Agreed!Our Energy suppliers want to maintain the status quo at all costs and are now just starting to add Solar (of all flavors) to their energy mix because the public is demanding it…
Expect to see more of this, from our Leaders:
Nuclear Power and the Not-So-Divided Japanese Public
http://wp.me/pDwKM-2lH
BTW: This is a great site for Nuclear info that is well researched.
Why you ask? Mostly because, with a few exceptions, the levels of naturally occurring radiation are higher.
As you spend more time on this site you will come to find out that we function for the most part in a world of facts. You would need to source your claim that the nuclear industry ever believed it was 100% safe - having spent 20+ in the Navy's nuclear propulsion program it was the knowledge that it wasn't a 100% "safe" program that made me and my crew focus that much more closely on procedural compliance, safe operations and frequent casualty drill scenarios.
Ad hominem attacks do not bolster your opinions…
Now if you'll excuse me, I have another meeting of "Young Nuclear Fascists" to go to. And right after I finish polishing my jack-boots I'm going to go drown some kitties and puppies.
[quote=funglestrumpet]I would have more respect for rhare's views if they were to cite sources for information on which they are based.
[/quote]
Okay, so let's assume the world says Yeah "thorium is the best fuel ever", and we decide to figure out how to build these reactors, note that they are being worked on but most say they hope to have a pilot scale reactor in 20 years (2030).
So lets be optimistic and assume we have only 20 years before the science and material technology will allow us to build a working scale reactor, 30 TWh/yr (like Palo Verde - largest US plant).
World electrical production in 2008 was 20,261 TWh, of which coal is about 41% of that generation, so that means to replace coal consumed in 2008 would need 8,307 TWh of production.
So at very large plants, to replace world coal use you need: 8,307/30 = 277 plants, or somewhere close to 800 reactors (3/plant). That's just to replace usage in 2008, EIA projects 53% growth by 2035, so that would mean you really need 1,270 reactors.
So, how are you going to build them? Who will build them? That a lot of highly specialized skilled labor in a technology that does not exist today. Who will pay for them?
For some more sobering facts, this gives a good view of Chinas role.
So I've shown you some math. Even if you started today, your looking at many decades to replace the generation capacity of coal in use today. So perhaps you should show some of your math versus that hopy-changy thing you've got going on there.
Space solar is ever less likely than the thorium reactor. Fortunately someone has already done a great job of the math for this one:
The bottom line is terrestrial solar power is much much much easier and cheaper than space based, why go to space when you can actually use a proven technology to get the same results.
I agree, Earth based Solar IS cheaper now but the concept of using NON-Earth based materials to built them in space will make them far less costly over time and the Sun shines 24/7 in Space so the power generated is much greater…
Thanks for your link, I'll check it out.
Naval reactors are yet another issue, one because of their size and another because of their operation by the Military; that said, there have been a number of military nuclear related accidents, as I'm sure you are aware… Accident happens and when a Fukushima happens it affects the Planet; how many accidents will it take before mankind learns we have to do better?IMO, Land based nuclear reactors pose the greatest threat to mankind not only because they can cause a Trillion Dollar Eco-Disaster but also they are typically run for profit by companies like TEPCO that tend to put safety way down their "To Do" list…
It is no surprize that tthe Nuclear Industry is doing everything it can to retain it's market share instead of investing in other forms of Energy generation that pose less danger for the USA and the Planet.
RE: Your meetings and the rest of your comment, I think you are over reacting to a preceived "attack" and the use of the word "Fascist" which I believe accurately describes those that want to push ever more nuclear at any cost for short term profits…
Great Chinese Coal Info… THX and Thumbs Up
Here's hoping the Germans are coming up with a much better system that China will then adopt or build upon! Anyone that has been in China knows what their air quality is like!
Not sure what you mean by "yet another issue"
Land based reactors don't cause eco-disasters but in the case of Fukushima they clearly contribute to and exacerbate them. Earthquake + tsunami + operating reactor plants = Disaster. It's a series function. Take away any of the three and we wouldn't be having this conversation.
You are dead wrong with your statement that power companies (deliberately) put safety way down on their "To Do" list. They conduct risk analysis which often times turns out to be flawed. I can't speak for official DOE and NRC policy, but I do know a lot of people in the industry, many of whom I trained and served with. They would take great exception with your statement and unless you can provide concrete evidence of widespread practices such as you claim then all you are doing is making an unfounded statement of opinion. Have there been cases of poor decision making with regards to safety? You bet. Chernobyl was such an event. Is the practice endemic and widespread throughout the industry as it seems you would have us believe? Not a chance.
You're starting to sound like an Arnie Gunderson shill.
Mike Vick beat me to the puppies…
I recently came across energy plan I could live with and it works like this:
I get a propane fueled truck and use propane as long as the price agrees with me. Because I can eventually use my farm resources to make methane, which is very near propane's carbon. Though I will most likely still buy some propane for use, I can reduce my dependancy on it.
I also get a propane electric generator and do the similar switcher-roo as my methane production increases.
What I like about the use of propane now-methane later is its easy and powerful enough to get us places and if we co-generate, we can take heat off the electrical generator.
We may add some solar and wind integrated into the design of the methane production just to make the production more effecient, but the bottom line is for the bang for the buck and that I can depend on methane production from sources like a toilet to the farm animals - means I can always have transportation and electricity.
I realize, this may not work for people in large populations…or would it? If sewer systems fueled public transportation, it just might and the change can begin now using propane and natural gas as the fuel of choice.
One more note, using natural gas to fuel trucks is already available to people and the convenience is over that of gas powered cars n trucks. People who use natural gas vehicles (mainly made by Toyota) can fuel up from the gaslines they already have at their homes.
I know the fracking arguement on natural gas, but I have heard solutions to it that don't involve chemicals into the ground. One safe fracking method is to pump anarobic microbes into the shale, which will not only break up the rock, but by their nature will also increase the pressure as they multiply (reducing the cost to pump it up from the ground.
I think coal has its place and will continue to grow in uses, but so will many other unique solutions that are on the drawing board now. It is going to take every input we can think of to ride the slide down of energy decline to a safe landing.
It is sad when even blog discussions are reduced to name calling by folks that think that they have the only answers, + forget the puppies talk, it is unnecessary and it makes you look silly …You want an example of a nuclear utility trying to soupup a reactor without getting permission from the NRC, here is a current on; it even has the engineering info for you to review, enjoy!
http://is.gd/qiXNdJ
Would you put up with this kind of "service", I know I would not…
[quote=CaptD]It is sad when even blog discussions are reduced to name calling by folks that think that they have the only answers, + forget the puppies talk, it is unnecessary and it makes you look silly …
You want an example of a nuclear utility trying to soupup a reactor without getting permission from the NRC, here is a current on; it even has the engineering info for you to review, enjoy!
http://is.gd/qiXNdJ
Would you put up with this kind of "service", I know I would not…
[/quote]
Please tell me you did not just cite an Arnie Gunderson "report" and expect anyone to believe he has a shred of credibility. He has inflated his resume in the nuclear energy industry and in some cases has been accused by some of flat out lying. Without getting into a pissing contest over this, I am a certified engineer on 4 different Navy power plants, the smallest of which had several hundred million times the power output of Gunderson's. If you are going to come into these forums and have Arnie Gunderson carry your water you can expect to get called out. You may call it name calling, but using Gunderson as a credible expert and trying to make an argument based on his "expertise" rightfully qualifies you as a shill for the other side. Besides, where have I heard the expression "Nuclear Fascist"???
He was licensed to operate a reactor that operated at room temperature and pressure in a fish tank. Max output? About 100 watts. It could, on occasion power a light bulb.
Gunderson has a long history of fear mongering while touting an experience base, and certification and experience history that he simply does not have. Read more here about your "expert" - some material is repeated because I didn't feel like re-editing the post cited: https://peakprosperity.com/comment/135433#comment-135433
"Gundersen has ZERO credibility with me - and many others. He inflated his resume, he overstated his experience. For one, the only reactor he was ever "licensed" to operate was a reactor at Rensselaer Polytechnic Institute from 1971 to 1972. This reactor was a 100 Watt reactor that operated at room temperature, at atmospheric pressure in an open tank of water. For the record, 100 watts is about the heat output of a freakin' lightbulb. One version of his resume read as follows:
“Critical Facility Reactor Operator, Instructor. Licensed AEC reactor operator instructing students and utility reactor operators in start-up through full power operation of a reactor.”
I'm taking some license, but in short, he instructed students how to turn on…a light bulb.
His "4 decades of experience in the nuclear industry" is a bit of a stretch. According to his resume, following his graduation in 1972, he worked at Northeast Utilities from 1972-1976. Digging around on the internet shows that he was assigned to the licensing group at NU and that he had no real design engineering responsibilities as he has recently frequently claimed.
There are many inconsistencies with other things Gundersen has said - here's a glaring one taken from a 2008 application to serve on the Diablo Canyon Safety Committee:
" Since 1970 Arnold Gundersen has been an expert witness in nuclear litigations at the Federal and State hearings such as Three Mile Island, US NRC ASLB, Vermont State Public Service Board, Western Atlas Nuclear Litigation, U.S. Senate Nuclear Safety Hearings, Peach Bottom Nuclear Power Plant Litigation"
Gundersen graduated from RPI in 1971. Do the math.
More discussion about his inflated resume and exaggerated experience claims here: http://atomicinsights.com/2011/02/arnie-gundersen-has-inflated-his-resume-yet-frequently-claims-that-entergy-cannot-be-trusted.html
More info about his fear mongering here: http://atomicinsights.com/2011/06/arnie-gundersen-going-international.html
(Note: this article was written a year ago and there is a statement in it that claims that the radiation released from Fukushima hasn't made anyone sick and that it was a non-fatal accident. While that may have been correct at the time, it is highly likely that there have been cases of radiation sickness since June 2011)
Here are some pretty good links to articles discussing what really happened at Fukushima - that contradicts claims that Gundersen made frequently, loudly, and incorrectly.
http://atomicpowerreview.blogspot.com/2011/06/fukushima-daiichi-update-saturday-june_18.html
A breakdown of what really happened at Unit 4 with respect to the spent fuel pool:
http://www.4factorconsulting.com/energy-industry/nuclear-power-and-the-witch-hunt
Full disclosure - these articles and debunks were written by current nuclear industry insiders. I know Rod Adams, we went through the training pipeline together and the US Navy's submarine community is pretty small. I trust Rod Adams. I DO NOT trust Arnie Gundersen. Some will argue that anything written by the nuclear industry is to be dismissed because they are biased and solely profit motivated. I am in no way saying that to some degree this does not exist in the industry, but to outright dismiss these articles is a poison pill argument.
Fukushima wasn't and isn't as rosy a situation as some would have you believe - it is bad, but as I have stated numeroues times, it is bad…locally. It is not the "Mass Extinction Event" some articles have labelled it. Nor is it the "biggest industrial catastrophe in the history of mankind" as Arnie Gundersen is claiming. The Union Carbide disaster at Bhopal still tops my list and is still causing problems in the area almost 30 years later. http://en.wikipedia.org/wiki/Bhopal_disaster
To wrap up, Gundersen has repeatedly exaggerated his very limited experience in the nuclear industry - some would say he outright lied. To say he lied is a pretty strong statement, and I won't go there. But there is no doubt in my mind that he has greatly exaggerated things. He has preyed on the fears of an uninformed audience by waving around a resume that doesn't stand up to scrutiny. Chris hitched his cart to the wrong horse by bringing Gundersen to the site - he flat out blew it on the discussion of the spent fuel pool in Unit #4. I think now would be a good time to get Rod Adams as a guest speaker on the current state of the accident response at Fukushima Daiichi, but as of yet that suggestion has fallen on deaf ears."
BTW - if you think my puppy comment was "unnecessary and only makes me look silly", you have a lot of my posts to read that are much better than that comment. I'm rather fond of an irreverent approach to many topics, and even when I'm mostly serious you can expect a distractor or two…
Your reply was long and contained lots of Anti-Arnie links but you failed to even comment on the list of Utility issues mentioned in the link… Why is that, since you consider yourself "nuclear knowledgeable," can you not see forest for the trees or is all nuclear just wonderful to you? I bet a Rod Adams Arnie Gundersen dibate would be very informative, especially if both kept to the facts and the conversation did not become name calling…
BTW: Where were all the "nuclear knowledgable" people's comments about Fukushima and the radioactive pollution it has and continues to cause Japan?
Any comment on the Japanese burning of radioactive tainted debris that is making its way to North America?
Unlike you, I salute your right to have an opposing opinion even if it is completely misguided; nuclear fallout from reactor accidents like Fukushima is a bigger worry than Global Warming…
In short, the USA has just been very LUCKY so far, since Fukushima proved that Nature can destroy any land based nuclear reactor, any place anytime 24/7/365!
How would you suggest the USA pay for a Trillion Dollar Eco-Disaster, should one occur here?
[quote=CaptD]Your reply was long and contained lots of Anti-Arnie links but you failed to even comment on the list of Utility issues mentioned in the link… Why is that, since you consider yourself "nuclear knowledgeable," can you not see forest for the trees or is all nuclear just wonderful to you?
I bet a Rod Adams Arnie Gundersen dibate would be very informative, especially if both kept to the facts and the conversation did not become name calling…
BTW: Where were all the "nuclear knowledgable" people's comments about Fukushima and the radioactive pollution it has and continues to cause Japan?
Any comment on the Japanese burning of radioactive tainted debris that is making its way to North America?
Unlike you, I salute your right to have an opposing opinion even if it is completely misguided; nuclear fallout from reactor accidents like Fukushima is a bigger worry than Global Warming…
In short, the USA has just been very LUCKY so far, since Fukushima proved that Nature can destroy any land based nuclear reactor, any place anytime 24/7/365!
How would you suggest the USA pay for a Trillion Dollar Eco-Disaster, should one occur here?
[/quote]
Since you have exactly ZERO experience in the nuclear field can you please be done with this discussion now. I don't even know where to start to begin to address your affinity for fear mongering which can only come from an acute ignorance of fact.
As soon as I saw the author of the article you provided I stopped reading. Gunderson has no credibility in the industry anymore. He discredited himself by fabricating and inflating his resume with respect to his qualifications and experience in the industry. He does generate quite the following by writing articles that do nothing but prey on the fears of the ignorant and uninformed - and voila, everyone becomes an expert because they can cite an Arnie Gunderson Fairewinds article.
Except they aren't experts and the article is non-objective and non-scientific. They are, in short, creative writing assignments meant to instill fear. Gunderson has a wide reputation for presenting the worst case scenario as an inevitable fact. Like the molten cores burrowing through the pressure vessels at Fukushima, melting into the ground and causing gigantic steam explosions when they hit groundwater. Except there was no core breach, there was no molten slag that ate into the bowels of the earth.
Just like there was no hydrogen fire in the spent fuel pools from zirc hydride and melting spent fuel cells. According to Arnie we needed to be all concerned over spent fuel - meanwhile a few hundred yards away, fully loaded fuel was at risk. Way to focus Arnie.
Unlike you, I have an experienced based, objective respect for nuclear power. I know how to operate a plant safely in just about every forseeable normal operating mode. I know how to respond to just about any casualty in a power plant. I know what the repercussions are of not operating a plant properly. I understand the risks, risk avoidance and risk assessment and when to apply them.
How much hands on experience do you have? None? So why do you persist in presenting material as if you knew what you were talking about? You clearly have an agenda - I suspect driven by your ignorance and fear. You lack objectivity. You cling to such statements as "nuclear fallout from reactor accidents like Fukushima is a bigger worry than Global Warming".
Really? REALLY??? Considering there are no current accidents in progress I would say your comment is a bunch of malarkey. Now if what you mant to say was "if there were to be multiple, simultaneous meltdowns and releases from all of the reactors in the world, the resulting nuclear fallout would be of significant global impact.", I might agree with you. I'll put the likelihood of such an event just slightly ahead of the likelihood that Kim Kardashian wins the Nobel Peace Prize in Physics.
A debate between Gunderson and Rod Adams would not be very interesting. One person brings an many years of experience in a real power plant, oh let's say, a plant with a power output larger than that of a light bulb. One person underwent an extensive period of training and certification beofer being allowed to operate a power plant. One person was frequently examined by an external oversight organization for aptitude in procedural compliance, completion of scheduled preventive maintenance, efficacy of unscheduled responsive corrective maintenance, proficiency in normal and casualty scenario operations.
The other person is Arnie Gunderson. He operated a heater in a fish tank - and then deliberately and willfully exaggerated his qualifications and experience. That calls into question one's integrity and character…Not exactly the kind of guy we want running Naval Nuclear Propulsion Plants and then moving into the civilian power industry.
Nobody is trying to say that Fukushima wasn't a significant event and that the cleanup and recovery will take a long time. No one has ever said that there won't be repercussions - people will develop cancer and die from exposure to radioactive material released during the accident at Fukushima Daiichi. But it is a largely localized event. However, the "End of Days" global "Mass Extinction Event" stories coming from Gunderson and his ilk are for lack of a better description, completely overblown bullshit stories - lacking technical accuracy, scientific objectivity and any shred of credibility.
You are free to choose where you want to hang your hat…
As far as how we'd pay for it? Well of course it would all be George Bush's fault. But then we'd just put in a call to Helicopter Ben Bernanke and Turbo Timmy Geithner and we'd fire up the printing presses at Treasury and print a whole boatload of nuclear powered bailout money.
Can't you just see the headlines now…Radioactive Quantitative Easing XII
Really now, I'm done.
Please don't go yet! I have some questions first.As I understand it, current plant designs assume that power will be available to run the cooling pumps for both the spent fuel pool and a scrammed reactor basically on a 24/7 basis for years after a plant shutdown. A power failure for any substantial amount of time (measured in the tens of hours) will result in an eventual major issue; how major depends on how much spent fuel is present, and how recently the plant was shut down.
Is my understanding correct? I know there are backup generators, and my understanding is the backups have about 7 days of fuel. Battery backups are present too (although I'm not sure if they can run the pumps) - my understanding is they're good for about 4 hours.
So based on this situation and my understanding, the implication is that if you have a grid power connection failure at a plant, and you cannot refuel the backup generators, in a little more than 7 days, you end up with a meltdown assuming the plant was running at the time of grid power loss. Likely too the spent fuel pool (with 5+ years of old cores in it?) will have some issues as well, and the fuel pools are not secured nearly as carefully as the active reactor core is. Issues with non-cooled spent fuel pools might include things like exploding buildings, fragments of old cores being blown into the air, etc.
If you could correct any misunderstandings I have on the implications of the design and the failure modes, I'd be most grateful. Given the extreme difficulty of getting something to work 24/7 over a long period of time, I am actually pretty impressed we haven't had more problems to date. That speaks to the skill of the engineering involved.
While natural disasters make me nervous about individual plant vulnerability, my true "doomsday" scenario would be the detonation of an EMP device over the continental US taking out 1/3 of the power grid for the better part of six months. 40 plants would lose grid power simultaneously. Presumably scheduling refuelling operations for the backup jennys for 40 plants would be "complicated" in such a scenario (given we lose the communications network a few days after the EMP event), resulting in multiple simultaneous meltdowns and spent fuel pool explosions all across the country 7 days after the event. This would seem to make a bad power-down situation into something a whole lot worse.
http://www.empcommission.org/docs/A2473-EMP_Commission-7MB.pdf
Please tell me where I might have gone wrong here. I design software systems for a living; you can present me with facts and I'll listen. :)
Unlike ANY other form of Energy generation, Nuclear reactors and their spent fuel pools requirement of constant cooling pose a special problem should ANY disaster strike! That is why they are now too RISKY to depend upon in the future; how would any Country "fund" a Trillion Dollar Eco-Disaster like Fukushima, where would people relocate to and for how long?The cause does not matter, it could be anything like:
~ Tornado strike?
~ Earthquake?
~ Human error?
~ Tsunami?
~ Power outage?
~ Pipe break?
~ Test gone wrong?
~ Old fuel issues?
~ Terrorist attack?
~ Hurricane?
~ Plane crash?
~ Heavy rains/River floods?
~ Metal Fatigue?
~ Nuclear Ransom?
~ Solar Flair?
~ EMP?
~ Lightning?
~ Dam Failure?
~ Fire?
~ Operator suicide?
~ Jihadist?
~ CME?
~ Carrington Effect?
~ Cyber-warfare?
~ Meteror?
~ Aliens?
~ Volcano/Eruption?
… Just to name a few possibilities how NPP's (nuclear power plants) can fail.
Thanks for asking…
You have some things correct, others not so much. The first thing is to separate an operational plant and spent fuel. I'll discuss the spent fuel in a bit. There is a bit of variation in the design of specific plants so I'll speak in glittering generality. You are correct in the observation that plants assume there will be power available to operate the cooling pumps. Under normal operating conditions, that power is generated from the plant itself as water is heated in a steam generator and that steam is expanded through steam driven turbine generators to produce electricity for both the grid and consumers and for the plant. Obviously the plant needs to be operating to do so. Plant designers also had to provide for the ability to operate the colling pumps when the plant is shutdown for scheduled maintenance and following emergency shutdowns. Typically, this is done by tying into the grid so there is continuity of power. As a defense in depth approach, there are backup power sources on site - usually emergency diesel generators, any one of which are capable of providing power to operate coolant pumps, associated support systems and instrumentation. Most plants have these generators as stand alone emergency systems that are only used in the event of an emergency. In some cases you may have shutdown maintenance on a portion of the electrical distribution system where these generators are used, but they are designed for emergencies. That said, plants have procedures in place to routinely test run these generators to make sure they will be available for operation if needed. Power plants also have contingency plans in place for generators to be delivered within a specified time frame from commercial industry in the event soemthing were to happen to their on-site generators. Fuel really isn't an issue since it is stored on-site. At the training plant I taught at, there was enough fuel to run the emergency diesel generators continuously for about 3 months before you would need fuel from outside sources. Chances are you would start to see mechanical failures of the generators before that time was up, but since we had 6 generators, each capable of providing sufficient power, mechanical failure wasn't an issue.
Battery back-up power exists, but you have a good understanding of the limitations there so it doesn't need to be discussed.
To correct your statement, a power failure for any substantial amount of time - absent planned casualty procedure response - MAY result in a major issue. The primary factor affecting the potential severity, is not so much when the plant was shutdown, but the reactor power history prior to the shutdown. If the core had been operating at near peak power for months and was shutdown, decay heat generation is a major concern. But understand, decay heat generation, while substantial, is not like heat generation from normal operations so the installed coolant circulation systems are more than capable of removing decay heat following a shutdown, even with with a high power history. As you know, decay heat generation falls off exponentially with time following a shutdown, so as time progresses, less heat is being generated so the coolant circulation requirements change. Immediately following a shutdown, you would need to operate coolant pumps continuously. All power plants have a band in which they are operated in terms of pressure and temperature. It is critical (no pun intended) to stay within the bands. You may have a 100 degree temperature band to operate in so after a few weeks, decay heat generation has fallen to the point where you can lower temps down to the low end of the band, secure pumps and allow the core coolant to slowly heat up before you need to run pumps again. Variations in plant designs will make the temp/pressure bands vary, but basically they all follow that operational profile.
Spent fuel really isn't an issue because it's, well, spent. Spent fuel cells aren't even removed from core power units for storage until the decay heat rate is so low they can be safely stored in unpressurized, open spent fuel pools. The water in the pools is for both coolnig and also radiation shielding. The cooling is done through natural circulation and convective heat transfer, but their is also radiative heating of the water from decay heat. The ability to add water to these pools is needed, but it does not need to be recirculated for forced heat removal like in the cores.
I was flabbergasted at how much attention the Fukushima spent fuel pools were receiving considering that a mere hundred yards away, 5 operating cores with unspent fuel and no coolant circulation ability were undergoing partial fuel matrix melting. Talk about a case of focusing on the hangnail instead of the sucking, penetrating chest wound… Frankly, Chris flat out blew it with his assessment of the spent fuel pools boiling dry and zircalloy matrix breakdown and hydrogen release and explosions and burning fuel and prompt criticality. But hey, bad news sells, even if it's wrong.
The real issue with the spent fuel pools at Fukushima Daiichi wasn't the fires and melting (that didn't happen) it was the loss of shielding that resulted in high radiation areas - some lethally high - that complicated emergency response at the site.
The emergency response workers at Fukushima Daiichi were rightfully focused on getting the plants stabilized as best they could and not worrying about spent fuel that was just never a significant issue.
Sort of…contrary to what CaptD would ike you to believe, a grid failure is not in and of itself going to cause a meltdown within 7 days. You need a catastrophic event - like an earthquake that shuts down the plants that were operating at near peak power (high decay heat generation) and likely caused significant structural damage to the plant PLUS a 45 foot high tsunami that destroys your emegency diesel generators PLUS a loss of external power into the plant to run the systems knocked off line. Fukushima was the perfect storm of BAD things that lead to core damage.
I think you keep overstating the spent fuel issue. While it is a concern, you aren't going to get exploding buildings (I assume you mean hydrogen explosions from decomposition of the zircalloy fuel matrix in a steam environment?) and pieces of cores tossed into the air. Remember, it isn't the core that is being stored, it is the fuel cells themselves. Most industry insiders refer to the "core" as a collective term to include the reactor pressure vessel and the fuel cell assmebly unit or power unit housed within the pressure vessel. In most cases, the spent fuel pools are stored near by the power plant but are not necessariy within the primary or secondary containment boundaries. The buildings at Fukushima blew up because of hydrogen buildup as the emergency response workers made the very deliberate decision to vent the system to lower pressure. As the steam was vented, hydrogen was stripped out and collected in sufficient quantity to detonate. The spent fuel pools were within the structure of the building but were not inside the primary containment boundary. Again, spent fuel may be an issue, but the real concern is the unspent fuel in the cores.
As to your observation that you are surprised we haven't had more problems to date and your statement that it speaks to the skill of the engineering involved? It also speaks to the rarity of the combination of events that could cause problems. No one is saying that there aren't any risks, but it can be said that the risk of such a combination of events leading to a Fukushima type event is extremely low. Otherwise it would have happened before…
While I don't consider myself an expert on EMP attacks, I do know quite a bit about them from my tour at US Strategic Command. I think you have overstated the threat of an EMP explosion over CONUS on a couple of fronts. The first (as we discussed via PM) is the size and number of warheads needed, plus the delivery system requirements to do so. Not many countries have the ability to do so. Even then, a HAB (High Altitude Burst) EMP attack is primarily designed to knock out communications through gamma and xray scintillation and atmospheric activation and won't have as much of widespread impact on the ground. There will be some affect, but it will be concentrated in a relatively small area. I'd be completely guessing as to the number of weapons needed to knock out all the nuke plants in the US, but I can state that it would be intuitively high. Assuming an adversary would have the intent and will to use, you could certainly launch enough weapons to completely overwhelm the US grid with the potential for the resultant problems at nuke plants you postulated.
But, such an attack would also correctly be interpreted by National Command Authority as an attack on US sovereignty and we would likely be reponding in kind. In other words, things would get pretty crappy, pretty quick and reactor plant meltdowns would be well down the list.
The other factors affecting the impact of an EMP burst are altitude and the strength of the Earth's magnetic field where the NUDET occurs plus the type of weapon used. While all nuclear weapons have an EMP effect, not all are created equally. The construction of the physics package within the warhead in large part determines how much EMP occurs and is in part a function of the physical relationship between the primary and secondary device.
Back in the '60s, the US conducted a test called STARFISH PRIME where a 1.4 megaton weapon was detonated 250 miles above the mid Pacific. It knocked out streetlights and triggered burgular alarms in Hawaii almost 900 miles away so the affect can be widespread. back then, electrical distribution systems were a lot more rugged than they are today, so the same test would have a much larger impact.
A few years after STARFISH PRIME, the Soviets conducted a test called the K Project where they detonated a weapon with one fifth the yield of STARFISH PRIME over a populated area and in an area where the earth's magnetic field was much higher It caused a current surge in a power line that fed back into a power plant and caused a fire. Go figure the Soviets would run off and conduct a test to out do the US that involved blowing up their own citizens
http://en.wikipedia.org/wiki/Starfish_Prime
http://en.wikipedia.org/wiki/Electromagnetic_pulse This one has some discussion about K PROJECT
Today's electrical systems are a lot less rugged than they were back in the day, so the affect could be large scale and potentially devastating.
But what you have to look at is the likelihood of such an attack. While very few things have a true 0% chance, the chance of a country striking the US with a coordinated attack using enough weapons to completely shut down the grid is not high. A single well placed weapon will have varying degrees of impact (as a function of radius from the aimpoint), but it won't be nationwide. I also can't speak to specifics about each power plant's emergency planning and whether or not their emergency elctrical generation and distribution system s are hardened against an EMP, but I do know such hardening exists and it's likely more widespread than you think.
So the bottom line is, there are a few countries who could launch such an attack on the US that would knock out our power grid and potentially lead to accidents at nuclear power plants, but the impact of the power plant accident would be localized - just like the accident at Fukushima is now almost entirely a local event, albeit a very significant one.
I just don't see the likelihood of such an attack being high enough to worry about.
I hope I took care of most of your questions - if not, please follow up and ask and I'll do my best to help out.
Now it's time to brave the 98 degree weather (106 heat index) to pick tomatoes and do some spot watering.
CapD-I'm interested in finding out specifically what are the risks of a cooling loss for a spent fuel pool. If the water evaporates entirely, what are we faced with? When armed with implications of technology failure, we can each be the judge of how likely we estimate such a situation might come to pass.
It is known that people often have a poor sense of how dangerous something really is. Air Travel. Smoking. Nuclear Plant Accidents. Driving home on New Years Eve. Its likelihood times impact.
Planes crash, yet we still fly. And per passenger-mile, air travel is a lot safer than driving. And how many people choose to smoke, when we KNOW it kills 5,000,000 people each year worldwide, and smokers die 13 years earlier than nonsmokers. The Fukushima disaster will never kill that many people ever, and yet smokers do this voluntarily to themselves. Yearly. One would expect a careful consideration of the actual risk to human life would end up banning smoking long before dealing with nuclear power, but that's just not how we operate.
At least nuke plants produce something useful - electricity. Occasionally they'll spew radiation when things go wrong, and then Cesium litters the area for a few hundred years.
I recall two people being asked about the chances of a fatal shuttle accident. The NASA administrator set the odds as 1:1,000,000. The aerospace engineer put it as 1:100. From our three commercial plant accidents, 430 operational plants, and 40 years of operation, simplistic math puts severe accident risk at 1:5700 per year. Of course an EMP event "Black Swan" would change that math overnight.
As a (software) engineer myself, I like to have the facts. Then I can decide for myself what the different danger scenarios are, and how likely they are to come to pass. Likelihood times impact.
Here's an interesting list of nuclear accidents I found while trolling the net.
"Since 1950, there have been 32 nuclear weapon accidents, known as "Broken Arrows." A Broken Arrow is defined as an unexpected event involving nuclear weapons that result in the accidental launching, firing, detonating, theft or loss of the weapon. To date, six nuclear weapons have been lost and never recovered."
http://www.atomicarchive.com/Almanac/Brokenarrows_static.shtml
[quote=davefairtex]I'm interested in finding out specifically what are the risks of a cooling loss for a spent fuel pool. If the water evaporates entirely, what are we faced with? When armed with implications of technology failure, we can each be the judge of how likely we estimate such a situation might come to pass.
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Again, the exact scenario is dependent on how much time has elapsed since the spent fuel cells have been used inside a critical core power unit and what the pre-shutdown power history was. Spent fuel is not transferred into a spent fuel pool until such time has elapsed that the decay heat generation rate is low enough that it can be stored safely with other spent fuel cells and a depressurized column of water. Since there will be some decay heat generation for several years there will be natural circulation of the water due to conductive heat transfer (and a small degree of radiative heat transfer). Warm water rises, cooler water sinks, decay heat is transferred away from the spent fuel cells safely. On occasion you will need to add make-up water to the pools - but since they are open to atmosphere the primary reason is normal evaporation, not water boiling away.
If structural integrity of the spent fuel pool were to be compromised such that you could no longer keep the spent fuel cells covered with water you would have two dynamics occurring. One would be a loss of shielding with resulting high radiation levels. The oxide layer on the outside of the spent fuel and structural components of the fuel matrix assembly can be activated and become radioactive. Depending on the type of decay, water is an extremely effective shieding agent. Water will completely attenuate alpha and beta particle decay, and is fairly effective at shielding gamma. Depending on the energy evel of the gamma particle, the tenth thickness of water shielding can be anywhere from 8 inches for a 1 Mev gamma particle, up to 48 inches for a 6 Mev gamma. So a four foot column of water surrounding a spent fuel cell with an on contact reading of 100 Rem would attenuate the dose rate to 10 Rem. Each additional 48" of water would attenuate the dose rate by another factor of ten. The spent fuel pools where I worked were 60 feet deep. Since water is not a free standing compound, i.e., it needs to be in a tank or pool. Most of these pools are constructed of concrete lined with stainless steel because of its corrosion resistance properties. Steel is also a good gamma shield, the tenth thickness is 2-4 inches depending on the energy level. The tenth thickness for concrete is 24 inches. Using my example above, a 100 Rem on contact reading would read 100 millrem if it was measured through 4 feet of water shielding, 2 inches of steel tank and 24 inches of concrete. 100 millirem general area readings are very easily controlled and stay times to work within such an exposure rate are well studied and planned for during maintenance shutdowns.
The biggest concern with a loss of water from a spent fuel pool is the loss of shielding. A secondary, but very real - although less likely - concern is the buildup of decay heat within the spent fuel cells as long lived fission product daughters decay. It is entirely possible that you could get blistering of the fuel cell zircalloy cladding that could result in a release of fission product daughters. Under the right (or wrong) circumstances, you could get some deformation of the fuel cells, a much lower likelihood is melting of the fuel cell matrix (since spent fuel isn't transferred into spent fuel pools until decay heat generation rates are very low.) A tertiary concern, with an even lower probability of occurrence is a partial loss of water, combined with high enough decay heat generation such that the water actually boils. In this case, you could get a reaction between the steam and zircally cladding that would result in the formation of zirc hydride and the release of hydrogen. Then you have a real danger of a hydrogen fire.
This is what Arnie Gunderson and Chris said had probably happened at FD Unit #4 "because there was smoke". What it turned out to be was stored lubricating oil that caught fire following the hydrogen explosion from core venting. Whether the oil caught fire because of the hydrogen explosion or damaged electrical wiring that came in contact with the oil is not known.
The short answer to your question of "If the water evaporates entirely, what are we faced with?" is: Probably a high radiation (> 100mr/hr dose rate) area in the vicinity of the pool(s). If there is more than one pool undergoing that scenario, the severity of the situation is compounded.
Point of order…a nuclear weapons accident and a nuclear power plant accident are two distinctly different events. I am aware of 11 US weapons that were lost and not recovered. All told, there are an estimated 50+ weapons lost - most a sea and most of them Russian. To provide a little clarifying information…
DOD Directive 5230.16 Nuclear Accident and Incident Guidance: http://usgovinfo.about.com/bldod523016.htm
Decent recap of major US nuclear weapons accidents: http://voices.yahoo.com/broken-arrows-nuclear-weapons-accidents-38221.html
2 of the "unrecovered" 6 (or 11) weapons were on B-52H flying into Palomares, Spain in 1966. The Buff, collided with a KC-135 in mid-air. The crew was able to jettison all four of the weapons on board. One landed in a field and was recovered, one landed in the ocean and was recovered, the other two were destroyed when they hit the ground and the high explosive triggers detonated scattering radioactive material all over the field. So while there was nothing to recover, the weapons weren't "lost" from the standpoint that they are out there somewhere lying around. The US came in behind and essentially removed the top 10 inches of soil from the field where the material was scattered - some 1500 tons of dirt were removed. To this day there is some gallows humor about glow in the dark tomatoes from that field…
Another of the unrecovered weapons is in a bog in Faro, North Carolina near Seymour Johnson AFB. In 1961 a B-52 carrying two gravity bombs exploded in mid-air and the two bombs fell to earth. One of the weapons went through 3 of the four arming steps to detonate, but the fourth step was the pilot's arming sequence so there was no possible way the weapon would have detonated. Since it was a retarded air burst delivery, that actually helped the recovery since it RTAB parachute deployed and the weapon floated gently to the ground where it was recovered quite inert. The other didn't deploy its chute and it hit a swampy bog at 700 miles an hour. Most of the physics package was recovered, but a portion of the thermonuclear device is at the bottom of the bog at a depth of around 200 feet. The Air Force now owns the land surrounding the site so while this bomb wasn't fully recovered, the Air Force knows where the remaining components are.
A fourth unrecovered weapon is suspected to possibly be at the bottom of Baffin Bay off Greenleand following another B-52 crash in 1968 that lost four gravity weapons. Two were immediately recovered, one was not recovered until 1979. The official story is that all 4 were recovered, but there is some question about the accuracy of that claim based on some old grey hairs at Thule who claim to know otheriwse.
A fifth weapon was on an A-4 SKYHAWK that fell from the deck of USS TICONDEROGA in 1965 and was lost in over 16,000 feet of water off the coast of Japan. That weapon was never recovered.
Dogs -
Thanks for the responses. Its inspired me to read up on the subject. I found a link to a series of 11 PDFs at the NRC website that is providing me a higher level of detail on matters relating to commercial nuclear plants, nuclear waste, radiation effects, and the like. Just change the 01 to 02, 03, etc to see the next PDF in the series. (I'm sure you know all this stuff, its basic enough that someone with my intro to physics background can easily understand it - I just put that in there for others who might be interested)
http://www.nrc.gov/reading-rm/basic-ref/teachers/01.pdf
So now I get the units - rem per hour, curies per gram, etc. 10 rads is unfortunate, and 1000 rads is death.
Missing for me is a conversion from curies to rem/hour. If an accident ends up emitting 100 curies, and that falls to ground, and now a particular square meter of earth downwind has 10 microcuries of contamination from the radioactive cesium deposited there, how many millirem/hr does a person receive as an external dose if they decide to camp at that spot for 10 hours? [We'll ignore for the moment the issues of internal doses, just to keep things simple]
I'm also curious as to the contact reading in rem/hour from various spent fuel assemblies - lets say the spent fuel ranges from 5-30 years old.
How long does it take for a fuel unit to be "used up"? I.e. how long does one fuel unit last in production?
If you have a collection of spent fuel with no water in the pool, do the spent fuel units start interacting with one another - and to what degree? Lets say the contact reading of a spent fuel unit in water is 100 rem/hour. What does it look like when the water goes away? How much higher does it get from interacting with other nearby spent fuel units? Let's assume the structure of the fuel pool remains intact so the units retain their spacing (i.e. they don't collapse and fall on top of one another).
Would the internal temperature of some of the spent fuel start to approach the 1800F level in this situation?
About how many curies/hour of radioactive products would be emitted from a dry spent fuel pool containing 30 years worth of (possibly interacting) spent fuel units, assuming the fuel pool was exposed to atmosphere and there was reasonable air circulation. I.e. the surrounding building is gone, the water is gone, but there are no further explosions, just a nice breeze blowing.
Numbers make me happy, because then I can judge for myself what I think bad really is. Related: I also don't believe that a priest should stand between me and God. :)
Apologies for the non-sequitur about nuclear weapons accidents. I know its apples & oranges; I just ran across the link and thought it was really interesting. Alarming too. I'm guessing the Captain of the Ticonderoga (that "lost" the A-4, the pilot, and the 1MT hydrogen bomb off the deck) didn't make Admiral.
[quote=davefairtex]Dogs -
Thanks for the responses. Its inspired me to read up on the subject. I found a link to a series of 11 PDFs at the NRC website that is providing me a higher level of detail on matters relating to commercial nuclear plants, nuclear waste, radiation effects, and the like. Just change the 01 to 02, 03, etc to see the next PDF in the series. (I'm sure you know all this stuff, its basic enough that someone with my intro to physics background can easily understand it - I just put that in there for others who might be interested)
http://www.nrc.gov/reading-rm/basic-ref/teachers/01.pdf
So now I get the units - rem per hour, curies per gram, etc. 10 rads is unfortunate, and 1000 rads is death.
Missing for me is a conversion from curies to rem/hour. If an accident ends up emitting 100 curies, and that falls to ground, and now a particular square meter of earth downwind has 10 microcuries of contamination from the radioactive cesium deposited there, how many millirem/hr does a person receive as an external dose if they decide to camp at that spot for 10 hours? [We'll ignore for the moment the issues of internal doses, just to keep things simple]
I'm also curious as to the contact reading in rem/hour from various spent fuel assemblies - lets say the spent fuel ranges from 5-30 years old.
How long does it take for a fuel unit to be "used up"? I.e. how long does one fuel unit last in production?
If you have a collection of spent fuel with no water in the pool, do the spent fuel units start interacting with one another - and to what degree? Lets say the contact reading of a spent fuel unit in water is 100 rem/hour. What does it look like when the water goes away? How much higher does it get from interacting with other nearby spent fuel units? Let's assume the structure of the fuel pool remains intact so the units retain their spacing (i.e. they don't collapse and fall on top of one another).
Would the internal temperature of some of the spent fuel start to approach the 1800F level in this situation?
About how many curies/hour of radioactive products would be emitted from a dry spent fuel pool containing 30 years worth of (possibly interacting) spent fuel units, assuming the fuel pool was exposed to atmosphere and there was reasonable air circulation. I.e. the surrounding building is gone, the water is gone, but there are no further explosions, just a nice breeze blowing.
Numbers make me happy, because then I can judge for myself what I think bad really is. Related: I also don't believe that a priest should stand between me and God. :)
Apologies for the non-sequitur about nuclear weapons accidents. I know its apples & oranges; I just ran across the link and thought it was really interesting. Alarming too. I'm guessing the Captain of the Ticonderoga (that "lost" the A-4, the pilot, and the 1MT hydrogen bomb off the deck) didn't make Admiral.
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Sheesh…I thought I finished Nuclear Power classroom training in 1983!!!
I'll work on your answers later today - after we get back from the beach. I should have it posted sometime this evening.