China to Pioneer Melt-Down Proof Reactors 846
pease1 writes "FT.com reports China is poised to develop the world's first
commercially operated "pebble bed" nuclear reactor. If successfully commercialized, the pebble bed reactor would be the first radically new reactor design for several decades. It would push China to the forefront of development of a technology that researchers claim offers a new "meltdown-proof" alternative to standard water-cooled nuclear power stations." This was mentioned in September of last year but now looks as though the plan is moving forward.
Funny... (Score:5, Insightful)
Face it: from a standpoint of physics, wind, water, and solar, and the mechanisms for extracted energy from them, are NOT ENOUGH to sustain any semblance of the current lifestyles, right or wrong, without drastic and dramatic changes that would have far-reaching economic and social implications. We need to REPLACE the power sources we aim to wean ourselves from. And nuclear is the answer. Yes, there can be conservation. Yes, there can be debate. Yes, there can be compact fluorescents and LEDs. But those will only affect so much. Our energy requirements, as well as those of the rest of the world, are growing, and we should be leading the fucking way on the front of nuclear power, INCLUDING fusion, building new plants, and making a lot of investments in this area.
And we're simply not doing that. Fuck it: people say Social Security is the "third rail" of American politics? Energy policy is the power plant that electrifies it.
Perhaps China's communist regime has an advantage after all: they can actually do things that will be GOOD for their country, like building nuclear power plants without endless ranting and raving from protesters, and storing waste safely in places like Yucca Mountain (because having waste at ~150 temporary, insecure facilities is certainly better than having it at one site, imperfect as it may be).
Re:Funny... (Score:5, Funny)
Nono, that's "nucular [radlab.com]". "Nuclear" stuff is good - "nucular" stuff is bad.
Re:Funny... (Score:5, Funny)
I like nuclear power because the FRENCH who are smarter than Americans like nuclear power.
Now I think between you and me, we've manage to troll the entire known universe with just two posts.
Re:Funny... (Score:3, Informative)
In some ways this has turned out well for us because we are jumping straight from Generation 1 to Generation 3/4 power plants, which are safer, produce less waste, and are cheaper to run.
Re:Funny... (Score:3, Informative)
A pebble bed reactor cannot melt down. The hotter it gets the less energy it produces. If it overheats the fission reaction fails.
This is where the Chinese are making what I believe to be a great decision. Why bolt 8 zillion safety mechanisms to prevent a meltdown when you can forego all that cost by bu
Re:Funny... (Score:3, Insightful)
Insightful? How is nuclear power going to replace oil? Nuclear plants produce electricty; over half our
Re:Funny... (Score:4, Informative)
Then you are back to burning fossil fuels to produce electricity, and then to produce H2, which will then be converted to electricty again to drive car motor.
It's easy to see that with each conversion there are inherent inefficiencies and energy is lost. If you are using fossil fuels to produce the electricity, it would be much more efficient to just burn the fuel in the cars engine to extract its energy in one step.
Re:Funny... (Score:3, Insightful)
Ah, the idiotic strawman of the pro-nuclear crowd rears its head again. Where are these mythical people who automatically engage in "endless ranting and raving" protests against anything involved with nuclear energy? I hear them vilified on slashdot a lot, but I never seem to meet any of them in real life. Probably because for the most part they don't exist. But it's a lot more convenient to blame these illusory peop
Re:Funny... (Score:3, Informative)
Meanwhile there are several coal power plants in the state that are polluting the air, making eating fish dangerous.
Re:Funny... (Score:5, Informative)
I believe these are the people you're looking for [cnn.com] (scroll down a bit).
Re:Funny... (Score:3, Informative)
The waste isn't nearly the issue that it's made out to be. The problem is that the risks are overhyped. Tens to hundreds of thousands of deaths a year are attributable to cancers and respiratory disease caused by fossil fuel burning to produce electricity. For example, most of the southwest corner of Colorado and the northwest corner of New Mexico have high levels of sulfur, cadmium, mercury, and even radioactives in the air because of coal-bu
If you think that's funny, check out this: (Score:5, Interesting)
From the ORNL [ornl.gov]:
I first heard this fact from a professor of mine, and it made sense at the time as coal is ultimately a source for uranium as well as radium. (That's where the Curies got their uranium from, after all.) This is the first time I did a web-search to verify his statement, and I wasn't surprised to see that it agrees with other people's calculations (Google for "coal radiation").
World balance of Power and Energy (Score:5, Insightful)
China, knowing this, is actively persuing alternate energy policy including nuclear, hydrogen and more novel approaches. They want to detach themselves from the oil addiction so that they have independence from the U.S. and U.S. controled energy interests.
Again, politics.
But, the results are inevitable: As a result of these politics, the Chinese will inevitably control more advanced and more important energy technologies (both economicaly and ecologically). So the conclusion to this will be exactly the opposite of that desired by the status quo (America controlled energy). However, the administration doesn't care because they will be retired, rich, fat and happy (or dead of old age) when China turns it all around on America and effectively takes control of world energy production.
Re:Funny... (Score:3, Interesting)
Check out the article, it's really interesting.
Re:Funny... (Score:3, Insightful)
Re:Funny... (Score:3, Insightful)
2. I didn't present it as the "only way out" of any crisis, but the energy density of nuclear power and return on investment is difficult to ignore.
3. There are problems. Yucca Mountain, for example, is LESS of a problem than the situation we are CURRENTLY IN. Is it perfect? No. Is there seepage? Yes. Will it last "10,000 years"? Probably not. But the current storage is leaps and bounds WORSE in every category, not to mention being in dozens of different locat
Re:Funny... (Score:5, Insightful)
I lived within 35 miles (as the crow files) of a nuclear power plant. You know which one I felt safer around? The one that wasn't spewing tons of shit into the air.
Yeah, there's a small possiblity of something happening and people getting sick with a nuclear plant. It might even spread to other areas and affect those people's lives for generations. What bothers me is that there is a 100% possibility that the coal burning plant I was living near was spewing shit into the air that was unhealthy.
Since you are so afraid of nuclear power plants why don't you move yourself and your family within two miles of a coal burning plant?
Re:Funny... (Score:3, Interesting)
Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance
U.S. Geological Survey Fact Sheet FS-163-97
pdf [usgs.gov]
archive.org cache [archive.org]
Karl S Kruszelnicki, What else might be in your Ceiling Dust?
link [lead.org.au]
archive.org cache [archive.org]
Re:Funny... (Score:4, Informative)
After that event, thankfully instead of giving up on natural gas, they added mercaptan to make it smell bad.
Re:Funny... (Score:5, Insightful)
Just because many people are unafraid of nuclear power doesn't mean they need to move into a reactor core to prove it. If you prefer oil dependence, why don't you prove it by moving your family to an offshore oil rig? Or into a pumping station in Iraq? Please.
There are risks involved, to be sure. That goes for anything. You don't fear propane stations do you? They're everywhere, and if they blew up in your neighborhood, you'd know it. But I'm not going to ask you to build a shack with a giant propane cannister in the middle to prove it.
There are plenty of safe ways to operate nuclear stations. Most of Europe has proven this. And America is supposed to be better, right?
Re:Funny... (Score:5, Insightful)
I'm not saying there is no danger associated with nuclear power plants; but rather, the danger is a bounded, quantifiable one, and the rate of civilian deaths per year from nuclear plants per gigawatt/hour generated is almost certainly lower than the corresponding rate for many forms of energy that our society uses.
Yeah, yeah (Score:5, Insightful)
So you're saying, then, that it's better for our nation as a whole to have waste stored in unmonitored, insecure, and in some cases failing, storage containers and sites at over 150 locations randomly scattered around the country, indefinitely, than in one place that is at least quasi-permanent?
And why do I have to live within visual distance of a nuclear power plant to (correctly) say that it's a very compelling answer to our power problems? Possibly because nuclear power has been so vilified by some people that others are irrationally deathly afraid of it?
Your argument is extremely poor, because:
1.) It's based on "non in my backyard", and,
2.) You make a fallacious argument that living closer to a power plant somehow makes one more able to comment about nuclear power.
The fact is, the city where I live doesn't have a nuclear power plant. Frankly, I wish it did.
Good job using nothing more than scare tactics to frame your argument. Why, exactly, would it be bad to live close to one of the 104 operating nuclear plants [doe.gov] in the United States?
Because of irrational fear and nothing more?
Or perhaps we should eliminate nuclear power altogether! I'm sure that would help us down the road to solving our energy problems!
Re:Yeah, yeah (Score:3, Insightful)
The notion that were in foreseeable danger of running out fuel is nothing but a lazy "scare tactic".
Denial, plain and simple. We are in foreseeable danger of running out of fuel. Let's critically think this, ok?
1. We now know (possibly we've always known) that oil supplies are finite.
2. We have watched numerous wells dry up (as well as some dry up then turn around and produce more than ever).
3. We can foresee the dangers to an oil-based economy of running out of fuel.
So, we know that we can run
Re:Funny... (Score:5, Insightful)
Re:Funny... (Score:5, Funny)
Re:Funny... (Score:5, Informative)
I wouldn't trust a sodium-cooled breeder worth anything - look at the MONJU accident, for example. Superhot liquid sodium in a building whose protective shell is made of concrete (which sodium explodes in contact with)? Not a good plan.
On the other hand, the BREST reactor (a Russian lead-bismuth design) is just great. Can survive on just convection cooling, uses an unreactive moderator, great temperature range, easy maintainance, low waste, anti-proliferation, etc. What isn't there to like?
Re:Funny... (Score:5, Funny)
I, for one, will happily support anything dealing with BRESTs, particularly if we're working to increase their exposure.
Re:Funny... NOW WITH HOT HOT PARAGRAPH ACTION (Score:5, Informative)
When people talk about breeder reactors as "producing more fuel than they burn", what they mean is that the reactor is run on either U-235 or Pu-239. It produces heat energy which is converted into electricity.
At the same time, excess neutrons from the reaction are reacted with an otherwise inert blanket of U-238 around the reactor, converting the U-238 into Pu-239 which can then be used to run the same reactor, or other reactors. It turns out that Pu-239 production is faster than Pu-239 or U-235 consumption.
It is relatively easy to use chemical methods to separate the produced Pu-239 from the leftover U-238 in the blanket, certainly MUCH easier than separating U-235 from natural uranium.
So it's not a perpetual motion machine because a resource is used up, i.e. the natural U-238, but that resource is plentiful and the overall process is easier than the conventional method of getting fissile fuel.
The reason that breeder reactors aren't widely used is partly technical, because they're fairly complex things to design and operate, but mostly political because the Pu-239 produced can relatively easily be used in bombs.
Okay... (Score:3, Insightful)
Let me just say: is it possible that traditional energy companies don't just *adore* nuclear power (or ANYTHING that cuts into their profits)? Sure. Absolutely.
But there is no organized conspiracy by ANYONE in the industry to foster a fear of nuclear power. There didn't need to be. The anti-nuclear activists and some (not all) of the environmentalist movement have done that all by themselves.
Nukes light lights, not turn wheels (Score:4, Insightful)
Until we get either lots of electric or partially-electric vehicles or nuclear hydrogen, nuclear is going to be used to light lights and run motors; it will compete primarily with coal and natural gas. Gas-fired turbines are cheap to build and easy to site. Coal plants burn cheaper fuel but are harder to site and take longer, and the utilities stayed away from nuclear after the WPPSS bond default [goodmoney.com] (stemming from cost overruns on two nuclear plants and consequent bankruptcy [cato.org]). The people who run utilities have a different mindset from dot-commers; they like their jobs, and they won't keep them if things stay even moderately exciting outside of things like hurricanes and ice storms. Surprises like having your multi-billion dollar plant go from 75% complete to 35% complete as a consequence of one NRC-mandated redesign, during a period of 20% interest rates (Carter administration - look it up) are things they can quite do without. The technological, financial and political risks of nuclear are much higher than fossil-fired, and are compounded by the duration of construction.
THAT's why nobody has build a new nuclear plant in the USA for the past 25 years. With luck, maybe things will change.
Re:Funny... (Score:3, Insightful)
Re:Funny... (Score:3, Insightful)
25% of the literate population
33% of the well-fed population
12% of the Nobel prize population
Given your reasoning, we should do our best to reduce literacy, food availability, and education. Rather than demanding that the US become poor so that the poor don't feel deprived, don't you think it would be better to make everyone rich? This is not as ridiculous as you might think. The overwhelming majority of people in the US live better than any ancient or m
Least Bad (Score:5, Insightful)
Re:Least Bad (Score:3, Informative)
Re:Even funnier (Score:5, Insightful)
You think just the same way that Timothy McVeigh used to on Usenet. I thought he was a dangerous nut before he murdered close to 300 people in his attempt to do exactly what you suggest. Try a google search and look for his posts on Usenet.
Bin Laden and McVeigh are both cut from the same cloth. The most powerful tool you have for changing your government is the Web.
Bin Laden has changed nothing, achieved nothing. The IRA achieved nothing. Mao and Stalin ultimately achieved nothing.
Ghandi won India's freedom without a shot being fired. Lech Walensa in Poland, the Velvet, Rose revolutions, far more is achieved with the power of speech than has ever been achieved with guns.
The East Germans I met in the 1980s never asked for guns, they wanted photocopiers and type writers. They knew what they needed.
Decomissioning waste (Score:5, Insightful)
Unfortunately these reactors will still produce quite a bit of waste, and will still need to be decomissioned. Given how poorly the western world handles these issues, i can't imagine how well it'll be done elsewhere...
Re:Decomissioning waste (Score:3, Insightful)
Why is it that we tend to assume that we (in America - which is what I assume you mean by the Western world) always do things better? So just because we do a poor job of handling our waste, that means China will automatically do a worse job?
Remember, this is a country with over 3000 years of continuous existence, compared to our 200 years. I would suggest to you that they may know more about
Re:Decomissioning waste (Score:3, Insightful)
This incredible naivité made my day. Thank you.
What is the world coming to? Don't the kids of today learn any cynicism while growing up!?
I could Google for some references on pollution in China, but you can do that yourself. (N B, China is a closed society that wants to look good.
This can only be good if... (Score:4, Funny)
Re:This can only be good if... (Score:5, Funny)
Judging from how many McDonald's french fries have to be eaten to produce a tank of biodiesel, nuclear energy produces no waist at all.
And I thought commies were bad! (Score:5, Insightful)
"If you don't like this nuclear facility next to your rice paddy, you can go to jail."
As China's growth continues to surge, there will be more examples of China taking the lead in things- both good AND bad. When the government can tell you what to do (or else), things get done.
Re:And I thought commies were bad! (Score:3, Funny)
Foreign Visitor: How is that new reactor going?
Government: Perfect, the answer to all our power needs.
Foreign Visitor: Why are those people bald?
Government: Ummmm, those are Charlie Brown impersonators, we can't get enough of that lovable Charlie Brown.
Foreign Visitor: and these three legged dogs?
Government: We love that Alice in Chains album too. Nothing else to see here, m
Proof (Score:5, Funny)
Just me then? OK.
Re:Proof (Score:5, Informative)
The reactive elements are spherical pebbles, each with just a tiny amount of radioactive material inside.
Individually, they do not have enough material to go critical.
when you put them all together inside the reactor, the shape of them puts its nearest neighbour just in range to react.
If the reaction begins to cascade, the elements heat up and expand. This automatically seperates them and cools the stack back down.
You can pour new elements into the top, and extract the lowest from the bottom in a relatively safe manner.
So what happens when the pebbles crack open? (Score:3, Interesting)
Imagine one peb cracking, and depositing the stuff on the bottom of the bed, which reacts more strongly with a few more pebs, causing a hot spot and some convection, which can crack more, etc.
Some things that seem to be missing from the popular accounts: just what the pebs are coated with, how tough they are, and how long they are supposed to hold up to constant expansion and contraction.
Re:So what happens when the pebbles crack open? (Score:4, Informative)
The reactor design (when functioning normally) is basically self-moderating. The "constant expansion and contraction" should only be a few degrees - it shouldn't be enough to cause serious thermal stress and/or fatigue on the pebbles.
I am not a nuclear engineer, so take this with a grain of salt...
Meltdown in China (Score:5, Funny)
China's rise to power (Score:5, Interesting)
Somedays I'm convinced that China will become the sole economic superpower in the world in our lifetime. The US may still have a powerful military decades from now but it really looks like the Chinese want success more than we do. The fact that they are moving ahead with nuclear power is an example. Here in the US, you just can't get any kind of nuclear power plant built. We continue to use rediculous amounts of electricity but resist any attempts at becoming self-sufficient. The Chinese are hungry to improve their country while we Americans have become complacent and feel like we will always be on top. Once our debt gets to the point that other countries will no longer invest in us, we'll sink like a stone and China will take over (economically). They just want success more than we do.
GMD
Be careful what you wish for... (Score:3, Interesting)
Europe wants success too. But they measure success as everybody gets a comfortable living, everyone is cared for and no person goes hungry.
Remember, one of the most successful countries of all time was Nazi Germany.
That's my point... (Score:3, Insightful)
Hitler turned Germany from a destitute war-torn nation into an world economic power house in ~10 years. That's "success" in a lot of people's eyes. And why what happened afterwards is even more of an abomination.
Debtor vs Lender (Score:3, Insightful)
We have gone from having the most enviable public school system in the industrialized world to having the flat-out worst.
We don't invest in infrastructure, we don't protect our borders from illegal intrusion, we don't care about pollution or graft. As long as we can have the appearance of wealth...not to be confused with legitimate wealth w
Re:Debtor vs Lender (Score:3, Funny)
Besides its not like China and the others will ever lose faith in the good old dollar. I'm sure they'll just keep buying US debt forever and ever...An
Re:China's rise to power (Score:5, Insightful)
The only other option for maintaining a huge military without a robust economy is to use it to dominate the economy and resources of the rest of the world though blackmail or outright intervention.
In many respects the Chinese, and the Japanese, are already funding the U.S. military because they are the primary purchasers of the U.S. governments debt which is necessary to support the huge deficits, and a big chunk of those deficits are going in to exploding defense and homeland security spending.
If the Chinese were to stop buying that debt they can place substantial pressure on the U.S. government unless someone else picks up the slack and that is likely to get worse not better. I'm not sure of the exact mechanics but I think if the chinese stop pegging their currency to the dollar, something the U.S. is pushing hard, that may also lead them to stop buying U.S. dollars and debt.
If the Republican's were so foolish as to actualize start privatizing Social Security in the near term that is going to place even more pressure on the U.S. deficits because:
A. the government will have to make up the shortfall it will create in paying out benefits to everyone over 55
B. The current large Social Security surplus that is funding U.S. government debt will disappear meaning there will be even less money going to support the excess of the U.S. government.
Based on the recent budget it appears the Bush administration plan is to continue inflating defense and homeland security spending, continue cutting taxes for the wealthy and slashing everything else(unless it benefits big corporations that support the Republicans (i.e. the Medicare reform sham for drug and health companies, Energy bill for big oil, coal and nuke, Social Security privitization for the big banks and investment firms, CEV and missile defense for Lockheed and Boeing).
Re:China's rise to power (Score:3, Insightful)
That is pretty silly rhetoric. No, the U.S. cant wipe every Chinese peasant off the face of the earth. The U.S. could really easily wipe out every major and not so major city and most of its military and industrial capacity. There is simply no way China would provoke the U.S. to that point, why would they, everything is going their way already if they just let America transfer all its wealth and IP to them through peaceful economic
Re:China's rise to power (Score:5, Interesting)
Nah, I don't really think America has to worry about its foreign debt too much...it's 4.4 trillion dollars...like they say, if you owe the bank $1000, you've got a problem...if you owe the bank $1000000, the banks got a problem. People won't stop investing because they're relying on the money coming back to them at some point in the future...so America can happily go on incuring more and more debt because they've gotten to a stage were other countries can't afford not to let them. Smart move when you think of it, building a superpower using other people money.
Re:China's rise to power (Score:4, Interesting)
The bank's problem, as you say ? Currency is just paper, or at least it has been since the USD stopped being pegged to gold in the 70s, and the effective ultimate world currency became oil. What will happen is that China will gradually keep more and more of the shoes and DVD players that they make for their own population, trigering inflation in those countries that depend too much on imports for the comfort of their citizens.
The US govt bet is that this process will be too slow and that the Chinese population will grow impatient, spoiled and greedy, undermining the central authority and breaking up the country into a myriad of third world, submissive entities.
Re:China's rise to power (Score:3, Interesting)
Re:China's rise to power (Score:3, Interesting)
Personally I think the US needs to shape up quite a bit very soon. Many of the current trends are similar to the culture of the Roman e
Re:China's rise to power (Score:4, Interesting)
If you read the Wired article you will see that we too pursued pebble reactors, but due to the fuel rod type being more viable for military applications (like for navy ships) that is where the research dollars went and voila that's why we are where we are right now.
Second, China is not the only one to pioneer this. There have been working Pebble Reactors in Germany and, get this, South Africa soon as well.
Simultaneously its not that they want to improve their country more than we do its a question of logistics.
China has relatively few, intact, natural resources and everything is imported from much further away than it is to the United States. There still is significant coal, oil, and natural gas production in the United States, while its mostly just coal within China, very dirty and quickly being depleted.
As well the United States borders on the pacific and atlantic, making it easier for us to get goods from different parts of the world. China is 'mostly' landlocked and in a situation of future conflict (North Korea, Taiwan, Japan is not the sleeping creature many perceive, etc.) it would be very difficult for China to rely upon shipping lanes for necessary resources, hence the push for domestic capacity.
Finally, China and India simply are out educating the rest of the world. They both put out more engineers per year than exist within the United States. They do not have as much resources 'yet' but its pretty fantastic when you stop to think that an engineer in his EARLY 30s could be the head of China's space program. That being said, when you can pick the best of the best from 1.2 billion people - you get some amazing individuals.
The Western World's technological dominance will not last forever. If you want to see this as the first harbinger of that, feel free, but it is not the only sign.
South Africa (Score:3, Insightful)
oh really...? (Score:3, Funny)
Geez... (Score:4, Insightful)
So, we continue to use oil and coal.
For those of you who don't know, pebble bed reactors will allow for the increased use of the radioactive elements until they pose no significant threat. To use an analogy, the battery is almost completely drained. Also, they are inherently safer due to improved design. Their default position is one in which the reactive elements are in no position to cause any sort of melt-down.
But hey, it has the word "nuclear" in it, so it has to be bad, right?
Buncha tree-hugging softies.
I'm out.
Re:Geez... (Score:3, Interesting)
An expansion in nuclear capacity, in the near term, is primarily going to reduce natural gas use which is increasingly used to produce electricty because its c
Re:Geez... (Score:3, Informative)
http://www.newton.dep.anl.gov/askasci/gen99/gen99 4 02.HTM [anl.gov]
Nuclear Waste can be recylced and refined. Among other ways, we can use a breeder reactor to re-enrich the spent fuel and reuse it in power plants. This would greatly decrease the amount of waste left over and the leftover would be much less radioactive. For some reason, no one seems to talk about this. Partly the reason we haven't done this is that Carter put a ban on them in the US. Overtur
Great for China (Score:5, Insightful)
We're going to hear more stories of bullet trains [people.com.cn], monstrous dam projects [chinaonline.com] and now advancements in nuclear energy production.
Good for China - start investing in them now.
China is going to be the defacto innovator (Score:5, Insightful)
just IMAGINE where we would be if we spent that $280 BILLION on the Iraq war funding technology to develop alternative fuels? When will we realize that fossil fuels are such an impediment and where we could get if we got real about losing the middle east (oil)?
Well that wouldn't work at all... (Score:3, Insightful)
The war on terror has been an incredibly useful device for the Republican party...they get to broaden their appeal to military types and flat-out bigots, they get free reign to pillage Alaska for a miniscule amount of oil, they get to paint criticism as "unpatriotic", and they get to defer serious debate because of course "we're at war!".
They wouldn't
Re:China is going to be the defacto innovator (Score:3, Informative)
BZZT, you do not understand oil market (Score:3, Informative)
Seriously, the breakdown of imports and been brought up a thousand times and shot down a thousand times. Until Arabs lose control of the liquidity of the market, they control oil prices.
Re:China is going to be the defacto innovator (Score:3, Insightful)
I'm not saying whether the argument is true (although the outcome does appear
Re:China is going to be the defacto innovator (Score:3, Informative)
I say move as much energy production to nuclear as possible, and then take an incremental approach to finding better, more realistic alternatives. Electric cars, for one, powered by nuclear-benerated electricity (ya know, just plug it in overnight) could be a step in the right direction.
However I also can't deny the forces at wor
What ever happened to Integral Fast Reactors? (Score:5, Interesting)
Re:What ever happened to Integral Fast Reactors? (Score:4, Informative)
Re:What ever happened to Integral Fast Reactors? (Score:3, Interesting)
In Galena Alaska [imdiversity.com] there is proposed a reactor with a sub-critical cylinder of fuel, with a neutron-reflective sleeve that slides along it as the fuel is spent. Only the part of the fuel encased in the sleeve reacts, and if it is not moved periodically the reaction will cease. If it gets too hot a
Safe Nuclear Power (Score:4, Insightful)
Even if Yucca Mountain (or some other ground storage facility) happens, it's years and years away, and it seems foolish to continue to generate nuclear waste with no place to put it.
Actually... (Score:5, Interesting)
Re:Safe Nuclear Power (Score:3, Insightful)
CanDU Reactors!? (Score:3, Informative)
Weapons potential? (Score:4, Interesting)
Talk about religion... anti-nuclear is just as bad (Score:3, Insightful)
In China (Score:3, Funny)
Melt-downs aren't the problem (Score:5, Informative)
The problem with nuclear power isn't the big scary scenarios that the mainstream anti-nuclear community put about. The problem is that economics suck, and probably always will. "Successful" national nuclear power programmes are propped up by artificial means--either direct government investment, or special-needs laws like the insurance liability cap, or both.
Sure, coal plants pump out a lot more garbage into the environment than nuclear plants, but coal plants have two big advantages: relatively small events don't wind up writing-off the whole plant; and you can take the damn things apart and fix them relatively cheaply because they aren't radioactive.
It isn't just "unreasonable regulatory burden" that makes nuclear plants expensive--it is the fact that the available energy density is extremely high, and any departure from equilibrium can result in sufficiently high energy density to result in plastic deformation of components of the core. Once that happens they're hellishly expensive to fix. Even relatively routine maintenance is extremely expensive due to the real safety requirements of doing engineering work in a radioactive environment.
"Inherently safe" design for fission reactors is an interesting area of research, and much progress has been made, but it isn't clear that any of them are really as safe as their designers would like to believe. And again, it isn't the possibility of catastrophic, world-ending melt-down that you need to prevent, but relatively minor excursions that will leave the containment intact but make a mess of the core.
Older designs, such as the CANDU (which has a negative temperature coefficient of reactivity, if memory serves, meaning a temperture spike will damp the reaction down) are already more-or-less "melt-down-proof". But they have also proven to be bloody expensive to maintain--far moreso than coal-fired plants run by the same utility.
These are all reasons I got out of the nuclear engineering business many years ago--the core physics of fission power is such that it is very hard to create reactors that are going to be economic to operate over the lifecycle of the plant.
--Tom
Re:Thank God China is doing the necessary research (Score:5, Informative)
God, when will this myth stop propagating? They haven't been net negatives since the 1970s; and of the dozens of studies done since then by everyone from the DOE to various universities (essentially all except anti-ethanol crusader Pimental) have shown a 30-50% positive energy balance, and with current tech it may be able to scale up as high as 70%.
Furthermore, even if it were a net negative, this is completely irrelevant. Example: During WWII, the Germans made petroleum from coal. This was a costly process that used many times more energy to produce the oil than the oil contained (they burned much of the very coal that they were converting in order to power the conversion). And yet, it largely fuelled the Nazi war machine.
The issue is converting a *non-mobile* source of energy to a *mobile* source of energy that you can put into your gas tank. If an ethanol plant takes in grid power, it's eating mostly coal. If it doesn't use grid power, it's most likely burning ag waste or other local non-mobile sources of energy. It's not like they're burning ethanol to produce ethanol
Of course, this is all irrelevant: Ethanol *IS* a net positive.
Don't make me come over there (Score:5, Funny)
Well, you'll be glad to know that the Chinese pebble reactors will, more than likely, not encounter any icebergs.
Re:Meltdown proof? Hah! (Score:5, Informative)
First off, meltdown aside, their moderator is *graphite*. Their emergency cooling scenario is that air will cool the reactor. Nice, except for the fact that even nuclear grade graphite will burn in extreme conditions quite fiercely (it was the burning graphite, more than anything else, that spread the radiation from Chernobyl). Hot graphite also produces explosive hydrogen gas in contact with water (in fact, many of these plants are going to be designed to produce hydrogen from water, so we know it will be present, even if in a different loop).
The very concerning thing is that they're so confident about them that they're not planning to build containment structures. Pebble beds are a nice design, mind you, but they're not *that* safe. A single graphite fire starts, and you've got another chernobyl that destroys a large swatch of land (it's not the casualties from nuclear events that are the problem, but the land rendered uninhabitable). Nuclear accidents have been, unfortunately, surprisingly frequent; it's the containment structures that have kept the danger that they pose limited.
Then, there's the problem with the pebbles themselves. Even in normal conditions, the German prototype experienced pebbles jamming. The safety against meltdown for the pebbles is that their expansion coefficient is designed to reduce the rate of reaction of the fuel; however, if the pellets jam against the sides as they expand, this safety won't help. This may or may not to prove to be an actual problem, of course.
I'd much rather see them go with a lead-bismuth breeder. It's a breeder (so you can utilize more fuel), it produces less waste, the waste is easier to handle, it's anti-proliferation, there's no graphite, there's no pellets to jam, etc.
Re:Meltdown proof? Hah! (Score:5, Informative)
Re:Meltdown proof? Hah! (Score:3, Informative)
Re:Meltdown proof? Hah! (Score:5, Informative)
Second the hydrogen production is not going to be from hot graphite in contact with water. The Hydrogen production will not be in any loop of the reactor but will be at the ends of power lines coming off the generator. This is not a safety factor with the reactor.
Third as far as lead-bismuth goes I only know of one production reactor that used that. The power plant for the Alpha class sub. Guess what it was a disaster. All of them have been withdrawn from service.
Should they still use a containment dome? I would say you bet. Seems like very cheap insurance to me. If nothing else it could help to protect if from terrorist attack or even milliatry action.
All of you points though are just not issues except for maybe the lead-bismuth breeder. I would have to do more research to see what the state of the art is with those.
Re:Meltdown proof? Hah! (Score:3, Informative)
Above 1250C, SiC degrades relatively easily in a reactor environment;. it has varying degrees of instability above 900C, and remember that PBMRs are definintely not low-corrosion environments. A coolant-devoid reaction in a pebble bed maxes out typically around 1600C (sometimes lower); too low for meltdown but not too low to seriously jeapordize the graphite.
> The hydrogen production will not be in any loop of the reactor but will
> be at the ends of the power
Re:Meltdown proof? Hah! (Score:3, Informative)
The concept of pebble-bed reactors was developed in the 1950s by a german scientist named Rudolf Schulten. The first prototype had been in use between 1966 and 1988 when the project was discontinued after the chernobyl incident. The protoype used helium as a coolant but other ine
Re:Meltdown proof? Hah! (Score:3, Informative)
And having many small nuclear power plants is much more safer than having one megasized nuclear power plant to power an entire city. Why? Simple, compare what happens if one huge plant fails than if one small plant fails.
And IIRC, the material to be heated
Re:Meltdown proof? Hah! (Score:3, Informative)
So, if you want to claim that it has been "tested" against failure, point to where they:
* Jammed the pebbles and then shut it down
* Ruptured the containment vessel while it was operating
* Detonated hydrogen gas in the hydrogen production loop to see if any wate
Re:Meltdown proof? Hah! (Score:5, Informative)
On the other hand, pebble-bed reactors do not rely on making it difficult to meltdown, they rely on the fact that the natural state of the reactor bed is a "safe" condition. (No, that doesn't mean you can stick your head in it, just that it will not maintain a chain reaction.) So, in the case of a pebble-bed reactor, if you take away all the coolant, the reactor shuts itself down. The coolant (or more accurately the heat-transfer media, since it's used to move heat from the reactor core to the heat exchangers to make steam to turn generators) is integral to the design of the reactor.
To have a sustained reaction, there must be coolant present. If the coolant is present, then the reactor cannot melt down, because it's covered in coolant. If the coolant were to be allowed to boil off, then the reaction cannot be sustained and the reactor shuts off. So, Coolant=no meltdown, no coolant=no meltdown. Please find the way to make the reactor meltdown in the above scenario...
Give up? That's the difference between engineering and physical law. I can engineer a damn tough ship, but physical law says that if I add enough weight, it'll displace more weight than an equal volume of water, and it will sink. On the other hand, if I have a pebble and it releases X number of neutrons, nothing I can do will increase that number of neutrons or moderate them in such a way as to cause a chain-reaction, except adding a moderator, which, in-turn controls the chain-reaction. It's like claiming that I can make a light bulb that's hot get hotter and melt-down by turning off the switch.
Pebble-beds have been built and tested in the harshest ways, and no reaction can be sustained when the pebbles were "exposed" without the sustaining material. The only way to make a pebble-bed melt down is to take the pebbles, grind them down, extract the fissile material and make a regular nuclear reactor out of them.
And that's the whole point.
Re:Meltdown proof? Hah! (Score:4, Interesting)
Simple: Pebbles jam. It happened in Germany. If they're jammed, they can't expand properly.
Of course, the biggest risk for a pebble bed is not meltdown but a graphite fire.
Re:Meltdown proof? Hah! (Score:4, Informative)
Re:Meltdown proof? Hah! (Score:4, Informative)
Why don't *you* RTFA? They're not building a CANDU, they're building a PBMR. Furthermore, pebble beds run in the 900C range, not 900F. Their "loss of coolent" scenario is as high as 1600C - plenty to burn graphite. I can skip all of your comments about "covered in water", because CANDU uses water as a moderator, not pebble beds (strange that you would think that CANDU uses graphite, however...)
AFAIK they are building THTR-Type Devices. That are Pebble Bed Reactors which are cooled by Helium.
This type of device is inherently safe from meltdown because
which is absolutely inert
The german THTR-300 at Hamm-Uentrop has been a demonstration reactor at commercial size (300 MW). It was shutdown after proving to work well.
The reason to cancel the further development and building was completely political because there is no chance to get public acceptance for any Nuclear Powerplants all over Germany after Tchernobyl and Three Mile Island.
The reactors themselves may be safe, but the problems of the required fuel production and handling, especially the waste disposal, are nowhere in the world sufficiently solved. Thats a truth whatever the Nuclear Industry and there political gofers may say.
CU
Re:Meltdown proof? Hah! (Score:3, Informative)
2) The "safety" mode of cooling is air cooling - i.e., if the reactor is ruptured, air can come in and cool it. In such an event, though, the graphite can burn.
3) The pressire is quite high in PBMRs; one that I read about was 69 bars for the core (a bar is roughly 1 atm). If it's not high, it won't run a turbine very well, now will it?
4) The German reactor was shut down due to a variety o
Re:Meltdown proof? Hah! (Score:5, Insightful)
On the other hand, in the U.S. Nuclear Reactors have killed how many civilians? So far as I know, the number of civilians killed in nuclear accidents at power plants is... zero. Yes, there have been deaths of workers, yes, you could argue that a few plants have leaked radiation here and there, but when you consider that the CDC is claiming 30,000 deaths a year from coal plants in the U.S., it makes for a hell of a weak argument.
Besides, the "safe" claim isn't even being made by the U.S. government, it's coming from China. As for me, I think nuclear is a great idea, and I'd rather be living 10 miles from Yucca Mountain than the 10 miles I currently live away from a coal plant that's rated one of the cleanest in America.
As for your "dirty bomb" statement, yeah, give it a try. Start by walking into a nuclear power plant, past the six layers of security. Then enter the core, ignoring the fatal dose of radiation you'll be bathed in. Grab hold of a few dozen pebbles, ignoring the heat that burns the flesh off your hands and arms. Take them home. Grind them up, again, ignore the fact that the fumes of the uranium or plutonium are among the most powerful and fastest acting poisons known to man. Use fluorine (a controlled substance also instantly fatal if breathed) to create UF6 to separate the Uranium from the graphite gas. Then use a million dollars of platinum to catylize the UF6 back to uranium metal. Stick it to 100 pounds of C4 and detonate it in downtown New York. Of course, the fact that you'll set off every airborne neutron detector that homeland security and the air force (and a half-dozen spy satellites) have before you leave your house might slow you down. Not to mention the continous man-hunt looking to find you.
You may not trust the government with this stuff, but consider the alternative. If there's one thing I'm not worried about in this country, it's how well our fissile material stockpile is guarded. When you realize that it takes three semis, twenty secret-service agents, the FBI and the army to move 20 grams of *spent* material to be used as the thermal warmers for the Pathfinder rover, you realize that the government is very serious about the security of this material.
story from "Managing Martians" by Donna Shirley
Re:PBR Fuel is clad in graphite (Score:3, Informative)
Re:Titanic (Score:3, Insightful)
If you want to make a comparison with the Titanic, you should carry it all the way. This reactor is meltdown proof, the way the titanic would be unsinkable had it been placed in a desert. That is to say, it is possible it could sink beneath the sand and vanish, but there is not any scientific support for a theory as to how it could happen.