[Herra Tohtori]

Klaustrophobia already covered this, but only the pools at No. 4, 5, and 6 have a hope in hell of doing that; the rest contain only spent fuel, which cannot go critical inside the reactor. The reactor has a geometry designed to encourage criticality, since that is what generates most of the heat.  And if it's so poisoned by fission products it can't go critical in a place where it is encouraged to do so, how can it do so laying in a pool?

The risk is probably very small and would require all the used fuel rods to melt and accumulate in one thick puddle on the floor of the pool.

Depending on the geometry of the floor of the pool, this might be impossible or not. I doubt it's going to happen, but the officials have mentioned the probability is not zero, and I'm certainly not qualified to revoke that assessment in any way.

Although pools 5 and 6 are at higher temperatures than normal (60 C instead of 25), I wouldn't be too worried about them yet.  The big question is pool 4, which may have gone completely dry (apparently the NRC seems to think so).  Certainly, some of the rods there were exposed for several hours (the two fires).

Yeah, pool #4 is the biggest problem right now. They have also managed to get electricity to the number two reactor, and other reactors should soon follow, so they now have at least power to possibly run the fluid circulation pumps, assuming those systems are not excessively damaged.

[Androgeos Exeunt]

I hope people know dropping iodine won't really help you when nuclear fallout wafts into town.

Correct. You must use vodka instead.

Does it really work?

[NGTM-1R]

Does it really work?

If you have to do the walking-ghost thing, I can think of worse ways to ease it.

[Klaustrophobia]

i received a bit of info at work today that suggests to me the fuel pool did in fact go dry.  as herra said, it isn't COMPLETELY impossible for the fuel to go critical.  subcriticality is less about fission product poisons than it is about lack of fissile material, so it COULD go critical just by sheer mass of fuel from the pool.  provided it melts, all runs together, solidifies into a sphere, contains some moderator, etc.  we can't know for sure unless it actually does go critical, or with about a decade of modeling and calculations.  hopefully we don't find out.

iodine tablets work against ONE particularly dangerous method of uptake for internal dose.  they are very effective against it, but do nothing against external dose.  rules about distributing it within X miles of nuke plants is as much placebo as actual effect (one that unfortunately is necessary and i actually agree with).  if you might potentially be exposed to airborne radioactive contaminants, yes go ahead and pop some iodine.  it can only help.  but don't think that makes you immune.  and ANY form of iodine intake will do.  you don't have to buy the pills.  dump a bunch of iodized salt on your lunch. 

[Herra Tohtori]

To be more specific, iodine tablets prevent the accumulation of radioactive iodine in the body by saturating it with regular iodine (specifically thyroid gland).

The radioactive iodine isotopes that temporarily enters the body will still do damage until it naturally exits - the only thing regular iodine does is prevent long term exposure from that particular element.

Oh and I don't know about other places, but in Finland, food salt is laced with iodine for this exact reason. It provides a certain source of continuous, sufficient iodine intake, which prevents iodine deficiency.

The thing is, if a person has been deprived of iodine and then exposed to radioactive iodine, the body basically takes it all in and stores it to thyroid gland, which is not exactly a good thing for health. So basically, if your iodine intake is already keeping you fully supplied with it, additional iodine tablets will have less of an effect anyway.


It's best to just avoid fallout altogether by protective gear or re-location, anyway.

[Kosh]

Germany is getting out of nukes completely because of this


Let the windmill chasing begin.

[ssmit132]

It was inevitable, really.

Would Germany even be at risk of similar earthquakes?

[karajorma]

The prevailing winds blow away from China across the Pacific.  The Chinese have no reason to be worried at all.

I know. It's pretty unlikely that the winds would blow in the right direction to cause a problem but if you live 600-700 miles from the site I can see a reason for concern at least. It's much stranger for America to be worried.

[BlueFlames]

The prevailing winds blow away from China across the Pacific.  The Chinese have no reason to be worried at all.

I know. It's pretty unlikely that the winds would blow in the right direction to cause a problem but if you live 600-700 miles from the site I can see a reason for concern at least. It's much stranger for America to be worried.

We have twenty-four hour cable news hammering us with any tenuous theory/fiction that they can find that suggests the Daiichi plant will be the next Chernobyl.  It's an irresponsible ploy to drive up ratings, since people watch the news, when there's a crisis that they believe will affect them.  The round-the-clock news stations will milk the fear for absolutely as long as possible, until another disaster occurs or the ratings return to their normal levels, despite the fear-mongering.

Incidentally, I heard the phrase, "China Syndrome" at work today and almost popped a vein for the sheer stupidity of the conversation in which it was mentioned.

[Androgeos Exeunt]

The prevailing winds blow away from China across the Pacific.  The Chinese have no reason to be worried at all.

You may be surprised, but pretty much the whole of Asia has banged their panic buttons to pieces. Only those who do their research see no reason to panic.

[newman]

Panic and bad PR the word "nuclear" produces at the moment aside, personally I'll be glad if this incident has an effect of us investing in infrastructure and research that allows us to gradually and eventually completely replace nuclear power. You can preach about people panicking and modern nuclear plants being safe in more tectonically stable parts of the world all you want; if the Fukushima incident proved anything it's the fact that there is -always- a set of circumstances you simply didn't account for.
I see a lot of people making fun of the people with anti-nuclear sentiments; the self-congratulatory "I'm so smart but the rest of the world doesn't understand my genius" attitude nearly every human on the planet has regarding some topic. Let me bottom line this for the aforementioned geniuses. I've been listening about nuclear power being safe for a better part of two decades. Yet in my relatively short 30 year long life I've now experienced two major nuclear incidents. Don't talk to me about safety, the only sane course of action is researching and developing infrastructure to eventually replace this inherently unsafe power generation method.

[Bobboau]

plant gets hit by the fifth strongest earthquake IN RECORDED HISTORY and has yet to actually cause any true damage and you call it "inherently unsafe" tell you what, you live 20 miles down stream of the hover dam on the day its hit by a 9.0 earthquake and tell me which is the safer technology. including this one, there have been a total of 3 major nuclear incidents seance the technology was invented, only one of them has caused any true havoc, your full of it man.

[newman]

Tell you what, go sell your smug genius to the families of the irradiated workers. While you're at it explain to them your concept of "true harm".
Also, if you can't discuss something without comments like "you're full of it", maybe you should grow up before entering a discussion. Rationalize your arguments in a civil manner or be dismissed as an immature kid. To be clear, I don't suggest we suddenly pull the plug on all nuclear power. I know full well we can't do that. But let's be realistic here: the world is run by people with money organized into structures, sometimes called lobbies. The nuclear lobby will have to be silent for a while, meaning now is a very good time to begin more serious research into better ways of power generation. I'm not Greenpeace so I'm not going to suggest we do away with what we have currently without having something to replace it. I'd just think that a safer way of generating power that doesn't include radioactive material would be a good thing, no? Things only get properly researched and implemented if there's a political will to do it.

[Herra Tohtori]

Mayhap it would be most productive to continue discussion about nuclear energy in a dedicated topic, but just a few pointers:

There's nothing inherently unsafe about nuclear power itself. Like most other energy extraction methods, it has a certain amount of issues that need to be addressed for safe and ecologically sustainable operation.

Evidently, the degree of redundancy in Fukushima was not sufficiently high, as all auxiliary methods of cooling the reactors and spent fuel pools were apparently knocked out as the diesel generators were incapacitated. In hindsight, this was a serious oversight, and it surprises me that the Japanese would have taken such a risk even back in 70's and not have upgraded the redundant safeguard systems to sufficient level, but Bobboau does have a point - considering the plant was hit by a major earthquake and the subsequent tsunami whose height overrode the protective barriers, there has been remarkably little damage - mainly because the containment buildings of the plant have mostly done their job, since so far it seems that releases of radioactive materials have been in small quantities and locally, as opposed to the case of Chernobyl where there was no containment building and the reactor blew its top away as it went critical, exposing the innards to atmosphere and causing hydrogen explosion and graphite fire that spread a lot of particles in the air with the smoke.

Compared to that event, Fukushima events have been very minor and caused by a good reason, as opposed to Chernobyl which was entirely caused by fundamental reactor design oversights and human error in operating the reactor; in both cases, insufficient safety measures have obviously contributed to the events, but hey, at least the Japanese HAD safety measures - the tsunami just happened to be bigger than anticipated. Plus the main protection against radioactive emissions have mostly worked as intended so far, even if cooling system redundancies have been knocked out.

TL;DR

Problem here is not so much nuclear power being unsafe, but an underestimation of the risks of natural hazards and the subsequently underwhelming protective measures taken against them.

[AtomicClucker]

Nuclear power will always have inherent risk and it also depends on the region where it's located. Where I live (yes, Utah) the governor is still insisting on building a nuke plant, especially when our beautiful state has a truly bad record of safety mandates, enforcement, and falsified building permits. Between the exploding gas refineries, leaking chemical plants, and bad construction permits; If the people were competent, I wouldn't be nervous, but for said human reasons, there's a serious consideration to leave if they actually approve it.

[newman]

There's nothing inherently unsafe about nuclear power itself.

Anything that has a snowball's chance in hell of humans coming in contact with nuclear material is potentially unsafe. You know, a few years ago I'd be right in your camp defending nuclear power. I was younger, cocky, and so damn sure that there's always a way to account for every possible eventuality. There isn't.

[Bobboau]

Tell you what, go sell your smug genius to the families of the irradiated workers. While you're at it explain to them your concept of "true harm".

right after you talk to a few families who have had loved ones burred alive in a coal mine, and guess what there are a **** ton more of them.

but I guess you are the only person who is allowed to be a genius, either that or you think it's some sort of insult, you know who else talks like that creationists, you have yet to justify your fearmongering tone so maybe you should learn to to grow up a little rather than running around like the sky is falling and everyone who doesn't agree with you does so only because they are arrogant and not educated.

[newman]

Seriously man, why do you keep insisting on personal attacks? Is that the only way you can rationalize your arguments? Pretty much all I'm saying here is that now's a great time to start some more serious R&D into safer power generation ways, since the political climate for that couldn't be better right now. I really don't understand what's with the OMG STONE THE BASTARD thing?

[headdie]

Nuclear fission is about as unsafe as we have ever gone in terms of power generation, it is literally the mechanics of a nuclear bomb with the breaks applied.  the thing is we have learned a large number of lessons about how to use it and minimize the risks, though constant vigilance and rigorous maintenance will always be required up to the point in time where the there is no nuclear material on the site.

I think the problem here is the questionable sanity in constructing a fission plant in a country that straddles 3 tectonic plates and is very close to the fault line for a 4th.  I know i am talking in hind sight and what a wonderful thing it is and i know that Japan has some unique energy issues but it still strikes me as an odd decision to make.

[QuantumDelta]

Would a tidal energy project suggestion and note that it would have been super-effective in the last few weeks be a bad idea?

That said, modern nuclear is seriously really safe.
1970s nuclear is not modern.