China The Dominant Superpower In 20 Years..... - What does this mean for US?

smurf975 · 2004-09-05 17:36:39

Hydro power sounds 'green' on first glance, but isn't, as Grypd pointed out: loss of valuable aerable land, flooding of cities, villages (and polluted grounds from factories, based there(!)
irrigation headaches downstream...
So: yay for the pebble bed reactors, bring 'em on!

From the same article (P3, last three paragraphs):

Coming to terms with nuclear energy is only a first step. To power a billion cars, there's no practical alternative to hydrogen. But it will take huge quantities of energy to extract hydrogen from water and hydrocarbons, and the best ways scientists have found to do that require high temperatures, up to 1,000 degrees Celsius. In other words, there's another way of looking at INET's high-temperature reactor and its potential offspring: They're hydrogen machines.
For exactly that reason, the DOE, along with similar agencies in Japan and Europe, is looking intently at high-temperature reactor designs. Tsinghua's researchers are in contact with the major players, but they're also starting their own project, focused on what many believe is the most promising means of generating hydrogen: thermochemical water splitting. Researchers at Sandia National Laboratories believe efficiency could top 60 percent - twice that of low-temperature methods. INET plans to begin researching hydrogen production by 2006.

So its looks like that the pebble reactor has another very imporant benefit.

deagleninja · 2004-09-07 08:23:55

Ok, you got me curious, so make me a believer. I am definately not pro-nuclear. I feel we should be using solar power everywhere on a new grid built by the government to transport energy to states that find themselves cloudy.

I see a lot of talk about how safe fission has become and it almost makes want to play with the spent nuclear rods, so what's changed? Are spent rods safe for use in constructing schools and hospitals? Is returned water friendly for fish afterall?

Perhaps I'm living in the stone age, but I thought our biggest problem with nuclear was railroads clogged with the stuff that has no place to hang its hat for the next 10,000 years.

SpaceNut · 2004-09-07 08:39:17

I believe that is why they were looking at the salt mines out west to create under ground caverns for this spent nuclear material and other contaminated materials. The quote by the government, safe material storage for self life.

Rxke · 2004-09-07 14:26:34

deagleninja, the pebble-bed reactors don't use rods, but... pebbles, containing a little 'dirty stuff'

And that makes all the difference, read the Wired article.

There are a lot of places where solar won't be feasible, I'm afraid, not in the short term. Not for powering big factories, etc... Sigh.

deagleninja · 2004-09-07 14:30:27

I did read the article, but I'll be honest, I didn't grasp a lot of it. Am I correct in assuming that these 'pebble' reactor use unrefined fuel which is much safer than processed uranium?

SpaceNut · 2004-09-07 19:25:09

I believe that it is processed uranium but each pellet is special coated with a ceramic jacket to encase each bead.

Euler · 2004-09-07 19:31:32

I did read the article, but I'll be honest, I didn't grasp a lot of it. Am I correct in assuming that these 'pebble' reactor use unrefined fuel which is much safer than processed uranium?

I think that the key to pebble bed reactors is that the rate at which the reaction occurs is regulated by the temperature of the reactor, rather than by control rods. If the reactor gets too hot, the material of the balls expands. This makes the reactor core less dense, and therefore slows down the reaction. The idea is that even if all safety systems fail, the reactor will not be able to melt down because the expansion of the pebbles will stop the reaction.

GCNRevenger · 2004-09-07 20:39:48

Its a little more "subatomic" then that... The spheres themselves don't grow much physicly, its that the Uranium atoms won't absorb Neutrons as easily, so the reaction drops below criticality and quits. The cross section of the region of the atom that can capture a Neutron and the range of velocities (energies) of Neutrons it will capture shrinks, so that the Uranium becomes less Fissile since it cannot absorb Neutrons as efficently as before.

Then all you have to worry about is decay heat, and that is manageable... It could probobly be engineerd so decay heat wouldn't even cause core damage even if no action is taken until it wears off, which takes a few months at most. In theory, a reactor could be built that would be truely, completly, inherintly safe... such a reactor can be tailored so there is no possible way a signifigant material release could occur under any concieveable circumstance.

Coolant leaks? No problem, reactor cools down, and Helium doesn't become radioactive. Even if the reactor vessel failed, the fuel elements themselves are capable of containing the fuel with no other systems needed.

Proliferation? The fuel is embedded in Silicon Carbide pellets little bigger than sand grains, which are wrapped in more Silicon Carbide and Graphite. No practical way to remove the fuel without a serious large-scale chemical separation.

Airplane hits the reactor? Terrorists blow up the vessel? Meteors? Earthquakes? Tornados? ...The fuel pellets are harder than rocks, Silicon Carbide shells, and easy to spot with a counter and pick up, no problem. And if that breaks? The Uranium fuel inside is in the form of little grains, again wrapped in Silicon Carbide, so it stays out of the lungs and tissues, and stays out of ecosystem since its coarse, insoluble grains. After a few months and the daugher particles are gone, environmental dispursion would render them pretty harmless.

Oh, and you can build a PBR of various sizes without too much trouble, and they are more efficent per-watt than regular light water cooled reactors, since its cooled by Helium. The idea is, don't build a giant multigigawatt reactor, instead build smaller 100's of MW rigs and build them small enough to move by TRUCK. No containment building required will reduce construction cost by order(s) of magnetude each.

Oh, and did I mention that you can use the heat directly to crack Hydrogen chemicly, thus vastly increasing the efficency of reactor versus PWR+Electrolosis?

deagleninja · 2004-09-07 21:01:12

Wow, I'm impressed. Thanks for the info Euler, GCN and SpaceNut. But what about the waste? When the nuclear fuel is spent, then what?

GCNRevenger · 2004-09-07 21:14:51

Nuclear waste has never really been the doomsday issue that its made out to be... the majority of the really harmful radiation is gone in only years or decades, not eons. Plutonium and Uranium themselves decay so slowly (radiation output is inverse of half-life), that they produce little radiation on their own. You can handle low-grade Uranium powder with rubber gloves.

That said, you still don't want to dump it into the ecosystem... But lucky for us, the fuel is already in its own disposal container, an essentialy impenitrible casing of hard Carbide and inert Graphite, so medium term storage above ground or in small repositories is practical until the bulk of the radiation is gone, and then you can quite simply put it into a hole in the ground and forget about it. The stuff just won't leak or disolve if it isn't mistreated, and if it is you only have a minor spill since it is so well encapsulated.

There is a lesson here... people are going to have to get over the "ohhhh no! radiation!" There IS an acceptable minimum dose, heck, your bones are slightly radioactive themselves. Once people get over this, or are forced to, then the handling of waste becomes a much much smaller engineering problem.

deagleninja · 2004-09-07 21:24:34

Hey I'll be the first to say 'GO NUCLEAR!' if we really can make it safe enough. I've never been against continued research, just the continuation of building new reactor with Three Mile Island tech.

You and I know that radiation isn't dangerous if dealy with properly, but the public is a different matter. What state wants to store tons of radioactive waste within their borders and hope that it doesn't get into their water table? This seems to be the real impediment to a nuclear society.

Like I said, make it safe, and I can sleep soundly at night. We really do need to do something to curb our CO2 emissions, perhaps this and hydrogen cells are the answer?

However, I remember reading somewhere that the world's supply of accessable uranium is due to run out soon. Any truth to that? Could be a wonderful reason to begin mining the Moon eh?

GCNRevenger · 2004-09-07 21:31:50

Well, the truth of the matter is, I don't think that you are going to get a reactor of a safer inherint design than this that uses nuclear fission efficently. Period... The fuel cannot leak from the fuel pellets as long as they remain intact, the casing is chemicly inert, so the stuff simply is not going to disolve and go into the water. Even if it did, the amount would be so small that it would hardly be detectable much less dangerous.

Nah, we have Uranium to last a while. A long while... we haven't be using that much of it, since there aren't many power plants or bomb factories running relativly speaking.

Hydrogen fuel cells are great... but where are we going to get the hydrogen from? Only nuclear power coupled with chemical extraction from coal really have the potential to supply the stuff... solar, wind, biomass etc don't even come close on a watt-for-watt kilo-for-kilo basis.

Commodore · 2004-09-07 21:47:08

I never understood the anti-Yucca crowd, except for the folks living in Nevada of course. But even then, do people know were the waste is stored now?

Its stored right in the plant were its produced, often right in residential areas. I live in upstate NY, were theres a Navy base that works on submarine reactors. Now thats about 40 miles from were I live. But I'll bet even the people living closest to Yucca will be safer than I am now.

And the whole fear that the containment won't last the ten thousand years or what ever is complete rubbish. As if the stuff is actually going to stay untouched for 10,000 years.

I'll bet within 50 years well have vastly improved containment technology.
I'll bet within 100 years we'll have a rocket reliable enough to send it to some distance astroid millions of miles from anyone.
I'll bet within 1000 years well have a FTL drive to send it into the void between galaxies, literally light years from anyone.

So I really don't see what the problem is.

ANTIcarrot. · 2004-09-08 05:13:22

An observation:

You all seem to be concentrating on the nuclear power plants, and forgeting about the system that supports them.

If there are lots of small pebble beds scattered over the country, then that's going to need several new nuclear processing facilities. Possibly bigger ones than at present.

The fuel will need to be shipped around more. This will increase security problems. Armoured convoys are being taken to pieces in Iraq. The same is easily possible in America.

Since it's 'perfectly safe' people might stop treating the threats so seriously. "Oh why not trim the budget a little? It's not like the stuff can be turned into a bomb or anything!"

Most obvious way a terrrorist could attack such a system would be to steal a small shipment of pebbles, grind them up into fine dust using any metal work shop, and then incorporate it into a dirty bomb. Or just dump the powder off a tall building in New York.

Engineers were quite satisfied that the Twin Towers could survive an aeroplane impact. And they were correct, for about an hour or so. Then they stopped being correct; mainly because they had never thought to acount for an aviation fuel fire. Columbia suffered a similar fate because the writers of a piece of software never thought to add a little tag saying, "Not suitable for calculating damage for foam pieces larger than 5cm!"

I can't help but wonder what the pebble bed enthusiasts have never thought to account for.

And humbug to hydrogen cars! All electric ones are much better.

ANTIcarrot.

GCNRevenger · 2004-09-08 06:44:37

Ummmm you do know, right, that Uranium is so un-radioactive, that its pointless to use it in a dirty bomb. Its (nontrivial) chemical toxticity is a bigger threat than its radioactivity infact... You might as well just put a toxic heavy metal in your bomb that isn't radioactive. And how exactly do you intend to grind little bits of silicon carbide up to very small sizes? The stuff is so hard, it will just wear down your grinder... its almost as tough as solid diamond.

And you are correct, the stuff can't be turned into a bomb, not without a major industrial-scale undertaking to chemicly remove, repercipitate, rerefine, recast, and remachine. And you certainly can't do this to hot spent fuel without a National-lab quality radiation protection system. Uranium Oxide is pretty useless for atomic bombs. Provided you can even get the stuff out of the ceramic pellets.

Finally, your comparisons and opinions about engineering taste of the Precautionary Principle... No, there is no such thing as a 100% catagoricly safe power plant. But right now, there is a nonzero chance that by the time you read this, you will be struck and killed by a meteor... To claim that "only if it is 100% safe" is acceptable, that just isn't rational. Of course it won't be! But how safe is safe enough? ...Skyscrapers fall down if they have a serious failure. Airplanes crash. Ships sink. All these things are inherintly unstable, but a PBR is the other way around: if it fails, it shuts off. It doesn't get any better than that.

Oh! And hydrogen cars ARE electric, they just use Hydrogen and free oxygen to produce much more energy per-pound than batteries.

SpaceNut · 2004-09-08 12:03:48

Let a Thousand Reactors Bloom
Explosive growth has made the People's Republic of China the most power-hungry nation on earth. Get ready for the mass-produced, meltdown-proof future of nuclear energy.
http://www.wired.com/wired/archive/12.0 … _tophead_7
Snipet:
Physicists and engineers at Beijing's Tsinghua University have made the first great leap forward in a quarter century, building a new nuclear power facility that promises to be a better way to harness the atom: a pebble-bed reactor. A reactor small enough to be assembled from mass-produced parts and cheap enough for customers without billion-dollar bank accounts. A reactor whose safety is a matter of physics, not operator skill or reinforced concrete.

John Creighton · 2004-09-08 12:43:42

Late last year, China announced plans to build 30 new reactors - enough to generate twice the capacity of the gargantuan Three Gorges Dam - by 2020. And even that won't be enough. The Future of Nuclear Power, a 2003 study by a blue-ribbon commission headed by former CIA director John Deutch, concludes that by 2050 the PRC could require the equivalent of 200 full-scale nuke plants.

Can china really build30 by 2020 and 200 by 2050

SpaceNut · 2004-09-08 13:28:15

I think that they can if they have the man power, Materials and if necessary the bucks in order to build them. The things that they probably will not have to put up with would a large amount of regulations and activist that would cause delay and or cancelation of the reactors being built.

smurf975 · 2004-09-08 16:33:37

Anyway you put its for China its better to have many of those pebble nuke plants then coal/oil/fossil burning plants or more of those huge dams that destroy a great deal of the country and makes millions of people move. Even when considering the nuclear waste.

Euler · 2004-09-08 17:19:00

Can china really build30 by 2020 and 200 by 2050

Actually, those estimates look low to me. Even 200 200MW reactors will only be enough to meet a fairly small portion of China's electricity needs.

GCNRevenger · 2004-09-08 17:28:00

Think about it... a truely meltdown-proof reactor, only a few meters wide and a few times longer, and real truely cookie-cutter mass produced plumbing, turbines, generators, etc. Able to operate with high reliability, short down times, and small operations staff.

The potential for small/medium PBRs is in the thousands of units worldwide, not hundreds or dozens.

John Creighton · 2004-09-08 18:58:38

Think about it... a truely meltdown-proof reactor, only a few meters wide and a few times longer, and real truely cookie-cutter mass produced plumbing, turbines, generators, etc. Able to operate with high reliability, short down times, and small operations staff.
The potential for small/medium PBRs is in the thousands of units worldwide, not hundreds or dozens.

It sounds too good to be true. Maybe soon oil, gass and cool power will be a thing of the past.

GCNRevenger · 2004-09-08 19:08:36

I fully expect it to cost a huge amount of money, a truely vast expenditure, particularly to make the fuel for the things... But what alternatives are there? A developed country needs roughly double or tripple the energy needed to power transportation as it does electrical consumption, and so if we are to move away from heavy fossil fuel combustion (oil, coal) there really aren't many options for producing that kind of multi-terrawatt energies.

Solar, wind, biomass, all that... all an almost trivial drop in the bucket. To generate the energy needed for tomorrow alone will be a daunting task, but to produce many times that to power a Hydrogen-based transportation system?

There are only two really practical large-scale sources of Hydrogen, the cracking of water or the extraction from Coal. A nuclear reactor can either break down water by electrolsis, or by direct thermochemical reaction, which basicly doubles the efficency of the system. Coal also contains lots of hydrogen, and if it is cooked with some Calcium minerals it can be forced to liberate this hydrogen and trap the left over Carbon as chalk... We'll need all the Hydrogen we can get if we are to say good-bye to burning oil, and no matter how much the Enviro-Nazis evangelize "renewables," the cold hard numbers are that they just can't meet the demand.

Euler · 2004-09-08 21:10:01

A developed country needs roughly double or tripple the energy needed to power transportation as it does electrical consumption,

No, we use more energy for electricity than for transportation. US energy http://eed.llnl.gov/flow/pdf/ucrlID129990-00.pdf]flow chart. On the other hand, if we want to meet the US's entire transportation needs through fuel cells using hydrogen from electrolysis of water, that might take more energy that our current electrical power generation due to the greater inefficiency involved. That is part of why I am skeptical about the viability of hydrogen fuel cells.

Rxke · 2004-09-08 22:46:27

I'm going to put the Wired article in Life support systems...

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