World’s First Thorium Reactor Designed

http://www.itheo.org/articles/world%E2%80%99s-first-thorium-reactor-designed

by sasoon • 12 years ago

115 54 12 years ago

msandford3• 12 years ago

I'm really glad to see that the concept is starting to take off.

It makes me sad that it's not happening in the US. If some folks in the government and business don't get their heads out of their asses a growth industry is going to bypass us entirely.

cstross• 12 years ago

Note that you can breed U-233 from thorium and use that in nuclear weapons. The critical mass of U-233 is about 50% higher than Pu-239 but otherwise it's usable in implosion-type bomb designs; the main hazard is the presence of U-232 as a contaminant (which is a high level gamma emitter and makes it dangerous to work with) -- the real question is how they plan to reduce the U-232 contamination level enough to make weapons-safe U-233.

As India is already a nuclear weapons power, this has no immediate proliferation implications ... but moving a nation of a billion-plus people onto an energy cycle that produces weaponizable material as a by-product might be considered unwise by some. Cf. concerns in the 1970s and 1980s about the implications of running a "plutonium cycle" fast breeder energy ecosystem.

msandford3• 12 years ago

If everyone in the world had enough energy to live a developed-world middle-class lifestyle -- and with thorium reactors this might be feasible -- might that not eliminate one of the driving forces behind global conflict?

I'm not saying it's a slam-dunk win for sure.

But I have noticed a lot of general apathy and aversion to violence in the developed world largely because people are just too busy living their lives; they have a lot to lose.

the real question is how they plan to reduce the U-232 contamination level enough to make weapons-safe U-233

I'm not convinced that anyone has this goal in mind. Maybe they just want to provide power to their countrymen and continue to lift India out of poverty. There might be nothing nefarious about this, unless you consider poor people getting less poor to be a problem.

madaxe_again3• 12 years ago

I don't understand the whole "it has to be capable of making bombs to be viable" thing.

I mean, the local coal power plant can't make artillery shells, but we're not shutting it down...

stox• 12 years ago

Oak Ridge had a Thorium reactor in 1965. This is not the first.

VLM• 12 years ago

The situation is actually even worse, here's a wikipedia link to a list of fifteen Th fueled reactors:

http://en.wikipedia.org/wiki/Thorium_fuel_cycle#List_of_thor...

mdellabitta• 12 years ago

I just went past one on the train to work. They're everywhere!

AlisdairO• 12 years ago

Oak ridge was a uranium MSR.

Gravityloss2• 12 years ago

Note that this very different to the molten salt LFTR design. With solid fuel it is very hard to prevent protactinium capturing neutrons, which means problems for breeding and waste and probably operational constraints as well. The LFTR is such a beautiful consistent design but it is very different from ordinary reactors.

Also the title is inaccurate as different thorium reactors have been designed, built and operated. See MSRE and THTR-300 for example.

msandford3• 12 years ago

I wish I had dug in further. I am substantially less excited now.

warfangle5• 12 years ago

The big problem with a molten salt LFTR is the materials necessary for the plumbing. Any metal will become brittle as it is exposed to the radiation emitted from the reactor core. And manufacturing ceramics into the precision pieces called for is not a solved problem.

LFTR designs are fantastic, amazing, and solve a lot of problems. There is a lot of materials science to be done to make them viable, though.

JohnHaugeland3• 12 years ago

You're confusing issues from pressurized reactors with LFTRs. The reason manufacturing ceramics for pressurized reactors is hard is the pressure and size involved. LFTR can be run at normal pressure at small scale; you can use a kiln as the pressure vessel if you want to.

Also, no, not any metal gets brittle; inconel and hastelloy handle radiation quite well for decades at a time, as does good old fashioned nickel. Beyond that, most reactor pressure vessels are a layer of metal then a layer of something that's really good at radiation, then the real pressure vessel, so that the interior layer's brittleness isn't very important.

We built and ran LFTRs commercially in the 1950s in New York State and Pennsylvania, before computers became a commercially realistic thing. They provided our grandparents no significant technical challenge.

The actual big problem with LFTR is primarily regulatory. The design hasn't been vetted to modern safety standards, which costs hundreds of millions of dollars, and the entities who are nuclear-aware and have that kind of money to throw around tend to be the existing nuclear companies, who can't switch to any other technology because they're deep in the Gilette Razor model, and anything that took out their existing fuel contracts would immediately bankrupt them.

There is /zero/ materials science needed to make a LFTR. I don't know where you got that idea. They're substantially easier than what we make today. The average auto body shop can pull it off.

swatkat• 12 years ago

The one mentioned in the article is Heavy Water Reactor with Thorium fuel. Here's its whitepaper: http://www.barc.gov.in/reactor/ahwr.pdf

Aardwolf2• 12 years ago

Nice specs!

Where does the Thorium come from and how abundant is it?

beedogs• 12 years ago

"Thorium is three times more abundant in nature than uranium. All but a trace of the world’s thorium exists as the useful isotope, which means it does not require enrichment. Thorium-based reactors are safer because the reaction can easily be stopped and because the operation does not have to take place under extreme pressures. Compared to uranium reactors, thorium reactors produce far less waste and the waste that is generated is much less radioactive and much shorter-lived."

http://www.forbes.com/sites/energysource/2012/02/16/the-thin...

rwcarlsen2• 12 years ago

Thorium is not a fissile isotope - meaning it can't be used for fission directly. It needs to be transmuted by neutrons into uranium 233 (which is fissile). By this measure, thorium isn't any better than Uranium 238 - which is 99.3% of naturally occurring uranium. So "All but a trace of the world's thorium exists as the useful isotope" - can be applied to uranium also. Uranium 238 is also a fertile isotope - and doing a completely fair comparison, uranium doesn't need to be enriched either... Except the only way we have to convert fertile isotopes to fissile isotopes is to expose them to a sustained, high neutron flux which is typically only economically achievable using enriched uranium (via the naturally occuring U235 isotope). Thorium breeder reactors need enriched uranium as much as uranium breeder reactors. So while thorium has some advantages, I wouldn't say that natural abundance or supply are particularly significant.

[Edit] corrected use of "fissile" -> "fertile"

orbifold2• 12 years ago

Roughly 3-4 times as abundant as Uranium, according to http://www-pub.iaea.org/MTCD/publications/PDF/TE_1450_web.pd.... To give you an idea on how much energy could be produced with this: A rough estimate shows that if all our current electric energy demand would be satisfied with Uranium, the reserves would run out in roughly 10 years. See http://johncarlosbaez.wordpress.com/2010/09/03/how-long-woul....

eloff• 12 years ago

This estimate doesn't seem to account for enrichment. For every KG of uranium mined, you get a much lower ratio of enriched fuel.

Tuna-Fish2• 12 years ago

rough estimate shows that if all our current electric energy demand would be satisfied with Uranium, the reserves would run out in roughly 10 years.

While strictly correct, this is extremely misleading. Current resources would be exhausted in a decade, but resources are defined as the known deposits extractable under current market prices. Should we actually start using a lot of uranium, the price would spike, which would lead to a lot more deposits becoming economically available. This has almost no effect on the cost of nuclear power, as the cost of the raw uranium isn't a large part of the cost of producing power.

The end game there is when the price rises sufficiently for extraction from seawater becoming profitable. The world's seas have ~1000 times more uranium than conventional ground-based resources.

Nuclear fuels will not run out in this millennium.

DennisP5• 12 years ago

That estimate for uranium assumes conventional reactors, which fission U-235. That's 0.7% of natural uranium.

For a real comparison, you should look at fast reactors, which use the rest of the uranium. That takes your estimate up to about a thousand years. But the estimate is looking at economically recoverable reserves, and if the same ore produces a hundred times as much energy, a lot more becomes economically recoverable.

Thorium would be 3-4 times more abundant than that. (But if seawater extraction works out, uranium will have the advantage again.)

Aardwolf2• 12 years ago

If it's 3-4 times bigger than the Uranium, and Uranium will last us 10 more years - Thorium would last us 30-40 years. What to do after that?

If there ever appears a new intelligent civilization millions of years after humanity, they'll be very disappointed to be on an Earth without any Uranium or Thorium!

prestadige• 12 years ago

This is great news. I've read about so many great nuclear projects in the past few years. Three thorium initiatives in China, India and Norway. ITER in Europe. Bussard Electrostatic Fusion. Travelling Wave Reactors. General Fusion's Steam Hammer Design. And there are many more. So it looks like an increasingly bad bet to say that they will all fail. Which is good, because we're going to need lots of energy in the future.

linohh• 12 years ago

I went to school next to THTR-300 which was built from 1971 on and is now defunct thanks to incompetence and huge failures in crisis management.

http://en.wikipedia.org/wiki/THTR-300

madaxe_again3• 12 years ago

That, and incredibly unfortunate timing. I dare say that had the incident happened two weeks earlier, or several years later, there would have been no uproar - but for it to happen several days after Chernobyl, and for them to then try to cover it up... couldn't be worse.

spenrose3• 12 years ago

The problem with nuclear power is not the primary fuel; it's the economics, especially the economics of big engineering:

http://www.carbontax.org/blogarchives/2013/11/21/why-officia...

http://www.forbes.com/sites/energysource/2014/02/20/why-the-...

seanflyon2• 12 years ago

Dealing with waste is also a major problem with most kinds of nuclear reactors. Safely dealing with spent fuel is expensive. For example, the largest meltdown in Fukushima was in a spent fuel storage pool.

DennisP5• 12 years ago

Fast reactors and liquid thorium reactors would produce about one percent as much waste for the same amount of energy.

DennisP5• 12 years ago

From the first link: "In those decades parts of plants were built, ripped out and rebuilt because of design and regulatory problems, leading to ruinous costs."

I've read about this before. Companies start building plants based on existing regulations. Along the way, the NRC changes the regulations, requiring tear-down and rebuilding. Meanwhile interest on the loan keeps building up. Add further delays due to political resistance and it's no wonder costs escalate.

It's not just the economics of big engineering causing the problem here. I think matters have improved somewhat in the U.S., but it's still going to be interesting to see how AP-1000 costs in the U.S. compare to those in China.

Incidentally, there are some arguments that liquid thorium reactors, and some other GenIV designs, could have significantly lower capital costs than conventional reactors. A big reason for that is that the basic physics of fuel and coolant provides substantial passive safety, rather than relying on lots of redundant active systems.

spenrose3• 12 years ago

The interweaving of complex shifting regulations with the economics of $B plants that take decades to build and involve tremendous amounts of radiation and energy is not some random coincidence, nor is the absence of Buffets and Icahns lining up to make a killing on the erstwhile Future of Clean Energy (as opposed to wind and solar). If thorium can't solve the political economy problems, then thorium is dead. A small loud group of techies yelling "don't you get it?!" and upvoting thorium posts on HN is just part of the ??? between underpants and the profit we will never see.

acd• 12 years ago

Fast breeder Thorium reactors and electric cars to the people! Cheap energy and clean cars.

JohnHaugeland3• 12 years ago

On what planet is this the world's first thorium reactor? We had running thorium reactors in the 1950s.

World’s First Thorium Reactor Designed

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