NRC Approves New Nuclear Reactor Design 299
hrvatska writes "The NY Times has an article about the U.S. Nuclear Regulatory Commission approval of the design of Westinghouse's AP1000 reactor for the U.S., clearing the way for two American utilities to continue the construction of projects in South Carolina and Georgia. The last time a nuclear power plant in the U.S. entered service was 1996. The AP1000 was discussed on Slashdot a few years ago."
Sour grapes (Score:5, Funny)
Now that the rest of the world is rethinking nuclear power, We Americans have changed our tune.
However, I think the US might be on the right track here. Of course, it helps that the risk of tsunamis in the southeastern US is right between that of a zombie outbreak and Ralph Nader winning the presidency.
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We should write out the rest of the list . . . So much potential for snark.
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Yes let the rest of the world stop using the only scalable sensible power source. If we can avoid letting the big corps and the nimbly's making it massively expensive we could be positioned to make a resurgence. It will never happen were to short sighted for that.
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Now that's a movie I'd pay good money to see!
Re:Sour grapes (Score:4, Insightful)
if a hurricane was a threat to a reactor design then it never should have been built.. hurricanes really are not that damaging..
why isn't thorium being developed? (Score:5, Informative)
Re:why isn't thorium being developed? (Score:5, Insightful)
Or the U.S. could just let them spend the money and take all the risks in terms of designing and testing the new reactors, then steal the designs and build the reactors themselves, forcing the Chinese firms to eat the R&D costs....
Wait, something about this sounds familiar. I sense a pot and a kettle are involved.
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That's LONG overdue. The US should ditch its counterproductive pride and let other "early adopters" take the risks.
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Yeah, that sounds exactly like what the US did in the 1800's with their massive pirating of the European industrial revolution, stealing the designs, flaunting their massive patent and copyright violations, outright theft of designs and ideas, and massive intellectual dishonesty.
Re:why isn't thorium being developed? (Score:5, Informative)
1. Current uranium-based reactors are more affordable than thorium reactors.
2. The path for licensing a thorium-based reactor in the US is exceedingly uncertain.
While a thorium-based fuel cycle may be a good idea, it's just not going to be done by any commercial enterprise today. The costs and risks are too high. When staring at a $5B initial investment cost, any electrical utility is going to favor the known route ... which, frankly, could just as easily mean building 10 natural-gas fired plants instead of 1 big nuke.
India, however, is going full-bore on a thorium-based fuel cycle, and has already built a few reactors that are capable of accepting thorium. Copied shamelessly [world-nuclear.org] from world-nuclear.org:
India's plans for thorium cycle
With huge resources of easily-accessible thorium and relatively little uranium, India has made utilization of thorium for large-scale energy production a major goal in its nuclear power programme, utilising a three-stage concept:
Pressurised heavy water reactors (PHWRs) fuelled by natural uranium, plus light water reactors, producing plutonium.
Fast breeder reactors (FBRs) using plutonium-based fuel to breed U-233 from thorium. The blanket around the core will have uranium as well as thorium, so that further plutonium (particularly Pu-239) is produced as well as the U-233. Advanced heavy water reactors (AHWRs) burn the U-233 and this plutonium with thorium, getting about 75% of their power from the thorium. The used fuel will then be reprocessed to recover fissile materials for recycling.
This Indian programme has moved from aiming to be sustained simply with thorium to one 'driven' with the addition of further fissile plutonium from the FBR fleet, to give greater efficiency. In 2009, despite the relaxation of trade restrictions on uranium, India reaffirmed its intention to proceed with developing the thorium cycle.
A 500 MWe prototype FBR under construction in Kalpakkam is designed to produce plutonium to enable AHWRs to breed U-233 from thorium. India is focusing and prioritizing the construction and commissioning of its sodium-cooled fast reactor fleet in which it will breed the required plutonium. This will take another 15 â" 20 years and so it will still be some time before India is using thorium energy to a significant extent.
That ship sailed long ago (Score:5, Informative)
Almost all of the post 1970s technology in the AP1000 came directly from the nuclear division of Toshiba in Japan after merging with Westinghouse. It's technology bought off Japan instead of China but still looks like what you are worried about.
India is leading with Thorium at the moment and appear to have taken the US advances and added a couple of decades of development. Accelerated Thorium (mixed fuel such as expired weapons material or used uranium fuel rods in addition to thorium) holds paticular promise.
Re:That ship sailed long ago (Score:5, Informative)
Westinghouse employee here. The AP1000 final design certification was approved in 2006 [nrc.gov], and the design (including the predecessor AP600) began long before that (mid 90s).
Toshiba acquired Westinghouse in late 2006 [mediaroom.com]. Prior to that, Toshiba had partnered with our domestic rival, General Electric to build plants in Japan. We sell Pressurized Water Reactors (PWRs), they sell Boiling Water Reactors (BWRs). They're pretty different.
Even now that they own us, there is very little technical collaboration between our two entities. If there's a technological connection between Westinghouse and Toshiba that predates any of that, I'm certainly not aware of it.
Re:That ship sailed long ago (Score:5, Insightful)
Almost all of the post 1970s technology in the AP1000 came directly from the nuclear division of Toshiba in Japan after merging with Westinghouse. It's technology bought off Japan instead of China but still looks like what you are worried about.
Beat me to the punch. The AP1000 is not a "new" design, it's a slightly warmed-over 1970s design that got NRC approval because it was close enough to the antiques currently in operation that no bureaucrat had to risk his pension by sticking his neck out and approving something that would be a genuine improvement (I'm lumping the Gen IIIs in with the Gen IIs here because they're mostly incremental improvements obtained from experience in running Gen IIs) . When the NRC approves anything Gen IV like a PBR or, heaven forbid, something genuinely modern like a TWR, then it's time to celebrate.
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The NRC should approve some more thorium reactors if it doesn't want to be buying technology off China 10-20 years down the line.
And what's so bad about buying them from China? They'll be cheaper that way, and any catastrophic design flaws can be worked out on the other side of the globe rather than here...
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Hmm. Thorium is intriguing, and quite possibly profitable. Perhaps more so than Uranium-based power plants.
However, there are two problems: 1.) a proper Thorium power-plant needs to be designed (correct me if I am wrong, but I believe the Thorium reactor most often cited is a Research reactor -> promising, but not commercial), 2.) we need to begin mining for Thorium, which I imagine requires locating various deposits, and extracting the ore in quantity (Uranium mining is rather developed, and a Google se
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Only 1.154GW? (Score:5, Funny)
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Great Scott!!
Could someone elaborate (Score:2)
Re:Could someone elaborate (Score:5, Interesting)
We wouldn't even have this level of civilian nuclear technology if it hadn't been bought off the Japanese. For some reason the US Nuclear Lobby mostly descended to the level of mere rent seekers in the 1980s so the only hope for advancement there is small startups based on military technology or input from overseas.
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"For some reason the US Nuclear Lobby mostly descended to the level of mere rent seekers in the 1980s"
There is no incentive to lobby for nuclear power. There are other ways to make money.
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I think the Department of Defense would beg to differ. They just designed a new reactor for their latest ship. http://www.fastcompany.com/blog/cliff-kuang/design-innovation/how-does-navy-design-nuclear-supercarrier-future [fastcompany.com]
Is it designed around passive nuclear safety? (Score:2, Informative)
Re:Is it designed around passive nuclear safety? (Score:5, Informative)
Sort of. Unlike Fukushima-style reactors, it doesn't require an external power source (like the DC generators that failed there) to cool the core following a shutdown, but it's not a purely passive system. Wikipedia's summary [wikipedia.org] is decent.
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Now, pointing out that there shouldn't be a single switchboard in a place it can get flooded which will cut off all power everywhere if it gets flooded I can get behind. Also, I've got some notes from Hurricane Katrina here... "do not put emergency generators in basement"
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That appears rather unlikely, seeing as the point at which they'd tap the grid to run their own systems would be the same point at which their turbines feed power onto it.
I would envision either an inductive tap on the main lines going out to feed back in a small amount of power back in at usable levels or a secondary generator attached to coolant lines that will put out enough power to run the plant at even low levels of activity (say, the first week after a "total shutdown"). I'd leave the choice between those to nuclear engineers, but absolutely no locally powered backup at a power plant seems silly (or negligent).
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Famous last words, I'm sure.
Purely passive systems have virtually no chance of meltdown, even on a theoretical level, since if the system should ever fail, for absolutely *ANY* reason, all the way up to and including total systems failure, the core will immediately start to cool down.
The cost for this safety is a small compromise in reactor efficiency, and I am at a complete loss as to why anyone would ever want to build a nuclear reactor that was not designed around a passiv
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Re:Is it designed around passive nuclear safety? (Score:5, Informative)
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Bible Belt Prophesy (Score:2)
YAY! Radioactive Christians glow in the dark :)
Or is this how the Zombie Apocalypse begins?
Westinghouse Sucks (Score:2)
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Nuclear plants and similar heavy industrial equipment are about the only products of the "real" Westinghouse that still exist. They had nothing to do with your POS TV set.
Like so many other venerable US brand names, The Westinghouse name and logo has been licensed for use on El-cheapo imported consumer electronics built by various "One Hung Low" outfits.
Hmmm (Score:2)
This reactor design in an improvement, but I would like to see a design which does not use a pressured coolant. I consider the usage of a pressurized coolant to be a possible point of failure.
By the by, didn't Westinghouse have an earlier standardized reactor design?
Approved, but financed? (Score:2)
I interviewed with NRC in 1991, they had "just approved" a new "advanced, passive cooling, highly safe" reactor design then. I asked the interviewer what my prospects were in an industry that hadn't built a single new facility in over 15 years, his response: "Oh, quite good, these new designs are coming online real soon now...."
Fast forward 20 years... new design approved, but, will it be built? Or, will we continue to operate reactors that are dependent on powered pumps for cooling water, designed in th
resources (Score:2)
Yay, nuclear. We'll NEVER run out of uranium. /s
Why are we still using PWR?? (Score:3)
There are newer, better designs like pebble bed [wikipedia.org], or molten-salt reactors [wikipedia.org] which, when it fails, fails by shutting itself down and locking the radioactive materials in the core. I see some people talking about the thorium [wikipedia.org] cycle reactors above too.
PWR can be safe, but frankly, there are far more effecient, potentially more cost effective and definitely safer designs out there. We have to stop using 1960 light-water reactor designs meant for nuclear submarines [wikipedia.org].
Re:but (Score:5, Funny)
Nuclear power is just as safe as any other electricity.
It's the heat source that is the problem.
Progress (Score:2, Funny)
Re:Progress (Score:5, Insightful)
Ignoring the massive earthquake, tsunami and the ancient reactor design of course...
Re:Progress (Score:4, Insightful)
In other words, ignoring things that happen in the real world, and that even a first-world country like Japan can't get around human nature (laziness) and business imperatives to cut corners and defer upgrades.
Nuclear power would be great, if we didn't have to depend on humans to run it.
Re:Progress (Score:5, Insightful)
Nuclear power would be great if humans didn't have irrational fear about things there don't bother to understand. If reactor construction had not stopped after the Chernobyl disaster, very few of these old, crappy designs would still be in use. Most of the problems in the modern nuclear industry are related to ancient systems that have had their lives extended due to the lack of replacement plant.
Re:Progress (Score:5, Insightful)
Funny, when they built those "ancient" systems they promised us those were safe too.
But then, concentrating material that will remain highly radioactive for longer than any empire in history has stood, and for longer than any region of the world has gone without war, could never be safe when you stop and think about it.
Re:Progress (Score:5, Insightful)
But they *have* proven *relatively* safe. It depends on the benchmark you judge "relative" to.
Fossil fuels kill people all the time. Coal miners, for example. The men on the Deep Water Horizons drilling platform. They sicken and kill people every single day through pollution. And if you believe in the scientific consensus on anthropogenic climate change, it is likely they damage ecosystems on a global scale and (statistically speaking) kill people through extreme weather events.
The problem is that the killing, sickening and destroying fossil fuels do aren't visibly tied to fossil fuel use. We know these things happen in an intellectual way, but we don't viscerally associate them with flicking on the power switch and burning a little more coal in a plant twenty miles away.
The problem with nuclear power is that its risks are at the opposite extreme. Nuclear disasters are exceedingly rare, so our assessment of risks is based on assumptions built on very little practical experience with nuclear disasters. We don't really have a good basis for judging the risks of having, say, ten times as many nuclear power plants as we do now. The nuclear economy scenario is full of situations where an error in some assumption has non-linear effects on the probability of outcome. For example if you assume the height of a once-in-a-century tsunami is six meters, but in fact it is twelve, you don't *double* the probability of an accident. You transform what is for practical purposes a statistical impossibility into a near-certain disaster.
So what's the rational thing to do? I think it is to move away from a fossil fuel economy and *toward* more diverse energy sources in which nuclear power will be a key part. But I wouldn't go on a crash course to try to solve all our problems in a decade by building as many nuclear plants as we can. The almost certain result of that will be ending up with lots of white elephant designs which proved to be more problematic than we'd hoped. A measured increase allows us to gain experience with designs, and to develop approaches to problems like decommissioning, nuclear waste and, for certain designs, nuclear proliferation. It also provides space for other technologies to take larger roles in the energy economy, spreading our risk over many sources and thus limiting our exposure to problems with any one. Getting ten percent of our energy needs from biomass might be very helpful to us as oil becomes more costly; trying to get 20% might have disastrous effects.
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Actually that's the main failure. Even if you discount the billions in development funds that were spent through the weapons side of things (the accounting is easier here in Canada) the actual price of the power it generates is much higher than hydro (and there's lots of that left, contrary to claims otherwise), much higher than coal, somewhat higher than natural case, only slightly cheaper (or slightly more, depending on the accounting) than wind and somewhat cheaper than PV.
Uh huh. Maybe you ought to back that up with some numbers. And I really like how you can just dismiss rival arguments with the wave of the hand. I sometimes wish I could do that in the real world.
The problem is that the cost of nuclear is unpredictable. It is generally higher now than it was when it was first introduced, which is why all those plants were abandoned in the 70s. Newer designs aim to address this, but their success in doing so remains to be proven. When the US plants come online, if they ever do, then I'll have a metric I'll trust. After all, AECL claims that their two CANDU6's cost $4 a watt in China, but when one looks at the $8.25 bid for Darlington B you'll see they are relying on artificial exchange rates to make that number.
They'll be built and the uncertainty will become less uncertainty.
Moreover, there's a serious fuel issue to consider. Uranium is basically a proxy for oil now. Don't believe me? Look it up. If oil goes up again, so will the price of nuclear. So, do you believe the price of oil will be going up in the future?
Of course, I don't believe stuff that someone just made up.
In the meantime the price of other sources has plummeted. Gas looks like it will remain flat for at least 50 years. Wind power has dropped from 15 to 6.5 cents/kWh in the last 15 years. It's likely bottoming out now, but that's still around what nuclear costs. PV has dropped from about $1 a kWh to something around 15 cents in the last 5 years, and it is just about 100% certain to hit 10 cents in 2012, if it hasn't already.
Gas doesn't look like it'll remain flat for 50 years. Don't even waste my time with bullshit like that. Wind power is heavily subsidized. I don't buy that cost per kWh until I see the unsubsi
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And dispersing poisons we can not control at all is preferable?
All our energy choices including "none" are paid for in dead and maimed.
We also kill tens of thousands of people each year driving to work. It's a perfectly reasonable tradeoff.
Re:Progress (Score:4, Interesting)
What I always wondered is why "spent" fuel (really an exotic blend of lighter, but still strongly radioactive materials that cannot sustain catalyzed fission) is glass cast, then buried.
The stuff has a half like of 10 million years? Sounds like a fantastic core for an RTG to me.
Make the glass cast waste able to be extracted from the RTG enclosure by making it modular, so that the core can be retained while the shell is disposed of/replaced when it wears out. The shell would be radically less raiological, and useful energy could be passively extracted from the spent waste, potentially for centuries.
But that would make sense. A large battery of rtgs in a warehouse could power a small city for pennies.
No. Instead we spend billions on fossil fuel instead.
Re:Progress (Score:4, Interesting)
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Vaccines for one-time, airborn illnesses that kill lots of people and where we might erradicate the disease? Yes, everybody should get them.
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However, when the subject of vaccines comes up, I've noticed quite a few Slashdotters do indicate that they trust and even partake of the common ones. (Again, however, I've not noticed that many of these indicate that they take untested vaccines and, indeed, it seems they are usually talking about vaccines that have been approved by the FDA which requires some de
Re:Progress (Score:5, Insightful)
The real problem with nuclear power is something everyone understands -- namely, people's ability for sloth and cheapness. A properly constructed and maintained nuclear reactor can be exceedingly safe. The problem is, those that run said plants will cut corners everywhere -- construction, maintenance, etc. -- and when they do, the consequences can be huge.
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hence the engineers creating designs which are redundant enough to survive mediocrity.
now hopefully they're built to spec... or at least halfway to spec.
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Naturally engineers never make mistakes. ;-)
Re:Progress (Score:5, Informative)
Re:Progress (Score:5, Insightful)
The real problem with nuclear power is something everyone understands -- namely, people's ability for sloth and cheapness. A properly constructed and maintained nuclear reactor can be exceedingly safe. The problem is, those that run said plants will cut corners everywhere -- construction, maintenance, etc. -- and when they do, the consequences can be huge.
I totally agree, having spent most of my 25 year US Navy career serving aboard nuclear powered submarines I have no problem living in the same ship as those 60's design reactors. The training and quality assurance programs that were required when I was on active duty insured safe operation.
Re:Progress (Score:4, Insightful)
Except for reactor construction did not stop after Chernobyl, a significant amount of reactors were built in Japan, but that didn't stop them from using the much older Fukushima plant.... One of the key issues with nuclear power that very few people seem to address is essentially the concentration of power generation that nuclear entails. For example the Fukushima plants provided almost 10% of the electricity consumed in the entire Tohoku region. Before the earthquake there was significant resistance towards transitioning away from the plant because of potential disruptions to factories, businesses, and homes. This dependence on one facility makes it incredibly difficult to shut down nuclear power plants, even if there may be valid safety concerns.
Now compare this to say coal fired plants. In the USA, there are 1436 plants providing 42% of the power, i.e. each plant provides an average of
In order for nuclear power to be practical, we have to come up with ways of seamlessly making up for this lost output in case a plant has to undergo an emergency shutdown. In Japan, the transition was not seamless, in Ibaraki prefecture where I live there were rolling blackouts, coupled with severe power rationing measures(it ironically helped that the earthquake put a lot of the factories out of commission for a while, significantly reducing power demand), and a mad dash to get coal and oil into the region ASAP so those plants could increase production. There has to be a better way.
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Re:Progress (Score:5, Informative)
I'm astonished you compared averages and attempted to use this to backup your argument. Go and have a look at the distribution of power produced by each of those coal plants. You'll see that the majority of the 42% comes from a few large scale coal plants, equivalent in scale to the nuclear installations.
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Nuclear power would be great, if we didn't have to depend on humans to run it.
Yes, a family of possums would be so much better.
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Indeed. Number of major nuclear disasters at plants run by humans: 20. Number at plants run by possums: 0.
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So what does this have to do with using new, safe(r) reactor designs, exactly?
Better to get them in place ASAP and replace the ancient ones, yes? Or do you propose using coal to blot out the sun, or some alternative (like fascist restriction of power production and use)?
You're like my kids. "I had a meatball with an onion in it once, and I don't like onions, so I'm never going to try anyone's meatballs ever again."
Everything would be better if humans weren't involved. However, things that were obscenely dan
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In other words, ignoring things that happen in the real world
And ignoring the subsequent, remarkable disaster recovery. I've noticed something. Nuclear power has to prove itself when things happen in the real world. And it has. Nuclear power critics don't.
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While I agree the passive cooling designs are promising, I think some people are counting their proverbial chickens before the designs are hatched. I think nuclear power can be done right, but that starts with getting a few of these promising designs built and thoroughly tested. It's not enough to get to the stage where you don't see a way the design can fail. *All* designs pass through that stage, then experience teaches us what we missed.
IIRC, it's a stretch to call the Ap1000 emergency cooling system "pa
Re:Progress (Score:5, Informative)
I'd call it "automated"
That's the first I've seen anyone characterize gravity as automation.
Since you appear to believe you have some credibility defining these terms, we should compare your thinking to those that actually do. To a nuclear engineer designing an emergency cooling system passive means no pumps, no power and no control. By that criteria the AP600/1000 designs are passive.
Everything about this emergency cooling system design relies on the integrity of containment. Containment, in this case, is a large free standing steel shell (as opposed to stressed concrete.) Threats to this vessel include kinetic impingement and corrosion. The former was the cause of a recent AP1000 design modification the NRC insisted on, based on a hypothesized attack involving an airliner. The latter can only be addressed through diligent and costly surveillance of the vessel throughout its lifetime ... just the sort of thing that tends not to survive bean counters.
The point is that there are plenty of legitimate criticisms that one can make of the design. Kibitzing about your peculiar notion of 'passive' isn't a very good one.
I think it is worth noting that the AP1000 design would have prevented core damage and radioactive release at Fukushima. The AP1000 design is exactly suited to the 'blackout' conditions that prevailed in Japan.
Re:Progress (Score:4, Interesting)
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The reservoir at the top of the AP1000 is used to provide evaporative cooling to the outer shell of the containment structure.
After 3 days the decay heat has reduced to around 0.2% of the original power. At this point convective and radiative cooling of the containment vessel is sufficient to dissipate the heat generated from nuclear decays in the fuel. The water within the containment vessel just circulates within the structure and is driven by the heat of the nuclear fuel. It is never vented.
Re:Progress (Score:4, Interesting)
That is fear mongering if I've ever seen it. Keeping water topped up is amongst the simplest things that can be done in an emergency. Even more so when you have 3 days to plan it.
I was working at a refinery when they pulled a heat exchanger out and the isolation valve was completely stuffed. Cooling water was pissing out the side and the level in the cooling tower was dropping fast. The first thing the operator did was open up a fire monitor and aim it at the cooling tower to re-fill the basin. That was done within 3 minutes. A call was placed to the local fire brigade as well incase the fire monitor couldn't keep up the flowrate (which in this case it just managed to do).
That was a 3 minute response time. I wonder what you could come up with in 3 days if you really needed to. The important thing about this is that it's simple and there's no engineering involved.
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You can read about the 0 to 3 days, 3 to 7 days, 7 days and beyond here:
www.ne.doe.gov/pdfFiles/AP1000_Plant_Description.pdf
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Re:Progress (Score:5, Interesting)
SUPO was an aqueous solution reactor tested at los alomos some time ago, although not for very long. it appeared to be self stabilizing, the closer it got to critical, the more bubbles were formed in the solution, which caused it to move further from critical.
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SUPO was also filled with highly corrosive fluids which dramatically limited the lifetime of the reactor designs and made their long-term feasibility and safety highly questionable. Newer designs are somewhat better due to the use of nitric acid, but this by no means eliminated the problem. In every other measure, notably in terms of power density and related economic figures-of-merit, solution reactors will never be competitive.
Re:Progress (Score:5, Informative)
There exist no reactor in the western world that is capable of having runaway, "amplified" chain reaction. If you have done any research, you would realize that positive void coefficient reactors are even illegal in the US and almost no one builds them. (CANDU is the only one that has a small positive void coefficient mostly due to Pu during course of running the reactor, but that is accounted for).
The problem is ALL reactors produce enough power that they can cause the reactor to melt.
Fukushima reactors were OFF. There was NO nuclear reaction. They melted because of something called daughter elements produced in fission. I guess one can say, the meltdown occurred precisely due to the scenario you are talking about
The only "safe" passive ones are the ones used in satellites where no runaway fission is even possible because it is relying on the native radioactivity
DING DING! That is exactly why Fukushima had a melt down.
I also question your understanding of AP-1000. The design is clearly passively safe. It requires no moving parts to maintain cooling of the native radioactivity of the daughter elements.
Re:Progress (Score:5, Informative)
Then what generated the heat that caused the meltdown?
Radioactive decay, not fission.
It still has a cooling system with moving parts. Why?
I am by no means a nuclear expert, but my understanding is that:
(a) the passive cooling is for when the reactor is shut down but cooling off (think Fukushima), not while operating
(b) normally you need to move the heat over to the turbines in the most efficient way possible
Re:Progress (Score:4, Insightful)
Radioactive decay, not fission.
The decay was an atom splitting into two smaller atoms and energy, which is fission. From the three dictionaries I looked up, "decay, not fission" is a contradiction, as the decay in question was necessarily *also* fission.
I am by no means a nuclear expert, but my understanding is that: (a) the passive cooling is for when the reactor is shut down but cooling off (think Fukushima), not while operating
The question was of why would fukishima need active cooling when passive cooling is so "easy" to do.
Re:Progress (Score:5, Informative)
No-one said passive systems were easy, in fact they are quite difficult to design and required modern computational power to produce. That is the stark difference between the old designs and the new designs such as the AP1000 - computing power. We can now model the nuclear, thermal, chemical and structural processes to a degree that was impossible when the first and second generation nuclear designs were produced. This is one of the reasons we can much more confident in the generation III+ reactors.
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Re:Progress (Score:5, Insightful)
The question was of why would fukishima need active cooling when passive cooling is so "easy" to do.
That's like asking why the Ford Model-T couldn't do 200mph since a modern Ford Mustang can.
The answer is because the Fukishima Reactor wasn't designed to be passively cooled, the AP1000 is.
Re:Progress (Score:5, Informative)
Nuclear Engineering (student) here.
>The decay was an atom splitting into two smaller atoms and energy, which is fission.
Fission in the context of engineering refers to the use of neutrons to force atoms to split, not to naturally decaying isotopes.
>The question was of why would fukishima need active cooling when passive cooling is so "easy" to do.
Because it wasn't designed to use passive cooling. Passive cooling requires your reactor to be designed to facilitate it (all gen 3+ are designed like thisâ"I believe the NRC refuses to certify anything that is nonpassive). Passive cooling refers to not requiring power to run the coolant pumps or anything. The AP1000 is designed to using convection of steam inside the containment building to cool the reactor.
Re:Progress (Score:5, Informative)
Re:Progress (Score:5, Insightful)
No. The decays in question occur when a neutron within fission product (the nuclei created after the U235) converts into proton together with an electron and a neutrino. Each decay releases around 1 MeV of energy (order of magnitude) as opposed the 200 MeV from the fission process. The processes reduces in intensity in time. Right after a scram the "decay heat" is 7% of the full power of the reactor. After 3 days it reduces to around 0.2% of the original power.
It was by no means easy to design an economical reactor with the kind of passive safety cooling provided by the AP1000. I can imagine why you think it was.
Re:Progress (Score:5, Informative)
Re:Progress (Score:5, Insightful)
Re:Progress (Score:4, Insightful)
But somehow, no matter what hits a nuclear plant (be it an earthquake or an asteroid), its still a nuclear disaster.
There's no "somehow" about it. If radioactivity escapes from the plant and causes health problems (or evacuations to avoid health problems) then it is a nuclear disaster because of the problems caused by the escaped nuclear material.
If an earthquake damages a nuclear plant but no radioactivity is released, it is not called a nuclear disaster because it isn't one.
Re:Progress (Score:4, Insightful)
Agreed. But what we should have taken away from the recent disaster is not how inherently unsafe nuclear power is, but how destructive the double-whammy tsunami was and that nuclear plants built in areas at risk of such disasters should have more fault tolerant designs.
If a disaster causes a technology to fail, the rational course of action is to make it disaster-tolerant; not to abandon it outright.
Safety Scissors (Score:2)
You made this statement sarcastically, right? Or are you going to split hairs and call this [wikipedia.org] some other type of accident other than nuclear... public relations perhaps?
Don't get me wrong, I think nuclear power *can be* and *usually is* used safely but 100% might be a bit overstated. We have a ways to go yet to call it anywhere close to 100% safe. Nothing is 100% safe, not even safety scissors, and a nuclear reactor is hardly as easy to operate safely as say, for example, safety scissors.
Re: (Score:3)
Re:Progress (Score:5, Informative)
Is an even older plant than Chernobyl.
Re: (Score:3, Funny)
http://hardware.slashdot.org/comments.pl?sid=2587564&cid=38467290 [slashdot.org]
Re:Progress (Score:5, Insightful)
"I dare you to name just a single nuclear accident in the last few years"
"Fukushima Daiichi?"
I wouldn't call that an accident. One must keep in mind that it was hit by an earthquake and a tsunami. What else would you expect?
If it were an error due to an operator or faulty equipment, then that would be a different story.
Re:Progress (Score:4, Insightful)
"I dare you to name just a single nuclear accident in the last few years"
"Fukushima Daiichi?"
I wouldn't call that an accident. One must keep in mind that it was hit by an earthquake and a tsunami. What else would you expect?
If it were an error due to an operator or faulty equipment, then that would be a different story.
If it wasn't an accident, who caused it on purpose?
Re:Progress (Score:5, Funny)
Re:Progress (Score:4, Insightful)
Re:Progress (Score:5, Insightful)
It is easy to criticize the event in the aftermath of three meltdowns and say that the design was flawed and that the response was mismanaged. You might even go as far as to say that the accidents weren't caused by the earthquake and tsunami, but by the failure of humans to properly design and operate the nuclear power plant (which in fact you did).
There is a point where you can't design for the most improbable events. A meteor landing in the ocean or North Korea bombing the plant aren't items you can design for. You also need to make a cutoff for earthquakes and tsunamis. An earthquake 10 times larger than any earthquake previously recorded in Japan's extensive seismic record might qualify. Add in the fact that seismologists didn't think the nature of the fault lines could even theoretically allow that powerful of an earthquake to occur.
You would have needed to build a 15m (45 ft) seawall to protect the plant from an event that experts didn't think could theoretically occur. The country that coined the term 'tsunami' didn't forget to design for it. They got hit by an extremely improbable occurrence that may not happen again for another 10,000 years. The probability of this type of massive tsunami destroying nuclear plants has not increased just because it happened recently. Nuclear plants are no less safe now than before the accidents. It is just more apparent that they have their limits, like any piece of technology.
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There is a point where you can't design for extra safety, but this is not Fukushima I. It used reactors that were obsolete at the time of construction and that should have been retired after Chernobyl, or at least after the Kobe earthquake in 1995. Only complete retards, blinded by greed and backed by "old boys" in the government regulatory bodies -- that is, the TEPCO management -- would have allowed Fukushima.
It is not the only serious accident in Japan either, and it isn't the only serious accident wher
Re:but (Score:4, Informative)
It only needs to be as safe as automobiles, and it far exceeds that.
Re:Good, good. (Score:5, Informative)
If you haven't seen, the scale of construction on these projects is mind-bogglingly large. See here for some juicy pictures of the site under construction [nuclearstreet.com]. It's just astounding.
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