russ_watters said:But we're not talking about radioactive scrap metal improperly left in a dump somewhere, we're talking about a French storage facility that even you have acknowledge you expect will not be compromised.
So I'll ask again: If the French facility poses no significant risk over 100 years
And if your answer is still no, then tell me what the expected harm is.
So, "safe", but not "safe enough"?nikkkom said:Yes, I expect that "not compromised" scenario is more likely than "compromised". This does not mean I think it's safe enough.
I disagree. The chances of compromise are low; but if it would happen, the consequences can be very bad.
What do you mean? A terrorist bomb? How big would it have to be to do that? How many people would the bomb kill vs the fallout? How likely is this percentagewise?Hypothetical example: tons of highly radioactive glass pulverized by an explosion in Paris.
All with materials for medical use. I think their benefit in cancer treatment is so large that we should continue to use them.nikkkom said:A selection of events since 2010:
That is not an argument without a quantitative assessment. Literally every action can cause very bad consequences, but usually the probability is small.nikkkom said:The chances of compromise are low; but if it would happen, the consequences can be very bad.
mfb said:All with materials for medical use. I think their benefit in cancer treatment is so large that we should continue to use them.
russ_watters said:What do you mean? A terrorist bomb? How big would it have to be to do that?
Then what exactly are we discussing?nikkkom said:I used these events to demonstrate that highly radioactive objects are being lost and sometimes kill people from time to time, despite all efforts to make that very improbable. I'm not making an argument that we should stop using these sources.
And a nuclear weapon to crack the container around it? We had the Castor test videos a while ago. They survive nearly everything. You can let a plane or a full train crash into them and they'll survive without leaks.nikkkom said:A 5 mm thick steel vessel? About 10-20 kg of high explosive would do.
mfb said:Then what exactly are we discussing?
And a nuclear weapon to crack the container around it? We had the Castor test videos a while ago. They survive nearly everything. You can let a plane or a full train crash into them and they'll survive without leaks.
In Germany they are stored in similar casks, and I'm quite sure France doesn't do that completely different. You don't leave things with potentially lethal radiation standing around freely.nikkkom said:UCs are not stored in casks by French. They are only transported in them.
No, you are just arguing that the fact that we can't keep medical waste safe means we should stop using nuclear power. It's like arguing that since we can't keep cars safe we should stop using planes... but keep using cars.nikkkom said:I used these events to demonstrate that highly radioactive objects are being lost and sometimes kill people from time to time, despite all efforts to make that very improbable. I'm not making an argument that we should stop using these sources.
russ_watters said:No, you are just arguing that the fact that we can't keep medical waste safe means we should stop using nuclear power. It's like arguing that since we can't keep cars safe we should stop using planes... but keep using cars.
As mfb pointed out, the same argument could be made about literally anything; from driving a car to showering to walking down the stairs. No, I'm pretty sure he was attempting to make a direct comparison between the waste he cited and reactor waste -- as if all things "nuclear" are equally scary. It wasn't a coincidence that the waste incidents he cited were of radioactive waste.etudiant said:In fairness, I don't think that is his argument.
Rather he is arguing that stuff happens, despite the best efforts of dedicated people to prevent it.
What does that mean? If it is an excessive risk in the same way as car accidents and plane crashes are an excessive risk and we should work hard to mitigate the risk, I agree. If it is an excessive risk in that we shouldn't be using nuclear power, I disagree.The experience on nuclear power is around 1 catastrophic accident per 20,000 reactor years, counting Fukushima as one accident.
Note that excludes a whole bunch of lesser mishaps, WIPP, Juelich, Windscale, Monju etc.
That is arguably an excessive risk, given the extent of the potential contamination that results. [emphasis added]
My understanding is the new Gen III reactors meet that criteria:What is needed is a convincingly idiot proof design, something that can manage being turned off on request at any time, irrespective of conditions.
If that is not possible, nuclear will remain under a cloud imho.
https://en.wikipedia.org/wiki/Generation_III_reactorPassive nuclear safety is a safety feature of a nuclear reactor that does not require operator actions or electronic feedback in order to shut down safely in the event of a particular type of emergency (usually overheating resulting from a loss of coolant or loss of coolant flow). Such reactors tend to rely more on the engineering of components such that their predicted behaviour according to known laws of physics would slow, rather than accelerate, the nuclear reaction in such circumstances. This is in contrast to older-yet-common reactor designs, where the natural tendency for the reaction was to accelerate rapidly from increased temperatures, such that either electronic feedback or operator triggered intervention was necessary to prevent damage to the reactor.
If the wind had been different, Fukushima would have contaminated Tokyo to well beyond acceptable levels. Japan was stupidly lucky.russ_watters said:What does that mean? If it is an excessive risk in the same way as car accidents and plane crashes are an excessive risk and we should work hard to mitigate the risk, I agree. If it is an excessive risk in that we shouldn't be using nuclear power, I disagree.
My understanding is the new Gen III reactors meet that criteria:
https://en.wikipedia.org/wiki/Generation_III_reactor
What is "beyond acceptable levels" in mSv for the population?etudiant said:If the wind had been different, Fukushima would have contaminated Tokyo to well beyond acceptable levels. Japan was stupidly lucky.
It is not "country wrecking". In the worst case you get slightly higher cancer rates in some regions. And even that has much lower different risk than plane crashes or dam ruptures. Plane crashes and dam ruptures happen frequently. Nuclear accidents with relevant release of radioactivity do not. It doesn't make sense to compare the worst possible incidents without taking the risk into account.etudiant said:That underscores that a bad nuclear accident has country wrecking potential, something much worse than a plane crash or even a dam rupture.
What do you suggest to improve the situation? Replace nuclear power by what?etudiant said:I don't think that is an acceptable situation.
That's not even true. The exclusion zone at Chernobyl is smaller than the distance from Fukushima to Tokyo, but Fukushima released only a tenth as much radioactive material, and much less efficiently. Even still; what are the odds that the wind could have been the required direction? Winds at that latitude tend to travel west to east.etudiant said:If the wind had been different, Fukushima would have contaminated Tokyo to well beyond acceptable levels.
mfb gave the obvious answer, but I'll expand. People often seize up on one tiny aspect of a major event to call "lucky" or "unlucky". This is narrow-minded based on one's preferred perspective. But if you add up the "luck" from that day, I sure hope you would agree that 16,000 dead and hundreds in billions of damage from one of the worst natural disasters in recorded history make it an overall epically unlucky day for Japan.Japan was stupidly lucky.
Even with what you described wrong, you still didn't describe country-wrecking potential.That underscores that a bad nuclear accident has country wrecking potential, something much worse than a plane crash or even a dam rupture.
Does it? How often are once-a-millenia natural disasters likely to hit nuclear plants that are unprepared to handle them? There has *never* been an accident with wide/significant consequences outside the plant that happened for only human-caused reasons. Never! That isn't to say it won't ever happen, but Fukushima cannot be used as an example in the risk analysis of the vast majority of nuclear plants. Since the risk can't ever be zero we can't say what it is, but it is certainly much less than once every few decades. (Note: I used to be generous and let people include Chernobyl, but I'm tired of being generous when arguing with people who are being unreasonable.) (Note 2: TMI was classified level 5, but that's marginal based on the definition and the actual effects of TMI: https://en.wikipedia.org/wiki/Inter...ale#Level_5:_Accident_with_wider_consequences )...past performance suggests a disaster every few decades.
You've made at least three errors/exaggerations by a factor of ten+ each, described above. So if you re-calibrate your assessment to be a thousand times safer, does it become an acceptable situation? If not, again, what does that mean? Just saying a situation is not acceptable does not suggest a course of action.I don't think that is an acceptable situation.
C'mon. You're saying that just because it is more expensive than projected, it might be significantly less safe than projected? That's just silly. The safety features are what they are. They either exist or they don't (they exist).Maybe Gen III will be much safer, but the hugely painful construction delays and deficiencies observed to date in Finland and France suggest that not all projections turn out as expected.
Of course there is no endeavor in human affairs where all projections turn out as expected. Major offshore wind farm proposals for the US have been in place for decades and so far none are anywhere near construction. Many nuclear plants have been built in five years in China and so too the US decades ago. The delays seen in current US construction are in no small part due to malevolent regulation, where the NRC changed major requirements on a plant after it had approved the design and construction was well underway.etudiant said:...
Maybe Gen III will be much safer, but the hugely painful construction delays and deficiencies observed to date in Finland and France suggest that not all projections turn out as expected.
jim hardy said:in US there's a concept named "Probabilistic Risk Assessment"(PRA) , a mathematical process whereby 'things' are evaluated and prioritized according to their likelihood and severity of consequence.. The PRA experts can make it look pretty esoteric to one at my level.
When Japanese archeologists found those stones way up the hill that'd been engraved "do not build below here you'll get washed away"
and historians uncovered records of huge tidal waves within a thousand years
the PRA folks should've raised their 'likelihood' number for 'Loss of All AC' to 1/1000 per year or greater
which would make their ' likelihood X consequences ' product significant enough to warrant action .
I can understand how the 'Modest Proposal' that one's Sacred Diesels(that's how we plant guys feel about them) are at extreme risk would be met with initial disbelief and take some time to percolate up through a bureaucracy .
In that bureaucracy you have competing forces - a group whose job it is to think up "What If's" and another whose job it is to assess them and recommend action or dismissal. Most warrant dismissal or minimal action.
With a bureaucracy you get all the human complications of power, prestige and personalities. . So they're prone to herd behaviors like vacillation and immobility and stampede that promulgate the mistrust you mentioned.
Tepco's bureaucracy failed them on this one. That's why i maintain that they needed somebody near the bottom and close to the facts of the matter, to bypass the bureaucracy and apprise those near the top that their company's whole net worth hung on a decades old PRA equation with a badly underestimated Likelihood term in it .. .
And that's how i see it in my 'view from the bottom'.
We like to place blame on an individual.
I suppose someplace there's a bureaucrat mid level manager who agreed to send back for further study that challenge to their tsunami likelihood assumptions . He gets my vote. But he's surely a lot wiser now and has suffered plenty already in self recrimination so why flog him? Act on the lesson and go on.
My old mentor was expert at shredding red tape.
But if you're at the bottom and decide to bypass middle management you'd better be doggone sure you're right.
It could've been done for this one. Challenger too.
Oddly, Three Mile Island was caused by bureaucratic over-reaction to a hypothetical "What If" . Proximal blame for that one lies with whatever bureaucrat issued the edict to operators "Thou shalt not fill thy Pressurizer" , over some What-If called 'Pressurized Thermal Shock' . Not long afterward they changed their edict to "Thou shalt overfill thy Pressurizer and let the water run out onto thy floor". That left Crystal River operators with a wet containment to clean up but proved the point.
That's how large brained mammals and large organizations learn - through our mistakes.
Progress not perfection..Wow i really rambled on that one,, eh? Old guys just do that. Thanks for reading it.
This is very vague, and tough to attach meaning to it. Could you please be more specific about this?Greg Wurn said:...my concern is the increasing release of long lived radioactive isotopes being incorporated into the food chain and increasing the occurrence of cancer and mutation, it could be centuries before we fully understand the cost of what nuclear waste that has already been dumped in our oceans.
Vague concerns are not quantifiable and as such, so far nuclear has shown to be by far the safest way to boil large amounts of water. It isn't even close.Surely we can come up with safer ways to boil water, ones with much less risk.
Greg Wurn said:increasing the occurrence of cancer and mutation, it could be centuries before we fully understand the cost of what nuclear waste that has already been dumped in our oceans. Surely we can come up with safer ways to boil water, ones with much less risk.