A different nuclear viewpoint. Who's open to thorium-fueled reactors?

[backscatter712]

I stand with just about all of DU in opposition to the current generation of uranium-fueled reactors. They're dangerous, as the situation in Japan is demonstrating (when something goes wrong, it goes REALLY WRONG!), they create large amounts of extremely toxic and radioactive waste that would have to be isolated for half a million years - not feasible. You could reprocess the waste and burn the nasty radioactive bits as fuel, but coincidentally, the technology to make that possible is exactly the same technology used to create weapons-grade material for nuclear bombs, so that's an intractable security and proliferation problem. Mining uranium to fuel these plants is itself an environmental disaster - you have to strip-mine huge amounts of land, use nasty chemical processes to extract uranium from the ore, you have to enrich it to make it usable for reactor fuel, (again, proliferation issues) and you have to mine a huge amount of land just to get a small amount of fuel.

But what if there's a different type of nuclear power plant that can solve these problems?

A liquid thorium fluoride reactor (LFTR) uses thorium as its fuel. One of the keys is that thorium is a fertile material, rather than a fissile material like uranium. You can't throw a huge pile of thorium together and expect it to react - it won't. It needs help, say from an external radiation source like a pellet of uranium, or from a particle beam. Also, LFTR reactors CANNOT melt down - the physics of this reactor type are completely different. The thorium is in the form of molten fluoride salt - the fuel is also the coolant. The designs being thrown about also don't use high pressures, so you reduce or eliminate the risk of pressure explosions. If things overheat, the designs just dump the liquid thorium solution into an emergency cooling tank, where the reaction is stopped, and the emergency ends there. Overheating also makes the nuclear reaction far less efficient, so that bit of physics makes it much easier to maintain safe equilibrium at a reactor - overheats are hard to make happen because the thorium doesn't react well when it's too hot. Finally, if exposed to air, thorium fluoride salt does not burn. The kinds of failures that are happening at Fukushima just aren't possible with a thorium design.

Also, thorium is proliferation resistant. You can't use thorium to build bombs - the physics just don't work. At worst, one of the byproducts of a thorium reaction is a uranium isotope, U-233, which can be used in theory to build bombs, but is an extreme pain to work with. Normally, any U-233 can simply be reacted in the reactor as it's produced (U-233 is useful as a fuel). Worst case scenario, as this is a liquid-fuel reactor, dump some depleted uranium into the mix, and well, the end mix resembles natural uranium, which isn't useful for bombs or fuel, and the only way to make it useful is expensive and unpopular enrichment facilities. In an LFTR reactor, U-233 gets contaminated with U-232, which doesn't cause a problem for power-generation, but U-233 contaminated with U-232 is useless for building bombs, without enrichment at expensive and politically problematic facilities.

Thorium's more plentiful than uranium, and in fact, because you don't need to enrich it, you don't need to mine as much of it. There's enough thorium on Earth to supply humanity's energy needs for thousands of years, and the environmental impact of mining it is far less.

Finally, the waste from a thorium reactor is far less problematic than with a uranium reactor. The initial byproducts that tend to build up in a uranium reactor get "burned" in the thorium reaction cycle, and while I'll be honest and say there's still some toxic waste, it's faaaar less difficult to deal with than uranium fuel waste. It will only have to be geologically isolated for 300 years, not half a million years, and the amount of waste is faaar less. Another bonus is that thorium reactors can be used to "burn" waste from the old uranium reactors - the neutrons in the reactor will accelerate the radioactive decay of old fuel rods, and break down the nasty radioactive isotopes into far more manageable stuff.

If we're to do nuclear power at all, the only way I'd think of supporting it is if the industry switched to thorium reactors.

Some quick information here:

http://energyfromthorium.com/joomla/index.php?option=com_content&view=article&id=64&Itemid=63
http://en.wikipedia.org/wiki/Molten_salt_reactor

[jpak]

1. Not me - not with my tax $$$

yup

[Cleita]

4. Mine either.

Nuclear fusion is just that. Trying to put lipstick on that pig just doesn't fly.

[Teaser]

8. this isn't fusion

.

[Cleita]

9. Then what is it?

[joshcryer]

Nuclear fission at atmospheric pressure in a molten salt that freezes if breached...

...and whose shut down mechanism is completely passive, overheat, it shuts down.

[Cleita]

18. I'll bet it does.

If it were such a perfect solution, why isn't anyone doing it? I think I would need to see a lot of information and studies before I sign on. I remember back when nuclear plants were sold with such rosy, ease of operation and clean energy sunniness.

[joshcryer]

29. Because the nuclear power industry was built on the back of the nuclear weapons industry...

...and it is extremely profitable to make money creating fuel assemblies than it is to operate plants.

To clarify further: the nuclear power industry makes its money refining uranium (to very high levels of radioactivity) and selling the manufactured fuel. Thorium reactors and integral fast reactors break this capitalist mode of operation.

You could hold some frozen salt in your hand from a thorium reactor, that's how safe it is. No high pressure blowouts. Put the reactor in an environmentally sealed 'container' of sorts (could just be a big plastic bowl filled with soil) and there is absolutely zero chance of even the biggest catastrophe going beyond the environmentally sealed container. ie, you could hit it with an abomb and the thing is going to blow up but all of the radiation will be completely localized.

[Statistical]

32. The DOE was very interest in Thorium. The DOD wanted bombs.

Then cold war kicked off in earnest and the fears of a missile gap. The rest is history. We kept using uranium because it was what we knew and had years of research and expertise in it. Kinda like we keep using gasoline despite it being inferior to alternatives.

[joshcryer]

11. Any reason?

[jpak]

17. There are better more advanced alternatives - efficiency & renewables

yup

[joshcryer]

30. Fair enough.

[Teaser]

2. I can be sold on it but

I'm deeply ambivalent about nuclear fission in general.

[backscatter712]

7. I'm with you - I'd need to be convinced its safe.

On paper, thorium reactors look far safer than the current uranium-fueled reactors, but I'd have to see how things worked when people actually build them. Still, experimental thorium reactors have already been built, and there's already been some significant research that's useful for building future thorium power plants.

But the process of a thorium reaction is significantly different than a uranium reaction, which IMHO makes it possible to do things far more safely.

[notesdev]

3. Me, big time

I believe it is our future regardless of how people feel about nuclear energy right now, because we have no other choice if we want to maintain the level of social complexity and prosperity we enjoy today.

Well, scratch that - there's one other choice, which is coal power - dirty and dangerous. But conveniently, one of the byproducts of coal power generation is the very fuel we would use in thorium plants.

The smart long term move is thorium nuclear power for electricity and coal gasification as a petroleum substitute. This country could be entirely self-sufficient for its energy needs under such a regime, which would eliminate the driving force for the global military empire and all the evils that result from it.

[Teaser]

5. What's the Energy Return on Investment?

and how efficient, relative to Uranium?

[backscatter712]

12. I'm not sure.

I tried to look that up, couldn't find hard numbers.

However, it is a nuclear fuel, which means it has a huge amount of energy per kilogram, especially when compared to coal and other fossil fuels.

Also, thorium's far more plentiful and easy to extract than uranium - for example, it's available for anyone to scoop up on Indian beaches. The U.S. government threw a bunch of thorium away - they didn't think it was worth anything. Just from the top of my head.

[notesdev]

13. ridiculously good

considering we THROW AWAY more than enough thorium to meet our energy needs because it's a coal production byproduct.

[backscatter712]

15. I think you're right.

Need some thorium, just dig through coal ash.

[joshcryer]

34. EROEI for uranium is around 500*, thorium is 250 times more efficient.

*assuming the uranium undergoes typical 3% burnup rates in a modern fission reactor and is not reprocessed or used in a breeder reactor.

It is, in a word, obscene. Your lifetime energy use translated into thorium is as small as a golf ball.

[Dappleganger]

6. I don't think that now's a good time for this discussion.

Not that you shouldn't have it, but that your feedback will be exceptionally negative while there's an impending disaster.

[k2qb3]

10. I'm very interested in Thorium in particular...

and there are several other technologies that are very interesting as well. We can build safer plants, if we build enough of them we can take the older plants offline faster. Nuclear doesn't have to be stuck in the 60's forever.

I believe China is building a Thorium reactor, which may sour the deal or prove it out, if anyone could screw up something as promising as Thorium it's China.

[bananas]

14. Nope - it's a bunch of hype. nt

[Teaser]

21. data?

why?

[joshcryer]

40. I've asked before, bunch of empty words.

[bananas]

43. See reports by MIT and IEER and others

MIT's 2003 report "The Future of Nuclear Energy" google for the link,

"Thorium Fuel: No Panacea for Nuclear Power" Fact Sheet by Michele Boyd (PSR) and Arjun Makhijani (IEER). (January 2009) at http://www.ieer.org/fctsheet/thorium2009factsheet.pdf

The PBMR was a modular reactor using thorium fuel, it was abandoned by Germany and South Africa, they both spent megabucks on it before realizing it was a waste of money.

[CJvR]

48. Odd thing.

Pointing out that an isotope is radioactive with a half life of 14 billion years as a problem, that hardly means it is radioactive at all. Hell it is three times longer than U238, which also decays into lots of nasty isotopes on it's way down to lead.

[MadHound]

16. First of all, why bother,

It, like other radiation based plants,the electricity produced is more expensive per kilowatt/hour than wind, solar or other green renewables.

Secondly, the technology and capabilities of wind, solar and green renewables has reached the point where they can fulfill all of our energy needs. The only impediments at this point are social and political ones.


Finally, even with thorium based reactors, you still have two unsolvable problems, namely what to do with waste, and the inability to prevent human error.

So in light of all that, again, why bother?

[backscatter712]

23. The waste problem is far smaller with thorium reactors.

The high-level toxic radioactives that build up in uranium fuel waste get consumed in the thorium reaction, so once the fuel's all used up, the resulting waste is far less nasty, and far less in quantity.

It's still an issue, but we're not talking about figuring out how to keep people away from it for half a million years, so I'd describe the waste disposal problem as manageable.

[MadHound]

26. Yes, it is still an issue, and a still a fairly substantial issue,

So again, why bother?

Since it economically foolish, going with the more expensive form of energy production, since we still face the the twin, unsolvable problems of waste with thorium, and since green renewables can now fulfill our energy needs, why bother?

It simply doesn't make sense any way you look at it.

[joshcryer]

31. Thorium reactors and integral fast reactors burn waste. We owe it to future generations to...

...burn up that waste so that it goes from having a 100k year half life to 300 years.

[MadHound]

33. What, so only our great, great grandchildren have to worry about it,

Again, why bother? The arguments against nuclear power in any form are now overwhelming. Economically it is cheaper to generate power from green renewables. Green renewables now have reached the point where they can fulfill our power needs. And you simply can't eliminate the twin devils of nuclear power, human error and disposing of the waste, even if that waste lasts for "only" 300 years.

[joshcryer]

36. Wait, why bother? 3-4 generations vs 2000+ generations?

Even if you did have a completely renewable infrastructure it would be completely irresponsible not to have a few dozen reactors burning a century of nuclear waste buildup (including the material used in nuclear bombs).

[MadHound]

38. So those reactors create more waste, which will need to be burned,

Which will then create more waste, which can't be burned. See the problem with this yet?

[joshcryer]

39. No, you don't understand at all, you really don't.

The thorium fuel cycle and the integral fast reactor burn 99.5%-99.9% of their fuel.

1000 tonnes of nuclear waste translates, then, into 5 tonnes of nuclear waste.

You come out with less waste than you had before because you're burning the waste.

Not a hard concept really.

When you're done burning the byproducts of current nuclear reactors then you can shut down the IFR/LFTR if you are so inclined.

[Jack_DeLeon]

19. I'd support it...

I'm no luddite.

[ljm2002]

20. Why?

Why not spend the same amount of $$ to develop solar, wind and geothermal? or wave energy, near seashores and large lakeshores?

All of these are safer, and can be done in smaller more decentralized installations, and can be used to build a new green energy industry that will employ people in decent jobs for years to come.

Yes, of course they aren't perfect. No energy source is perfect, as we can plainly see. But why continue to pursue these gigantic, technological, centralized sources that require huge investments of equipment and are complex, when we already know how to produce energy in ways that are easier to handle?

If every roof had solar where I live, instead of swamping the grid during the summer months we could be supplying most of our own energy (I'm guessing we might not be able to pump back into it during the hot days as we all have AC). Towns could have their own solar and wind plants, closer to where it needs to be supplied, creating more efficiency since the power would not have to travel a long distance which always means losing more of it.

Technology is great. The people who developed nuclear bombs and nuclear energy are indeed brilliant minds. But just because we can do something, does not mean we should do it. There are plenty of well-understood ways right now that we can produce energy to maintain a decent lifestyle in a post-industrial world. More telecommuting, more high speed rail, electric cars within the cities, solar panels, etc... that is how I see a better future.

[wtmusic]

22. LFTRs have their own set of problems.

If by open to them you mean continuing research, yes - by all means.

Whether any new nuclear will be practical for decades to come (from a PR point of view) is right now highly debatable. We have to find some kind of resolution to the current catastrophe. Then the nuclear industry has to step back and take a hard, hard look at itself. See what can be learned, and what really can't be learned. After that point (six months? two years? five years?) this discussion would be productive.

[jp11]

24. I am, too late to get into reading all this but certainly sounds promising if there

were more information available on it.

[backscatter712]

47. Here's a good site to look at.

http://energyfromthorium.com/

[Thegonagle]

25. You know, on a night like tonight, all I can think is...

...What the fuck is Thorium?

Because those Uranium and Dirty Plutonium (or whatever the hell it's called) reactors are all the nuclear reactors I care to think about right now.

Do you mind reposting in about 20 years?

[SolutionisSolidarity]

27. We need to shut down these old reactors.

I'm not opposed to new ones in principle. There are newer designs, some like what your proposing and others that are more traditional, that are supposed to shut down passively without any power supply required. We need to demand they be constructed according to the strictest seismic standard, though. What they did in Japan was absolutely unacceptable. There have been several 8.0+ sized earthquakes in the vicinity of Japan over the past century, and they decided that they could design it for a 7.5 magnitude earthquake and call it a day. An earthquake 8.1 in magnitude directly hit Japan in 1946, but no one cared enough to spend the time and money required to do it right. It's this kind of cost cutting that really concerns me when it comes to nuclear power in general.

Edit - Also, now I know where I've heard about thorium. Cobalt thorium G in Dr. Strangelove - the special payload of the Soviet Doomsday device that had a half life of 93 years. That's not a comforting association.

[backscatter712]

46. I'm doubting that "Cobalt Thorium G" is a real substance.

I do remember talk of jacketing hydrogen bombs in Cobalt-60 - a real isotope, which would essentially give the bomb the most deadly radioactive fallout possible, and would render wide swathes of land toxic and uninhabitable. You'd have to be crazy to build such a bomb, but then again, the world of the Cold War was a crazy place.

But real thorium is different stuff from what was in Dr. Strangelove.

[eridani]

28. Possible--just not anywhere NEAR earthquake faults n/t

[Xithras]

35. I don't think it's quite ready for wide scale deployment.

But I don't have a problem with the concept of thorium reactors in general, at least if you're using particle beam. I'm not sure that the uranium pellet method is a huge step above where we're at now. One mechanical failure preventing pellet withdrawal, and you have a potential meltdown situation. With a particle beam, all you have to do is "unplug" it and the whole thing just shuts down.

I'm cool with continued research, but the widescale deployment of thorium reactors should only come after they've been thoroughly vetted for safety.

[joshcryer]

37. It's almost entirely conceptual and even the biggest LFTR advocates see it 20+ years out...

...it's not a serious contender for sustainable or green energy.

[Xithras]

45. I was thinking about thorium reactors in general, and not LFTR in particular.

FYI, India is bringing the worlds first thorium AHWR online this year, and there are a number of others in development. Even in the AHWR configurations it's far safer than our current designs.

For what it's worth, the Chinese announced their intention to heavily fund LFTR research about a month ago, so this technology will certainly be available at some point. In the energy market, 20 years isn't all that long.

[jberryhill]

41. The current reactors were sold as failsafe, too

What I can't figure out in all of this is WTF happened to the notion of failsafe engineering in the first place.

The failure mode in Japan was definitely foreseeable. These things were supposed to be failsafe, but I seems as if you pull the plug and these things blow up.

[joshcryer]

42. They had three backups, all three failed. They did fail to engineer for a massive tsunami...

...apparently. Obviously you want the last failure mode to be one that does not rely on any mechanical control at all. Molten salt reactors (which thorium can be) solve that. Thing fails, salt plug melts, salt drains. Have tens of dozens of drain pipes drain the thing into a pan and it stops running, there'd be a lot of latent heat but it wouldn't require any sort of active cooling.

[jberryhill]

49. Active backup is NOT failsafe design

I don't care what failed. The point is that failsafe design doesn't care what fails either.

If your backup requires fuel or power, that is not a failsafe backup.

These things were supposed to be failsafe. Period.

[diane in sf]

44. No thank you, still too expensive and relatively dangerous compared to efficiency and renewables.