Energy Department teams up with Bill Gates to move mini-nuclear plants to market
washingtonexaminer.com
washingtonexaminer.com
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.
Good old solid nuclear fuel can be upwards of 15 g/cm3.
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.
Would you mind expanding on this? Why?
The fluoride cooling salt used by Moltex does not use lithium or beryllium. Instead, it's sodium-zirconium fluoride or sodium-potassium-zirconium fluoride, with no isotope separation required. The atomic mass of these isotopes is high enough that the neutron spectrum remains hard. In fact, Moltex's design adds a bit of hafnium (a strong thermal neutron absorber that is chemically very similar to zirconium) to the coolant salt to shield the walls of the reactor from thermal neutrons.
One issue with fluoride salts in homogenous reactors is that the salt must be kept a bit oxidized, so uranium does not disproportionate into UF3 and U metal. The metal would plate out on surfaces, which is a no-no. Unfortunately, this means the salt must be oxidizing enough that it will dissolve chromium, so ordinary stainless steels cannot be used.
By using a barren coolant salt, Moltex can make the salt reducing enough that chromium is stable (they do this by using a sacrificial anode of zirconium metal.) Their design can use stainless steels that have already been tested and proven for use with the neutron exposures of fast reactors.
The chloride fuel salt in Moltex (and Terrapower) don't have that chemistry issue; uranium is more chemically stable there.
For thermal reactors, particularly if you want to breed, then you have to be very careful wrt losing neutrons (since you're barely with your nose above water to begin with), so there parasitic neutron capture becomes a very important parameter. And yes, in that regime FLiBe turns out to be a pretty good choice.
For fast reactors, you have more excess neutrons so you have a bit more freedom. Cl, being heavier, allows a slightly harder spectrum, which is good, though not that critical. That being said, there are many fast spectrum paper reactors using flouride salts as well (not FLiBe, but FLiNaK, or some ZrF salts etc.).
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.
dang or sctb, could you update the link to the energy.gov one?
I'd guess they figured out the traveling wave concept wasn't workable, and switched to another design.
https://www.smh.com.au/business/bill-gates-and-china-partner...
I think the confusion may lie in that people equate fast reactor with sodium. It's a fast MSR.
Isn’t that smaller than the average power plant?
Many of the plants in the US have more than one reactor.. but you can see on this page, plant capacity/units is about 1gw/ea [edit: corrected, thanks], and many of the single reactor plants are about that size also: https://en.wikipedia.org/wiki/List_of_the_largest_nuclear_po...
Note, that page has the largest plants.. about ~45. There are only 61 in the US. So there are a few smaller ones not in the list. If you built a 1100mw reactor, it would be ~#42 largest plant.
A small reactor is under a few hundred megawatts. A micro reactor is on the order of tens of megawatts. It's quite hard to make economic reactors below that.
And space is a much different story for economics. Out there, fully enriching your fuel probably makes sense because weight is so expensive. My comment was limited to terrestrial reactors.
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.
Operating costs are also not the problem for nuclear plants, they are dirt cheap to run relative to their energy production. It's the upfront capital cost of building a large plant that makes them uneconomical currently, which is why smaller-scale designs like this one are appealing.
Edit: http://www.world-nuclear.org/information-library/economic-as... is informative regarding the economics.
Regarding economics, there are lots of reactors in the USA that have their capital cost completely paid off but they're still expensive because of high Operation and Maintenance costs. A lot of this is expensive retrofits and added security costs post 9/11. More of it is that cheap natural gas in deregulated markets has brought electricity prices way down and therefore electricity sales revenue way down. This is why some nuclear plants in the US are shutting down early before their lifetime is up. It's a great tragedy because these plants are massive carbon-free baseload electricity sources. Nukes in the US make 60%+ of the carbon-free energy of the country.
The cost of retrofits is a good point, especially given that our nuclear fleet is getting pretty old. I am also worried about the glut of cheap natural gas and its tendency to stifle other technologies. It's almost unbeatable right now price wise, but I'm a bit concerned about what will happen when that changes. Renewables are great, but base-load power is still a problem.
Seems entirely too little too late. We need enough of these to power US infrastructure and electric transportation ASAP.
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.
Without storage, renewables are already close to or below 2 cents/kWh (unsubsidized). Can nuclear startups make generating units as fast as automated fabs can spit out solar panels?
Presumably, both get cheaper as you make more, but anyone can make batteries and ship them around the world with little notice. Tesla’s Hornsdale Power Reserve system was built in 90 days. I don’t know of any nuclear plants that get built faster than 10 years.
And the Brits are demonstrating just how woefully optimistic costs, build quality, and schedules can be even with that kind of protracted delivery expectation :
https://jeremyleggett.net/2018/08/22/why-the-uk-nuclear-rena...
If you're familiar with dispatch stacks, you know that 3c/kw is REALLY attractive. Regulation or no regulation, I don't think you're gonna get down to 2c or 1c with a new nuclear plant.
Maybe I'm wrong, and one day someone will figure out how to build SUPER cheap nuclear plants?
But I doubt it.
Best I would think they could do is some sort of hybrid system that uses nuclear generation, and then storage via a conventional hydro storage system or something maybe? I'd have to do the math on that. But yeah... 2c? That's very hard to do.
Doesnt suprise - gallon of gas in most european countries (sold by liters and funny thing - you first pump then pay!) is about 40% more than same amount in USA. it has been like this forever and doesnt look like will ever change.
They can claim this plausibly for two reasons: first, they can build a MUCH smaller containment building, due to lack of water or other volatiles in the nuclear island. Second, their design isolates the turbines from the nuclear island with a molten salt "thermal battery". This allows some dispatchability in their output, but more importantly it means turbine trips have no effect on reactor stability, which means non-nuclear-grade turbines can be used. This is apparently a very large cost savings.
[And yes, I know some designs are theoretically not able to melt/blow up]
The nuclear capacity factor, on the other hand, is rather high. Upwards of 90%, and sometimes even upwards of 100% (due to the powerplants being able to produce more energy than they were designed for).
If you factor that in, a nuclear plant has about a 4.5x capacity compared to a solar plant, meaning you'd have to spend 13.5c/kw for solar with the same capacity.
Of course, this varies greatly based on where you are. In sunny climates, solar's capacity is more like 30%, while in northern climates, it can be 15%. And I'd imagine the cost of new nuclear very much depends on regulations - in the US, it might as well be infinite.
£100+ billion in 2013 https://www.theguardian.com/environment/2013/jun/23/britain-...
£161 billion in 2017 https://web.archive.org/web/20170516093449/https://www.gov.u...
£234 billion in 2018 https://www.gov.uk/government/publications/nuclear-provision...
... and counting.
Almost no one cares if your desktop computer can last 40 years. And PV is improving so fast that making it last 40 years would be nearly as pointless.
And nuclear does not improve in a "slow paced", I don't know where you got that impression, there's been a lot of innovations on the last 10 years.
I believe the .03 figure for the solar plants was $/kW and therefore had no bearing on total energy generated.
I think you would need a solar plant that incorporated energy storage to deliver nameplate power overnight for 40 years to be making an apples to apples comparison.
Another case for the importance of specifying solar variant.
Solar thermal plants with storage (molten salt, not battery) are above 70% CF already. eg the Torresol in Spain.
This is 3cent/khw and 15 c/kwh
This means it is cost per final energy produced i.e. after taking into account capacity factors, day/night, etc
This means it is cost per final energy produced i.e. after taking into account capacity factors, day/night, etc
Australia has long debated taking the world's nuclear waste, numerous commissions have found it feasible and safe. The community is overwhelmingly against it though.
Compared to runaway global warming, even widespread radiation poisoning seems trivial. And such poisoning is both hypothetical and extremely unlikely to be widespread.
We need a change in a number of habits. We need actual leadership, and not only gov types. Etc.
Nukes are the easy short term way out. The issue is what that means over the long term and how it impacts the other vectors in entity. of this problem.
Without a wake up call we'll continue to mindlessly zombie on, as we have been. Nukes __might__ slow that (but only if they don't also create a false sense of overconfidence). However, they're not going to alter the course. They alone are not going to change the end.
[1] https://en.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_repo...
Another consequence is that these reactors can use most of our existing stockpile of nuclear waste as fuel. It's the only technology that can actually reduce our waste stockpile instead of just storing it somewhere.
Storage for 300 years is generally considered a solved problem. I think the basic idea is to encase the waste in blocks of glass and bury them somewhere.
As for the waste, that is a problem, and it’s entirely solvable. Much easier to solve than raging forest fires and the growing inhospitablity of climate change.
Shortage? No. But energy could always be cheaper.
or mixed with a suicide belt's "materials"
And yes, the fuel they are talking about is a lot more radioactive than a banana or whatever.
I just worry that somebody with ill will or even just bad luck will defeat security measures "en detail", if the material is moving around in smaller parcels. Also, more people "legitimately" possessing a reactor and radioactive material will hardly decrease the risk of intentional abuse.
It would appear to carry an increased risk of hidden problems and groundwater poisoning. There might also be issues with corrosion and accessibility for maintenance.
That said, I'm not ruling it out. A lesson these new approaches to nuclear engineering is that we never figured out the right defaults the last time around. We were too focussed on making bombs and submarines.
> we already know the impacts of underground nuclear explosions
Nuclear plants should never fail by way of nuclear explosion. If this is a possibility it is a bad reactor design.
Fast reactors have always had this potential problem, since they require a much higher density of high enrichment material. A larger fast reactor might have a ton of plutonium in it; in an accident where fuel is melting and moving around unpredictably it's hard to prove that a prompt supercritical mass of Pu won't assemble somewhere. Edward Teller famously warned about this in 1967.
This is one advantage of MSRs as fast reactors: the fuel is already dispersed in salt, so such rearrangement is less plausible.
- Not really. Check out the dramatic experiments at EBR-II (fast reactor) demonstrating unprotected loss of coolant at full power. It shut itself down. Without damage. And started back up later that day, and operated that year, as a research reactor, with better uptime (capacity factor) than the fleet at the time.
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.
What a long halflife does is increase the time until that steady state is reached. If we operate a nuclear economy for a million years then a hell of a lot of that long lived isotope will have accumulated.
We could use these reactors to eat the nuclear waste we have right now.
I would also like to know why no one invest in Nuclear Fusion?
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.
https://www.thirdway.org/infographic/the-advanced-nuclear-in...
Radioactive material everywhere in private hands.
It is not a pretty sight. But hey, keep advertising nuclear. How much do they pay you?
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.
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.
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.
Nuclear power stations are not a mass manufactured product. The most pass produced ones still amount to decade long projects. There are no nuclear reactors that amount to "just add water" replicate designs, and there wouldn't be any in foreseeable future.
Just look at small coal firing powerplants, even smallest ones suitable for use in utilities are horrifically inefficient, horrifically expensive per kW/h, and still involve tons of on-site and custom engineering solutions every time. All and every vendor of "turnkey" powerplants market them as such, but just ask any power engineer if it is actually so: coal feed systems have to be optimised for type of coal used, flue solids capture systems have to be customised, foundations have to be custom engineered to accommodate heavy machinery (imagine a turbine shaft of many tonnes to get few mm bend due to soil subduction), and of course the geometry of the plant has to accommodate position of coal storage, flyash storage, transformer sites, administrative buildings and etc.
>"Assuredly" based on what?
Based to watching nation scale efforts of gen 4 reactor commercialisation failing every time. All of them wanted money from day one, and all were sure that "this time we got it right."
>Their investors have less of an interest in "advancing [their nations'] science and industrial competence" than in turning a profit.
Given the known level of intellectual ability of a successful finance professional (aka "Pro Investor") in a Western country, this doesn't surprise me at all.
You're arguing a car is impossible because horses only run so fast. Coal is a bad model for nukes because coal has a low power density per unit of fuel. You have to burn lots of fuel to get a meaningful amount of power, and burning lots of fuel takes lots of space. You naturally get a large plant.
There is no similar fundamental restriction on the size of a nuclear reactor. RTGs, for example, are tiny (albeit inefficient) nuclear reactors [1]. Here we have commercial efforts to miniaturise nuclear power plants so they can be mass manufactured.
"Past projects were X so it will always be X" doesn't make sense in a barely-explored and novel technological domain.
> the level of intellectual ability of a successful finance professional (aka "Pro Investor") in a Western country
"Pro investors" (which I take to mean generic fund managers) aren't backing nuclear start-ups. VCs with domain expertise, laboratories, engineers and utilities (together with the public sector) are.
[1] https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
Nuclear engineering is by far not a barely-explored and novel technological domain, but an industry with near 70 year history with extremely high barriers to entry.
For you, it should be reasonable to believe that engineers and physicists with multiple postdocs, people of far greater intellectual achievements that you, me, and probably most of this website's demographic, were banging their heads non-stop for the last 70 years on the problem of making nuclear power stations economical. Nothing what came from years of their work indicate that anything but big and simple PWRs and BWRs makes sense economically.
It took decades to shave everything that can be shaved off the construction of gen 3 plus reactors to arrive at their current designs. Anything that will be employed in a design claiming bigger efficiencies has to be using less than a bare minimum used by them and that's not a lot:
- Nuclear safe superalloys - check
- Large scale forging - check
- Refueling infrastructure - check
- No mechanisation beyond control rods and pumps - check
- Advanced sensing - check
- Fuel assemblies - ridiculously cheap in relation to everything else
- On-line chemical filtration and corrosion control - check
- Steam power plant - check
Really, the only opening for lower costs are reduction in operation expenses - less scientists on site, less consumables, less or not manual labour intensive servicing, less frequent and cheaper refuelling. Besides refuelling costs, that's not a lot.
One of the game changers are new superconductors. These are smaller, lighter and cheaper than anything we've had before. They're a very recent product of American and European colliders. Their use is common across many compact designs.
> Anything that will be employed in a design claiming bigger efficiencies has to be using less than a bare minimum used by them
Not necessarily. For example, a low-efficiency design that is simple to mass manufacture could be cheaper to build and operate than an expensive, efficient design.
Furthermore, for each element you list as being necessary there are designs which do without them. For example, Tri-Alpha uses direct energy capture (no steam power plant). Several companies eschew refueling in favor of capsulation. Large-scale forging is an odd thing to list when we're talking about minitiarrisation. Et cetera.
A small amount of research would show many arguments you present as established fact to be untrue or unfounded.
The other big savings for an MSR is a very large reduction in the size of the containment building. This is because there isn't water in there that would turn to large volumes of steam during an accident and that would have to be contained by a large pressure-bearing structure. Moltex claims their containment would be a factor of five smaller per unit of power output, compared to a LWR. This would be a huge cost advantage.
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.