Slashdot Mirror
Things Get Worse at Fukushima
An anonymous reader writes "Radiation levels are skyrocketing around Japan's Fukushima nuclear plant as reports indicate that a radioactive core has overheated and melted through its containment vessel and onto a concrete floor. Radiation levels inside reactor two were recently gauged at 1,000 millisieverts per hour — a level so high that workers could only remain in the area for 15 minutes under current exposure guidelines."
This is part of the planned failure mode of the reactor. To be sure, it's fairly far on the "stuff is breaking" scale, and there are definite consequences (such as fears of leakage into groundwater). But this is not going to be a Chernobyl-level catastrophe.
However, fingers crossed that nobody else dies. Japan's already had enough fatalities this month.
Wait! I learned everything I know from Slashdot, and Slashdot says nuclear power is safe and no one will get hurt.
None of this leaking stuff can be happening. La-la-la-la . . . I can't hear you!
Just to be clear, they are absolutely not implying it has melted through the containment, but, rather, the reactor pressure vessel.
They've set back nuclear energy for decades, at a time when we most need it.
Guess we had better get used to more carbon dioxide.
SJW: Someone who has run out of real oppression, and has to fake it.
There are, as well, media sources that say this *isn't* so, and that this is mostly a Media Hysteria. For example: http://www.theregister.co.uk/2011/03/29/tv_news_goes_hollywood/
If you want news from today, you have to come back tomorrow.
This disaster will very likely change the way that nuclear power generation plants are approved and evaluated in the future. Unfortunately, a promising technology will almost certainly be set back, perhaps irreparably. The silver lining, however, is that alternative nuclear technologies may finally get a fair shake. Alternate fuels and reactor types offer so many possibilities to possibly exceed the efficiency and safety levels that we put up with today but have thus far been unable to obtain funding compared to the currently developed reactors. That confidence in our current strategy is being eroded rapidly. This isn't some second-rate system like Chernobyl, it is close-to-state-of-the-art.
"Here Lies Philip J. Fry, named for his uncle, to carry on his spirit"
This is what I see on this board.
It is an interesting mix to be sure.
The situation seems very bad, but headlines screaming "radiation at 10,000,000 times the safe limit" (which turned out to be wrong) are not helping.
Worse seems to be the nuclear fanboys ignoring the fact that that plant is fsked, in precisely the manner that antinuclear folks said could and eventually would happen.
I am very small, utmostly microscopic.
This is speculation by ONE guy in an article in the Guardian, hardly a bastion of calm, rational, journalism. NONE of the other usual online sources have corroborated this at all.
An actual meltdown, with the core sitting on the floor of the building, would be front page news across the world, yet only this one article says this is the case.
It's actually one red square - the measurement was off by a factor of 100 and later corrected.
http://www.eimai.in/incorrect-measurements-that-led-to-alarm-in-fukushima/3348/
"I zero-index my hamsters" - Willtor (147206)
The article above seems to be fear-mongering. This washington post article discusses what seems to be a more plausible failure mode. Apparently there are gaskets around the control rod penetrations in the bottom of the vessel, and the temperature may have increased enough to damage them allowing primary water to escape into the concrete containment structure. There are also many other penetrations in the vessel for plumbing that may have been damaged during the quake.
Our sun, a nuclear fusion source which is already working reliably for more than 5 billion years, produces an extreme amount of energy. Within 6 hours, deserts on Earth receive more solar energy than we use in a whole year globally. Why do we keep ignore this most power full energy source? For the world energy demand (18.000 TWh) we need only a surface area of 188 x 188 square miles with Concentrated Solar Plants. This is a small thumbnail on the map of Africa. Germany has seen the light and is investing 500 billion euro's in Desertec. A CSP plant runs 24 x 7 hours on full power (even when the sun is away because it can store sun heat in molten salt). These CSP plants can easily replace nuclear and coal power plants.
And they probably don't know either.
The reactor may have melted through the base of its pressure vessel, but it's hard to tell. The high radiation levels could either be from a melt-through or from a leak as attempts are made to force water into the reactor pressure vessel. The latest JAIF status report contains almost all the hard data that's coming out. Everything else is secondary speculation based on that limited data.
No data seems to be available about pressure or temperature inside the reactor. That's listed as "unknown" for unit 2. The sensors involved were probably destroyed in one of the fires, explosions, or building collapses. Pressure in the containment vessel for unit 2 is listed as "low", whatever that means.
A full meltdown is now a real possibility. The JAIF chart has been showing "Fuel rods exposed partially or fully" for units 1, 2, and 3 for ten days now. Reactor pressure vessels are tough, as are containment structures, but ten days of no core cooling is well beyond design limits.
Understand that the water spraying operation refers to the containment structure, which is normally dry. Inside the containment is the reactor pressure vessel, which is a boiler. Getting water inside there, which is needed to cover the core and achieve cold shutdown, requires forcing it in against steam pressure. This has to be done in a highly radioactive environment, in a fire-ruined building where the walls and beams have collapsed, the pumps are damaged, and valves which are usually operated remotely have to be operated by people turning handwheels. Some people are trying very hard to do that. Some of them will probably die. If they succeed, there will be a local mess, but it will be manageable. If they fail, there will be a meltdown.
160,000 three mile islands you mean.
it's now 10% of chernobyl, but hey, who's counting? this is slashdot. we're just denying.
https://www.nytimes.com/2011/03/30/world/asia/30japan.html
nuclear power: it's safer than ponies.
Interestingly enough, every one of those but #6 is true.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
This misinformation has been bandied about quite a bit, but the fact is that while Reactor 1 had reached the end of its operating license in March, the Japanese government had actually just extended the license for another 10 years in February. The "entire complex" was not by any means scheduled for shutdown, particularly units 5 and 6, which are undamaged and will likely be restarted at some point.
Paraphrased since it was hours ago and I was driving... "Traces of plutonium have been found around the Fukushima site, and although the amounts discovered were no higher than if the soil samples were taken from any random soil around the world, the scientists determined that the specific isotopes of plutonium found were from the plant." They then continued to explain why it was super dangerous.
What I heard was "DANGER DANGER! The soil around the Fukushima site is identical to the soil in your backyard. That's not a good thing! You must Fear It! Fear It!"
Construction on the Fukishima reactor began in 1967 (wikipage). It is easy to forget that Plate Tectonics was only accepted as a reasonable explanation of geological phenomenon in the 1960's. According to this excellent New York Times article,
"After an advisory group issued nonbinding recommendations in 2002, Tokyo Electric Power Company, the plant owner and Japan’s biggest utility, raised its maximum projected tsunami at Fukushima Daiichi to between 17.7 and 18.7 feet — considerably higher than the 13-foot-high bluff. Yet the company appeared to respond only by raising the level of an electric pump near the coast by 8 inches, presumably to protect it from high water, regulators said."
The tsunami that overwhelmed the plant recently was 46 feet high, far higher than anything they seemed to expect. If you read the NYTimes article, you get a sense that the nuclear safety bureaucracy hadn't adequately integrated modern plate tectonic theory into its safety programs. The 18 foot high maximum tsunami prediction is symptomatic of this.
From the article, it seems that Japan had based its tsunami predictions on historical records, instead of predictions from Plate Tectonic Theory. Computer simulations of plate movement would have given far larger predictions for maximum tsunami heights, predictions that would have agreed with the height of the recent tsunami. I think a strong argument can be made that Japan's nuclear bureaucracy had not taken into account modern Plate Tectonic Theory in its safety practices. They seem to have instead relied on past records of earthquakes and tsunamis. I am not suggesting that individual people were unaware of Plate Tectonic Theory, but instead that their bureaucratic rules didn't seem to acknowledge it. Since construction on the reactor began in 1967, planning of the reactor must have begun much earlier. It is easy to imagine that the initial reactor designers were unaware of the Theory of Plate Tectonics and its implications.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
Posted this above as well, but Unit 1 at Fukushima had just been relicensed for another 10 years in February.
The fact of the matter is that a utility will always apply for an extended operating license and will almost certainly get one. The only plant shutdowns I know of in the US, apart from TMI Unit 2, were when something too expensive to repair needed replacement, such as the ComEd Zion plant outside Chicago, which needed a new $460 million steam generator. So since there is so much better in the way of designs available, why aren't utilities rushing to replace these ancient reactors instead of asking for extended licenses, you ask? Economics of course - an existing plant is almost all sunk cost, and the utilities are in business to make money. They will build new reactors only to add capacity, and they will build the cheapest design they are permitted to.
My main objection to nuclear power is that these plants are operated by businesses. Unlike a solar farm or even a coal plant, the worst case failure for a nuclear plant is very, very bad. You have a business trying to maximize profit knowing that the worst case failure costs will be shifted to the taxpayer. This is a recipe for disaster. I have no issues at all with the state of reactor technology, and the US military operates dozens of reactors that *move around* and has for 50 years without a major accident (the Russians haven't had as much success there, though). If these things were being operated by some agency like the military with those levels of discipline, perhaps we could all rest assured. When it's some utility executive who wants a bigger bonus, I am not at all confident.
That was The Guardian. This is what the real BBC had to say on the subject.
Meanwhile, Yes, Prime Minister had a few things to say about the press:
"Don't tell me about the press. I know exactly who reads the papers: The Daily Mirror is read by people who think they run the country, The Guardian is read by people who think they ought to run the country, The Times is read by the people who actually do run the country, The Daily Mail is read by the wives of the people who run the country, The Financial Times is read by people who own the country, The Morning Star is read by people who think the country ought to be run by another country, And The Daily Telegraph is read by people who think it is."
"Prime Minister, what about the people who read The Sun?"
"Sun readers don't care who runs the country, as long as she's got big tits."
I realize this was not a chemical reaction, however, I still can't figure out that reaction was stopped at the time of earthquake according to various sources. Graphite rods were inserted into the core to stop the reaction.
So where is this heat coming from. Is the fission on going, wouldn't that mean the reaction wasn't stopped, it is still on going!
Can someone explain this to me?
When a Uranium atom splits by fission, it leaves behind two unstable isotopes. These isotopes soon undergo radioactive decay themselves. These decays produce a significant amount of heat, which can't be "turned off" because it is natural radioactive decay (as opposed to the original induced fission, which can be stopped by absorbing the neutrons which cause fission). The fuel rods are not merely hot and simply need to be cooled off - they are still generating their own internal heat due to these natural decays. The only way to get rid of these decaying isotopes is to wait for them to decay naturally, which is an exponential process.
Some of the isotopes have a short half life, which causes them to generate a lot of heat, but this large heat load decays away quickly and is gone after a couple days. A majority of the isotopes have half-lives in the years to decades range, which means they produce a moderate amount of heat for several years, which is why spent fuel needs to be stored underwater. Once the fuel is about 10 years out, enough isotopes have decayed that it can remain at safe temperature just by radiative cooling, and so can be stored in dry storage containers.