer to the reactor (but still more than 100 miles away) measuring 1.40 microsieverts per hour.

These are not dangerous levels -- not even close. Other data I've seen suggest that people will not become ill until radiation levels reach 1.5 million to 2 million microsieverts. We're nowhere near that, and almost nobody expects to get there. To see current data, check the second group of info at the Tochigi radiation page (http://www.pref.tochigi.lg.jp/kinkyu/houshasen.html). Note that it uses military time, so 10 pm will display as 22.

The next consideration is where the wind is blowing. The best-case is a westerly wind that blows emitted radiation over the Pacific; the worst is a northerly that blows it over Tokyo. For wind currents, view the following map:

http://jasonkelly.com/wp-content/uploads/2011/03/Japan-wind-map.png

The arrows show wind direction and their colors correspond to the meters/second shown at bottom right. You can forecast by pushing the forward arrow at the top where it shows 16 and 12 (March 16, 12 pm). The upper-left pulldown takes you to different region zooms on the map. The image above is static; visit the live, interactive map (http://www.weather-report.jp/com/home/kishomap/fusoku/japan.html).

When you do, notice by forecasting with the forward arrow button that the wind's supposed to keep radiation flowing out over the sea. Great! What's more, it's a fairly strong wind.

Thus, with very low levels of radiation and a strong wind out to sea, I find the situation facing Tokyo to be less dire than depicted. It's possible that it will deteriorate, of course, but it'll probably get better. US Energy Secretary Steven Chu said yesterday that more than 30 experts from the Energy Department and 17,000 pounds of monitoring equipment for early detection of ground contamination had been deployed to complement Japan's efforts.

The laudable civility of Japanese citizens is holding strong. Rolling blackouts are scheduled every day, but with people following requests to self-ration their energy consumption, most haven't been necessary. Nobody complains, they just dial down electricity usage and adjust their lives accordingly. Ditto the response to gasoline shortages and emptying food shelves. An air of camaraderie permeates the tragedy.

These are good people in bad times, but they're going to get by with a little help from their friends.

I invite you to leave acomment.

Jason Kelly


Jason Kelly & Co.
Plaza Kei 101
Wakamatsu-cho 615-6
Sano, Tochigi 327-0846
Japan


And a further update...


Jason Kelly
Posted March 16, 2011 at 5:30 pm | Permalink

Many have emailed this morning’s news reports in America, showing alarm that the Tepco workers needed to evacuate the Fukushima plant due to elevated radiation levels. However, that was about 12 hours ago, lasted only one hour, and you can see in the above article that radiation levels in the Tokyo area didn’t rise during the day. This is a perfect example of why i prefer watching the data.

Notice at the updated radiation page that Tochigi’s levels have dropped even further since I captured the screen above. At noon, they were 0.224 microsieverts per hour. At 4pm, they were down to 0.216 at the station nearest my office.

[Greyfox]

Good update. It's slowly coming under control. Still a bit tense at the site as you can imagine. The operators are doing a great job.

[Bertilak]

Latest update.

Although radiation levels are going down the likelihood of things taking a turn for the worse has increased.


UPDATED AT 1:30 AM JAPAN TIME, FRIDAY

As of 11 pm Thursday (10 am EDT), radiation in Tochigi City near my office was down even farther since Wednesday's report to only 0.183 microsieverts per hour (μSv/hr). Recent history of this measurement:

* 0.224 μSv/hr Mar 16 at 12 pm
* 0.216 μSv/hr Mar 16 at 4 pm
* 0.195 μSv/hr Mar 17 at 10 am
* 0.189 μSv/hr Mar 17 at 4 pm
* 0.183 μSv/hr Mar 17 at 11 pm

Wind across Fukushima is heading southeast at 1-10 meters per second, still blowing emissions over the Pacific.

The situation at the plant looks worse, however, and the concern is that the containment vessel will be breached and that the spent-fuel pool is without water and emitting radiation.

"Right now we have indications at the site of radiation levels that ... would be lethal within a fairly short period of time," Nuclear Regulatory Commission Chairman Gregory Jaczko told the House Energy Committee Wednesday. "So they are very significant radiation levels. It is certainly a more recent development that we have seen these very, very high readings. ... We believe at this point that Unit 4 may have lost a significant inventory, if not lost all, of its water. ... There is no water in the spent-fuel pool and we believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures."

Thus, while radiation levels are low now, they may not stay that way. I'll keep monitoring and update as I can, and include other measurement station data.

The US military began voluntary evacuations at four military bases in Japan. See the article in Stars and Stripes (http://www.stripes.com/news/pacific/military-begins-voluntary-evacuation-of-families-in-japan-1.137999) and consult the map below:

http://www.stripes.com/polopoly_fs/1.138063.1300381104!/image/1418562849.jpg_gen/derivatives/landscape_490/1418562849.jpg

Going to bed. Tempted to stay there. More this evening, US time.

I invite you to leave a comment (http://jasonkelly.com/2011/03/radiation-update/#comments).

Jason Kelly


Jason Kelly & Co.
Plaza Kei 101
Wakamatsu-cho 615-6
Sano, Tochigi 327-0846
Japan

[jwcarlson]

http://www.nei.org/newsandevents/information-on-the-japanese-earthquake-and-reactors-in-that-region/


UPDATE AS OF 1:30 P.M. EDT, THURSDAY, MARCH 17:

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


UPDATE AS OF 11:35 A.M. EDT, THURSDAY, MARCH 17:

Fukushima Daiichi
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.

Access problems at the site have delayed connection of a temporary cable to restore off-site electricity. The connection will provide power to the control rod drive pump, instrumentation, batteries and 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.

TEPCO officials say that although one side of the concrete wall of the reactor 4 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.

Fukushima Daini
All four reactors at the Fukushima Daini plant have reached cold shutdown conditions with normal cooling being maintained using residual heat removal systems.

[Greyfox]

Good post Jacob. I was just getting ready to post that link myself. We will be running this event on our simulator early next week. It has been a bit difficult to get the information as to the exact timing of the sequence of events but we think we have it now. The game continues to be to keep the core covered, spent fuel pits cooled and restore some source of power. There have been several injuries at the facility but given what they have to accomplish and the hoops they are having to go through the operators there are doing a great job. There has been a lot of misinformation spread. Some of it overly optimistic and some that paints the picture bleaker than it is. The link to NEI is your best source for accurate information at this time. They are updating every few hours.

[Bertilak]

Jacob and Dave,

Yes, that is a good source of information. I have passed it on to Jason Kelly (the guy I originally quoted from).

[jwcarlson]

I was tired of seeing post after post of what amounts to editorials and people quoting them as actually what's going on. The media's sure making hay though...

[Seraphim]

I have mixed emotions about this whole situation. Obviously, I'm no nuclear proponent due to what I percieve as an unacceptable risk/reward ratio if all goes wrong.

Yet, given the magnitude of the catastrophe that struck the plant it is remarkable that they have held things together as well as they have so far. God willing, they'll be able to rein this situation in shortly.

[Greyfox]

I have mixed emotions about this whole situation. Obviously, I'm no nuclear proponent due to what I percieve as an unacceptable risk/reward ratio if all goes wrong.
Yet, given the magnitude of the catastrophe that struck the plant it is remarkable that they have held things together as well as they have so far. God willing, they'll be able to rein this situation in shortly.


We as an industry have not done a satisfactory job of educating the public with regards to what the risks really are. So this is not a surprising position. For the foreseeable future Nuclear has to be part of our energy mix because there is no safer alternative readily available. Wind and solar though highly touted are very expensive to build and have environmental issues of their own. The fact that these plants, though ruined for further production of electricity, will result in pretty much nothing more than some very mild LOCAL contamination, no civilian deaths, no workers deaths (due to nuclear), and frightening the world at large. It is a testament to how well they are built. The new generation of plants are built and designed even better. Nuclear Power does not frightened me. Our media's willingness to put out any information and speculate on things they know nothing about and put the world at panic state just to sell a story or get you to come back after a commercial break is what we ought to fear. There seems to be very little in the way of accurate news anymore from anyone. Never let the facts get in the way of a good story seems to be the rule.

[DunEdinRanger]

I have mixed emotions about this whole situation. Obviously, I'm no nuclear proponent due to what I percieve as an unacceptable risk/reward ratio if all goes wrong.

Yet, given the magnitude of the catastrophe that struck the plant it is remarkable that they have held things together as well as they have so far. God willing, they'll be able to rein this situation in shortly.

OK, let's review this:

An 8.9 Magnitude Earthquake hits Japan. It is the strongest recorded Earthquake to hit Japan. This is above the design parameters for the plant.

A 23 foot high Tsunami almost immediately overhwelms coastal areas, causing a loss of auxiliary power needed to maintain cooling of the reactor cores, even though the plant had shut down safely.

So, now, how much pollution would a refinery have caused under similar circumstances? How about a fossil fuel fired power plant? What constitutes "acceptable risk"?

It does not matter what is being designed, it is impossible to account for every possible contingency, and everything going wrong.

If anything, what has happened at a 40 year old Reactor, buffeted by an Earthquake and a Tsunami proves that Nuclear Power is safer than its critics maintain.

[Topgumby]

I had an epiphany regarding the media several years back, when I was asked to give an interview to a TV reporter regarding a type of firearm that had been used in a local crime.

I gave the technical details, answered some questions and corrected some factual errors that she ran past me. The news story that aired used some video, but no sound from the interview, and the same reasonable, polite reporter I had talked to, reported as fact some of the details I had been very careful to correct her on.

I always keep that in mind when I read anything from a news source on something technical that is also an emotional hot button.

Interesting conversation here, gents.

[Seraphim]

OK, let's review this:

An 8.9 Magnitude Earthquake hits Japan. It is the strongest recorded Earthquake to hit Japan. This is above the design parameters for the plant.

A 23 foot high Tsunami almost immediately overhwelms coastal areas, causing a loss of auxiliary power needed to maintain cooling of the reactor cores, even though the plant had shut down safely.

So, now, how much pollution would a refinery have caused under similar circumstances? How about a fossil fuel fired power plant? What constitutes "acceptable risk"?

It does not matter what is being designed, it is impossible to account for every possible contingency, and everything going wrong.

If anything, what has happened at a 40 year old Reactor, buffeted by an Earthquake and a Tsunami proves that Nuclear Power is safer than its critics maintain.

I certainly hope your final paragraph turns out to be the end result. But, if they cannot contain this, if the attempts at cooling fail, the thing that is more troubling than an oil spill etc. about this is that radiation is far reaching, and has some rather dire immediate and long term health implacations, which I think is the boogeyman that nuke opponents are really concerned about.

The comment above about local damage may sound fine, unless the local is local to you or me. That goes for long term storage of the spent nuclear fuel.

[Bertilak]

There is an update from Jason Kelly in Japan: http://jasonkelly.com/2011/03/japan-situation-update/

I will not post the whole thing this time as it is lengthy, but here is his summary:

OVERVIEW

Radiation Levels Still Safe | The Tokyo area remains free of harmful radiation levels.
Power Plant Struggling But Better | Efforts that have been criticized were not foolish, and better assets are coming online.
Evacuations Proceeding, Unnecessarily | The call to evacuate became shrill after a US official suggested a wider clear zone around the reactors, but there was no data supporting the need for that.
Worst-Case Scenario Not Cataclysmic | Even a meltdown would probably not expose the public to deadly amounts of radiation.
One Week Has Passed | As I wrote this, we reached the one-week anniversary of the quake — the longest week of my life.
The full update addresses each of those bullets.

[The Nid Hog]

OK, let's review this:

An 8.9 Magnitude Earthquake hits Japan. It is the strongest recorded Earthquake to hit Japan. This is above the design parameters for the plant.

A 23 foot high Tsunami almost immediately overhwelms coastal areas, causing a loss of auxiliary power needed to maintain cooling of the reactor cores, even though the plant had shut down safely.

So, now, how much pollution would a refinery have caused under similar circumstances? How about a fossil fuel fired power plant? What constitutes "acceptable risk"?

It does not matter what is being designed, it is impossible to account for every possible contingency, and everything going wrong.

If anything, what has happened at a 40 year old Reactor, buffeted by an Earthquake and a Tsunami proves that Nuclear Power is safer than its critics maintain.

In terms of earthquakes, you might be right. Certainly the only earthquake of this magnitude to strike the region was probably around 800 AD (on the other hand, they have had other damaging earthquakes, including some of lesser magnitude that are closer to the surface, etc.). However the size and scope of the tsunami was not that unusual. The Meiji-Sanriku tsunami in 1896 saw waves of between 38 and 39 meters strike much of the same coastline, and the area has been damaged by large tsunami every 40 or 50 years.

http://www.telegraph.co.uk/news/worldnews/asia/japan/8380614/Sanriku-Japans-Tsunami-Coast.html

As you say, damaged refineries are likely to also cause a great deal of problems. Fortunately the fire and explosions at the Cosmo Oil refinery in Chiba seems to have been contained. I haven't seen any report on the extent of the effects of the damage there, but I did see notice that the refinery is operating again.

The discussion and analysis here has been interesting, but I think we're all operating on a deficit of information. The US and Japanese governments and the on-scene supervisors from Tokyo Denryoku don't seem to be able to agree on exactly what's happening, so I'm personally unwilling to feel too optimistic or pessimistic until, God willing, this whole event is brought under control. Readings taken here or there are interesting and I've learned a lot from Greyfox's posts, but I think that the consequences of this incident are only going to become clear after the fact.

Here's a link to the current NYTimes article about the situation with the Sendai reactors:

http://www.nytimes.com/2011/03/19/world/asia/19japan.html?_r=1&hp

In all this discussion of the reactors, it's easy to lose sight of the terrible losses to the earthquake and the tsunami. I'd encourage anybody who is interested to look at making a contribution to the relief efforts. The Red Cross is there for the long haul and is generally pretty efficient with donations. Doctors without Borders do excellent work, but they have announced that they will withdraw their medical teams if they feel that conditions at the reactor become too dangerous. As noted in another thread, the Salvation Army also has people on the scene.

[Salty O'Rourke]

While the people of Japan have legitimate concerns regarding the danger of radiation escaping from these plants, the fears expressed about the potential for massive radiation clouds wafting to the US and poisoning everyone are overblown. Each one of these plants could melt down and the radiation released wouldn't come close to the levels produced by the two nuclear devices dropped at the end of WWII, not to mention the radiation released during all the atmospheric nuclear bomb tests conducted during the 50s by the US, France, etc.

My biggest fear is that this is going to turn the public off to exploring alternatives to oil/coal for power generation.

And no, I'm not an industry spokesman, just an old history major who knows you often have to look back to look forward. Probably explains why I shave with 100-year-old technology...

[babafats]

http://www.wired.com/wiredscience/2011/03/japan-nuclear-crisis/

This is a good compendium of level-headed assessments of the situation to date, and includes a nice basic description of how nuclear fission reactors work. Well worth a read.

[Seraphim]

OK, so if even with a full meltdown "things won't be so bad..." result, why are they fighting this thing so furiously, putting at immediate risk the guys who are on site? Why not just leave, let the thing meltdown, and come back in a month or two and then go about cleaning up the remaining mess?

[jwcarlson]

http://www.nei.org/newsandevents/information-on-the-japanese-earthquake-and-reactors-in-that-region/


UPDATE AS OF 11:20 A.M. EDT, FRIDAY, MARCH 18:

Reactors 1, 2 and 3 at the Fukushima Daiichi nuclear power plant are in stable condition, with workers continuing to provide seawater cooling into the reactors. Containment integrity is believed to be intact on reactors 1, 2 and 3, and containment building pressures are elevated but are within design limits.

Site radiation doses have been decreasing since March 16. Radiation dose rates are fluctuating based on some of the relief operations, such as adding cooling water to the used fuel pools. Recent readings at the plant boundary are about 2 millirem per hour. Radiation dose rates at reactor 3 range between 2,500 and 5,000 millirem per hour.

The Japanese Self-Defense Force restarted cooling water spray into the Unit 3 reactor building and spent fuel pool at around 1 a.m. EDT on March 18. Plans are to spray 50 tons of water on the reactor 3 reactor building/spent fuel pool using seven fire-fighting trucks.

A diesel generator is supplying power to reactors 5 and 6. TEPCO is installing high voltage cables from a nearby transmission line to reactors 1 and 2. Once electricity supply is re-established, priority will be given to restoring power to reactor heat removal systems and cooling water pumps. Workers are seeking to install electrical cables to reactors 3 and 4 components in about two days.

Fukushima Daini

All four reactors at Fukushima Daini remain shut down with normal cooling being maintained using residual heat removal systems.

Daiichi Accident Rated 5 on International Event Scale

New International Nuclear and Radiological Event Scale (INES) ratings have been issued for the accident at the Fukushima Daiichi and Daini nuclear power plants, the International Atomic Energy Agency said.

Reactor core damage at the Daiichi reactors 2 and 3 caused by a loss of cooling function has resulted in a rating of 5 on the seven-point scale.

The loss of cooling and water supply functions in the spent fuel pool of reactor 4 was rated a 3, or “serious” incident. The loss of cooling functions in the reactors 1, 2 and 4 of the Fukushima Daini nuclear power plant has led to a rating of 3.

The rating for the Chernobyl accident was 7, or a “major accident” on the INES scale. The Three Mile Island accident was 5, or an “accident with wider consequences.” For more information on INES, see the IAEA’s website and this IAEA leaflet.

[rajagra]

If the reactors hadn't shut down automatically as a safety measure, would they have continued to be cooled under their own power, avoiding the whole nuclear incident?

[babafats]

If the reactors hadn't shut down automatically as a safety measure, would they have continued to be cooled under their own power, avoiding the whole nuclear incident?

There are several backups to keep the coolant flowing if the reactors are shut down, but the generators which provided power were put out of commission when the tsunami wave hit, and other backup systems failed. Then generators had to be brought in, which left the system uncooled for a while.

[Salty O'Rourke]

OK, so if even with a full meltdown "things won't be so bad..." result, why are they fighting this thing so furiously, putting at immediate risk the guys who are on site? Why not just leave, let the thing meltdown, and come back in a month or two and then go about cleaning up the remaining mess?

A meltdown has the potential to produce serious local environmental consequences; the global consequences are what's being exaggerated.

[jwcarlson]

If the reactors hadn't shut down automatically as a safety measure, would they have continued to be cooled under their own power, avoiding the whole nuclear incident?

Depends if the tsunami would have knocked out the power generation system or not. There's a lot more than a steam turbine and a power cord going to the cooling system. I think a lot of that (transformers and such) were probably damaged in the tsunami just like the backup generators were.

I don't think you're implying that it would have been better NOT to automatically shutdown the plant... A shutdown plant is a known quantity vs. a plant that's still operational in a situation like this.


There are several backups to keep the coolant flowing if the reactors are shut down, but the generators which provided power were put out of commission when the tsunami wave hit, and other backup systems failed. Then generators had to be brought in, which left the system uncooled for a while.

"Several" may not be the right word. There are probably two back up diesel generators. This plant is fairly old. Some more modern plants have at least four back up generation sources.

[babafats]

You are correct, sir. I reread the article and they describe only two: backup generators and battery power.

[rajagra]

Depends if the tsunami would have knocked out the power generation system or not. There's a lot more than a steam turbine and a power cord going to the cooling system. I think a lot of that (transformers and such) were probably damaged in the tsunami just like the backup generators were.

I don't think you're implying that it would have been better NOT to automatically shutdown the plant... A shutdown plant is a known quantity vs. a plant that's still operational in a situation like this.

Yes, I am suggesting that it might have been safer to leave the reactors running. Or to restart them after the tsunami hit and the situation was assessed. Maybe a considered response may have been better than blindly following procedures.

If the following picture is accurate, all of the key components to keep the reactor running safely are held within the containment chamber. Only the coolant supply is external, and availability of water was not reported to be a problem, just the ability to pump it.

152186 (http://www.bbc.co.uk/news/science-environment-12737508)

[Greyfox]

Yes, I am suggesting that it might have been safer to leave the reactors running. Or to restart them after the tsunami hit and the situation was assessed. Maybe a considered response may have been better than blindly following procedures.

If the following picture is accurate, all of the key components to keep the reactor running safely are held within the containment chamber. Only the coolant supply is external, and availability of water was not reported to be a problem, just the ability to pump it.

152186 (http://www.bbc.co.uk/news/science-environment-12737508)

NO WAY is a reactor producing 1100 Million watts safer running in this situation that it is shutdown. :thumbdown The problem right now is decay heat AFTER the reactor is shutdown. That is less than 1% of the power that is produced when the reactor is on line. Nuclear Power 101 in the event of a casualty is to get rid of the nuclear fission process. The situation would be infinitely worse with a critical reactor. There was no way to restart the reactor without electrical power which was lost almost immediately. Are you sure you don't work for CNN or Fox or Huffington?:001_smile These guys were not blindly following procedures. This was an automatic reactor shutdown. Surely you are not suggesting to override safety functions on the fly because someone got a bright idea in the middle of a crisis are you? They are doing what they need to do given the situation at hand. They are also working with a design that has stood the test of time and is better engineered than most anything on this earth. The last thing this world needs is a Nuclear cowboy. Your idea and thought process on this matter is seriously flawed and just plain bogus.

[rajagra]

The problem right now is decay heat AFTER the reactor is shutdown. That is less than 1% of the power that is produced when the reactor is on line.

Normal cooling can cope with 100% of the power that is produced. Things only went tits up when the cooling failed, which may not have happened if they kept the plant running. They can lower the output as well as turn it right off. I don't know why you are so hostile to the idea that things might not have turned out so bad if they did things differently.

There are lessons to be learned, and this is a question that SHOULD be asked. Not to point the finger of blame, but to improve procedures and designs.

[Bertilak]

There are lessons to be learned, and this is a question that SHOULD be asked. Not to point the finger of blame, but to improve procedures and designs.

In the spirit of answering a question ...

Perhaps the urgency of shutting down the reactor is to avoid whatever happens *next*. Maybe a big aftershock. Maybe another tsunami. Maybe a volcanic eruption. Maybe the cooling already did, or soon will, fail due to the stresses of the earthquake or the tsunami. Lots of unknowns. Why add a huge, active, power source to the mix?

But perhaps this question and other we here on B&B haven't thought of were already asked and answered long before the event.

[rajagra]

I am merely pointing out the irony that safety procedures (even if well thought out) may have lead to disaster rather than prevented it. I don't want an argument, so I'll butt out now. Anyone unwilling to even consider the possibility is welcome to ignore the idea.

[BCatl]

If the shutdown here was truly automatic (shutdown of the main power) then that was an unfortunate irony. This was pointed out soon after the earthquake by the BBC. I don't think there was earthquake or Tusnami damage to this plant to begin with. In other words, the main power should have never been cut off.

Regarding the backup generators, Martha Raddatz reported this week that the backup generators were not damaged by the earthquake or the Tsumani. At least some of them were low on fuel and a TEPCO employee had been told to fill it (or them) and it slipped his mind. Human negligence. I have only seen this reported by ABC News on an embedded video which was on their site Wednesday I think. Don't know if it's still there.

I don't think they are out of the woods yet. They finally raised the threat level today.

At any rate, the final report on this event will make interesting reading (if it can be trusted).

[jwcarlson]

I am merely pointing out the irony that safety procedures (even if well thought out) may have lead to disaster rather than prevented it. I don't want an argument, so I'll butt out now. Anyone unwilling to even consider the possibility is welcome to ignore the idea.

It's about percentages of risk. There's not really any place to "roll the dice" in a situation like that.

And the shutdown was automatic.

[BCatl]

Here is that video I mentioned about about the plant worker who did not put fuel in the backup generator(s). Martha Raddatz ABC. Mar 16.

She mentions this a little more than half way thru the video.

http://abcnews.go.com/GMA/video/us-nuclear-team-arrives-in-japan-13146047

I have not seen this reported anywhere else.

[Greyfox]

Normal cooling can cope with 100% of the power that is produced. Things only went tits up when the cooling failed, which may not have happened if they kept the plant running. They can lower the output as well as turn it right off. I don't know why you are so hostile to the idea that things might not have turned out so bad if they did things differently.There are lessons to be learned, and this is a question that SHOULD be asked. Not to point the finger of blame, but to improve procedures and designs.

The cooling failed 2 minutes into this event because of a loss of all AC power.

I am not hostile. But this has been my career for 4 decades and I am well informed on how these things work. Procedures are devoloped to best mitigate these accidents based on 1000's of years of cumulative reactor operating experience by people who are trained and tested on their knowledge and ability to respond. They would NEVER leave a reactor critical in a situation like this. It is absurd.

If you think I am tired of hearing so called experts that don't know a neutron from a gamma particle or spent fuel pit from a reactor core telling the world what is going to happen and what they should have done then you would be right. There is an old saying that a lot of folks in the media should remember. Something along the lines of if you don't know what you are talking about it is best to be quiet and thought a fool rather than to speak up and removed all doubt.

[Bertilak]

If you think I am tired of hearing so called experts that don't know a neutron from a gamma particle...

Does anyone remember the old Amos and Andy show?

The two main characters were actually Amos and the Kingfish. The Kingfish was always trying to lure Amos into some outrageous scheme to make them both rich, or at least move some cash from Amos' pockets to the Kingfish's pockets without letting the wiser Andy ruin things.

One scheme was investing in nuclear energy. The Kingfish says to Andy:

"Let me explain this to you. There's the neutrons, the protons and the morons. (pause) That's where *you* come in."

:laugh:

[rajagra]

They would NEVER leave a reactor critical in a situation like this. It is absurd.

No matter how absurd you think the idea, what is the answer to my question?:


If the reactors hadn't shut down automatically as a safety measure, would they have continued to be cooled under their own power, avoiding the whole nuclear incident?

Yes or no?

If the answer is yes, then your defensive responses are a little uncalled for.

[Seraphim]

Can someone tell me how to compare the different irradiation measures? Rotegens, millirem, sieverts, etc, etc???

Thanks

[Greyfox]

These reactors can not operate at power (critical) without AC power. Some of the pumps are very large and require an offsite power source to run them until the reactor is producing enough to be self sufficient. If the loss of off site power and the earthquake causes an automatic shutdown of the reactor due to seismic activity sensed as being at the design basis, an instrument detected an unsafe pressure, temp, power or anything else the automatic reactor protection system would shut the reactor down. This is designed to prevent continued operation outside of design safety limits. Once that happens there is no production of electricity from the reactor other than some batteries. At that point plants rely on off site electrical power to provide electricity to support a safe shutdown of the reactor to get rid of decay heat. In the event that off site power is lost then emergency diesel generators automatically start to provide power to run those pumps and operate valves as required. Keep in mind that most of these pumps require at least a 4KV power supply. Some pumps require up to 6.9KV. When the diesels started at the Japanese plant and loaded the required pumps, valves etc. required to keep the plant safe they were lost a short time later due to losing their fuel supply. It's not clear based on the updates that we get if it was due to the tsunami taking out the tanks or if water got in the fuel. That will come out in the report. Certainly the tsunami took out their switchyard and their off site power source. At this point they were left with a battery source rated for about 8 hours. Those batteries are designed to provide instrumentation, some valves, some very small DC motors etc but NOT large pumps. So in effect with normal power gone due to the reactor automatic shutdown, the offiste power source gone and failure of the emergency power system the situation degraded over time to where it is now. For those of you who may have served in the Nuclear Navy and are use to a completely self sustaining system of electrical distribution the commercial designs are different and rely on off site power sources for some loads. Even a submarine has to go to emergency diesels or battery backups if the reactor shutdown.

So a couple of things. The shutdown was automatic to keep the core safe from unsafe operating conditions. There was NOTHING the operators could have done to prevent this. This is a design feature. If a commerical plant of present design loses all AC power and can not restore it they will end up in the kind of situation that exist in Japan. You must be able to cool the core and keep it covered. Plants in the US have to demonstrate their ability to cope will a total loss of AC power for an extended time. All efforts at the facility will be to restore the AC power before that time ends and trouble begins. If necessary they can in normal situations bring in a diesel on a flat bed truck or fly it in and hook it up and start it. Obviously with the natural disaster that took place in Japan they have not been able to do this yet. There is word that power was restored to a couple of units with another to have power in the next day or two.

As far as your question goes rajagra the short answer is NO. There was nothing the operators could do to attempt to override an automatic shutdown signal nor would any one want them to. It functioned as designed. Otherwise the situation would be a whole lot worse. I'll be happy to attempt to answer all questions and will be willing via PM to provide any information as to how these plants work. But if you don't understand what the problem is and the design of these plants you certainly can not get the information that you need from our media. Some of the questions asked are similiar to "Where does the white go when the snow melts?"

[Seraphim]

Raj, I think you raised a reasonable question. The basis for your inquiry is that the plant can usually cool the reactor even when it is going full blast, so I can understand why the idea of just keeping things running seems like it may have merit. I think Greyfox answered that though, the cooling pumps require an extremy high current draw that requires hooking up to the outside power grid.

[Greyfox]

Can someone tell me how to compare the different irradiation measures? Rotegens, millirem, sieverts, etc, etc???

Thanks


This one is pretty good Seraphim. Read the basic defintions first and then what is really important is the dose rate and effective dose rate values. They even list the "best guess" values for short term and long term effects.

http://www.ccohs.ca/oshanswers/phys_agents/ionizing.html

[Seraphim]

Thanks!