Their design also uses molten salt, but contains the fuel-bearing chloride salt inside tubes. A separate, non-fueled salt circulates around the tubes.
For reasons of chemistry, this enables them to use a fluoride salt outside the tubes, and unlike homogenous fluoride-based MSRs the reactor structure can be made of stainless steel rather than more exotic (and expensive) nickel-based alloys. It also reduces the volume of chloride needed, which is an important cost savings if the chlorine has to be isotopically separated to reduce production of 36Cl (which has a halflife of 3x10^5 years.) The high cross section of chlorine for thermal neutrons is also why chloride MSRs are necessarily fast reactors.
Moltex's design retains the major advantage of MSRs, which is the absence of volatile materials in the containment building. It is the vaporization and pressurization of these materials in an accident which forces the containment to be large and strong.
Have you looked at the press release that yazr linked to? It sounds like this is a new design for Terrapower that is similar to the concept that you prefer. It would be great for someone that is familiar with the design issues to confim if this is the case.
Mini-nuclear plants. 1100 megawatts. These are completely in disagreement. Terrapower focuses mostly on large plants to power an increasingly urban world. The media has gotten that Terrapower does small reactors wrong for over a decade.
Does anyone know how big this thing is, physically?
If you can put the reactor vessel, and associated 'hot' parts into a 40ft Iso container, and ship it cross country for installation/recycling, that might improve on the economics of existing reactors. If you can't do that, I'm not sure how it's going to be cheaper than other options.
I don't think we're facing any critical electricity shortage, at least in the continental US. This is just one of many new power generation systems being pursued. It is neither too little, because any amount helps, nor too late, because the need for more electricity is going to continue forever. I'm not sure how this is a negative thing.
My main concern (I'm not a nuclear engineer) is that smaller nuclear plants means lots of radioactive material (fuel/waste) is being moved and stored in a piece-meal fashion, enabling "small scale" accidents or even theft.
I've always thought if the reactor was so small then why can't we just by default build the reactors underground? Isn't the underground a more stable area to begin with? Even during earthquakes? Reactor waste could be stored at the location permanently and if the reactor gets the 1 in a million accident then the whole place is already basically built in a cement/rock containment vessel. If a serious meltdown occurs then it would be easy to just start pouring lead or cement into the facility. Even if there was a small nuclear explosion we already know the impacts of underground nuclear explosions.
Most modern designs are specifically designed to not create materials that are easily weaponizable, which reduces the value of them (and thus theft). Accidents are an issue, and what do do with the waste is a huge question that will decide whether or not nuclear plants are economically feasible moving forward.
No reason a bunch of small reactors can't be put together at one site. The reason for building small is just to reduce construction time risk, and maybe allow factory mass production.
Also not a nuclear engineer, but "mini-nuclear" anything doesn't conjure up anything good for me either. Hopefully, unlike in the tech world, the nuclear world thinks about and implements safety first rather than as an after thought.
I heard Bill Gates on a ted talk a long time about talking about some sort of nuclear power that would burn waste and was like a candle. I think this isn't that.. but anyway, it'll be nice if we have excess power.
That's the traveling wave reactor which is just a breeder that doesn't need reprocessing. The first will be sodium metal cooled (not salt). This is a fluid fuel reactor that has similar reprocessing reducing goals.
Will this type of reactor produce material that can be used in nuclear bombs and produce waste we will have deal with for millions? Of years. Is it "just" a smaller version of the current types of reactors?
I've never understood this. If the waste product is radioactive for millions of years then doesn't that mean it's not very radioactive?
Wikipedia has this to say:
Since radioactive decay follows the half-life rule, the rate of decay is inversely proportional to the duration of decay. In other words, the radiation from a long-lived isotope like iodine-129 will be much less intense than that of a short-lived isotope like iodine-131.¹
So my understanding is radioactive products are dangerous because body takes up the elements and they're either chemically toxic, dangerous because of radioactive decay, or both.
So isn't this solved by vitrifying the waste and burying it? Glasses tend to be extremely chemically inert.
I'm not convinced the spectre of nuclear waste warrants the paranoia it receives.
The only waste from molten salt fast reactors is fission products, i.e. atoms that already fissioned. Encase them in glass and they'll be back to the radioactivity of uranium ore in 300 years.
We could use these reactors to eat the nuclear waste we have right now.
Sometimes it fractionates me, how we manage to move from 1 to 1000x the computation power and yet Nuclear technologies seems to move at a very very slow pace.
I would also like to know why no one invest in Nuclear Fusion?
People have started investing in fusion. Tokamak Energy and a new company spun out of MIT's fusion program have both gotten tens of millions, for fairly mainstream designs. There are also companies using more speculative designs, the biggest being Tri Alpha, which started in 1999 I think and has about $500 million invested. There's also Helion, which got a modest investment from YCombinator.
One reason fission moves slowly in the U.S. is the NRC. A couple years ago I got to sit in a meeting between a bunch of U.S. reactor startups and a former head of the NRC. The reactor people's main complaint was that the NRC required detailed blueprints before it would even look at a design. It would take several hundred million dollars to get to that point, and then the NRC would give a flat yes or no. With a no you were done, and with a yes you still have nothing but a paper reactor. It's a very difficult environment for investors.
Good news for Japan if this gets developed successfully. We have a ton of nuclear reactors on some of the most seismically active land on the planet - only a matter of time for another Fukushima.
Smart people like Bill Gates are interested in nuclear because of the low footprint associated with the unbelievably high energy density of nuclear fuel. 1.5 soda cans of the stuff fissioned in a conventional reactor releases enough energy to power an average american's entire life (including transportation, heating, and electricity). The waste created is about 2 soda cans of toxic solid stuff that can be easily, safely, and practically stored in deep crystalline bedrock like the Finns are doing. Other energy sources dump their (more dilute) waste into the air causing lung disease (worldwide fossil fuels are estimated to kill 3 million per year this way) and global warming (death toll still unknown). Intermittent renewables are energy harvesters with free fuel but they require vast swaths of land, concrete, steel, fiberglass, storage, transmission, rare-earths, lithium, etc. etc. Nuclear has tiny land, material, waste, carbon, etc. footprints due to its energy density. The risks associated with radiation are just overblown by almost everyone. Nuclear reactors have net saved 1.8 million lives already, and counting [1].
I think this is a great idea. That said, this article seems like a puff piece for the DoE under Trump. Nor does the article linked really support the headline either.
Consider the source.
"When Anschutz first started the Examiner in its daily newspaper format, he envisioned creating a competitor to The Washington Post with a conservative editorial line. According to Politico, "When it came to the editorial page, Anschutz's instructions were explicit—he 'wanted nothing but conservative columns and conservative op-ed writers,' said one former employee." The Examiner's writers have included Michael Barone, Tim Cavanaugh, David Freddoso, Tara Palmeri, Rudy Takala, and Byron York."
I myself is against idea of small scale nuclear. Economics is not of its side. Every single nuclear facility is has a lot of fixed expenses to keep it running. Think of the amount of qualified cadres needed to run it: every nuclear power station is effectively a small science institute on its own.
Multi-gigawatt facilities are the ones where nuclear has biggest the payout.
The few nuclear power stations that are being completed these days are single reactor designs and effectively experimental plants. This is why digits on economics got unfavourable recently.
Fuel costs are negligible in comparison to every other operating expenses. This way, simple PWRs and BWRs on multi-gigawatt scales are the only designs making sense economically. Next gen CANDUs make great sense for fuel economy (and economic costs of refuelling), but even then, frequent refuelling needs are not as dramatic as the higher costs of CANDUs. Heavy water price has only been going up - and even something like an international initiative to setup a global heavy water "bank" will help little.
4th Generation reactors - the first few reactors are assuredly can't run at profit. Their sole purpose are to be research facilities. Any nation constructing them should have full realisation that constructing gen 4 only servers the purpose of advancing its science and industrial competence, not and making money in any immediate future.
I used to feel this way: that large nukes are the answer because they provide megacity-scale energy for an increasingly urban world. But as I've studied the nuclear industry a few things have eroded away at this belief.
First, iteration. You can iterate on the design and supply chain of a small niche nuclear reactor much faster than a large baseload one. And you can do so without bankrupting the likes of Westinghouse or Areva. Once you figure out a new design at small scale, you can scale up. We did with with the current reactor designs and we should do it again for the newer fancy ones. I think this is what Oklo and similar reactor companies are planning on.
Second, and more novel, is that you can imagine large-scale nuclear farms of small reactors. Build small reactors that are sized to handle their own decay heat without fancy safety systems and manufacture them in a factory. Put them out there on shared security infrastructure and siting. There's more energy produced from internal combustion engines than all baseload plants in China, for instance. "You want scale? I'll give you scale!"
And finally if you still need to go big, there's also the potential of large modular reactors. If you build huge power plants in shipyards on floating platforms you can get economies of scale AND economies of mass production, while improving safety by being intimately coupled to the ultimate heat sink: the ocean. Wild idea politically but technically very intriguing. Would require much more remote operation than current plants because a crew of nuclear rough necks would have high salaries. But totally doable, and could probably decarbonize the world very rapidly.
> Every single nuclear facility is has a lot of fixed expenses to keep it running
Counterintuitively, economies of scale are more frequently found in small products which can be mass manufactured than big projects which must be custom built. This isn't an ironclad law. But neither is "nuclear must be big."
> the first few reactors are assuredly can't run at profit
"Assuredly" based on what? This article is about a commercial reactor project. One of many. Their investors have less of an interest in "advancing [their nations'] science and industrial competence" than in turning a profit.
[+] [-] pfdietz|7 years ago|reply
An issue with this sort of reactor is the entire primary loop becomes loaded with fission products, and becomes intensely radioactive.
I prefer the MSR (molten salt reactor) design by Moltex. http://www.moltexenergy.com/
Their design also uses molten salt, but contains the fuel-bearing chloride salt inside tubes. A separate, non-fueled salt circulates around the tubes.
For reasons of chemistry, this enables them to use a fluoride salt outside the tubes, and unlike homogenous fluoride-based MSRs the reactor structure can be made of stainless steel rather than more exotic (and expensive) nickel-based alloys. It also reduces the volume of chloride needed, which is an important cost savings if the chlorine has to be isotopically separated to reduce production of 36Cl (which has a halflife of 3x10^5 years.) The high cross section of chlorine for thermal neutrons is also why chloride MSRs are necessarily fast reactors.
Moltex's design retains the major advantage of MSRs, which is the absence of volatile materials in the containment building. It is the vaporization and pressurization of these materials in an accident which forces the containment to be large and strong.
[+] [-] rjvs|7 years ago|reply
[+] [-] acidburnNSA|7 years ago|reply
Good old solid nuclear fuel can be upwards of 15 g/cm3.
[+] [-] jabl|7 years ago|reply
But in the end the decisive factor is the neutronics. Turns out that in the fast spectrum chloride salt are better, in the thermal spectrum flourides.
[+] [-] iamgopal|7 years ago|reply
[+] [-] yazr|7 years ago|reply
https://www.energy.gov/ne/articles/southern-company-and-terr...
This is a new sodium liquid fuel design.
It is NOT the travelling wave reactor, which has been championed by TerraPower for the past 10 years.
These are 2 very very different designs which is confusing to me.
[+] [-] jabl|7 years ago|reply
I'd guess they figured out the traveling wave concept wasn't workable, and switched to another design.
[+] [-] donttrustatoms|7 years ago|reply
I think the confusion may lie in that people equate fast reactor with sodium. It's a fast MSR.
[+] [-] loeg|7 years ago|reply
dang or sctb, could you update the link to the energy.gov one?
[+] [-] acidburnNSA|7 years ago|reply
[+] [-] NickNameNick|7 years ago|reply
If you can put the reactor vessel, and associated 'hot' parts into a 40ft Iso container, and ship it cross country for installation/recycling, that might improve on the economics of existing reactors. If you can't do that, I'm not sure how it's going to be cheaper than other options.
[+] [-] JumpCrisscross|7 years ago|reply
Isn’t that smaller than the average power plant?
[+] [-] ianai|7 years ago|reply
Seems entirely too little too late. We need enough of these to power US infrastructure and electric transportation ASAP.
[+] [-] caymanjim|7 years ago|reply
[+] [-] yazr|7 years ago|reply
Cost wise, however, i agree nuclear is late to the party.
In 2018, we had large contracts for solar(+storage!) at 3cent/kw (in the US, Mexico and Saudi Arabia).
European new nuclear came in at 15c/kw.
[+] [-] bayesian_horse|7 years ago|reply
[+] [-] anonymous5133|7 years ago|reply
[+] [-] aidenn0|7 years ago|reply
[+] [-] DennisP|7 years ago|reply
[+] [-] qubax|7 years ago|reply
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] tootie|7 years ago|reply
[+] [-] danschumann|7 years ago|reply
[+] [-] acidburnNSA|7 years ago|reply
[+] [-] ToFab123|7 years ago|reply
[+] [-] TheSpiceIsLife|7 years ago|reply
Wikipedia has this to say:
Since radioactive decay follows the half-life rule, the rate of decay is inversely proportional to the duration of decay. In other words, the radiation from a long-lived isotope like iodine-129 will be much less intense than that of a short-lived isotope like iodine-131.¹
So my understanding is radioactive products are dangerous because body takes up the elements and they're either chemically toxic, dangerous because of radioactive decay, or both.
So isn't this solved by vitrifying the waste and burying it? Glasses tend to be extremely chemically inert.
I'm not convinced the spectre of nuclear waste warrants the paranoia it receives.
1. https://en.wikipedia.org/wiki/Radioactive_waste#Physics
[+] [-] DennisP|7 years ago|reply
We could use these reactors to eat the nuclear waste we have right now.
[+] [-] ksec|7 years ago|reply
I would also like to know why no one invest in Nuclear Fusion?
[+] [-] DennisP|7 years ago|reply
One reason fission moves slowly in the U.S. is the NRC. A couple years ago I got to sit in a meeting between a bunch of U.S. reactor startups and a former head of the NRC. The reactor people's main complaint was that the NRC required detailed blueprints before it would even look at a design. It would take several hundred million dollars to get to that point, and then the NRC would give a flat yes or no. With a no you were done, and with a yes you still have nothing but a paper reactor. It's a very difficult environment for investors.
[+] [-] mrhappyunhappy|7 years ago|reply
[+] [-] inamberclad|7 years ago|reply
[+] [-] Aloha|7 years ago|reply
[+] [-] foota|7 years ago|reply
[+] [-] dmix|7 years ago|reply
[+] [-] acidburnNSA|7 years ago|reply
https://www.thirdway.org/infographic/the-advanced-nuclear-in...
[+] [-] acidburnNSA|7 years ago|reply
[+] [-] Baal|7 years ago|reply
Radioactive material everywhere in private hands.
[+] [-] acidburnNSA|7 years ago|reply
[1] https://pubs.acs.org/doi/abs/10.1021/es3051197
[+] [-] Aloha|7 years ago|reply
Consider the source.
"When Anschutz first started the Examiner in its daily newspaper format, he envisioned creating a competitor to The Washington Post with a conservative editorial line. According to Politico, "When it came to the editorial page, Anschutz's instructions were explicit—he 'wanted nothing but conservative columns and conservative op-ed writers,' said one former employee." The Examiner's writers have included Michael Barone, Tim Cavanaugh, David Freddoso, Tara Palmeri, Rudy Takala, and Byron York."
That said, don't take my word for it, look at their home page (https://www.washingtonexaminer.com/) and judge for yourself.
[+] [-] baybal2|7 years ago|reply
Multi-gigawatt facilities are the ones where nuclear has biggest the payout.
The few nuclear power stations that are being completed these days are single reactor designs and effectively experimental plants. This is why digits on economics got unfavourable recently.
Fuel costs are negligible in comparison to every other operating expenses. This way, simple PWRs and BWRs on multi-gigawatt scales are the only designs making sense economically. Next gen CANDUs make great sense for fuel economy (and economic costs of refuelling), but even then, frequent refuelling needs are not as dramatic as the higher costs of CANDUs. Heavy water price has only been going up - and even something like an international initiative to setup a global heavy water "bank" will help little.
4th Generation reactors - the first few reactors are assuredly can't run at profit. Their sole purpose are to be research facilities. Any nation constructing them should have full realisation that constructing gen 4 only servers the purpose of advancing its science and industrial competence, not and making money in any immediate future.
[+] [-] acidburnNSA|7 years ago|reply
First, iteration. You can iterate on the design and supply chain of a small niche nuclear reactor much faster than a large baseload one. And you can do so without bankrupting the likes of Westinghouse or Areva. Once you figure out a new design at small scale, you can scale up. We did with with the current reactor designs and we should do it again for the newer fancy ones. I think this is what Oklo and similar reactor companies are planning on.
Second, and more novel, is that you can imagine large-scale nuclear farms of small reactors. Build small reactors that are sized to handle their own decay heat without fancy safety systems and manufacture them in a factory. Put them out there on shared security infrastructure and siting. There's more energy produced from internal combustion engines than all baseload plants in China, for instance. "You want scale? I'll give you scale!"
And finally if you still need to go big, there's also the potential of large modular reactors. If you build huge power plants in shipyards on floating platforms you can get economies of scale AND economies of mass production, while improving safety by being intimately coupled to the ultimate heat sink: the ocean. Wild idea politically but technically very intriguing. Would require much more remote operation than current plants because a crew of nuclear rough necks would have high salaries. But totally doable, and could probably decarbonize the world very rapidly.
[+] [-] JumpCrisscross|7 years ago|reply
Counterintuitively, economies of scale are more frequently found in small products which can be mass manufactured than big projects which must be custom built. This isn't an ironclad law. But neither is "nuclear must be big."
> the first few reactors are assuredly can't run at profit
"Assuredly" based on what? This article is about a commercial reactor project. One of many. Their investors have less of an interest in "advancing [their nations'] science and industrial competence" than in turning a profit.