Fukushima Reactor 1 melted down, 2 and 3 may have too
arstechnica.com
arstechnica.com
[1] The term is not officially defined by the International Atomic Energy Agency or by the U.S. Nuclear Regulatory Commission. However, it has been defined to mean the accidental melting of the core of a nuclear reactor, and is in common usage a reference to the core's either complete or partial collapse. "Core melt accident" and "partial core melt" are the analogous technical terms.
All reasonably modern reactors are built so that the reactor containment vessel completely contains the nuclear fuel, even during a period of full meltdown.
Even some basic cursory research on your part will help you understand the whys and hows.
GE/NRC documents also describe all these multiple layers of containment as an impenetrable defense-in-depth strategy.
Well, it turns out that the outer concrete building is mostly just environmental. The roof blows off and panels blow out. The pressure vessel has an assortment of through-holes for pipes and can't actually be trusted to hold in the temperatures and pressures seen by an actual meltdown. The concrete containment has an achilles' heel in this flimsy toroidial suppression pool.
When it came down to it, none of it was able to hold up to the temperatures and pressures and hydrogen explosions seen in this actual meltdown. Many of us were led to believe that inserting the control rods would immediately "stop the reaction" and prevent a meltdown from occurring.
These reactors melted down, all layers of containment were breached, radioactive materials were released into the environment, rendering a 20km radius uninhabitable for the forseeable future. And this is with the control rods in.
So sorry if people don't simply accept your word that such-and-such "completely contains the nuclear fuel, even during a period of full meltdown". I don't think you really know.
I'm not sure how much you were "led" to believe that, given that the control rods became fully inserted immediately after the earthquake, where they did in fact "stop the reaction". The entire crisis revolved around the removal of decay heat, not halting the reactors.
These reactors were presented as fail-safe systems. It turns out that they do not, in fact, fail into a safe state. They are more like airplanes over the ocean, literally months away from the nearest safe landing spot.
The entire crisis revolved around the removal of decay heat, not halting the reactors.
Perhaps you find that to be a meaningful distinction, but most people do not. Especially when the result is fundamentally similar: a meltdown, containment breach, evacuation, contaminated residential area, etc.
I mean this in the :-) nicest possible way :-), but I don't think you 'get it'.
The end result: a few people with radiation burns, a local shortage of electricity, and a release of radiation that - while significant - doesn't come close to the radiation released by the thousands of atomic bomb tests performed in Nevada this last century. An area will be uninhabitable for a while.
Lessons learned: nuclear power is pretty darn safe, although you shouldn't build 50s-style reactors near the coast in a tsunami zone. If you do, don't live nearby. No surprises there.
The most significant thing made apparent by this nuclear disaster, personally, has been how carefully authorities are forced to step around an uneducated public and a wild, hysterical mass media. How can we ever have transparency and full disclosure while the press are inclined to behave this way?
A bomb might have 100 pounds of nuclear material, fairly efficiently exploded, releasing a lot of energy.
A burning, melting reactor might have 100s of TONS of fuel pellets, which can be aerosolized and distributed to the four corners.
While it's true that reactors contain far more radioactive material, they don't typically "aerosolize" much of it - Tchernobyl was pretty much a worst case scenario in that regard, and Fukushima thankfully was not.
I would say that it was a surprise to everyone involved. Or are you saying that everyone who lives near a nuclear reactor shouldn't be surprised when their homes become uninhabitable? I wonder if the nuclear industry would agree with that statement.
And it's misleading to call these reactors antiquated. They were built with projected lifespans that go well past the present day, and if you replace them or reduce the lifespans it (badly) affects the cost of Nuclear power.
BTW, if you think that was badly-sites and antiquated then I've got a few others you might want to avoid:
Diablo Canyon, California (Yes, that is the sea): http://papundits.files.wordpress.com/2009/08/diablo_canyon_n...
San Onofre, Ca: http://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_S... (Yes, that's a beach it's build on)
Yeah, better tell everyone in San Diego: http://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_S...
Are they doing anything in light of the Fukushima disaster?
No, but similar age I think
Are they doing anything in light of the Fukushima disaster
I believe they put out some press releases telling people how safe it was.
So, yeah, it wasn't Chernobyl, it wasn't TMI, it was its own Fukushima Daiichi style of meltdown disaster better in some ways and worse in others.
But the many experts and analysts who went on record early saying this wasn't going to be a major disaster and that it was a "victory for nuclear engineering" were flatly proven wrong and it reveals the blind pro-nuclear bias in their thinking.
In this comment: http://news.ycombinator.com/item?id=2339304
I said "No matter what happens at Fukushima Daiichi, even if all four of the reactors and their spent fuel rods turn into slag candles fused into the foundation of the plant, a rational person would say 'Gee it really is great that we don't have magnitude 9.0 earthquakes with accompanying tsunamis every year, if we did, and they can do this to a nuclear plant, it would be foolish to take those risks.'"
That was my comment about the difficulty in having rational discussions on emotional topics.
In this comment : http://news.ycombinator.com/item?id=2328783
I noted "I dislike the medidiots who conflated a hydrogen explosion with a nuclear explosion. There is however one risk here that neither folks in the media, nor have I seen yet on HN, and that is the danger of old fuel meltdowns."
And in this comment: http://news.ycombinator.com/item?id=2324764
On the very controversial (in terms of coverage) blog posting about not being worried about the accident:
"2) Its important to understand that since the reactor is shut down, its only source of heat is the decay products from when it was running, minus the heat they pulled off while running on battery power. Further the engineering design target (one assumes they test to that target) is that if you integrate over all the heat you generate from all the byproducts from a reactor that was running at 'full' and now has all of its control rods inserted, is less than the heat you would need to add to melt the containment vessel (the flask) You won't be able to restart it but you won't have the core melt through the vessel either."
Which seems to have been the case. (comments about holes in the vessel that are plugged by graphite and can leak small amounts of fuel out the bottom of the reactor came later, but the original design continues to keep nearly all the fuel in the reactor's flask.)
And perhaps my most polyannaish post in this comment: http://news.ycombinator.com/item?id=2324328
"And as others have pointed out, if you get a "full meltdown" with the control rods fully inserted, the resulting uranium/boron alloy is not critical.
In short hand, once the rods are in, its game over, just a question of how hard the final result is to clean up.
If you keep it under the melting point of the core you can just pull the fuel and dispose of it in the normal way, if not you have to clean out the non-critical slag core."
Seems to be where we'll end up. removing the remains of the fuel rods from the bottom of the reactor where they ended up after the fuel pins lost their integrity.
I'll reiterate, bad accident, not a 'huge disaster.'
Could it get worse? I can imagine scenarios where it could. The waste fuel pond structure could crack and all the water could drain out of those ponds, that would lead to a lot of gamma rays for anyone line of sight to the rods and a possible criticality event if enough neutrons were generated. Will it get worse? At this point it seems the events that would be required are improbable at best. An asteroid or sufficiently large space rock hitting the plant would be sufficient, another 9.0 earthquake disrupting power again, a pipe rupture in the existing cooling recirculation system which sent coolant water outside the building.
Most of this basic information was very well established and confirmed by multiple sources. Those of us who knew this was a huge disaster unfolding were not "right by accident".
And you missed the second part "After experiencing a 9.0 earthquake, which scrammed the reactors, and then a 47' tsunami which destroyed the cooling systems."
And you missed the third part "Nobody was killed."
Everytime we have a 9.0 earthquake and a 40' foot Tsunami I expect to have deal with a lot of damage and loss of life and general scrambling around because so many things are put under strain at the same time.
You could look at this and say "How often do we have 9.0 earthquakes?" and you could see that over the last 112 years we've had six. You might ask about how many of those occurred where we might build a nuclear plant (2) and how many were accompanied by a tsunami on the same coast (1). And you might conclude that this is a pretty rare occurence, probability suggests that it is one you, your children (if you have any), and their children (if they have any) will never see again.
You also said "Most of this basic information was very well established and confirmed by multiple sources. Those of us who knew this was a huge disaster unfolding were not 'right by accident'."
The place where I and perhaps other disagree with you is when you use the phrase 'huge disaster' here. I've not checked all the comments but most people said early on that this was no doubt the worst possible accident these plants could experience, there were folks who expressed confidence in the layers of systems which are designed to keep such accidents from becoming 'disasters.' What wasn't clearly articulated I guess was the definition of disaster.
There are many square kilometers around Chernobyl which were rendered uninhabitable from that accident. In Fukushima's case nowhere will be rendered un-inhabitable. While there are people evacuated currently, those evacuations are temporary. In all likelyhood no one will have died or suffered permanent injury from the Fukushima accident (again due to a variety of safety systems). That wasn't the case in Chernobyl.
So an accident which doesn't harm human life, doesn't damage any property not belonging to the power company, and doesn't do any lasting or even long lived damage to the environment, does not rise to the level of 'huge disaster' in my opinion.
And looking back at some of those comments they acknowledge that the lack of data from the plants directly left only speculation as an option and they covered the scenario that TEPCO seems to have observed after regaining access to reactor #1's control room. That the engineering of the plants defensive systems, in the absence of the cooling system, the backup system, and the backup backup system, contained the accident's results to the pressure vessel and the containment structure. Water used in the response has collected in the concrete basements under the reactors. The longer lived radioactive by products of the fission process have (as far as anyone can tell) remained contained within the structures designed to contain them. The reactors themselves are a total loss and can probably not be economically be recovered so will no doubt be dismantled.
It is the worst possible accident you could have at the plant. As with a luxury car's crumple zones and air bags and other safety gear, the plants systems designed to contain and mitigate the accident have done their jobs. Protecting lives and property.
From the moment the wave washed over the plant everyone knew it was a serious accident, the only question has ever been what were the long term ramifications of that accident.
My guess is that the plan will involve dismantling reactor #4, using the building and space as a processing center to process recovered material from reactors 1, 2, and 3 separating out the long lived waste from the low energy / short lived waste. The low level waste will become non-waste on its own by alpha/beta decay and the remains of the fuel will be stored with other high level waste that the plants generate.
There was a 9.0 earthquake near a population center. There are 15037 people confirmed dead and 9487 people missing. Estimates of material loss range up to $300000000000. Also, a powerplant broke.
The reactor was hit by a natural disaster of unprecedented proportions, it broke, it caused dangerous side effects. Congrats, welcome to the technological age. What happens when a tsunami or a 9.0 quake hits an LNG storage facility that creates a giant explosion that destroys a lot of real estate and kills a lot of people? Will people blame the technology of LNG or will they just blame the natural disaster?
I disagree. I think the second-worse nuclear disaster in history is a huge disaster, especially since it looks like it will leave a large area uninhabitable.
Even by the INES standards, INES 7 (ie, Fukushima) is defined as a "Major Accident": Major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures
I do understand your point of view here though.
It is the worst possible accident you could have at the plant.
It's not, and not by a long way. For example, there was no damage caused by any aftershocks, which was incredibly lucky.
People are told these reactors are safe in the event of a terrorist missile attack - it's pretty clear they are no where near that safe.
From the moment the wave washed over the plant everyone knew it was a serious accident, the only question has ever been what were the long term ramifications of that accident.
This is wrong. Read, for example Brave New Climate (one of the main envio-nuclear advocacy sites). Quote: There is no credible risk of a serious accident. 12 March (ie, 2 days after the Tsunami): http://bravenewclimate.com/2011/03/12/japan-nuclear-earthqua...
I disagree. I think the second-worse nuclear disaster in history is a huge disaster, especially since it looks like it will leave a large area uninhabitable.
This isn't born out by the monitoring done by the US Dept of Energy [1] and others. There has been some Cesium-137 detected outside the plant, but its in trace amounts rather than large quantities.
If you look at the data collected by the DoE you will see two things, first that they haven't detected any deposits that have occurred after March 19th, and second that their highest reading was 91uSV/hr (9.1mRem) which corresponds to 218 mRem/day. which is high (relative to background radiation) and below what is considered a public health hazard of 1000mRm over 4 days. (slide #10 in the link). Third to get that dosage you would have to lay down in the dirt 24/7.
So no area outside the plant will be 'uninhabitable' [2] Some places will no doubt be targeted for local decontamination, the Cesium will decay on its own making each year after the accident less of an issue than the day before. Is it great? No.
It's not, and not by a long way. For example, there was no damage caused by any aftershocks, which was incredibly lucky.
Actually that wasn't luck, the plant is designed to handle violent earthquakes, it would be astonishing if there were an aftershock greater than the main shock. Anything signficantly less than an 8.0 was part of the design.[3]
People are told these reactors are safe in the event of a terrorist missile attack - it's pretty clear they are no where near that safe.
Think about that statement for a moment. The energy released ina 9.0 earthquake is the equivalent to 475 million tons of TNT, or 23,000 bombs the size of the one that hit Nagasaki. [4] If North Korea dropped a nuclear bomb into the plant it would clearly destroy it, but there isn't a terrorist organization on the planet that has the capability of deploying that much energy to the plant.
I understand that nuclear power can be a scary thing to some people. But if you take the time to educate yourself on the risks and the engineering which goes into keeping those risks from turning into accidents. It might be possible to get past the fear factor and see them in a more balanced light of power delivered over time vs their risk factors.
[1] http://blog.energy.gov/content/situation-japan/
[2] I am predicating that on no further release of any material which is unlikely given the state of the reactors.
[3] http://online.wsj.com/article/SB1000142405274870355540457619...
[4] "Question: How much energy was released by this [9.0 quake off Indonesian coast] earthquake?
Answer: Es 20X10^17 Joules, or 475,000 kilotons (475 megatons) of TNT, or the equivalent of 23,000 Nagasaki bombs. "
http://earthquake.usgs.gov/earthquakes/eqinthenews/2004/us20...
Actually that wasn't luck, the plant is designed to handle violent earthquakes, it would be astonishing if there were an aftershock greater than the main shock. Anything signficantly less than an 8.0 was part of the design.
And yet the reactor vessel was breached. Given that it was already breached, I believe a significant aftershock (not of 8 magnitude, but maybe a 6.5-7) would have caused additional damage and/or spread contamination worse than it was.
>>People are told these reactors are safe in the event of a terrorist missile attack - it's pretty clear they are no where near that safe.
Think about that statement for a moment. The energy released ina 9.0 earthquake is the equivalent to 475 million tons of TNT, or 23,000 bombs the size of the one that hit Nagasaki. [4] If North Korea dropped a nuclear bomb into the plant it would clearly destroy it, but there isn't a terrorist organization on the planet that has the capability of deploying that much energy to the plant.
You and I both know comparing the "energy released by the earthquake" with something like a deliberately positioned shaped charge on the reactor vessel is silly. A properly designed shaped charge would be almost infinity smaller, and yet almost sure to cause a breach - eg: http://www.globalsecurity.org/military/systems/munitions/m15...
It's pretty clear that a "sensible" terrorist organization wouldn't need anything like a nuclear bomb to cause a significant incident, and probably a leak too. It's always been claimed (since Chernobyl anyway) that the reactors have defenses in depth and multiple containment layers. It turns out that this is misleading at best, or a lie at worst, because the outer containment vessels are - in some cases - only designed to contain a pressure leak. Sometimes (eg this case) they are designed to blow out if the pressure is too much!
It's only a "major disaster" by nuclear standards. Compared to the loss of life that we routinely accept in coal mining and the air pollution from burning it, it's barely a blip. (http://spectrum.ieee.org/energywise/energy/renewables/coal-p...)
March 27, 2011: "This all fits in well with my discussion Criticality Accident? Unfortunately."
http://powerandcontrol.blogspot.com/2011/03/worst-case-scena...
"That (contaminated) water is seeping into the ground table, and there will be contamination on that site for a long time to come. It could also move inland. This is ground water, it doesn't have to move out into the ocean. It is clearly moving into the north"
http://www.youtube.com/watch?v=9CAeixB19d4
I don't believe that TEPCO is actively monitoring plutonium and uranium, which is heavy and more likely to seep into ground water than to be blown into the air. I hope that people in Tokyo do have some independent monitoring stations setup. Anybody know any links?
http://www.greenpeace.org/international/en/news/Blogs/making...
According to TEPCO (and GE documentation) the containment vessel did in fact contain the core material. Looking at the measurements reported, (both from TEPCO and other agencies) there isn't an indication of either groundwater or watertable contamination.
[update: The TEPCO folks early on said they did see some groundwater contamination with Iodine. They also point out that the plant is 'downstream' of the water table with any nuclides most likely being carried to the ocean rather than to either of the rivers higher in the water table. The engineers will know more when they open things up and start cleaning them out.]
The 'news' is that cleanup will take longer because rather than pulling fuel pins out of the reactor and sending them off to be either re-processed or disposed, the core material at the bottom of the reactor will have to be removed piecemeal by what is probably custom equipment.
This was the same procedure used at TMI to remove material that had migrated to the bottom of the reactor after having melted.
I don't think anyone disputes that this was a tragic event and at seems nearly the worst possible accident (it could have been worse if all reactors were at full power) but it hasn't killed anyone yet, this incident is unlikely to be the principle cause of death for anyone in the forseeable future. And yet tens of thousands of people are dead because they couldn't flee the wall of water, so the tsunami was a disaster, the damage to the nuclear plant was not.
When you see a head-on collision and the person in the car walks away because the airbags went off, we don't argue for banning driving because the car is destroyed, there is $50,000 worth of damage to the guardrail, and hundreds of people lost work because they were caught in the traffic jam. We say, "Isn't it amazing how safe cars are these days! That accident would have killed them even 10 years ago."
We have had a head-on collision between a late model nuclear reactor and an incredibly and extremely unlikely large magnitude double disaster and so far, the safety systems that were built into the reactors and upgraded over the years have kept everyone safe. Slowly, steadily, and with good engineering practices.
The results of that disaster are being addressed and will be cleaned up and repaired. I realize that someone walking away unhurt from what would have been a fatal collision might feel that it was a miracle, but it might just have been good engineering.
And what about the 70,000+ people in the 20km evacuation radius who have no idea when or if they'll be able to return to their contaminated homes? (or even bury their dead) You're going to tell them Fukushima Daiichi is not a disaster?
At least the people who fled the tsunami are able to rebuild on that land.
The land is not contaminated at all, and no one died, so no, it's not much of a disaster as these things go.
http://www.mext.go.jp/component/english/__icsFiles/afieldfil...
It will be a closed zone for decades. Almost all of the (external) dose in the area right now is from these two isotopes; the rest have decayed. (There's a model of this in [1]). These two will not decay away quickly; Cs-134 has a half life of 2 years, and Cs-137, 30 years.
[1] http://www.rri.kyoto-u.ac.jp/NSRG/seminar/No110/Iitate-inter...
I believe you have misinterpreted the data. The highest measured readings were 91 uSv/hr. That is equivalent to 9.1 mRem/hr (1 mRem = 10 uSv). The lowest dose in the 'red' zone is 19 uSv/hr or 1.9mRem. Public safety is considered to be 'at risk' if you are exposed to > 1000 mRem over 4 days. You can't reach that level in places where they read 91 uSV/hr (best you can do is 9.1244 or 873.6 mRem/4 days. And where its only 1.9mRem you only get 182 mRem/4 days.
The bottom line is that it is safe to go anywhere in the current 80km radius circle, if you are the government and want to minimize radiological hazard you will go through the area that shows the highest activity and identify and clean up any hot spots.
That information btw is in the DoE's contribution to this report.
The second part you missed is that Cs-134 will be down to noise in less than a decade due to decay which will reduce overall dosage. (I've noticed that no one has published the ratio)
So is there contamination from the plant in Japan? Yes.
Does is pose a public health risk? For the most part no.
Will any part of the area be 'off limits' this time next year? Probably not.
Will monitoring continue and specific areas be targeted for decontamination? Almost certainly.
The tsunami is obviously independently of that the far worse disaster.
We can reason about the 'relativeness' of disasters. There are the folks who are alive and homeless because their homes were destroyed by the water, and there are people who are alive and homeless because of the evacuation zone around the reactor.
Given the readings for radioactive nuclides outside the Fukushima plants [1], once they are fully engaged in the process of the cleanup, the plan is to allow everyone to return to their homes. Living and working in Fukushima Prefecture will be no more and no less hazardous than it was before the tsunami, and the houses and farms and infrastructure is generally intact and ready to move in.
For folks who lost their home in the tsunami, once the roads and infrastructure have been repaired, they can begin re-building their lives.
So when we think about the relative scale of the disaster to people we might assign a value 'x' to someone who is evacutated for a period of time, and then returns to their home and neighborhood as it was pre-evactuation. And a value 'y' to someone who evacuated and at some point will return to the land where they used to live and can start rebuilding their lives and community.
I can't speak for the people, I don't live there, but if I were told I was going to be a member of either group x or group y I would prefer to be in group 'x' as it would seem to me to be the 'lesser' of two disasters.
So at some level, everything is a disaster, but in this discussion I continue to feel that the tsunami/quake combo was the 'real' disaster and the ongoing work to stabilize the reactors which were damaged by that disaster as one of many responses to the disaster akin to people working to prevent cholera and other outbreaks and to restore basic services like drinking water and electricity. Those people who are involved in surveying damaged buildings, recovering downed power lines, clearing debris from water treatment plants are in some ways more at risk of a life threatening injury than the engineers working to get the Daichi plant stabilized and into clean-up mode.
[1] "Gamma Dose Rates in 47 Prefectures
Gamma dose rates are measured daily in all 47 prefectures. On 10 May the value of gamma dose rate reported for Fukushima prefecture was 1.7 µSv/h. In all other prefectures, reported gamma dose rates were below 0.1 µSv/h with a general decreasing trend."
"Gamma Dose Rates in Areas More Than 30 km from Fukushima Daiichi Plant
Gamma dose rates reported specifically for the monitoring points in the eastern part of Fukushima prefecture, for distances of more than 30 km from the Fukushima Daiichi plant, showed a general decreasing trend, ranging from 0.1 µSv/h to 20.3 µSv/h, as reported for 10 May."
Let's say we're unlucky enough to live in that 20.3 µSv/h environment. Our daily dose is 487 µSv. Our monthly dose is 14 mSv. Our yearly dose is 178 mSv, way above pre-Fukushima radiation worker permitted dosage.
Sigh, when writing that, you knew that the radiation dose will certainly be much lower in just one year.
I'm completely for technological progress, including full speed nuclear. Yet, without hitting the current nuclear establishment hard in the nuts, they wouldn't let the progress happen, and will be continuing to build, if permitted, these old designs, or nothing will be built at all. The human race thus is kept hostage - either old and dangerous or nothing. There is no debate whether nuclear is safe or not. It is just a PR of the existing industry trying to sell old dusty designs and their minor tweaks wrapped as the necessary component of the technological progress of the human race. The real answer is - existing nuclear is dangerous, costly, and huge portion of its cost is socialized (as typical for any monopolized industry). The nuclear energy, if/when it is developed using even existing today state of human race technology (not 50 years old) can possibly be made safe and very effective.
Edit: among my best hopes for advanced nuclear and thermonuclear is that Musk will need a source of energy on Moon, Mars, etc... and there is no nuclear industry yet capable to reach beyond the Earth to limit the progress there
If anything, Fukushima is an example of how little attention we should pay to the anti-nuclear movement, because an inevitable side effect of their cause is the prolonging of older reactor's lifespans, when much safer designs could be replacing them.
Unfortunately. if limitations are lifted or eased, we'd immediately get more of the same Fukushimas from the industry, and the anti-nuke movement is the only force keeping it from happening.
You say that as though the engineers are willing to sign off on any old half-baked plan. Maybe things are different in Japan, but around here, you have to get engineers to approve things personally and there are serious consequences for someone who signs off on something unsafe.
Yes.
Certainly, there are a lot of things we have learned since that plant was designed that could be done better and if it had been just a tiny bit better, there wouldn't have been any leaks at all. But we can make plants a lot stronger these days. And we probably should be doing exactly that.
When people like the founder of Greenpeace are pro nuclear, the only people anti-nuclear are radically anti-nuclear. They do not give a damn about old versus new tech.
The nuclear industry just wants to save money by pushing the old tech.
Together they create the false dichotomy of either old or nothing.
I wish we had an anti-nuclear movement which distinguished between old and dangerous and what we could have with new tech. Even if they were against both, if they were at least much more against the old an dangerous, that would be great.
But the current ani-nuclear forces are not that rational.
From practical point of view, the most developed, i.e. it was successfully prototyped 40 years ago (http://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment), is Molten Salt Reactor :
http://en.wikipedia.org/wiki/Molten_salt_reactor
nice quote from the article: " Since it uses raw fuel, basically just a mixture of chemicals, current reactor vendors do not want to develop it. They derive their long-term profits from sales of fabricated fuel assemblies." :)
The principal difference of this type of reactor is that all the stuff (fuel, fission products, etc) aren't piled and accumulated in the reactor core. Instead, it is flows in, burns, flows out, filtered/reprocessed, flows in ...
General scare tactic utilised by the industry to preserve status-quo is expressed nicely here:
http://en.wikipedia.org/wiki/Generation_IV_reactor
"As one director of a U.S. research laboratory put it, "fabrication, construction, operation, and maintenance of new reactors will face a steep learning curve: advanced technologies will have a heightened risk of accidents and mistakes. The technology may be proven, but people are not"
Basically - if you force us to make something new, it will be even more risky and we've warned you.
Another quote from there : "Nuclear engineer David Lochbaum has explained that almost all serious nuclear accidents have occurred with what was at the time the most recent technology. " .
Complete BS - nor Chernobyl, nor Fukushima have nothing to do with their technology being most recent as 1.their technology hasn't been most recent 2.it has to do with morons - Chernobyl, and unplanned for high tsunami - Fukushima and if i remember TMI was also not about new technology.
I think the opposite. I recall many many people on this site asserting with absolute certainty that nothing bad could happen at Fukushima immediately after the earthquake. Anyone that suggested otherwise was demonized as an uninformed faermonger.
I'm not anti nuclear, I think it's a better option than coal, but the pro nuke people have done the cause a great disservice with their wrongness and refusal to cop to it.
Reread this for one example, and tell me which side sounds as if it doesn't deserve attention.
Hacker News nuke threads are almost as puzzling to me as BitCoin threads, but I keep coming back for some reason.
Absolutely. There's been a ton of research, but too little actually being built. This would be a good time for Japan (and elsewhere) to replace any vulnerable reactors to designs that can work with passive cooling.
That brings me back to my original point. I was not taking sides on pro/anti nuclear. I fear for my friends' lives in Japan. Because their government is weak and useless and saving face. That is why I was asking for independent monitoring links for plutonium and uranium. So that they can use scientific data to determine their own fate.
I don't know about leakage, but they've been very clear that the fuel had melted down for a very long time now, at least since after that first week. The only question has been how substantial has the fuel damage been, and now at least for Unit 1 we know the answer.
> I fear for my friends' lives in Japan. Because their government is weak and useless and saving face.
Independent monitoring should be used, but if you're really worried why don't you ask your friends to take actions assuming that there is plutonium and uranium all over the place (e.g. air masks outside, frequent washing of vehicles/hands/outerwear)? I hate to say this but it's not like knowing exactly how much radioactivity is out there would change the actions they should take too much one way or the other: wash that shit off, don't eat foods/liquids that are contaminated.
Plus, you really shouldn't ask for merely plutonium/uranium, as if radioactive Strontium or Cesium that the government is reporting figures for are that much better -- they're also nuclides of concern, so if you don't trust the government then you should also push for independent monitoring of those radionuclides.
Isn't there just the tiniest clue, in the massive quantities of 1+ Sv radiation from the water, that some of the materials have been washed out of the reactor?
Isn't there just the tiniest clue in the fact that the basements are full of water, that the RPV and containment are holed?
This blog has info translated from Japanese,
http://ex-skf.blogspot.com/2011/05/asahi-shinbun-core-meltdo...
I hate seeing coal ads that more or less state that it's safer than nuclear energy.
I - for one - disagree quite strongly with that.
I think that it's very unfortunate that somehow Nuclear power has picked up a lot of support from people who think opposition to it is unscientific.
I think that if you look even moderately closely at it you'll find that the risk modelling associated with nuclear power closely resembles the risk modelling that Feynman tore to shreds when done on the space shuttle after the Challenger disaster.
For example, people will tell you that this disaster was so bad because of the combination of earthquake and tsunami knocked out the support infrastructure. They'll even give you odds on each individual problem occurring.
But they don't look at the system as a whole: If an earthquake and tsunami did occur, it was almost certain that support infrastructure would be knocked out. In actual fact they were very, very lucky that no aftershock produced another significant tsunami in the area.
The stupidity of those assumptions is obvious in retrospect, but nuclear fans are papering over it by saying it is a one-off problem, and associating anti-nuclear people with smelly, uneducated hippies from the 1970s.
Well.. it's NOT a one off problem, and the risks aren't as low as they make out. Take seismic risks in the US. Quoting the report of Safety/Risk Assessment Panel for Generic Issue 19 (ie "IMPLICATIONS OF UPDATED PROBABILISTIC SEISMIC HAZARD ESTIMATES IN CENTRAL AND EASTERN UNITED STATES ON EXISTING PLANTS"):
Updates to seismic data and models indicate that estimates of the seismic hazard, at some operating nuclear power plant sites in the Central and Eastern United States, have increased
Using available seismic hazard and plant seismic fragility information, the Safety/Risk Assessment found that the increase in coredamage frequency for about one-fourth of the currently operating plants is large enough to warrant continued evaluation under the Generic Issues Program
http://msnbcmedia.msn.com/i/msnbc/Sections/NEWS/quake%20nrc%...
So.. those risk assessments done when the plants were approved? They were wrong, and in 1/4 of plants in the Central and Eastern US core damage would occur during a seismic event within their design tolerances.
Still calling this an unfortunate setback?
I hate seeing coal ads that more or less state that it's safer than nuclear energy
I hate seeing coal ads, but nuclear isn't the answer. (Oh, and don't believe the whole "no renewables can produce baseload" lie, either. Do some reading on solar-powered pump-hydro, geothermal and tidal power)
Yeah, its true that if you are involved in the coal industry you are much more likely to die than if you are involved in the nuclear industry.
Yes, day-to-day pollution from a coal plant (especially old ones) is much worse than day-to-day operation of a nuclear plant (which is why they need to be replaced).
But there is zero chance that an accident in a coal plant will affect more than (say) 1000 people, and yet there is at least a 1/12,000 chance [1] that it will affect 100,000+ with a nuclear station.
[1] The first commercial nuclear power station was commissioned in 1954. There are ~25,000 days since then, and there have been 2 INES Level 7 accidents: http://en.wikipedia.org/wiki/International_Nuclear_Event_Sca...
Why not look at the whole picture -- and factor in the day-to-day damage as well?
It seem coal's day-to-day damage surpasses even the nuclear disaster scenario.
Nuclear is often put forward as a solution - I'm pointing out the huge risks that has.
Heh, the flip side is that there is a 100% chance that the pollution created by the coal plant over its lifetime will kill thousands of people. But to your point, that is an argument based on facts, not emotion. And emotionally the people living near the coal plant, while dying due to the effects of its pollution will not have been frightened that one day it might have an accident that would cause them to evacuate for a few months.
Obviously I agree that coal is a disaster. At the same time I don't think that replacing coal with nuclear power is acceptable.
However, since this thread is pretty much dead (except for us two!) I'll say this:
I'm not as anti-nuclear power as I might appear here. For example, I'll happily say that the panic associated with a nuclear leak is usually unjustified. I'll even go so far as to say that nuclear power might have a place in the future of power generation.
What I don't like is the uninformed cheerleading by many technophiles of nuclear power.
There are real risks associated with nuclear power, and they are grossly understated by those in the industry, which then gets parroted mindlessly by many. There are plenty of examples on this thread of blind acceptance of "facts" put forward by the nuclear industry (disclaimer - I'm not accusing you of this). A trivial amount of research is enough to raise pretty significant questions on them.
The trend towards blind acceptance of those claims, and the whole "nuclear is cool" thing is what I try & push back strongly against.