Shouldn't we disable Nuclear Reactors in California?

[clancy688]

According to former NRC Chairman Nils Diaz, NRC studies, which have not been released, “confirm that the likelihood of both damaging the reactor core and releasing radioactivity that could affect public health and safety is low.”

Very interesting. That's the same information as in the german study regarding plane crashes. The germans called it "can't be safely ruled out" and the americans called it "likelihood is low". It's exactly the same thing. Fascinating what you can do with words...

Personally I think the "likelihood is low" thinking is exactly what brought us to TMI and Fukushima.

 

[daveb]

Fukushima, yes, they may have underestimated certain events in the PRA. (I haven't seen it and probably could only understand portions of it if I did anyway). On the other hand, even if the liklihood of an event of this nature is accurately assessed at below 10^-6, the fact that it happened now, albeit very unlikely, doesn't necessarily negate the process of PRA. It's similar to a person calling heads 5 times in a row for 5 coin tosses, getting five heads, and stating with 100% certainty that there are either 2 heads, or the coin is unfair. It was highly unikely, but it could still have happened.

As for TMI, most of the fault with that was due to operators not believing their instruments.

 

[clancy688]

Hm...

There is one thing I'd like to know. It seems that most US citizens are in favor of nuclear power. But then why is the newest plant in the US from ~1980?

Why did you decide to stop building NPPs...? And why didn't you start again in the nineties and the 21st century when more and more energy was needed?

Don't misunderstand me, please. I'm just curious.

 

[NUCENG]

Very interesting. That's the same information as in the german study regarding plane crashes. The germans called it "can't be safely ruled out" and the americans called it "likelihood is low". It's exactly the same thing. Fascinating what you can do with words...

Personally I think the "likelihood is low" thinking is exactly what brought us to TMI and Fukushima.

Remember, the important thing is that even though the probability was low, the NRC has regulated significant increases in plant security that has resulted in millions of dollars of added costs and modifications at every plant. We didn't use a low risk to justify ignoring the problem. Would utilities have done that voluntarily? Probably not, but that is why an independent regulatory body could have made a significant difference in Japan. I posted Japan's response to questions from the Convention on Nuclear Safety. TMI emphasized that lesson 32 years ago. Hopefully Japan will learn that lesson now.

 

[NUCENG]

Hm...

There is one thing I'd like to know. It seems that most US citizens are in favor of nuclear power. But then why is the newest plant in the US from ~1980?

Why did you decide to stop building NPPs...? And why didn't you start again in the nineties and the 21st century when more and more energy was needed?

Don't misunderstand me, please. I'm just curious.

Political reality is that immediately after TMI, there was little or no support for nuclear power in the US. Planned plants were cancelled, some in the middle of construction. But rather tha throwing the baby out with the bathwater and shutting down the remaining nuclear plants it was decided to operate them as safely as possible to end on life.

NUREG-0737 was kind of a summary of all the post-TMI requirements. There are too many to even list here, but that might make another useful thread.

Funny thing about us Americans, we tend to reward performance. All those investments, modifications, increased training, and analysis made the remaining plants more reliable. Nuclear generation grew even though no new plants were built. Political reality changed. Go to www.nrc.gov[/URL] and check out the applications for combined construction/operation licenses. Also look at descriptions of the new plant designs in terms of passive (Power-independent) safety design. Will the Fukushima accident put a dent in that? It already has.

Will the US follow Germany in phasing out nuclear? Maybe, when we have designed a distribution system that can service a country as large as the US, supporting wind or solar energy and still remaining stable. Maybe, when something better comes along. But probably not this week.

 

[NUCENG]

Fukushima, yes, they may have underestimated certain events in the PRA. (I haven't seen it and probably could only understand portions of it if I did anyway). On the other hand, even if the liklihood of an event of this nature is accurately assessed at below 10^-6, the fact that it happened now, albeit very unlikely, doesn't necessarily negate the process of PRA. It's similar to a person calling heads 5 times in a row for 5 coin tosses, getting five heads, and stating with 100% certainty that there are either 2 heads, or the coin is unfair. It was highly unikely, but it could still have happened.

As for TMI, most of the fault with that was due to operators not believing their instruments.

Fukushima risk for tsunami was evaluated using a method developed by the Japan Society of Civil Engineers, but only considered historical events since the late 19th century. From information I have seen on this forum. NISA had "suggested" plants revaluate seismic risk a couple of years ago. TEPCO was in the process of re-analyzing the plant to withstand a ground acceleration of 600 gal for an offshore earthquake but hadn't completed it. TEPCO had reportedly ignored appeals to reexamine tsunami risk during that process but those appeals were denied. IAEA safety standards guidance for reevaluating seismic and tsunami risks is also fairly recent. TEPCO may have completed an IPE PRA analysis (determines probability of core damage events for design basis events and equipment failures), but may not heve even started a IPEEE analysis for frequency of external events (seismic, flooding, tsunami, typhoon, etc.) In short, my interpretation is that TEPCO had never adequately performed any analysis to justify the magnitude or frequency of tsunami hazards at Fukushima or any of their other plants.


At TMI they believed some instruments that were misleading them while disbelieving other instruments that were accurate. Their training had not covered the exact scenario, even though another plant had had the same event (stuck-open PORV) shortly before the accident. Specifically they focused in on the rising pressurizer level indication that told them there was a danger of the pressurized going solid making pressure control problematic. The pressuriozer level was rising because the plant was being depressurized and they ignored indications that there was an ongoing loss of coolant accident that led to boiling in the core.
Many of the vulnerabilities that led to TMI no longer exist. Others still depend on reducing potential for human error and continuously reassessing design bases.

 

[clancy688]

NUREG-0737 was kind of a summary of all the post-TMI requirements. There are too many to even list here, but that might make another useful thread.

So in 1979 the US suddenly burned its hands with nuclear power and shuddered back? And when they recovered from that shock, safety requirements had made new reactors to expensive?

Or is there a change now, and new reactors are suddenly economical despite those expensive safety requirements? The NRC website you referred to lists over two dozen new reactors.
But as far as I know, no new reactor is being built right now.

 

[Danuta]

No, apparently you don't know what would happen. The matter has been studied in depth by others.http://www.fas.org/sgp/crs/homesec/RL34331.pdf

Obviously *I* don't know what would happen. How could I? The whole point being if we can trust what has been studied "in depth" by these others. And this "in depth" study of theirs, is it like the "in depth" study of earthquake and tsunami risk assessment done at Fukushima? Meh.

 

[NUCENG]

So in 1979 the US suddenly burned its hands with nuclear power and shuddered back? And when they recovered from that shock, safety requirements had made new reactors to expensive?

Or is there a change now, and new reactors are suddenly economical despite those expensive safety requirements? The NRC website you referred to lists over two dozen new reactors.
But as far as I know, no new reactor is being built right now.

Apparently there are over two dozen reasons to think they aren't too expensive, but we'll see.

 

[clancy688]

Apparently there are over two dozen reasons to think they aren't too expensive, but we'll see.

Well, I just wanted an explanation for over 30 years without building a new NPP. I can't believe that TMI alone was responsible for that... maybe for the first 10 years, but what's with the period after that?

Maybe they are not expensive anymore, so there are over two dozen new plants being planned. Maybe it's something else. I just want to know the reason. Don't worry, I won't give you any anti-nuclear opinions etc. I just want to know the reason for that gap.

 

[daveb]

But as far as I know, no new reactor is being built right now.

One of the main reasons for this is it takes a long time to obtain all the necessary permits and licenses required for just constructing a new plant. There are plants "in the works", that are doing environmental impact studies, etc. http://www.nrc.gov/reactors/new-reactors.html" describes the different licenses and permits.

Another reason it's taken so long is because there was not a lot of public or even political backing for new plants because of the memory of TMI and then Chernobyl. That started to change a while back, but now with Fukishima, I imagine that will again reverse.

From Wikipedia:

Health and safety concerns, the 1979 accident at Three Mile Island, and the 1986 Chernobyl disaster played a part in stopping new plant construction in many countries although the public policy organization Brookings Institution suggests that new nuclear units have not been ordered in the U.S. because of soft demand for electricity, and cost overruns on nuclear plants due to regulatory issues and construction delays.[

 

[Luca Bevil]

No, apparently you don't know what would happen. The matter has been studied in depth by others.


http://www.fas.org/sgp/crs/homesec/RL34331.pdf

Thanks for the interesting link.

The answers I was looking for is there for me and anyone to read and draw one's own conclusions.

"Nuclear power plants were designed to withstand hurricanes, earthquakes, and other extreme events. But deliberate attacks by large airliners loaded with fuel, such as those that crashed into the World Trade Center and Pentagon, were not analyzed when design requirements for today’s reactors were determined. Concern about aircraft crashes was intensified by a taped interview shown September 10, 2002, on the Arab TV station al-Jazeera, which contained a statement that Al Qaeda initially planned to include a nuclear plant in its list of 2001 attack sites.
In light of the possibility that an air attack might penetrate the containment structure of a nuclear plant or a spent fuel storage facility, some interest groups have suggested that such an event could be followed by a meltdown or spent fuel fire and widespread radiation exposure. Nuclear industry spokespersons have countered by pointing out that relatively small, low-lying nuclear power plants are difficult targets for attack, and have argued that penetration of the containment is unlikely, and that even if such penetration occurred it probably would not reach the reactor vessel.
They suggest that a sustained fire, such as that which melted the steel support structures in the World Trade Center buildings, would be impossible unless an attacking plane penetrated the containment completely, including its fuel-bearing wings."

Having a bit of structural engineering competence myself I formed my own opinion on the matter of resilience of typical concrete NPP structures, especially outside the containment vessel.

On the "force-onforce” security exercises referred to in the first pages I have no experience to comment not being (and not being interested to become) a military expert.

 

[daveb]

On the "force-onforce” security exercises referred to in the first pages I have no experience to comment not being (and not being interested to become) a military expert.

I was taking a tour of San Onofre (a friend's wife was the Senior Reactor Safety Officer), and she relayed an amusing story about how she was working the graveyard shift one night. Apparently, the security forces there (and probably at every NPP) conduct mock exercises for training purposes. This particular night, she saw one of the forces (dressed as a ninja) enter the outside of the control room and put a hunk of playdough on the glass. He waved at her, smiled, and left. She promptly picked up the phone to someone and told them she has just been killed in a massive explosion which took out the control room.

Moral of the story, these guys train a lot I would guess.

 

[NUCENG]

Well, I just wanted an explanation for over 30 years without building a new NPP. I can't believe that TMI alone was responsible for that... maybe for the first 10 years, but what's with the period after that?

Maybe they are not expensive anymore, so there are over two dozen new plants being planned. Maybe it's something else. I just want to know the reason. Don't worry, I won't give you any anti-nuclear opinions etc. I just want to know the reason for that gap.

And I was seriously trying to answer that. It was political reality that the public didn't want new nuclear construction. Some states banned new nuclear plants. The major architect engineer firms that would have built new construction saw that legal fees and wrangling would cost more than the plant itself, and there was plenty of work at existing plants. Political climate, lack of economic justification and increased non-hardware costs put the US nuclear industry into hiatus. The doors started to crack open as the plants proved their worth and reliable safe nuclear power became at least an argument for new construction. Oil shortages and expenses of imported oil helped. Concern over the environment and global warming helped. We have even seena founder of one of the biggest "green" organizations change from anti to pro nuclear. Plants were uprated and licenses were extended for existing plants. Major blackouts revealed the need for stable reliable baseload generation.

Are nuclear plants expensive to build? Yes they are. But once built fuel costs for nuclear are a lot lower than buying and transporting 100 car coal trains to a fossil plant every day. Costs of Oil and natural gas are going up faster than nuclear fuel costs and may soon be having declkining production. If carbon taxes become reality, nuclear economics will get another boost. Yhe per KW cost of construction, fueling, operation and maintenance of nuclear plants is already competitive with fossil generation. It is far cheaper than dsolar and wind power, but those industries are still developing. Times change, public opinion changes, Honest Really, that's what happened.

I won't worry about anti-nuclear propaganda and I do respect anti-nuclear activists that deal with us honestly and on something like a reasonable, technical basis. We do not claim that nuclear power is risk-free. We want to focus the debate on whether the benefits justify the risks of nuclear power. That is where the facts lead. But I recognize emotions are something else and the impacts at TMI, Chernobyl, and Fukushima are an emotional issue.

When a three-pack a day smoker sitting on a barstool tells me that we have to shut dowm the nuclear industry because even an additional microsievert will make him die of cancer as he drives home drunk, I am less than apt to listen. (I don't drink but have friends who do and I'm willing to be a designated driver.)

That is one benefit of this forum. Most people here (even the covert anti-nuclear types) tend to try reason at first. At some point others will drop their act of reasonableness because there are people here with the knowledge and experience co call them on unfounded claims and propoganda. The real value comes when I find someone who can support his basis of beliefs and it comes down to two opposing viewpoints honestly exchanged with respect. That is where I have to reevaluate and justify my own beliefs.

 

[NUCENG]

Thanks for the interesting link.

Having a bit of structural engineering competence myself I formed my own opinion on the matter of resilience of typical concrete NPP structures, especially outside the containment vessel.

On the "force-onforce” security exercises referred to in the first pages I have no experience to comment not being (and not being interested to become) a military expert.

And your "bit of structural engineering competence" is better than those with detailed knowledge, intelligence about the terrorist threat, and a whole lot of structural engineering experience. That sophistry is guilding the lilly. Using it to qualify what is, after all, only your opinion is meaningless. What facts or references are you basing your technical opinion on?

I am happy you admit you are not a military expert. So we need not worry about your expertise on anti-aircraft missile batteries.

 

[Morbius]

Where did the plutonium for the first nuclear bombs come from? Nuclear reactors, of course. Hanford, Windscale... those were nuclear reactors. No civil reactors. But still nuclear ones.

Clancy,

Again - SO WHAT!

Some of the first uses of airplane technology was for fighter / bombers. The very first jet powered aircraft the Me-262 was a military aircraft.

The very first use of Cray supercomputers were for simulating nuclear weapons.

Now we have such computers calculating protein-folding for medical research. Do we say - "Oh that is a BAD technology. Naughty, naughty. That first use of those computers were for bad nuclear weapons. We can't have that - we need to be pure as the driven snow. Therefore, we can't use these BAD computers to calculate our protein folding...

GEESH - give me a break.

The technology is amoral. It's only fuzzy-thinking anti-nukes that want to label nuclear power technology with the broad brush of being associated with nuclear weapons because they can't make their arguments any other way.

Dr. Gregory Greenman

 

[Morbius]

Let's take the Columbia disaster for example. The thermal shield got a hole punched in through a part of foam hitting it at high speed.Either way, I've said it often enough. German scientists researched commercial plane crashes on NPPs and came to the conclusion that the impact would penetrate the walls.

Clancy,

That's because those thermal tiles are one of the few things on the planet that are even more fragile than foam. Those tiles are extremely brittle and there's not much "substance" to them. That's why they have such a low heat conductivity - there's not much there.

The German are DECADES behind the USA in the science and technology of nuclear power and the analysis of plane crashes. The Germans don't have anything like the USA's national laboratories and the monumental advances those labs have made in the past two decades in the science of numerical simulations on massively parallel suipercomputers.

The F-4 Phantom test was not a "be all and end all" test. It was part of a much larger program of study. The F-4 test helped validate that computational models in the computer programs. These structural analysis codes have been researched and refined for a couple decades now due to the demands of the USA's nuclear weapons programs, the USA's nuclear power programs, the USA's NASA programs...

The real lesson from the F-4 test was that the computer models do a very good job at simulating the particulars of that test. The full-sized airliner hitting a full-sized containment is a problem run on the F-4 validated simulation software - and that's the analysis that shows that reactor contains DO stand-up to even the largest airliners.

One thing also learned from the F-4 test was that the fuselage of even the largest airliners are no match for the containment building. The most threatening part of an airliner is, not surprisingly, NOT the fuselage. After all, its a light-weight aluminum SHELL.

Dynamic structural mechanics tells us that you don't need just "mass", that density is far, far more important that just mass for penetration. ( That's why the military uses rounds made of depleted uranium - for it's density.) On an airliner, the densest components are the engines.

That's why Sandia has done full-scale testing of launching full-sized jet engines into containment walls. In those tests, there's no penetration of the engine through the wall.

http://www.nytimes.com/2002/09/20/national/20NUKE.html

The NY Times does bring up that tired old yarn about the wall moving that the anti-nukes always bring up about the F-4 test. A simple calculation that any high-school physics student should be able to do by employing conservation of momentum can EASILY show that the energy that went into moving the wall is less than 4% of the energy available in the collision. Over 96% is available to do damage to the wall.

http://www.public-action.com/911/jmcm/USYDENR/

"Only the containment building at a nuclear powerplant" is designed to withstand such an impact and explosion, says Robert S. Vecchio, principal of metallurgical engineer Lucius Pitkin Inc., referring to the hijacked Boeing 767 airplanes, heavy with fuel, that slammed into each WTC tower.


Dr. Gregory Greenman

 

[clancy688]

@NUCENG

Thanks for your reply!

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

Clancy,
Again - SO WHAT!

You do realize that you're running in circles?

"Nuke power is not connected to the military."
"Yes it is."
"SO WHAT?"
"Nothing what, I only corrected you..."
"You did NOTHING, you're WRONG!"
"No I'm not, look at the facts..."
"SO WHAT?" ...

I never said something bad about nuclear technology being a children of the nuclear weapons programs. That's the way of nearly all technology. And I'm not one naive pacifist. Still you're rumbling about something like "bad technology". I don't like nuclear technology because of the possible disaster consequences, not because of its history...
All I did was pointing out the history of the nuclear programs and you immeadiatly got it in the wrong throat. So would you please stop that meaningless rumbling for the sake of the whole discussion?
Still it seems like you can't discuss on a reasonable level with me as long as you think I'm die hard anti-nuclear...

The German are DECADES behind the USA in the science and technology of nuclear power and the analysis of plane crashes. The Germans don't have anything like the USA's national laboratories and the monumental advances those labs have made in the past two decades in the science of numerical simulations on massively parallel suipercomputers.

That somehow sounds like an insult to my nation... ;)
Well, I guess you're right with having way more supercomputers. Still, that's a little arrogant. We too have some pretty nice racks. Not as many as you of course. But denying us any technical expertise is a little bit hard for a high-tech country which's also seen as such from our nations, like america.

That's because those thermal tiles are one of the few things on the planet that are even more fragile than foam. Those tiles are extremely brittle and there's not much "substance" to them. That's why they have such a low heat conductivity - there's not much there.

You're right. That was a bad example to use.

Dynamic structural mechanics tells us that you don't need just "mass", that density is far, far more important that just mass for penetration. ( That's why the military uses rounds made of depleted uranium - for it's density.) On an airliner, the densest components are the engines.

That's why Sandia has done full-scale testing of launching full-sized jet engines into containment walls. In those tests, there's no penetration of the engine through the wall.

Interesting. What containment walls did they use? A couple of posts above I posted a german assessment of major plane crashes (747) at NPPs. It disregards the penetration of the walls of newer NPPs (~1980) but it isn't so sure anymore for older NPPs (~1970).

And last but not least, I quote myself:

As for your scientific accuracy, do you mind replying on the other topics of our previous discussion?
Such as evacuations out of mountain villages because of tsunami damages and Fukushima prefecture C137 contaminations (magnitude: 10^7) which are not as high as the ones in Nagasaki (magnitude: 10^4)...?

But it would probably be better to outsource that in the right thread: https://www.physicsforums.com/showthread.php?t=501637

Any comments? As long as you keep ignoring those former errors of yours, I can't take you serious.

~~~~~~~~~~~~~~~~~

 

[Luca Bevil]

And your "bit of structural engineering competence" is better than those with detailed knowledge, intelligence about the terrorist threat, and a whole lot of structural engineering experience. That sophistry is guilding the lilly. Using it to qualify what is, after all, only your opinion is meaningless. What facts or references are you basing your technical opinion on?

I am happy you admit you are not a military expert. So we need not worry about your expertise on anti-aircraft missile batteries.

It was ironical.
I am a chartered engineer and in Italy for my degree that means that I am entited to perform legally binding structural evaluations, which in fact I have performed in my career.

Apart from that (which is after all peronal and irrelevant to the point being discussed and that I am consisentently making and that you are only trying to rebutt on personal basys which have nothing of technical in nature) my point is (I'll repeat it once again in the hope of discussing in technical terms and not personal attacks):
GE Mark I reactors, at least the ones we can look at in Japan, have lines that go outside the containment vessel, into the turbine building. Being the turbine building a normal civil building in structural terms it would be completely destroyed in a deliberate large airliner crash, which in turn would make what I am sure your competent expertise would call a "beyond the design basys accident".
Consequences at least in Japan plants, would be most likely worse than Fukushima, since no emergency water feed&bleed strategy would be achievable with all feed and fire lines destroyed, in any case no less than Fukushima in my opinion in the luckiest of the impact scenarios.

You have countered this claim telling me that I would become "food for fish" (which apart from the less than sensible consideration of my person likened to a terrorist) makes really no sense since the attack would be suicidal in any case.

I was willing to consider that also structural internal strenghtening could have been carried out in the US (needless to say I was talking about the world, I am not particularly obsessed with US security), but the document just linked here makes quite adamant that this is not the case, or at least has not been required by the NRC.

I'll try to quote the relevant part

In response to comments, the NRC staff proposed in October 2008 that the aircraft impact
assessments be conducted by all new reactors, including those using previously certified
designs.19 The NRC Commissioners, in a 3-1 vote, approved the change February 17, 2009, and it was published in the Federal Register June 12, 2009. The new rule added specific design requirements that all new reactors would have to meet:
Each applicant subject to this section shall perform a design-specific assessment of the
effects on the facility of the impact of a large, commercial aircraft. Using realistic analyses,
the applicant shall identify and incorporate into the design those design features and
functional capabilities to show that, with reduced use of operator actions:
(A) the reactor core remains cooled, or the containment remains intact; and
(B) spent fuel cooling or spent fuel pool integrity is maintained.
As noted above, NRC rejected proposals that existing reactors—in addition to new reactors—be required to protect against aircraft crashes, such as by adding “beamhenge” barriers.

NRC determined that damage from aircraft crashes at existing reactors would be sufficiently mitigated

Once again: showing an F4 hitting a large chunck is completely irrelevant to the structural integrity of buildings tha do not have such structural dimensions.

I hope I made my point in a clear enough manner this time.

 

[NUCENG]

It was ironical.
I am a chartered engineer and in Italy for my degree that means that I am entited to perform legally binding structural evaluations, which in fact I have performed in my career.

Apart from that (which is after all peronal and irrelevant to the point being discussed and that I am consisentently making and that you are only trying to rebutt on personal basys which have nothing of technical in nature) my point is (I'll repeat it once again in the hope of discussing in technical terms and not personal attacks):
GE Mark I reactors, at least the ones we can look at in Japan, have lines that go outside the containment vessel, into the turbine building. Being the turbine building a normal civil building in structural terms it would be completely destroyed in a deliberate large airliner crash, which in turn would make what I am sure your competent expertise would call a "beyond the design basys accident".
Consequences at least in Japan plants, would be most likely worse than Fukushima, since no emergency water feed&bleed strategy would be achievable with all feed and fire lines destroyed, in any case no less than Fukushima in my opinion in the luckiest of the impact scenarios.

You have countered this claim telling me that I would become "food for fish" (which apart from the less than sensible consideration of my person likened to a terrorist) makes really no sense since the attack would be suicidal in any case.

I was willing to consider that also structural internal strenghtening could have been carried out in the US (needless to say I was talking about the world, I am not particularly obsessed with US security), but the document just linked here makes quite adamant that this is not the case, or at least has not been required by the NRC.

I'll try to quote the relevant part

In response to comments, the NRC staff proposed in October 2008 that the aircraft impact
assessments be conducted by all new reactors, including those using previously certified
designs.19 The NRC Commissioners, in a 3-1 vote, approved the change February 17, 2009, and it was published in the Federal Register June 12, 2009. The new rule added specific design requirements that all new reactors would have to meet:
Each applicant subject to this section shall perform a design-specific assessment of the
effects on the facility of the impact of a large, commercial aircraft. Using realistic analyses,
the applicant shall identify and incorporate into the design those design features and
functional capabilities to show that, with reduced use of operator actions:
(A) the reactor core remains cooled, or the containment remains intact; and
(B) spent fuel cooling or spent fuel pool integrity is maintained.
As noted above, NRC rejected proposals that existing reactors—in addition to new reactors—be required to protect against aircraft crashes, such as by adding “beamhenge” barriers.

NRC determined that damage from aircraft crashes at existing reactors would be sufficiently mitigated

Once again: showing an F4 hitting a large chunck is completely irrelevant to the structural integrity of buildings tha do not have such structural dimensions.

I hope I made my point in a clear enough manner this time.

An electronic engineer who doubles as a civil/structural engineer. Congratulations.

All right you raise technical arguments this time so let's look at them.

I note that the target for your aircraft has moved from the reactor building annd containment to the turbine building. The turbine building is a lower height structure than the reactor building itself. This makes it harder to hit, not impossible, just more difficult.

There are lines that leave containment and go to the trubine building. Do you mean the Main Steam Lines? There are two isolation valves (MSIVs) in each of those lines which isolate the reactor from the turbine building in an accident. Or there are ther feedwater lines which also have isolation valves to prevent backflow that might drain the reactor. This portion of the plant is called the steam tunnel and is seismic category 1 and well below the surrounding buildings. That would make it an extremely difficult target to hit with an airliner.

Since the emergency diesel generators in Japan were in the turbine buildings they are not just normal civil buildings. They will also be seismic class I or seismic II/I meaning that the failure of the building must protect the vital areas inside the building including the EDG rooms.

Apart from the diesels and any vital electrical distribution equipment the loss of the turbine building would not be a beyond design basis accident, it wouldn't even be a DBA.

When an aircraft attempts to take out the turbine building are you assuming the destruction is sufficient to take out all distribution lines to the switchyards and the diesels to cause a station blackout? That could become a beyond design basis accident if like Fukushima the station blackout duration exceeded the battery capacity time. This requires even more skill and accuracy and physical separation may make this impossible.

Ok so assume that the pilot is lucky and accomplishes the perfect impact to cause a station blackout. You quoted the discussion of requirements for new plants to be hardened against aircraft impacts as a design basis event. That means no core damage.

For existing plants you also quoted the results of NRC assessments that concluded that the added security features after 9/11 would sufficiently mitigate the effects of an aircraft impact. That means radiation releases and core damage would not expose the population to radiation in excess of the existing legal limits.

I will let you argue about the F4 impact test with Morbius who knows more about that test than I. I have not discussed that test in my posts. But I have read his defense of that test and it sounds reasonable and is consistent with the regulatory decisions made on this threat.

Finally, the line "Luca Brazzi sleeps with the fishes." was a well-known line from the movie "Godfather." The point I was making at the time was that any terrorist attack on a nuclear power plant was not only a suicide mission but most probably an unsuccessful suicide mission.

 

[Luca Bevil]

Well if you go back to my posts I'have always mentioning the impact not specifically against the containment vessel.
I might not have been clear enough so I'll refrain from quoting my original statement again, but that really is not important.

Let's go to technical discussion.
"Normal" residual heat removal toward "cold shutdown" needs (I'll recap only for the casual reader, I am well aware of your expertise and experience on the topic) not only the regular closed loop functioning of the deputed water lines, but also the outgoing water to be refrigerated in an exchange heat, in the condenser, with secondary loop refrigerant water before being fed-back to the reactor.
The fact that MSIVs and othr valves could in fact shut down will prevent immediate drainage but it will not ensure the operability of normal cooling.

If the condenser is located, as it is in Fukushima turbine buildings, it will not survive a "perfect" impact.
Turbine buildings we have seen in Fukushima are of course sismic but they have not walls of 1m + concrete. Nothing even remotely comparable with the Twin Towers or Pentagon structure that were nonetheless tragically penetrated on September the 11th.
They are in fact normal, albeit sismic civil buildings.

With condenser destroyed, widespread damage from jet fuel ignition and explosion, most likely electric switchboard/equipment damaged, residul portion of pipes (if any) that need to be intercepted to allow any "sea water-like" kind of extreme mitigation measure,
I do not think the Fukushima design would have withstood such an impact (on probabilities of such a tragic event I would like not to comment) any better than it did withstood the flooding.

Having read the excellent technical level of your posts on the long Fuku thread I find hard to believe you would think that specific plant would survive such an accident.

Is it possible that US plants have hardened contermeasures for such ipotetic accident ?
I have no internal knowledge to rule this out but this possibility was not suggested by your posts (that rather focused on the efficiency of security active response), nor it seems to be acknowledged in the linked official document.
It seems unlikely that an effective structural reinforcement of this proportion can in fact be carried out on an existing structure, without disrupting for months normal plant production.

That does no mean I rule out different more limited measures, having been carried out, such as relocating some electrical switchboard or component, it just does not seem such measures would be effectve against a direct hit, but I'll be glad to hear your comments on this.
If in fact that is the case I can only be happy for the US people, but US nuclear security does not solve the problem the world over, our friend Clancy here has just written that the oldest plants in Germany will not resist such an attack.
What is more France and UK opposition to include such scenarios in european nuclear stress test look quite suspicious to me (why oppose such a request, officially made be the EU commissioner on energy, if everything had been considered ?).

Since we are discussing in technical terms, the spent fuel pond situation in US mark I reactors is in your opinion safe ?
It seems to me rather risky in case of an impact of a plane on that floor with just a few degrees of descent angle...

Then again I am basing my risk perception on the Fuskushima structures that in case of reactor 1 just show a light steel framework, and in case of reactors 3 and 4 just show ordinary concrete pillars.

 

[Argentum Vulpes]

Ok for every engineer on this thread that wants nuclear power shut down, please tell me how you are realistically going to replace 111,777 MWe (134,470 MWe w/ Russian power) that has a capacity factor of 70% or greater. Those numbers are for Europe. In the USA 8,007 MWe with a capacity Factor of 91% will need to be replaced.

If anyone can give me a source for electrical power, that has been proven on the same scale, that will put out those numbers I'd be glad to hear it.

 

[Luca Bevil]

Well this is rather political. So I'll keep very short.

As far as Italy is concerned we had already banned nuclear power in 1987.
No much to substitute here.
We just banned a proposed reintroduction with 3G+ AREVA EPR proposed by the Berlusconi government.

I hope the country will progressively increase renewables generation, in a smart grid integration concept.

As far as the world is concerned it is rather clear that this current safety level cannot be sustained. I hope in scientific advances preferably from intrinsically secure renewables power and may be from some selected IVG nuclear technology that seems a bit more concerned with passive safety.

 

[clancy688]

Ok for every engineer on this thread that wants nuclear power shut down, please tell me how you are realistically going to replace 111,777 MWe (134,470 MWe w/ Russian power) that has a capacity factor of 70% or greater.

Let's think about it... probably by not shutting every NPP down right now. As for Germany, we have 17 reactors left. Nearly all of them are shut down because of the moratorium or routine maintenance. Before we were exporting electrical energy. No the exports/imports of electrical energy are basically +- zero.
So even at the moment we can cope with having nearly everything shut down instantly. And that won't happen. The oldest plants will stay offline. As for the rest, they'll stay in service until 2021.
So we still have ten years for building new gas plants, new offshore wind parks, etc. And in the worst case we can restart old coal plants (no, I certainly don't want to discuss CO2 emissions, thank you).

The energy producers were panicking about widespread blackouts if we shut down even some of the NPPs. Now nearly all of them are offline. And exactly nothing happened. And as said above, we're not importing electricity at the moment to make up for the lost capacity.

Of course that won't work for countries like France which make up 80% of their energy with NPPs. But at least for us germans, it works. And you have to ask yourself how all these other nations without nuclear power can handle their energy need if there's no alternative to nuclear. To make matters short:

That there's no alternative to NPPs and that shutting down NPPs will result in lost capacity we can't replace is an irrational fear.

So pro- and contra-nuclear people are on equal terms.

Pro-nuclear: "Your fear of a beyond design basis accident is irrational!"
Anti-nuclear: "Your fear of widespread blackouts if we shut NPPs down is irrational!"

 

[mheslep]

In the USA 8,007 MWe with a capacity Factor of 91% will need to be replaced...

101,212 MWe in the US for 2011, and rising.
http://www.eia.gov/cneaf/nuclear/page/nuc_generation/usreact11.xls

 

[NUCENG]

...

L: "Normal" residual heat removal toward "cold shutdown" needs (I'll recap only for the casual reader, I am well aware of your expertise and experience on the topic) not only the regular closed loop functioning of the deputed water lines, but also the outgoing water to be refrigerated in an exchange heat, in the condenser, with secondary loop refrigerant water before being fed-back to the reactor.

The fact that MSIVs and other valves could in fact shut down will prevent immediate drainage but it will not ensure the operability of normal cooling.

If the condenser is located, as it is in Fukushima turbine buildings, it will not survive a "perfect" impact.

Turbine buildings we have seen in Fukushima are of course seismic but they have not walls of 1m + concrete. Nothing even remotely comparable with the Twin Towers or Pentagon structure that were nonetheless tragically penetrated on September the 11th.

They are in fact normal, albeit seismic civil buildings.

With condenser destroyed, widespread damage from jet fuel ignition and explosion, most likely electric switchboard/equipment damaged, residul portion of pipes (if any) that need to be intercepted to allow any "sea water-like" kind of extreme mitigation measure,

I do not think the Fukushima design would have withstood such an impact (on probabilities of such a tragic event I would like not to comment) any better than it did withstood the flooding.

N: Your English is better than my Italian but I think I understand your point as follows:

“Damage to the condenser and closure of the MSIVs and Feedwater isolation valves removes normal cooling. The Turbine Buildings at Fukushima will not withstand the aircraft impact sso the diesels will be destroyed and cooling will be lost.”

If that is not what you meant, please correct me.

First, my disclaimers

I spent more time on this than any previous post on the thread. This qualitative discussion is as far as I can go on this issue. It is based on a couple of open sources and discussions that are public and some amateur speculation about an aircraft approach to Fukushima and what I see on the plant layout drawings posted here. I have not used plant security information for any of the pants that I have worked. I have not seen the DOE national labs analysis or calculations on this topic, notr have I( discussed this scenario with anyone who has.

Next. The Scenario:

First look at the maps that have been posted and the photographs of the Fukushima Site. An aircraft would have to approach from the sea due to higher terrain to the west. The turbine buildings are the first target as the aircraft approaches from that side. Assume the aircraft makes the perfect strike (Low Probability) and manages to destroy the condenser and the diesels as well. The turbine building acts as a first barrier protecting the reactor building and the electrical distribution switchyards beyond that. So the single attack will not take out Offsite Power (low probability) causing an extended station blackout that is not recoverable in a short time (lower probability).

Meanwhile, as you surmise, normal cooling is lost. Battery operated HPCI and RCIC systems provide high pressure makeup and cooling using either the Condensate Storage Tanks or the Torus. Heat is rejected to the torus through the SRVs and high pressure pump steam exhaust. These systems operate independent of AC power providing time if fires or other damage to the switchyard need action. (low failure probability) The plant will be at a condition called Hot Standby and can be stable for several hours. Eventually the plant will be depressurized (Low failure probability) as the torus heats up and loses the ability to condense steamor batteries are exhausted. Then low pressure ECCs system (RHR and Core Spray) need to operate using AC systems powered from the switchyard. (Some possibility of failure if fires continue).

Over at the Spent Fuel Pool if Offsite AC power is available Fuel Pool Cooling continues. (low failure probability) If not fuel pool heatup begins but time is available before boiling begins.
At this point we leave Fukushima. After 9/11 attacks the US NRC ordered significant added capabilities to extend core cooling and makeup and alternative methods of injecting cooling water to the core and spent fuel pools. You would expect that the equipment to perform these functions is self-powered and prepositioned for use. Those capabilities may be delayed until fires are out, but time to extinguish or suppress fires is available according to the analysis and evaluations performed by national labs and NRC. For existing plants core damage may occur (low probability of failure), but the containment function and other safety systems will prevent radiation releases to the public in excess of the legal limits (Very Low probability of failure). For new construction plants, there will be no core damage because this event is now part of design basis (Very low failure probability).

We left Fukushima because as I have posted previously Japan told the Convention on Reactor Safety that they have a stable society and therefor no need to address terrorism despite the lessons of 9/11 and the sarin gas attack on the Tokyo subway. I have no idea if a Japanese industry that covered up shroud cracks, used buckets to dump enriched uranium into a criticality accident, ignored tsunami risk and dismissed possibilities of terrorism after being attacked could be safe in any event.

The points above where probability comes into play are my guess of the approach that the National Labs and NRC used in their analysis. The section of the report you quoted tells me that the attacked plant (existing) may be a write-off, but the risk to the public is low.

The confusion about an attack on containment is obvious. In the scenario where the attack is on the turbine building there is a low probability of containment failure, even if core damage occurs. If the initial attack is on containment and a breach is made, then core damage would lead to radiation release to the public. The problem for the terrorist is that a single aircraft cannot easily cause the loss of all the things that need to be taken out to cause both core damage and containment failure.

L: Having read the excellent technical level of your posts on the long Fuku thread I find hard to believe you would think that specific plant would survive such an accident.

N: I don’t. But as I saw it you were using Fukushima to say that an entire industry was ignoring the terrorist threat because we hadn’t installed missile batteries or built AREVA’s walls. That is so wrong I can’t let it pass unchallenged. There is more than one way to solve a problem. In my honest, professional, and informed opinion, it is really not justified to shut existing US plants down in view of an aircraft attack, but we can agree to disagree on that.

L: Is it possible that US plants have hardened contermeasures for such ipotetic accident ?
I have no internal knowledge to rule this out but this possibility was not suggested by your posts (that rather focused on the efficiency of security active response), nor it seems to be acknowledged in the linked official document.

It seems unlikely that an effective structural reinforcement of this proportion can in fact be carried out on an existing structure, without disrupting for months normal plant production.
That does no mean I rule out different more limited measures, having been carried out, such as relocating some electrical switchboard or component, it just does not seem such measures would be effective against a direct hit, but I'll be glad to hear your comments on this.

N: Did you mean “hypothetical”? Sorry, those questions about structure reinforcement or relocation of safety equipment are too specific about security issues. They would be possible responses to make a plant more resistant to damage. However, I won’t comment about specific actions.

L: If in fact that is the case I can only be happy for the US people, but US nuclear security does not solve the problem the world over, our friend Clancy here has just written that the oldest plants in Germany will not resist such an attack.

What is more France and UK opposition to include such scenarios in european nuclear stress test look quite suspicious to me (why oppose such a request, officially made be the EU commissioner on energy, if everything had been considered ?).

N: I’ve probably already been blacklisted by Japan, and shot at by Lithuania, and have fought a skirmish with Italy. Please don’t ask me to take on Germany, France and the UK, too. (Eh, Borek, how is that for diplomacy?) I think those countries have to answer that question, because they haven’t told me..

L: Since we are discussing in technical terms, the spent fuel pond situation in US mark I reactors is in your opinion safe?

It seems to me rather risky in case of an impact of a plane on that floor with just a few degrees of descent angle...

Then again I am basing my risk perception on the Fuskushima structures that in case of reactor 1 just show a light steel framework, and in case of reactors 3 and 4 just show ordinary concrete pillars.

N: The entire issue of spent fuel is a cesspool that deserves its own thread. Politics, lies, delays, lack of leadership, incompetence, and criminal stupidity are words that come to mind. But I will say this:

The word safe is meaningless. There are risks with spent fuel. The location of the spent fuels pool in a BWR is vulnerable to some damage scenarios. New plant designs relocate the fuel storage to a more protected location. The amount of fuel in spent fuel pools is also a vulnerability. That is where my issues really explode. Is it easy to exploit those vulnerabilities , no, but still easier than I would like. What to do about it is:

1. Make a decision whether to reprocess fuel or not.
2. Cut through the political BS and designate a geological repository site, even if it is temporary.
3. Get as much fuel out of the pools as decay allows.
4. Do this before we license another nuclear plant.

My final comment : No decision is a decision to increase risk.

 

[zapperzero]

Technology is amoral. ( Not immoral - amoral. )
Dr. Gregory Greenman

 

[NUCENG]

Let's think about it... probably by not shutting every NPP down right now. As for Germany, we have 17 reactors left. Nearly all of them are shut down because of the moratorium or routine maintenance. Before we were exporting electrical energy. No the exports/imports of electrical energy are basically +- zero.
So even at the moment we can cope with having nearly everything shut down instantly. And that won't happen. The oldest plants will stay offline. As for the rest, they'll stay in service until 2021.
So we still have ten years for building new gas plants, new offshore wind parks, etc. And in the worst case we can restart old coal plants (no, I certainly don't want to discuss CO2 emissions, thank you).

The energy producers were panicking about widespread blackouts if we shut down even some of the NPPs. Now nearly all of them are offline. And exactly nothing happened. And as said above, we're not importing electricity at the moment to make up for the lost capacity.

Of course that won't work for countries like France which make up 80% of their energy with NPPs. But at least for us germans, it works. And you have to ask yourself how all these other nations without nuclear power can handle their energy need if there's no alternative to nuclear.


To make matters short:

That there's no alternative to NPPs and that shutting down NPPs will result in lost capacity we can't replace is an irrational fear.

So pro- and contra-nuclear people are on equal terms.

Pro-nuclear: "Your fear of a beyond design basis accident is irrational!"
Anti-nuclear: "Your fear of widespread blackouts if we shut NPPs down is irrational!"

Sorry Clancy, but
"(no, I certainly don't want to discuss CO2 emissions, thank you)." is an intellectual cop out.

http://www.spiegel.de/international/germany/0,1518,767900,00.html

Any increase in dependence on fossile fuels or biomass cuts into the German commitments to the Kyoto Protocol. So we may see the irony of the United States that didn't ratify KYoto building nuclear plants while the Germans and Italians abandon Nuclear and increase carbon emissions. C'mon, isn't that just a litle bit funny? {GRIN}

 

[NUCENG]

Funny, but totally irrelevant. The quote was that technology (or science) is amoral not that the technician (or scientist) is amoral. If you were aiming at humor you missed. Implying that Morbius is a nazi sympathizer would be contemptible and must not have been your intent. So please expand on your abbreviated post and explain what you were trying to say so badly.

 

[Bodge]

Let's all hope no black swans float down the Missouri River into the Fort Calhoun NPP.

 

[clancy688]

Sorry Clancy, but
"(no, I certainly don't want to discuss CO2 emissions, thank you)." is an intellectual cop out.

Of course. But the initial question was if it's possible to shut down NPPs, and it certainly is. I wanted to answer this initial question without having to discuss any non-related topics. Saying that we won't met the Kyoto protocol then is totally correct, but nothing than a distortion to the initial question.

There'll be a price to be paid. That's a given. Overall, the article tells us that we may not met our target of -40% compared to 1990, but -30-33% is still not to be scoffed at. I'm not familiar with the US numbers, but what's the US 1990 to 2020 target, and what's the real number you probably will reach? I'm pretty sure that even with over two dozen new NPPs you won't even reach somewhere near 40%, while we come to 30% with shutting down NPPs... ;)

Shutting down all NPPs was always planned in for our 2020 emission goals. Remember, the phase out of nuclear power was already decided in 2000. At least until some politician dip-garbages decided to phase-out the phase out in 2010, with phasing out the phase out of the phase out hastily after a certain event in 2011.

 

[NeoDevin]

Slightly off topic, but puts things in perspective:

More people (35 according to wiki) have died from the recent http://www.guardian.co.uk/world/2011/jun/10/e-coli-bean-sprouts-blamed" than have died from the Fukushima "disaster". I'm wondering when all the people currently calling for bans on nuclear power will be calling for similar bans on organic farming?

 

[clancy688]

Slightly off topic, but puts things in perspective:

More people (35 according to wiki) have died from the recent http://www.guardian.co.uk/world/2011/jun/10/e-coli-bean-sprouts-blamed" than have died from the Fukushima "disaster". I'm wondering when all the people currently calling for bans on nuclear power will be calling for similar bans on organic farming?

Kthxbye~

(I'm really getting annoyed by all those smarty-pants crawling out of their holes and telling us Fukushima isn't as bad as "event x with y deaths". Go to the https://www.physicsforums.com/showpost.php?p=3355924&postcount=56", at least E.Coli didn't make 150.000 people lose their homes forever)

 

[Luca Bevil]

@ NUCENG yep, your last post is now excellent and on par with your usual contribution, and is almost exactly what I think would more or less happen:
- in case of Fukushima basically a complete disaster, likely worse than the current one,
- in the US mitigated by several specific measures and with different probabilities of damages or releases in an accident of a very severe nature, as for the details in your post.
- And with a decision to be made ASAP as far as the spent fuel management is concerned especially in the oldest MarKI containments.

That word was in fact "hypotetical", sorry for the error.

I do not remember writing that the US should shut immediately down all nuclear reactors or not even all Mark I BWRs for that matter, what I wrote was:

" It means nothing (the F4 hitting concrete video): at least for Mark I BWR reactors it is sufficient for a plane to strike the turbine building to destroy the pipes making up the feedwater and fire injection lines to set-up a "Worse than Fukushima" scenario, with not even sea water emergency injection trough fire extinguisher lines possible .

OR it could be enough to disable both grid connections and EDGs, with or without attacking planes

OR it could be even simpler to attack the completely undefended (at least in many japanesse NPP) secondary pumps...

it should be more than enough for concerned governments to act immediately on strenghtening security and/or shutting down undefensible installations..

Would we see this soon enough or do we need a new apocalypse or almost apocalypse type of accident ?"

As you can see I made no exclusive or not even specific mention to the US, and my statement was related to the relevance of the F4 vs "wall of concrete" test.

I do however wish that "nuclear stress test in europe" will be carried out with outmost severity and transparency, including the threats posed by terrorists (albeit I can agree that some specific is better kept undisclosed, but only if disclosing it would reduce the measure effectiveness).

We can probably also agree to disagree on the likelyhood (probabilites) of some of the events in the chain you so precisely describe, or in more political terms about what actually "low probability" should mean when radioactive releases are at risk.


regards

 

[Argentum Vulpes]

@ mheslep:

Yes you are right by the EIA number I've low balled the nuclear numbers in the USA. However my numbers came from the NRC and Bloomberg (tabulated the numbers nicely) on current production. http://nrc.gov/reading-rm/doc-collections/event-status/reactor-status/ps.html"

@ Luca Bevil:

How pragmatic of the Italian people to have voted down nuclear power, yet the largest supplier of your country's power imports (13% of electrical power on the grid) is France. Let's hope that France doesn't decide to switch over to LNG, because your country's second largest supplier of LNG will have another market to sell to. Granted Russia would love that, I would hate to be relying on Russia for LNG given some of there recent antics with shutting off the tap.

You can hope your way into darkness and spoiled food waiting for large base load renewables to come on-line.

http://www.geni.org/globalenergy/library/national_energy_grid/italy/ItalyCountryAnalysisBrief.shtml" for Italian power information.

@ clancy688

Yes you could build LNG plants to replace NPP, however that replacement would pump 93 million tonns of CO₂ into the atmosphere. 141 billion kWh put out from the remaining 17 NPP in Germany, with a LNG plant putting out 1.321 lbs/kWh of CO₂. Again off shore wind and PVs and other renewables will only give a small amount of peaking power, the majority of base load will have to come from coal, oil, biomass, or LNG. All of those sources produce CO₂, so how about we replace all water from firefighters with petrochemicals, and air dropped fire suppressant with coal dust? Also how much would you like the Russians providing the fuel source that keeps your house warm and you lights on after the shenanigans that have been pulled in the past? Then again when Gerhard Schroeder lost his position of chancellor he promptly went to work for Gazprom.

Links for http://www.eia.gov/cneaf/electricity/page/co2_report/co2report.html" NPP numbers