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Thorium Faces the Hurdles on the Course

Baroness-Bryony-WorthingtonThe Indians are looking to build a nuclear reactor based on thorium rather than uranium, offering the first chance in some years to see if the thorium fuel cycle is scalable enough to establish it as a viable element to use in future nuclear energy plants. Thorium was used in early American facilities such as Fort St. Vrain in Colorado and Peach Bottom in Pennsylvania.

it’s not exactly an earlier Beta-VHS feud, though standardization doubtless had something to do with the decision to use uranium. Also, thorium has a somewhat more complex fuel cycle: it has no fissile isotopes, so must always be seeded by uranium or plutonium to be useful – they convert the thorium to uranium-233, which is fissile.

But why use thorium at all, especially since using it does not foreclose the use of uranium?

The Washington Post takes a stab at it:

[Thorium] is less radioactive than the uranium that has always powered U.S. plants, and advocates say that not only does it produce less waste, it also is more difficult to turn into nuclear weapons.

Another point: there’s a lot of mined thorium in the world – almost all of it unused. We ran a post awhile ago about a rare metal mining operation called Pea Ridge that was positively stuffed to the brim with thorium – and had no market for it.

More on the thorium reactor:

“A molten-salt reactor is not a pressurized reactor,” said John Kutsch, director of the Thorium Energy Alliance, a trade group based in Harvard, Ill. “It doesn’t use water for cooling, so you don’t have the possibility of a hydrogen explosion, as you did in Fukushima.”

Kutsch calls the molten-salt reactor a “liquid-fluoride thorium reactor,” and if thorium boosters really want to use it here, they’ll have to get it through the design licensing process at the NRC. That takes time, is resource intensive and requires a company to sit tight while the bills pile up.

Those aren’t reasons not to do it, or even reasons to become discouraged, but new designs from startup companies are a tough proposition. There’s fuel fabrication plants to build and license – that takes time – and coping with an energy and manufacturing infrastructure that has been built to support light water reactors. There are a lot of hurdles on this race course. (Not that the United States and the NRC are the only ways forward – see the recently licensed AP1000 for a counter example.)

But is it impossible to clear those hurdles? No.


Interestingly, the Post actually seeks out someone to bad mouth thorium, which is like dropping an anvil on a kitten. What’s the point?

“There are small boatloads of fanatics on thorium that don’t see the downsides,” said Dan Ingersoll, senior project manager for nuclear technology at the Oak Ridge National Laboratory in Tennessee. For one thing, he said, it would be too expensive to replace or convert the nuclear power plants already running in this country: “A thorium-based fuel cycle has some advantages, but it’s not compelling for infrastructure and investments.”

Ingersoll has a strong point here: thorium is fun to knock around because it is an element with a fan base, not just advocates and companies working on it. That can give it an air of frivolity. But his points against it only resonate if we freeze technology in place and  go no further. From this perspective, it’s almost as if thorium were dismissible because it has a strong case. 

And it isn’t really dismissible. “Replace or convert” need not be the only options (although replace seems eminently doable as older facilities retire some years hence). A lot of new designs are percolating through the small reactor community – TerraPower, Hyperion – so the thorium fuel cycle is not really so outlandish.

Be sure to check out the Thorium Energy Alliance here. (That web site, though. Oof!)


Visit the Weinberg Foundation (in England) for some more hard core thorium advocacy. It even has a quote from Baroness Worthington:

The world desperately needs sustainable, low carbon energy to address climate change while lifting people out of poverty. Thorium fuelled reactors, such as the Molten Salt Reactor (MSR) pioneered by the late Alvin Weinberg, could radically change perceptions of nuclear power leading to widespread deployment.

The baroness is an environmental activist in the House of Lords. So there you go. Alvin Weinberg, who died in 2006, was a nuclear physicist also much in favor of thorium.

The Baroness Bryony Worthington.


Anonymous said…
The real question is, "What goal do you want your nuclear reactor to meet".

If your goal is to replace the present reactors or even double the present nuclear electricity output then the new generation III reactors will do just fine.

If your goal is to burn up nuclear reactor waste, then a fast reactor like an IFR will do just fine.

If your goal is to provide power, electrical and process power, to everyone on earth. then you really need to give the Liquid Fluoride Thorium Reactor LFTR a good hard look.

Not only does LFTR not use water, it does not use pressure (think safer). The output temperature is as hot as coal boiler temperatures. At the right price, LFTR might simply replace coal burners. The high output temperatures could also be used for process heat (cement, fertilizer, hydrogen, desalination).

So, only if you want to live in a low carbon society that looks and lives a lot like ours, do you want LFTR to be successful. Only if you are aiming to actually solve the energy problems of this century, do you want LFTR.

Aim High - Develop LFTR

your word verification is very hard to pass!
Bill said…
"Thorium was used in early American facilities such as Fort St. Vrain in Colorado and Peach Bottom in Pennsylvania."

It was also tested in the Shippingport reactor in the 1970s.

[I agree, the new verification is hard for a human to read. Has there really been a problem with spammers here?)
Anonymous said…
"The definition of insanity is doing the same thing over and over and expecting different results."

His sunk cost fallacy aside, Dan Ingersol would have us maintain the status quo and do pretty much the same thing we have been doing for over half a century now albeit with placing more water on top for more defense in depth. He would have us continue to dither about with 1950s technology albeit one with a better safety and environmental record per energy produced than present commercial alternatives.

However, this does not get the job done! The U.S. market share of light water reactor electricity has been stuck at around 20% for about 20 years now. Given climate change, peak oil, and all the challenges our society faces we need a massive and worldwide adoption of nuclear energy and for this, while it is a start, a piddling 20% market share is an insufficient solution!

The consequences of failing to expand nuclear energy are too high to trust that these new LWRs are going to get the job done. We need to explore our other options and the evidence collected by Oak Ridge National Labs overwhelmingly suggests Thorium Molten Salt Reactors can succeed where the LWRs have failed to burst through this 20% market share. At the very least we can build MSRs in areas where there is insufficent cooling water for LWRs.
David Bradish said…
You'd be surprised about spammers, a lot of them easily get past the word verification. Half the comments we see are spam. It's Blogger that makes it tough for you guys with the verification, sorry, not much we can do.
We "fanatics" do use the brand "thorium" extensively, because it gets press attention. However, the key technology is the liquid fuel form -- molten salt, which acts as fuel carrier, high-temperature heat transfer agent, moderation contributor, passive safety agent, high power density enabler -- all at atmospheric pressure. Learn more at
Jim Van Zandt said…
"There’s fuel fabrication plants to build and license"

Actually, no. Fuel fabrication is difficult for current power reactors. For the LFTR, or any of the molten salt reactors, the fuel is just dissolved in the salt. That's one reason the current nuclear industry isn't enthusiastic - fuel fabrication is where they make their money.

The reference design for the LFTR does require isotopically pure Li7, which is why the first generation MSRs may use something else.
Anonymous said…
Jim, I can find no mention of a factory to make salt for LFTR but let's think about it a little.

The fluid fuel in LFTR contains fluorine, lithium, beryllium, a fission isotope, and a fertle isotope. Of course the lithium 7 will be separated in a factory but what about the rest of the fuel?

Beryllium is really poisonous! There is a picture of the original Oak Ridge staff making the carrier salt. They are in full body suits with breathers! I don't think you want to ship beryllium to each reactor site and include the equipment at each reactor site to mix in beryllium. It is much cheaper and safer to handle and ship the salt from one specially equipped factory. There will be tons of this stuff for each reactor.

Fluorine is really poisonous! Isn't this the stuff the eats glass? I suppose the fluorine might be shipped to the reactor as a gas but I would guess that the enriched uranium would be delivered as uranium fluoride directly from the enrichment factory. I think starting the first LFTRs on enriched uranium is more likely than using reprocessed spent fuel.

Two factories, both with approved processes and safety practices, are needed: one for the salt preparation and one for the U235 preparation.

It is interesting to think about what needs to be delivered to the LFTR plant on an on going basis. Thorium, of course, but is it in metallic or oxide or fluoride form. The amount of lithium, fluorine, and beryllium would not change much but small adjustments might be necessary. Some chemical engineer will need to balance site cost, safety, and transportation needs to decide what equipment and what size equipment each reactor needs to process incoming materials.

I can find no Oak Ridge document about which chemical processes would be done in a centralized factory and which would be done at every LFTR site. If someone could point me to such an article, I would appreciate it.
DW said…
But wait! There's more! On Fuel...

No only do you not need 'fabrication of the fuel', you don't even need *enrichment*! It slices, it dices but it doesn't need enrichment. That is it "dissolves in salt..." in it's RAW state.

Thorium only has to be "milled", like raw copper ore going into a foundry.

As the blog entry points out, there are *thousands* of tons already mined and accumulating since it's a byproduct of many mining operations.

And, you only need 1 ton of it to make 1 GW year of electrical generation.

And, it leaves only 1 ton of waste that is dangerous for only 300 years (similar in this regard to the IFR).

The overall footprint is less than half that of a LWR for the same units of energy.
Anonymous said…
"it doesn't need enrichment"

Isn't that only true for an accelerator-driven design? Is it true for the molten salt design folks have been touting?

Are you proposing to build an accelerator at every thorium NPP? How much would that cost?
Joffan said…
Here's the deal.

If the LFTR enthusiasts can contain the impulse of some within their ranks to impute imaginary dangers to existing nuclear technology, I won't mention that an ambient-pressure high neutron flux is a handy tool for making weapons material.
DW said…
Joffan is correct, thorium/LFTR supporters should support ALL nuclear efforts and stop trying to counterpoise them as if there is a real choice at this point. There isn't and LFTR R&D has to develop and be supported but 'dissing' Gen III isn't helping anyone.

LFTR does NOT need enrichment. Period.

It goes in raw as I stated. That is some milling has to take place to clean out the non-thorium parts of the ore. Powered, mixed with salt, it gets dropped in at the rate of about 7lbs a day to keep a 1GW plant running.

Accelerator systems also use raw, 100% refined thorium, or, any heavy metal, basically. A common heavy metal neutron generation is mercury, for the neutron spalation, then it hits' a blanket of thorium which can, in a one stage process decay over a month, to U233 and then fission.

Anonymous said…
"Thorium was used in early American facilities such as Fort St. Vrain in Colorado and Peach Bottom in Pennsylvania."

Both of which were gas-cooled reactors, not LWRs or liquid fluorine. just to keep the discussion clear.

Are you sure you really want to cite Fort St. Vrain as a thorium success story?

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