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World’s First Thorium Reactor Designed

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Re: World’s First Thorium Reactor Designed

#31

Post by Aardwolf »

orbifold wrote: post #15
Aardwolf wrote: post #9

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

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... .

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!

Re: World’s First Thorium Reactor Designed

#32

Post by maxerickson »

venomsnake wrote: post #30
Tuna-Fish wrote: post #26

Earlier quoted context omitted.

> 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, whic…

How about energy return on energy investment. You have to vaporize a lot of water (of course you will have all those gold, iron, rare metals "waste" which will help the economic case).

Research has focused on other methods:

http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_se...

Re: World’s First Thorium Reactor Designed

#33

Post by ChuckMcM »

rwcarlsen wrote: post #22
beedogs wrote: post #14

Earlier quoted context omitted.

"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 i…

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 doin…

Or, if you're doing research in the UK, you use a particle accelerator to convert it on the fly. Once it starts you're good to go (you can keep it going using neutron flux in the reactor) so you have the particle beam starter engine :-)

Re: World’s First Thorium Reactor Designed

#34

Post by Tuna-Fish »

Aardwolf wrote: post #31
orbifold wrote: post #15

Earlier quoted context omitted.

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... .

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!

See my post: https://news.ycombinator.com/item?id=8036690

Uranium will simply not run out. The "10 years" figure stems entirely from misunderstanding what the word "reserve" means in mining.

Also, there is 3-4 times more natural thorium than natural uranium. Of natural uranium only 0.7% is U-235, which is useful in a traditional reactor. Breeders can use all of it. Thorium reactors are all breeders. Assuming only resources extractable at current market prices, using uranium breeders the reserves would last ~1400 years and the thorium reserves would last ~5k years.

Re: World’s First Thorium Reactor Designed

#37

Post by JohnHaugeland »

warfangle wrote: post #25
Gravityloss wrote: post #4

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 operate…

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.

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.

Re: World’s First Thorium Reactor Designed

#38

Post by seanflyon »

spenrose wrote: post #24

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-...

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.

Re: World’s First Thorium Reactor Designed

#39

Post by DennisP »

spenrose wrote: post #24

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-...

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.

Re: World’s First Thorium Reactor Designed

#40

Post by DennisP »

seanflyon wrote: post #38
spenrose wrote: post #24

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-...

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.

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