What does your cite of an incident from the 1950’s have to do with anything currently being discussed in this thread? How does it demonstrate that the design (which is on public record) is or isn’t more dangerous than the Chernobyl design, for instance? How does it demonstrate that the plants being discussed in Japan could or could not potentially cause more harm if there is in fact a melt down than Chernobyl? How does your cite show that (presumably) the Japanese people are being lied to concerning safety measures in their plant, or that we have to take all this at ‘face value’??
In short, what the hell does it have to do with anything in this thread or with the assertion I was responding too??
My cite merely backed my claim that sometimes ironclad assertions by the authorities are not what they are claimed to be. Your posts have all been “we have assertions by the authorities!” Yes, if the science is perfectly understood, which we know hasn’t always been the case, and if the authorities are acting in good faith, which we know hasn’t always been the case, you’re probably right.
You are confusing the two ways that the term “meltdown” is used. So are many, if not the majority, of news accounts I’ve seen, so it’s understandable. But it’s the core (ho, ho) of the confusion.
The fuel rods in a working reactor need to be constantly cooled. If the cooling fails they will generate so much heat that they will begin to melt, rendering them useless and dangerous. It seems certain that more than one set of fuel rods in Japan have started to melt. Pumping in seawater is a de factor admission of that, since that will destroy the reactor. Many people and many news articles have referred to that as a meltdown.
That’s bad, but the whole point of a containment dome is that melted fuel rods are contained within so that the environment is not placed in danger. Chernobyl did not have a containment dome, which sends everyone in the industry gibbering at the thought. AFAIK, every modern commercial power plant not built under that specific design has containment domes. That’s what makes Chernobyl special and different.
Is there a danger that the superheated fuel rods could break the containment dome? Yes. That’s also called a meltdown, more popularly, the so-called China Syndrome. That’s also what is so highly unlikely, especially so in this case where the engineers are actively pumping water onto the rods to keep them below the danger point. Nobody is yet 100% certain that this won’t take place but the work being done seems to be correct.
The first type of melt down has occurred. The second type is highly unlikely to. The first type is serious, mostly because some venting of radioactivity seems inevitable. But it is not a huge health or environmental crisis. The second would be a gigantic health and environmental crisis, but it has never occurred outside of Chernobyl. (Including Three Mile Island.)
Unless we can agree on these two definitions, we’ll be talking past one another. The rods have melted, but there has been no containment breach is a better way of phrasing it.
At a guess a fluu-blown meltdown of the core which then burns its way out of the reactor vessel and lands on the containment room floor. Hopefully the containment vessel would do what it is meant to do and it goes no further.
Not saying this will happen. Indeed I have no idea of the chances of that happening but seems the worst-case scenario. (Well, it’d be worse if the motlen mess breached the containment vessel.)
Reasonable bad breaks? The core melts down; as they continue to pour water on it and vent the resulting steam, we would see sufficient release of radioactive steam that people shouldn’t be within several dozen kilometers downwind. The Low pressure system CNN and BBC forecasts show running up the east coast there causes wrap-around winds blowing from the northeast toward Tokyo. People in Tokyo are advised to take iodine pills and the cancer rate over the next few decades is maybe 5% higher than normal… The cores in the dead reactors are rusting piles of miscellaneous metals, or a molten glob of cooling heavy metals in the floor of the containement building. The Nuclear Power utility has to maintain dead containment bukdings, probably by encasing them in even larger containment buildings. FOr the next decade, the government spends a fortune testing agricultural products of the area for contamination - not because they are but to reassure nervous consumers.
Which of course proves NOTHING. And has no relevance to the discussion.
Um, no…my assertions, such as they have been, are about asking for cites to back up statements by others. However, that said, we can, you know, LOOK AT THE FUCKING DESIGNS AND COMPARE AND CONTRAST. We don’t have to take the word of authorities, though simply handwaving that in the past some authorities haven’t been honest with the public really says nothing about this current situation and might only be relevant in so far as it was the Soviets who initially tried to cover up the full extent of the disaster at Chernobyl, and that it was their system of state controlled media that allowed them to do so.
The design of both plants is public knowledge (now…it wasn’t in the case of the Soviets before the incident IIRC). I don’t think the authorities acting or not acting in good faith has much relevance to this discussion. And while I am probably right (snort) all I’ve REALLY asked in this thread is for people to back up their assertions…I was just lurking in the thread before that to check my own perceptions and perhaps learn something.
reactor 2 at Fukushima Dai-ichi has gone totally dry at least twice and is unable to be refilled adequately. officials haven’t ruled out total meltdown possibilities and haven’t said the vessels are undamaged.
Yeah, but it came close (for some definitions of “close”) to occurring at TMI. The worst case would be what’s called a cold water accident – the molten core bores its way down to the water table and the resulting steam explosion is not unlike a dirty bomb.
So you want cites that some things might not be fully understood and that the published plans are indeed faithful to the actual onsite plant and that no one’s ever acted in bad faith or covered their butts? Nobody can meet that standard.
In many industrial accidents, the thing that "can’t " happen happens, and you know it. I could cite reports all day in which engineers said “x cannot happen” and x then ensued, and you’d say each one of them wasn’t this plant in this earthquake. And we’d both be right.
My point is that human assertions of complete understanding and control are not always true. That’s an unassailable point.
Another difference with Chernobyl is that the world is watching, this time. Nobody but the Soviets themselves were allowed to monitor what was happening at Chernobyl, but Japan is allowing and welcoming foreign assistance. So you’d have to have a conspiracy of not only the Japanese government, but all of the other governments in the developed world to mislead the public this time.
No, I want cites to backup the assertions being made that I quoted earlier. How hard is this to understand?? If they can’t be backed up, then the poster of those assertions should back down and say that they were his own out of the ass assertions and have no current relation to reality. I’d accept that.
Then my advice is don’t make a solid assertion of fact in GQ. Save that for GD where things aren’t as rigid.
And my assertion is that if someone makes a statement of fact IN THIS FORUM, then it shouldn’t be a big surprise to be asked to back it up with SOMETHING. I don’t see this as being an unreasonable request and I’m truly baffled by your posts in this thread.
Three Mile Island was bad. The core was largely exposed and without coolant for hours. About fours into the accident fully half the uranium in the core had melted (they did not know that at the time). Basically, you would be hard pressed to come up with something worse to do to the reactor.
You also had radioactive coolant spilling into the containment vessel.
TMI was bad to be sure yet, as designed, the public was protected.
IIRC, according to the IAEA scale of 1-7 (7 being the worst), the Japanese are at 4, TMI was a 5 and Chernobyl was a 7.
Your cold water accident would require the core to breach the reactor then breach the containment vessel then melt down to the water table. China Syndrome basically. It didn’t happen at TMI so I doubt it can happen in a Western reactor.
Well, reading back, I see the original claim was “if worst comes to worst, it will be worse than Chernobyl.” I guess that we’re interpreting what “worst comes to worst” means. That’s about as factual as the initial claim got…seems kind of fuzzy to me. I mean, the worst that could happen is our understanding of the system is dead wrong, and your confidence in it is misplaced. But I guess you regard that as impossible.
Well, TMI didn’t stop by itself. The disaster had been exacerbated by human intervention (particularly, by the plant operators developing an incorrect mental model of what was really going on) and, improbably enough TMI was stopped by human intervention – by that rarest kind of human intervention, someone new to the scene who figured out that the mental model was flawed.
Everyone here is talking about core-melting, design, and radiation release, which was generally subsumed in OP.
But now since radiation release is assuming center stage in this thread, what are the health-affecting parameters of any foreseeable meltdown?
Assuming that the tsunami hadn’t done any damage to the facility and the control rods had been dropped, how long would the normal cooling systems taken to cool the residual radiation down? Would we still be waiting for days like we have been?
Chernobyl was about a raging fire sending the actual radioactive particles into the air. The only radioactive things going into the air from Fukushima now is steam.
tl;dr: Worst case scenario - mildly radioactive steam is vented, NO HEALTH RISKS, NOTHING HAPPENS.