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China to Pioneer Melt-Down Proof Reactors
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.
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
watch this
The US is eventually going to have no choice but to go back to the nuclear "well" like it or not if we want to keep this standard of living.
In all likelyhood, extractable oil supplies are finally in the process of peaking, permanently altering the supply/demand equation for crude.
Coal will work for awhile, but IMO should be considered much dirtier than nuclear power.
We may be able to switch to a hydrogen based fuel cell economy for cars, but the hydrogen is going to take a lot of energy to generate. It's going to have to come from nuclear; there just aren't any other commercial technologies available to take its place.
The US is shooting itself in the ass by not beginning to build new nuke plants now. I'm glad to see someone is actually moving this technology forward. Nuclear waste is manageable.
Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)
http://www.lawrenceperson.com/
Speaking as a US citizen *we* want success but some of *us* will shout down and protest any and all attempts to research and/or build Nuclear Reactors.
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.
Not just China. I know someone who has just accepted a job to help develop a pebble bed reactor in South Africa. And he is not a nuclear scientist but an electrical engineer: i.e. they are actually building something. See also http://en.wikipedia.org/wiki/Pebble_bed_reactor
Paul Beardsell
Should this spread from China to the increasingly energy-hungry South Asian and African nations, will it have to be as heavily controlled as conventional reactors? Is it possible to use a pebble bed reactor to create weapons grade uranium or plutonium?
Where did you get those numbers?!
;-)
Brazil runs a very successful ethanol program for many years now. It had a low a couple years ago, when engines running on gasoline had a technical edge (largely due to imported vs homegrown technology issues), but now most factories (GM, Fiat, Volkswagen) offer cars with dual fuel engines. In fact, since 1986 I only had two fossil-fuel running cars. My current one has never even tasted gasoline
True - ethanol still creates CO2, but at least you can grow it on the field and hope it absorbs a lot of CO2 before you harvest it.
I think if ethanol was that bad a fuel we would have noticed that by now.
http://www.dieblinkenlights.com
Certainly not until waste disposal and security issues are dealt with. The Yucca Mountain plan is a technological and political failure, and the more fissionables are around the more likely they are to fall into the wrong hands.
And we can't sensibly say to the developing world, "We're building fission plants, but if you start building any you'll get bombed."
Sticking fission reactors everywhere also would have far-reaching economic and social implications. And military and environmental ones too.
Resources would be better spent on efficiency, and fusion and renewables research, than on building fission power plants.
It's a shame that so many otherwise intelligent people are so caught up in the Gernsbackian romanace of "man has harnessed the power of the atom!". (And yes, it's a shame that so many otherwise intelligent people have an irrational fear of anything involving the world "nuclear".)
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
...nuke waste can, for the most part, be recycled. The media, however, is too busy playing boogeyman, and leading us down the path to being a 4th world country with horse drawn wagons and biomass generators providing citizens enough electricity to light a 20W bulb.
--- Ban humanity.
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.
Sometimes seventeen/Syllables aren't enough to/Express a complete
Hah, where are my mod points when I need 'em?
Good post. Funny how we're fine blowing a half trillin dollars fighting a series of wars over one terrorist attack, but we can't spend anything to secure our borders, increase our domestic infrastructure security, or develop alternative energy sources that would give us the option of just leaving the Middle East to itself.
When these wars are over and we're done "spreading liberty", we'll be totally broke, our currency will be totally devalued, and we'll be living in a police state ourselves while our e-vote-fraud elected President talks about liberty.
Oh, well. We lasted longer than most "great nations".
I dont think going nuclear is going to do much to eliminate dependence on oil any time soon, unless you make a second large leap and move transportation to hydrogen or electricity which would be more feasible if you had a huge abundance of cheap electricty. You also have to phase out home heatin oil which is still used extensively on the East Cost.
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 cleaner than coal, and the big win is to stop using coal for power generation because it is a HUGE contributor to greenhouse gas, and very dirty unless you install extensive and modern pollution control equipment. That equipment don't stop CO2 and I'm not sure they entirely solve nitrate, sulfate, mercury and lead pollution.
I'd have to agree that pebble bed reactors might be a lesser evil at this point but they aren't entirely risk free.
In particular you have to insure the integrity of the coating around the pebbles. They can and have developed serious defects in manufacturing handling. If you do compromise the exterior coating you find that inside they are propbably graphite moderator. If you get graphite hot and its exposed to Oxygen it burns furiously. It was a key contributor to Chernoybl being the epic disaster it was. You aren't supposed to have compromised coatings coupled with exposure to Oxygen in these reactors but if the unexpected happens, which it usually does in "accidents", you could end up with one or more burning or exploding pebbles which could damage more pebbles around them and you end up with a conventional chain reaction and a giant burning pile of radioactive laced graphite. Its kind of a worst case scenario, and its not real likely but just don't let pro nuke fanatics tell you that there is zero risk of an accident with these reactors because there is never zero risk in anything that is full of radioactivity and operating at high temperatures.
No doubt China can press full steam ahead and it might work for them. Thanks to being a dictatorship they can overlook safety issues and cover up accidents unless they turn epic. The world should cheer them on because China has become one of the world's largest and dirtiest users of coal, their whole country is turning in to an ecological disaster as a result, and most of the pollution and green house gases are being shared with the rest of the world.
@de_machina
That's because they both suck. Life is tough. Your easiest two choices aren't always good ones.
Fossil fuels are going to hose the climate, and nuclear power is a totally unacceptable WMD proliferation risk. Just look at the current Iran situation. It's a no-brainer that we don't want any more countries playing around with nuclear fuel cycles.
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.
That's mainly because nobody has put in enough resources into the research that would be required to make them more viable. If solar power got the multi-$Trillion dollar levels of investment that oil-related exploration, production and military security have received, it would probably be well on the way to providing 100% of the world's energy needs right now.
(I'm not talking about hippies putting expensive silicon collectors on their roofs to run their TVs either. A viable solution would probably be ocean-based and involve plastic photovoltaics or bioengineered photosynthesis.)
> Please find the way to make the reactor melt down in the above scenario
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.
Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
Actually, there's a really good article called Who Killed Nuclear Power? on the demise of the US Nuclear power industry. It turns out to be a complex mix of economics and politics, surrounding the both the Three Mile Island incident and the end of the 1970s oil crisis - it was believed that the planned power plants were not going to be needed and would no longer be economical.
Check out the article, it's really interesting.
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
Read the article, this reactor design (the CANDU) does not rely on pebble expansion for reaction moderation. The coolant itself (heavy water) provides the moderator that makes the reaction possible. Without the heavy water, there's no reaction. The generator also runs in the 900 degree F range, which is not hot enough to flash-ignite graphite. The Chernobyl reactor didn't ignite the graphite until the core reached 2200 degrees farenheit. The pebble-bed without coolant would probably back down to only a few degrees over ambient temperature without the moderating heavy water. The reactor efficiency is so low (195MW vs 2GW for a typical U.S. reactor) exactly because the pebble-bed never gets to insanely high temperatures.
So, the only time it's hot is when it's covered in water. Difficult for the graphite to ignite without an oxygen source. When it's exposed to air, the pebbles are already cooling to near ambient temperatures and can't get to the several thousands degrees it takes to ignite graphite.
Even a graphite fire is not dangerous if contained in a containment vessel. Chernobyl was only a disaster because the Russians used a single-wall design for their containment vessels, and the initial steam explosion blew that off the building. Then the core was exposed to open air. All U.S. reactors are double-walled and would have contained a Chernobyl type meltdown.
Read the article and research the design. Meltdown is prevented in this design by physical law, not by thermal expansion. (Okay, that's a physical law, but it's not the one we're depending on.)
Life, the Universe, and Everything... in my image.
It's the same device used during Cold War...the fear of the big old baby eating communist held many people in a manageable state for DECADES, even if the actual menace was, in retrospect, very limited.
Unfortunately there is no end to the fear of terrorism is, evidently, fear of being awe-struck by unexpected events..it can be evoked at any time, for instance with some other sniper killing bypassers or everything else unusual and violent.
What is missing, imho, from the picture is that people aren't afraid of terrorism...a very vocal minority, as usual, screams in terror..but it's a minority that is (probably) already terrorized by abstract concepts as "sin" and "dirty word".
From the ORNL:
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").
Ben Hocking
Need a professional organizer?
Coal contains trace radioactive elements, and when thousands of tonnes of coal is burned, trace amounts add up to significant amounts. And those radioactive elements can go right up the flue stack and into the air.
Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance
U.S. Geological Survey Fact Sheet FS-163-97
pdf
archive.org cache
Karl S Kruszelnicki, What else might be in your Ceiling Dust?
link
archive.org cache
The significant problems we face cannot be solved by the same level of thinking that created them. -Einstein
Ocean based might work.
... irresistable.
I've always been taken by the idea of SPSS, though. Just take a mirror and a stirling engine in orbit, convert the output to microwaves, and beam them down to a chosen target. You'd need to be a bit picky about the exact frequency you used...it has to penetrate fog and rain without much loss, so you pick a frequency that finds water transparent. You don't want it to be too low a frequency, or it won't be directional enough, and your antennas will need to be too large. At a guess a wavelength of a foot might work. (Need to check and be certain that people and cows don't start acting as antennas...you might need a longer wavelength.) Put the antennas out in the pasture (or on top of the windmill?).
I understand that a well designed antenna gets well over 90% conversion..but that would only apply to the waves that it intercepted, so you'd want antenna farms laid out in circles, with sufficient(?) antenna overlap. The antennas at the edge shouldn't be receiving anything. If they do, you need to feedback a control signal.
This will, unfortunately, generate heat as the energy is used or lost, but that's true of any energy generating system.
The interesting thing is that this would be relatively inexpensive to test. (You start with a very small test plant.). Also, if it works, it could be used to power other objects in orbit. (For that you probably use a maser to transmit the power, but I'm not sure of the efficiencies of that conversion. Perhaps a spare bank of klystrons (or whatever you use with power transmission).
N.B.: Of course this would require some testing and development. Even getting the Stirling engine to work in a vacuum would require experimenting on lubricants. (You REALLY want to keep the failure rate down!) But I think it could be a lot easier than many of the proposals I've seen.
P.S.: Yes, one could use solar cells. But I find the idea of steam engines as the power source of the future to be
I think we've pushed this "anyone can grow up to be president" thing too far.
The Mag-Lev that connects Shanghai's Long Yang Road subway station with Pudong International Airport has a maximum speed of 431kmph (there is a spedometer in each car to advertise its cruising speed). This is not its actual maximum speed, but given the length of the track (I think it only goes about 40km) it doesn't make sense to accelerate further.
While the TGV has gone 500kmph in speed tests, it rarely passes 350 when actually carrying passengers. Having said that, the TGV is a much smoother ride than the Mag-Lev, but then it is also much more mature technology.
I do believe the Mag-Lev in China is the fastest train in the world, at the moment, in terms of actual speed achieved in regular use. Of course, a mag-lev design removes track friction and so it makes perfect sense that it should be faster than any rail-based alternative.
The Mag-Lev was designed by Germans, though, IIRC, so I'm not sure it's an example of Chinese innovation.
You forgot Thorium. Thorium, which is plentiful, can be bred into U233. Also, there are "proliferation resistant designs" that propose using such http://www.thoriumpower.com/ technology.
Intersting that for all your knowledge of the pressure of a PBMR, you assume (completely incorrectly) that the primary coolant loop is used to turn the generators. There is no reactor design that I know of where this is true. The primary loop carries radiation, and the idea of pumping radioactive material through a turbine from high to low pressure (because that's how turbines work after all) would mean all of the equipment in the generator house would quickly become radioactive. Not very conducive to generator maintenence.
On the other hand, in the real world, the heated primary loop runs to a heat exchanger where it heats the secondary loop, usually water from a river or lake, that is flashed to steam, run through the turbine and then used to pre-heat the incoming water in those big concrete cooling towers that everyone associates with nuclear reactors (even though most coal and gas fired plants have them as well.) The water is then either recycled (rare) or returned to the water source (river or lake) at slightly elevated temperatures. This means that the secondary loop is only "exposed" to a minor dose of radiation (through radiation leakage through the heat exchanger) before it is dumped. The overall radiation level is usually barely higher than background on release of the secondary coolant.
Thus, the primary coolant (in this case Helium) is locked in a closed cycle at a fixed pressure and exchanges heat to the secondary coolant loop. It never sees a turbine and is probably driven by high-speed impeller pumps in a closed loop. No turbines. The gas is kept at high pressure because helium is such a rotten carrier of heat. Liquid sodium is much better, but poses all kinds of other problems. The U.S. uses a lot of water steam, but high-temp steam is extremely corrosive.
Again, surprising that you would think that the primary loop is used for turning the turbines.
Life, the Universe, and Everything... in my image.