No, he was right on this one. It did melt down, almost as badly as Chernobyl #4 did, but thankfully without the explosion. What a difference containment (and different engineering) makes.
Ok, then you're going to correct the wiki that says "partial meltdown", right? Chernobyl didn't melt down, it blew up and then the graphite caught fire. Graphite reactors, well, yeah, not known for their safety. Yes, then it did melt down, but that was after the fire started. You are welcome to criticize the silly experiment they were running there, you'll get no argument from me on that.
So, in fact, the comparison to Chernobyl was utterly, entirely misleading, and completely overstated. In short, it was alarmist twaddle.
Well, 13 megacuries of 90Xenon and 17 curies of 135Iodine were released, according to the Kemeny report.
Thats about 2.5 orders of magnitude more than one of the entries to the wiki says. Of course that talks about Krypton and Iodine radioisopes and you are talking about Xenon.
(from the wiki)
According to the Rogovin report, the vast majority of the radioisotopes released were the noble gases, Xenon and Krypton. The report stated, "During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released." This resulted in an average dose of 1.4 mrem to the two million people near the plant. The report compared this with the additional 80 mrem per year received from living in a high altitude city such as Denver.[36]
Asto the evacuations, what I recall of the evacuation is how many people didn't take the advice. I don't have numbers, but many people continued to answer their phones, and this was well before cell phones. It was a VOLUNTARY evacuation, remember, and you've cited the number, if I recall correctly, that MIGHT have chosen to evacuate.
And of course the wiki says 1/2 of the melted, or most of it melted, or the top 1.5 meters melted. Take your choice, I guess.
But some measurements quoted from the wiki:
Also, white-tailed deer tongues harvested over 50 mi (80 km) from the reactor subsequent to the accident were found to have significantly higher levels of Cs-137 than in deer in the counties immediately surrounding the power plant. Even then, the elevated levels were still below those seen in deer in other parts of the country during the height of atmospheric weapons testing.[39] Had there been elevated releases of radioactivity, increased levels of Iodine-131 and Cesium-137 would have been expected to be detected in cattle and goat's milk samples. Yet elevated levels were not found.[40]
In the aftermath of the accident, investigations focused on the amount of radiation released by the accident. In total approximately 2.5 million curies of radioactive gases, and approximately 15 curies of iodine-131 was released into the environment.[68] According to the American Nuclear Society, using the official radiation emission figures, "The average radiation dose to people living within ten miles of the plant was eight millirem, and no more than 100 millirem to any single individual. Eight millirem is about equal to a chest X-ray, and 100 millirem is about a third of the average background level of radiation received by US residents in a year."[47][69]
Somehow, it seems to me that we're not seeing meaninful comparisons with some of the numbers you cited.
It seems to me that you're playing the same alarmist game. Given your clear escape from context in arguing about the effective magnitude of the New Madrid quakes in Georgia, I have to presume you went looking for an argument.
So when the data is all straightened out, and is testable and verifiable, let me know, ok?
Thorium reactors are an obvious way to go, but we seem stuck on using enriched uranium here in the USA.
Never mind the obvious. The other obvious is that we can solve our radioactive waste problem in the same way, and get power out of it, while eliminating the more horrid isotopes.
The problem is that the use of waste constitute "reprocessing" in US terms, something that is banned.
And banned for no good reason other than the same kind of hysteria in evidence in the OP and elsewhere in this thread.
that underplaying the seriousness of the accidents that have happened, and off-handedly sneering at people who bring up criticisms, is a very bad practice.
Thorium reactors are an obvious way to go, but we seem stuck on using enriched uranium here in the USA.
Never mind the obvious. The other obvious is that we can solve our radioactive waste problem in the same way, and get power out of it, while eliminating the more horrid isotopes.
The problem is that the use of waste constitute "reprocessing" in US terms, something that is banned.
And banned for no good reason other than the same kind of hysteria in evidence in the OP and elsewhere in this thread.
Again, agreed. See, I'm not unreasonable, nor am I arguing for the sake of arguing. This latter problem is just bureaucracy at work, it seems to me, and an excellent example of one of the reasons why it is important to have leadership which has scientific training, at least enough to know the issues.
Tell me, though, if you know. My understanding of the LIFTR reactor is in two parts: the fact that it uses thorium instead of uranium or plutonium, and the fact that it is a molten salt reactor (msr).
The thorium part is what makes the reactor economical with respect to uranium and and plutonium. The fact that it is an MSR is what makes it possible to completely fission all the fuel load (regardless of type of fuel), as the reaction-poisoning fission products may be removed from the fuel in a continuous chemical process, returning the remaining fissionables (not just fissiles) for further "burning". Also, the fact that it is an MSR is what gets us away from high pressures, as the salts have a much higher heat capacity than unpressurized water does. Is that a fair statement about thorium reactors, or is there more?
Who sneered? Not I. My insistence is that the facts of the case speak rather than a slanted pro or a con interpretation of the facts (and, yes, I'm going to respond on your longer rebuttal, but it will take research time that I don't have this weekend). I have no more patience with those who believe that some kilocuries of noble gas release poisoned thousands and lead to multiple mutational freaks in the area, than I do with the fantasy that a walk in Plutonium Valley (at the NNSS in Nevada) without a respiration mask on is healthy.
Yes. Providing that the use of neutrons can be turned on and off that way. My understanding, though, is that once you change 232thorium into 233uranium, it is fissile and starts producing it's own neutrons upon fission. I can't imagine that the researchers promoting this idea aren't aware of that, so there is probably something faulty in my understanding. If you know what it is, please enlighten me.
The Liquid Fluoride Thorium Reactor (LFTR) has a similar feature. As with all MSR reactors, it allows for the continuous chemical removal of decay products from the fuel (as it is liquid). Therefore, when you pull the plug* on the reactor and drain the fuel into non-critical storage, the heat stops, since most of the heat-producing, decaying fission products have already been removed from the fuel and handled by the normal operating procedure. It is reported that a test reactor back in Weinburg's days was shut off in this way on the weekends when there was no one to tend it. On Monday, they'd heat up the storage tanks to liquify the fuel and pump it back into the reactor, and it was good to go.
* - The "plug" is a literal plug of the fuel which was cooled in the pipe to the storage tanks, causing it to solidify. The cooling fan was power by the reactor's generation system, such that if the reactor failed, the fan would shut off, and no longer keep the plug from preventing the draining. It could presumably also be hooked to a seismograph which could open a drain. A false draining could be remedied in a few hours rather than months.
No it isn't. Shadron said 13 megacuries of Xenon, Wiki says 2.5 megacuries of Xenon and Krypton, but doesn't mention that the majority of that (over 2 megacuries) was Xenon (see here, volume II part 2, page 48 of the pdf). Shadron said 17 curies of Iodine, Wiki says 15.
Shadron's numbers may not have been exactly accurate (although since they're estimates there may well be other sources giving different numbers), but he's not even close to an order of magnitude off, let alone 2.5 of them. If you're going to sneer at those who object, perhaps you should try checking your own arguments first.
Ok, then you're going to correct the wiki that says "partial meltdown", right? Chernobyl didn't melt down, it blew up and then the graphite caught fire. Graphite reactors, well, yeah, not known for their safety. Yes, then it did melt down, but that was after the fire started. You are welcome to criticize the silly experiment they were running there, you'll get no argument from me on that.
You know, I'm sure enough about the damage to make a statement in the JREF forum about it. I'm not sure I want to do the same for the wikipedia, though. Am I allowed that much ambiguity? It goes without saying that with the exception of 6 sem-hours of atomic/nuclear physics in undergrad, that I'm self-taught in this area. Here I speak for myself; in wiki, I must speak from a much wider expertise, which I feel I'm not allowed to don.
Yes, Chernobyl blew up - twice, in the space of a few seconds, the second of which apparently involved a nuclear excursion. So I stand by my wording. No one ever was able to explore the reactor vessel after the event, so we don't know how complete the meltdown was, but OTOH I can make all sorts of loosey-goosey statements about "they were the same except for..." and compare Hiroshima against a fireworks display, couldn't I? I therefore stand corrected on the fact that they were the same except for....
Finally, many have come to the conclusion that nuclear purity grade graphite cannot be burned. There is even a couple of people on youtube who tried lighting a piece with a blow torch, unsuccessfully. No one seems really sure what it was that was "put out" at Chernobyl after nine days; perhaps it was the red hot mash of corium dissolving through the bottom of the reactor vessel and draining into the basement, forming the "elephant's foot" and other photographed pouring features. The initial fires were from pitch on the roofs of the various bays receiving the red hot debris; they were extinguished by morning.
So, in fact, the comparison to Chernobyl was utterly, entirely misleading, and completely overstated. In short, it was alarmist twaddle.
Do try to keep your unprecise put-downs to yourself. I'll thank you to keep conversations with me on a (pseudo-) professional level, as I do for you.
Thats about 2.5 orders of magnitude more than one of the entries to the wiki says. Of course that talks about Krypton and Iodine radioisopes and you are talking about Xenon.
Addressed by Cuddles above. There are various amounts published by various organizations, some with axes to grind. I'd thought I'd quoted an official report, but I can't find it now.
Now who do we believe?
wiki said:
According to the Rogovin report, the vast majority of the radioisotopes released were the noble gases, Xenon and Krypton. The report stated, "During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released." This resulted in an average dose of 1.4 mrem to the two million people near the plant. The report compared this with the additional 80 mrem per year received from living in a high altitude city such as Denver.[36]
Unless you can tell me you (or wiki, whoever he is) were on the roof making measurements, I assume you know that such things can be wildly imprecise guesses. You have your source and I have mine.
Asto the evacuations, what I recall of the evacuation is how many people didn't take the advice. I don't have numbers, but many people continued to answer their phones, and this was well before cell phones. It was a VOLUNTARY evacuation, remember, and you've cited the number, if I recall correctly, that MIGHT have chosen to evacuate.
Again, it's a guess. I wasn't there and I doubt you were, so trying to make an argument based on it is going to be precarious. I blame his estimates in the precise degree that I blame yours. They can't both be accurate, but both can be precise, within the precision allowed by the guesswork involved, especially from 40 years in the event's future.
And of course the wiki says 1/2 of the melted, or most of it melted, or the top 1.5 meters melted. Take your choice, I guess.
But some measurements quoted from the wiki:
Somehow, it seems to me that we're not seeing meaningful comparisons with some of the numbers you cited.
Fortunately, for this we don't really have to guess, for there is the witness of the video cameras descending through the reactor a couple of years later when the dismantlement began. I'll leave that to speak for itself. See, for example,
Even better with regard to the top of the reactor is this from the PBS Frontline [EDT: Not Frontline, but The American Experience] program (see 4:20 ff):
(BTW, I'd recommend watching the latter entire program; it's sort of gripping, especially in it's detail about the personalities involved and the personal heroism of Jimmy Carter (who was a nuclear engineer in the Navy) in visiting the site.)
How exactly does that fare against your summary:
jj said:
Yeah, I know. The guy on the air claimed something more like "melted completely down", not "the top 10% of the reactor core split the zirconium casings", which is more accurate.
It seems to me that you're playing the same alarmist game. Given your clear escape from context in arguing about the effective magnitude of the New Madrid quakes in Georgia, I have to presume you went looking for an argument.
So when the data is all straightened out, and is testable and verifiable, let me know, ok?
First of all, you certainly know as well as I that we have all the data on these things we're ever going to get. It's not likely going to improve with tons more meta-analysis, just as we're never going to really know whether anyone besides the 51 or so officially logged deaths for Chernobyl is anything like the correct number. To quote official sources is one thing; to face the reality that the officials had to cope with at the time is altogether another, not even contemplating effects of the massive Soviet paranoia toward adverse news.
It seems to me I'm not an alarmist; I am an advocate of nuclear power, particularly some of the 4th generation designs. OTOH, I am also not an advocate of white-washing the actual experiences of the past. That has never been a successful way to promote anything, IMO. Minimizing the lessons which an unlucky (or perhaps unprepared) past have so freely given to us is just plain dumb, in my estimation.
No it isn't. Shadron said 13 megacuries of Xenon, Wiki says 2.5 megacuries of Xenon and Krypton, but doesn't mention that the majority of that (over 2 megacuries) was Xenon (see here, volume II part 2, page 48 of the pdf). Shadron said 17 curies of Iodine, Wiki says 15.
Shadron's numbers may not have been exactly accurate (although since they're estimates there may well be other sources giving different numbers), but he's not even close to an order of magnitude off, let alone 2.5 of them. If you're going to sneer at those who object, perhaps you should try checking your own arguments first.
I'm sorry, but if you bother to read the wiki, at least the wiki in place when I replied, the numbers are all over the place. Furthermore, if you read the results of actual measured contamination in the ecosystem, it's not commensurate with most of the claims, either.
For reasons that I certainly can't justify, different people's numbers are all over the continent, so to speak.
Well, actually, I was at the edge of the so-called plume (in New Jersey), more or less directly downwind, and the guys over in our physics department could measure the stuff, but you know as well as I do that the way they measured it was by observing a slight increase in a couple of beta decay energies. In terms of biological load, it was measurable. Barely. In terms of comparison to background, it wasn't significant, and the level of caesium wasn't high enough to worry about accumulation in bones, etc. Compared to Bikini, etc, it was off the bottom of the graph.
My half-brother was closer. He and his wife were in the voluntary evacuation area. His "cold war" equipment (he was ex-military, working at a military base) wasn't capable of noticing. He didn't evacuate. His neighbors didn't, either, I know, I called him to ask the day after. His son was downriver (Maryland, not in the air plume), with similar "cold war" kinds of equipment, and didn't notice much of anything either, beyond some hysterical people.
So, actually, yeah, I was on the edge of it, and I know people who were in the middle of it, (no, not working at the plant) so I do have some anecdotal level of information to deal with it.
The news media hyped the (Rule-10) out of it.
ETA: Oh, and the official sources I saw (it's been a while) are no more consistant than anything else. (sigh)
No, they are not. I just repeated the exact numbers you quoted in your post. Wiki, both now and when you quoted it, said 2.5 megacuries of Xenon and Krypton, and 15 curies of Iodine (those numbers are from the report I also linked which you apparently didn't bother looking at, so you really shouldn't be trying to get in an argument about who hasn't read what). Shadron said 13 megacuries of Xenon and 17 curies of Iodine. There can be absolutely no dispute about these numbers, since they are still right there in the posts for all to see. You then claimed that Shadron had given numbers 2.5 orders of magnitude higher than stated in Wiki. This is very obviously not true. There can also be absolutely no dispute about that either. The only sane thing to do is to simply admit you were wrong on this point.
I don't know about any specific projects at the moment, but as someone who works at a particle accelerator I can confidently say that accelerator driven reactors are a very long way off being able to provide commercial power because accelerators are not anywhere near reliable enough. For example, where I work we finally managed to get above 48 hours MTBF (mean time between failure) last year. Or take the LHC, which has managed a single run of over 100 hours with stable beam, and had 33 beam dumps during a 2 month period last year ("The LHC from commissioning to operation",
Mike Lamont, IPAC 2011). That will of course improve as commissioning continues, but after over a year of operation the most advanced particle accelerator in the world is nowhere near reliable enough for a power plant.
Accelerator driven reactors are a great idea for the future, since they have essentially no safety concerns other than waste, but they're not really something we can except to see in commercial use any time in the near future.
Yes. Providing that the use of neutrons can be turned on and off that way. My understanding, though, is that once you change 232thorium into 233uranium, it is fissile and starts producing it's own neutrons upon fission. I can't imagine that the researchers promoting this idea aren't aware of that, so there is probably something faulty in my understanding. If you know what it is, please enlighten me.
The Liquid Fluoride Thorium Reactor (LFTR) has a similar feature. As with all MSR reactors, it allows for the continuous chemical removal of decay products from the fuel (as it is liquid). Therefore, when you pull the plug* on the reactor and drain the fuel into non-critical storage, the heat stops, since most of the heat-producing, decaying fission products have already been removed from the fuel and handled by the normal operating procedure. It is reported that a test reactor back in Weinburg's days was shut off in this way on the weekends when there was no one to tend it. On Monday, they'd heat up the storage tanks to liquify the fuel and pump it back into the reactor, and it was good to go.
* - The "plug" is a literal plug of the fuel which was cooled in the pipe to the storage tanks, causing it to solidify. The cooling fan was power by the reactor's generation system, such that if the reactor failed, the fan would shut off, and no longer keep the plug from preventing the draining. It could presumably also be hooked to a seismograph which could open a drain. A false draining could be remedied in a few hours rather than months.
I wish I had your understanding, never mind the knowledge to confirm or deny any part of your analysis. My point in posting was, as I'm sure you appreciate, to bring a potentially important advance in nuclear energy production to the table, so to speak.
I have previously been a nuclear power "sceptic" but I'm at the stage where I see it as the only real option for large scale, reliable energy production. In an ideal world renewables would be all we needed but it's not that world it's the real world and in Europe particularly we need to identify energy sources that are domestic rather than imported from the former eastern bloc.
If it is safe or even only relatively safe, nuclear has to be pursued.
Again, you pick one set of numbers out of the wiki, I pick another.
Let's see, one claimed to be measuring argon, one claimed to be measuring all noble gases, one claimed to be measuring xenon, (and there were some more as well that I don't recall), and I seriously doubt that you can have less noble gas emission (in terms of radioactivity), for instance, than you have xenon emissions alone. The "information", as I said in the original comment wherein I pointed out that the measurements purported to measure different things, range over about 2.5 orders of magnitude. All of your objections will not change this.
That does not make me wrong, it makes the wiki rather horridly inconsistant, but I think I said that 3 or 6 times already.
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. My point in posting was, as I'm sure you appreciate, to bring a potentially important advance in nuclear energy production to the table, so to speak.