Why China Is Building a Thorium Molten-Salt Reactor

Months after satellites picked up a massive nuclear fusion facility in China's Sichuan province, the country's nuclear industry has blown the lid off fission tech.

During a private meeting earlier this month, researchers at the Chinese Academy of Sciences revealed the successful operation of a thorium-powered nuclear reactor located in the Gobi Desert. The team had achieved "full-power operation" last June, according to South China Morning Post, and recently succeeded in reloading the reactor while it was powered up — a world first.

It's a major milestone for nuclear power. Thorium offers a more accessible but less weaponizable alternative to uranium, according to the World Nuclear Association, which notes that "thorium-based power reactor fuels would be a poor source for fissile material usable in the illicit manufacture of an explosive device."
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futurism.com

China Fires Up World's First Thorium-Powered Nuclear Reactor

Researchers at the Chinese Academy of Sciences revealed the successful refueling of an operational Thorium-powered nuclear reactor.
futurism.com futurism.com
 
Because:

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After all, molten salt reactors, of any sort, have worked so well in the past...
 
I'll wait. If it succeeds, news will be blaring horns. If not, a couple articles on how certain milestones were achieved... and then the immediate program fade into oblivion.
 
A quick search online finds some very recent research which shows promising concepts for managing the material degradation that plagues the technology.

Ultimately, I suspect the success of MSRs will depend on whether the prime goal is to generate low Carbon power or breed fissile weapons grade material, and what the politics of the host nation are.
 
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edwest4 said:
Mister Gardner,

Have you studied the reactors that have used thorium?
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Yes. Molten salt reactors using whatever combination are bad news in terms of maintenance and safety. Thorium breeder reactors aren't a bad idea. Molten salt reactors are.

The specific one here, using thorium fluoride, isn't something new. The US experimented with this system back as far as the 60's. While the articles above don't mention it, it's likely that this reactor uses a graphite moderator, just another potential disaster waiting to happen. It doesn't help that the resulting fissile material can be used in nuclear weapons either.

There's a lot of downsides to this.
 
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Thank you for your reply.

Thorium - World Nuclear Association

Thorium is more abundant in nature than uranium. It is fertile rather than fissile, and can be used in conjunction with fissile material as nuclear fuel. The use of thorium as a new primary energy source has been a tantalizing prospect for many years.
world-nuclear.org
 
edwest4 said:
Thank you for your reply.

Thorium - World Nuclear Association

Thorium is more abundant in nature than uranium. It is fertile rather than fissile, and can be used in conjunction with fissile material as nuclear fuel. The use of thorium as a new primary energy source has been a tantalizing prospect for many years.
world-nuclear.org
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Yes, it is. About 4 to 5 times the amount of uranium. Building a thorium breeder reactor is a good idea, but I'm leery of one using molten salts to do it. Molten salt reactors don't have a good reputation or history behind them.
 
T. A. Gardner said:
Yes, it is. About 4 to 5 times the amount of uranium. Building a thorium breeder reactor is a good idea, but I'm leery of one using molten salts to do it. Molten salt reactors don't have a good reputation or history behind them.
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Are you sure that you don´t confuse molten salt reactors with liquid metat reactors ?
 
T. A. Gardner said:
Yes. Molten salt reactors using whatever combination are bad news in terms of maintenance and safety. Thorium breeder reactors aren't a bad idea. Molten salt reactors are.

The specific one here, using thorium fluoride, isn't something new. The US experimented with this system back as far as the 60's. While the articles above don't mention it, it's likely that this reactor uses a graphite moderator, just another potential disaster waiting to happen. It doesn't help that the resulting fissile material can be used in nuclear weapons either.

There's a lot of downsides to this.
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This is nonsense, molten Salt is allready in long term use in solar power plants and despite those are not commercially succsessfull, they prooved that molten salts are not critically for maintenance. These reactors are extremely save, even a total lack of cooling would not have any dangerous consequences, the freeze plug would melt and the molten salt would be drained, that's all. I havent seen any molten salt reactor with a graphite moderator (it might exists).

There are many different types of molten salt reactors, some (Terra power) are using the salt just for heat transfer and some use a fluid reactorfuel.

Thorium is might be about 4 to 5 times abuntant than Uranium, but so, it is 200 to 250 times more abuntant than Uranium 235. Only 2 % of the Uranium can be used in conventional light water reactors and only about 7 % of the 2 % are actually burned. With a closed fuel cycle (burning virtually all the Thorium) the supply is around 3000 x higher compared to U235.

Thorium reactors produce almost no transuranic waste and molten salt reactors can even transmutate the waste of current light water reactors.
 
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The issue is the corrosiveness combined with radiation. The molten salt causes grain boundary erosion, and the radiation then causes the cracks generated by the erosion to propagate at an accelerated rate. Individually they are manageable, combined they're enough of a problem that research into appropriate materials is ongoing.
 
Corrosion only apears when oxygen is present and even than, the oxygen will be eaten up when coroding metal.. Andasol in Spain is using the same type of (hot) salt which is proposed for most SMR.

Salt bath are also quite common for heat treatments of metal which should be much more problematic because of open tops, inpurities and comparable or even higher temperatures.
 
How soluble the atoms of metals within a given alloy are into the molten salt mixture is a significant factor in the rate of corrosion.

Really good article here
 
Intrestingly, radiation reduces the corrosion significantly (by a factor of 2-3). This artikle is quite promising, a MSR should have a longer operation time than Andasol. Despite that, Thorcon plans to exchange the reactor every ten years and to reuse the filling (after adding fresh Thorium) for the next reactor.

One should keep in mind, that the molten salt is not pressurized, so even if there would be cracks through th wall, it would simply cause the salt to drain out, cool down and the reaction wild stop. All the fission material will be inclosed in a block of solid salt.
 
Nicknick said:
Intrestingly, radiation reduces the corrosion significantly (by a factor of 2-3). This artikle is quite promising, a MSR should have a longer operation time than Andasol. Despite that, Thorcon plans to exchange the reactor every ten years and to reuse the filling (after adding fresh Thorium) for the next reactor.

One should keep in mind, that the molten salt is not pressurized, so even if there would be cracks through th wall, it would simply cause the salt to drain out, cool down and the reaction wild stop. All the fission material will be inclosed in a block of solid salt.
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The problem is you end up with everything involving this reactor being highly radioactive. The salts, the core, the plumbing, etc. This greatly increases the amount of 'stuff' that you have to deal with that's radioactive.
 
T. A. Gardner said:
The problem is you end up with everything involving this reactor being highly radioactive. The salts, the core, the plumbing, etc. This greatly increases the amount of 'stuff' that you have to deal with that's radioactive.
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The same holds true for conventional reactors. After spending billions, no safe way to store nuclear waste underground has been found. I was surprised to see video on TV of nuclear waste in 55 gallon drums being dropped into the ocean. I have also heard that abandoned mines are being considered.
 
edwest4 said:
The same holds true for conventional reactors. After spending billions, no safe way to store nuclear waste underground has been found. I was surprised to see video on TV of nuclear waste in 55 gallon drums being dropped into the ocean. I have also heard that abandoned mines are being considered.
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The promise with molten salt reactors is that neutron poisons like xenon bubble out, and If you're running the thing as a breeder/fast spectrum reactor you can burn many of the others in situ.

Fuel waste becomes pretty much a non issue.
 
edwest4 said:
The same holds true for conventional reactors. After spending billions, no safe way to store nuclear waste underground has been found. I was surprised to see video on TV of nuclear waste in 55 gallon drums being dropped into the ocean. I have also heard that abandoned mines are being considered.
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Yucca Mountain was a safe repository. The material was put in casks that were pretty close to indestructible. Aside from that, the waste is mostly long-life alpha emitters which aren't that big a safety hazard. Reprocessing is possible and should be done in any case. Water as coolant isn't a big issue on its own as it loses any added radioactivity in a matter of weeks.
 
Pixelbrick said:
The promise with molten salt reactors is that neutron poisons like xenon bubble out, and If you're running the thing as a breeder/fast spectrum reactor you can burn many of the others in situ.

Fuel waste becomes pretty much a non issue.
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On the other hand, the salts are often corrosive and always highly toxic aside from being radioactive.
 
T. A. Gardner said:
The problem is you end up with everything involving this reactor being highly radioactive. The salts, the core, the plumbing, etc. This greatly increases the amount of 'stuff' that you have to deal with that's radioactive.
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The used fuel of conventional reactors is much higher mass of nuclear waste. In standart light water reactors, only 5 % of the Uran (U235) contributes significantly to the power production whereas the remaining 95 % (U238) are responsible for almost all of the really nasty stuff (transuranic elements) which are very dangerous and very long lasting. In a fast Thorium reactor, all of the Thorium can be split as well as other heavy elements, therefor the amount of long lasting heavy elements is very small (or even negative, if nuclear waste is burned as fuel. The radioactive waster of a MSR is therefore less dangerous, short lived and can partially be recycled. It even can be negative, if nuclear waste from conventional reactors is used as fuel.

A fast MSR doesn't need any refuelling within 10 years and after that period, the content can be freshed up with new Thorium and the removal of the fission products for a new reactor, so that the amount of waste is extremely small.

BTW, the plumbing gets always slightly radioactive, but the amount of radioactivity is way smaller than that of the waste fuel!
 

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