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NRC Approves New Nuclear Reactor Design
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."
Nuclear power is just as safe as any other electricity.
It's the heat source that is the problem.
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. It's just astounding.
"Diplomacy is something you do until you find a rock." --Richard Pound
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.
Lets start refering to The War Against Terror by it's initials. . .
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. From what I understand Thorium (especially LFTRs) are far safer. They are "walk away safe". My suspicion is that it is too late for the US to catch up though. As the article mentions..China already has a bunch these coming online in 2013...while it just got approved in the US. China is also filing more patents...they are progressing much fast than the states at this point. China and thorium: http://www.telegraph.co.uk/finance/comment/ambroseevans_pritchard/8393984/Safe-nuclear-does-exist-and-China-is-leading-the-way-with-thorium.html The US and their history with thorium and further thorium info: http://www.youtube.com/watch?v=P9M__yYbsZ4
Ignoring the massive earthquake, tsunami and the ancient reactor design of course...
Still 56MW short of doing anything useful...
Is an even older plant than Chernobyl.
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.
Remain calm! All is well!
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.
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 is decent.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
It is not a new design, it's just the newest of the old designs (1980s via Toshiba in Japan) that haven't had a single reactor commissioned yet. The first AP1000 is due to start running in the next year or two. Things move slowly in civilian nuclear power so it's just about the first design to take the lessons from Chenobyl into consideration.
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.
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.
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.
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.
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.
+1. If a building collapses due to an earthquake, it's not a civil engineering disaster, it's a NATURAL DISASTER. But somehow, no matter what hits a nuclear plant (be it an earthquake or an asteroid), its still a nuclear disaster.
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.
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
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
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.
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.
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.
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.
JoeR
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.
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.
"Don't be a martyr -- BE THE ONE WHO GOT AWAY!"
"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.
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.
Nuclear engineer here. Decay is not Fission. Fission is splitting the atom. Decay is the act of a radioactive atom to reduce itself closer to a stable groundstate. Fission is controllable and is directly related to neutron population, and if we stop neutron production with control rods, fission stops. Decay is not controllable, and happens all the time no matter what until the material reaches a stable ground state. All light water plants, except the AP1000, need active cooling. (The GE ESBWR doesnt need active cooling either, but its design isnt approved or even completed yet). After shutdown the core is still boiling about 600 gpm of water at 1000 pounds pressure (in a BWR). this is due to the radioactive WASTE products decaying. The fuel isn't doing anythign after shutdown, but the waste products are trying to become stable again.
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.
Nuclear engineer here The plant actually runs on generator power under normal conditions. Nuclear plants have 4 AC power sources. The normal source is taking generator power BEFORE it goes out to the power grid in through the auxiliary transformers and then using internally for 4160 and 6900V power. Because this power hasn't gone to the grid yet, we don't "pay" for it. Additionally, when we are shut down, we can disconnect the generator and backfeed power in through the aux. transformers for power. This is typically an emergency/contingency action or an outage action to allow us to work on the reseve power system. The standby source comes in from a different grid (or a different part of the same grid), and comes in from the reserve auxiliary transformers (sometimes called startup transformers). Because this is bringing power in from the grid, we "pay" for it (we get billed by the grid). The emergency reserve transformer (sometimes called backup transformers) comes from a completey different grid than everything else. They power ONLY safety systems. Normal systems cannot use it. The diesel generators are safety seismic and environmentally designed backup power systems. There is 1 DG for each primary safety division which has a decay heat removal function, and an additional DG for coolant injection. Most plants also have a fourth or fifth DG for DC power chargers only. There is enough fuel on site for a minimum of 1 week for all generators running 2% above maximum theoretical load of all equipment under worst case design conditions. The reality is you can probably get another 2-3 days past that since it assumes that like, air coolers and air heater are both on at the same time in the same area, and once you've stabilized an accident or emergency condition you can put most of the redundant safety systems into standby to conserve fuel.
Sattilites use RTGs, not nuclear reactors. And RTG makes use of decay heat and the seebeck effect to generate a voltage difference. Very different from a nuclear reactor. As for nuclear power plants, the chain reaction is not "amplified", it is a chain reaction, nothing more or less. We actually control it using control rods and neutron absorbers. These plants can shutdown in less than 3 seconds, and only once has a plant failed to scram when called upon, and the backup scram system automatically did the job instead.
The problem is the NRC notices this stuff. I'm going to take a guess you've never been questioned by the NRC, but I have (nuclear engineer). They get on top of even the smallest hint of bullshit or mistake in logic or even poor quality packages. They would have already known that you are missing a safety system which they REQUIRED you to have and you LEGALLY COMMITED to have and you would have your project stopped and reviewed again which would caost MUCH MORE than 15% to get the project moving forward again. We are told to never ever challenge our NRC commitments or requirements, because the cost of messing up is a LOT more than what you 'could' gain by cutting something.
"who caused it on purpose?" It was an act of God. That is what Gods do. They make stuff and then they destroy it again, just like a small child playing in the mud.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
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.