The Kemmerer Unit 1 project... would be used to demonstrate the TerraPower and General Electric-Hitachi Natrium sodium fast reactor technology. [0]
https://en.wikipedia.org/wiki/Sodium-cooled_fast_reactor
[0] https://www.nrc.gov/reactors/new-reactors/advanced/who-were-...
Nice, I like the sodium fast reactor concept. Produces less waste, can be passively cooled when shut down, and doesn't run pressurized so reactor vessel can be thinner.
Sodium leaks can be nasty, but they can be dealt with.
Are there any nuclear alternatives that don't include strapping low grade bombs to the reactor core (PRW/BWR: water separation -> hydrogen + oxygen -> boom, like happened @ Fukushima) or using coolants that instantly start violently combusting when exposed to air or moisture (sodium)?
I love the promise of nuclear energy, and I understand that every single engineering decision has tradeoffs, but these tradeoffs just seem so bad? Are there really no better options?
I was also curious. Claude answers: https://claude.ai/share/244fc2f5-1c4d-4e52-b316-e9cc34c8b98b I would be interested in a real expert's critique/commentary of this answer.
I like the pebble-bed design because it seems the most intrinsically safe of the three.
Pebble beds are very safe but also very fuel inefficient.
There have been some sodium cooled designs that have used a closed cycle gas turbine using nitrogen as the working fluid for the secondary circuit, in order to avoid any issues with sodium-water reactions with a traditional steam Rankine secondary circuit.
There are also fast reactor designs using lead as the coolant rather than sodium. These are interesting, but less mature than sodium cooling. Sodium is better from a cooling and pumping perspective though.
The improvement is more on the fuel cladding for classic pwr or pebble bed reactors... But even without all this, nuclear is one of the safest sources of power on the planet, because we made it so
The AGRs are advanced reactors that use an inert coolant, CO2. In fact they have been designed to cool down quicker than any credible loss of coolant. And have been in service since the 70s, with some slated to go on until 2030.
I mean the LWR fleet has proven to be incredibly safe by any objective measure with deaths per TWhr as good or better than wind/solar. The very incident you mentioned had a direct death count of 0 or 1 depending on who you ask. Industrial shit blows up all the time, you just don't hear about it because it's normal and accepted.
What needs to improve about nuclear is our ability to deliver it on time and on budget. Safety is already more than adequate.
That is never going to happen until we are building more of a consistent design. I think every LWR is use today is a custom bespoke piece of equipment.
China has a liquid uranium in the vein of the lftr design allegedly operating.
That I believe is the safest design, but I'm not a nuclear engineer.
And the verbiage that many will glance over yet will have the greatest future impacts for all alive is: "...includes an energy storage system..."
Todays U.S. meeting "Roundtable on Ratepayer Protection Pledge" with the U.S. President himself leading that meeting garnished commitments from Big Tech as it relates to energy. In time Big Tech Energy divisions will be thing and some citizens will be paying their utilities bill to them.
In Texas and Massachusetts you can actually pick your power provider while paying the natural monopoly for the wires. In time I hope we all can do this.
This is how it works in NYC, but the wires are almost twice as expensive as the power. (If you add taxes and the numerous weird fees, the total bill is a solid 3x the cost of the power.) It's really all about the grid maintenance and management these days.
Heh, wouldnt NYC be best case scenario for a grid? It has high density, large number consumer base etc?
If only they could sort the underground cabling...
We do this for gas. IMHO you end up paying monopoly rates for the pipes and then stupid game prices for the gas. Maybe the savvy consumer comes out ahead but seems like a net negative to me.
It's not monopoly rates, it's actual utility rates. The only problem here is if the utility is allowed to make a profit. Gas pipes, electric lines and internet connections are like roads in today's society. Can't really live without them.
So assuming the pipe maintenance is done at cost, with no money not being spent on the network. What would your better net positive solution even look like?
People can live without gas pipes. One of the big tasks at the moment is planning to stop people building new gas pipes that won't be used enough to justify the price and how to phase out the existing gas pipes so the pricing doesn't enter a "death spiral" as people start leaving the network, leaving the government to bail it out.
We do that in Northern California as well. There are only a couple of options though.
There are large solar power stations on the grid in California owned by tech firms so you may indeed already be paying, indirectly, Apple for energy.
Their hoped-for completion date is "2031". Anyone want to hazard a guess about what their actual completion date for this plant will be?
Presumably it’ll end up like the NuScale one, raise a few billion for design and prototyping and then every 6 months or so increase the target wholesale price by 50% until it makes no sense at all economically to begin primary construction. They’ll reverse IPO along the way and manipulate the stock enough to get insiders paid out while the carcass of a company trundles along.
No. They have Bill Gates as a founder. Bill Gates understands that nuclear is a long game.
> They’ll reverse IPO along the way and manipulate the stock enough to get insiders paid out while the carcass of a company trundles along.
I'm not sure what "reverse IPO" means, maybe you mean they'll be acquired by a SPAC, like NuScale was. I doubt it. Bill Gates founded Terrapower in 2008, he is not looking for a quick buck.
In theory, at least, they have finished their design, had it reviewed by the NRC, and had it approved, so there should be no significant design changes.
But that also applies for the current generation of reactors and nobody can build them to schedule or budget in the USA or Europe.
To reference Admiral Rickover's 'Paper Reactor' memo [1], TerraPower is now going to commence transforming their paper design into a practical reactor. Historically, this does not usually prove successful.
Yep. NuScale received design certification as well and still ended up with multiple huge revisions. It’s not easy to build any nuclear, much less a FOAK reactor.
But when that fails, you can just siphon up taxpayer money via your connections to the ruling cabal.
https://www.thedailybeast.com/tiny-trump-linked-firm-in-line...
> so there should be no significant design changes
The NRC frequently changes requirements for reactors while they're under construction. The NRC does not waive the right to demand changes merely due to prior design approval. This is a novel (for the US) design, so there will be unanticipated changes as the project progresses.
Russia has been operating two sodium cooled fast reactors for decades. The BN-600 and BN-800 are both operating today. The early history of the BN-600 was... interesting, suffering (at least) 14 sodium fires due to leaks. This "Natrium" design is similar; a sodium pool with two sodium loops. They are taking on the additional challenge of storing a massive quantity of molten salt. It's going to take a lot of effort by many steely eyed missile people to make this happen.
Trump issued an EO in 2025 that's supposed to make the NRC more circumspect about requiring changes of approved designs. Then there is all the pull Gates has. Wyoming is no hotbed of anti-nuclear activism. So that's all to TerraPower's favor. But TerraPower will need to fully utilize all the tailwind it can find to make this work.
No, but I'm certain the polymarket gamblers do.
I did have the same thought, had a quick look (I'm not a polymarket user) and couldn't find a market relating to this project.
Put it this way, if it's in commercial operation by 2031 I'll eat my hat.
If the DOW needs fissile material, then you might be impressed at how fast things are done. The obstacles are mostly discretionary.
There is one, its hard to find. It only has about 19k of volume, so its very thinly traded.
Can you link to it? I'm curious.
China have 28 nukes under construction right now, and have built more in the last 30 years than the rest of the world combined.
Even with all that experience and expertise, their questionable environmental policies and questionable worker rights, it still takes them SEVEN years to build a single nuke.
The claim that anyone else can do it faster with zero recent experience isn’t only laughable, it’s downright fraud.
The Chinese CAP1400s took 5 years and that's a new design to them. The first NPP was built in 1951 (ish) and took 18 months from blackboard to grid interconnection. Some designs take longer, others are shorter. Some parts of Vogal were rebuilt 3x times due to the federal government changing the design requirements multiple times during construction. Another challenge is that NPPs are built rarely enough that its hard to be a supplier to the nuclear industry so many parts are custom built per project. That doesn't have to be the case. The idea there is a hard limit of 7 years, sorry...that just isn't so.
it takes about 5y for latest units. And their env/worker policies are not that questionable in this regard. Heck, Japan did finish it's first ABWR FOAK in under 4y so China is in fact slow here. The question is rather why China bans inland expansion
China and Russia are about on par in build times now. Korea is next with APR, Barakah having about 8y/unit, W-house and EDF are the slowest for many reasons
Wow, that's A lot. Even though there's diminishing returns with more workers, they'd probably build them faster if they weren't scaling out so much concurrently, right?
Seems like we could match a 7 year clip at a much smaller scale. We'll be forced to at some point, but we need to overhaul the regulatory mess and fix the grid first. Hopefully that happens long before battalions of Chinese drones and droids take over the world.
This is huge, historic even.
You know what would be even bigger? Building perfectly safe and fine AP 1000s that already exist many times today and can be built whenever you want to.
0 under construction in the US
Westinghouse plans 10 AP-1000 reactors in the USA
https://www.world-nuclear-news.org/articles/westinghouse-pla...
Yes, it would be better if they had already started, but the ship is turning.
It is not. The right wing is instead waking up to reality. Apparently they like extremely cheap distributed electricity. Who could have guessed that.
Why MAGA suddenly loves solar power
The Trump-led attack on solar eases as the right reckons with its crucial role in powering AI and keeping utility bills in check.
https://www.washingtonpost.com/business/2026/03/02/katie-mil...
True but additional context: Wikipedia says that two came online in 2023 and 2024, and two more are partially constructed, seeking additional funding to continue. Lots more internationally.
How is this fundamentally different from Nuscale approval? Like Nuscale this is also brand new design, sodium fast reactor, that hasn't been commercially deployed and is likely to run into usual ballooning budgets and western nuclear construction roadblocks/delays
If there’s more than one approval a decade maybe the odds will be higher it won’t be a bloated mess.
Or you just have two bloated messes
They're already building this one. Nuscale didn't break ground AFAIK.
Maybe. There is a long road from "approved" to "operational".
Great, hopefully the ship is turning around slowly. I have been hearing from pro-carbon "environmentalists" for 30 years that "we should have built nuclear 20 years ago but doing so now would be pointless". Meanwhile we may have just reached peak-coal today if we are lucky. Well past time to stop listening to anything those grifting charlatans have to say.
> Well past time to stop listening to anything those grifting charlatans have to say.
Are you describing the "just build nukes" party here?
Cause we've been waiting a while for this nuke solution to actually ship but every example is far more expensive all while the nuke lovers block solar and wind for the same reasons.
There is no for-profit companies that are in it to save the planet, despite what the brochures say. Unfortunately for non-carbon power companies, their main competition is each other rather then fossil fuel sources.
No.
They got what they wanted. They are still successfully killing solar and wind projects.
I'll be surprised if this project actually gets built, though.
I don't think killing solar and wind projects is what the greens do. The problems with solar and wind are entirely due to the laws of physics. They get large advantages in the energy markets in most places. They have been very effective in preventing nuclear though which ironically does so much real world damage to their cause that all the rest of what they do is a drop in the bucket.
Our problem isn’t energy production, it’s storage.
Nuclear power plants aren’t flexible enough for sudden changes in energy consumption.
Nuclear power is one of the most flexible sources of power, especially PWR's with ALFC or even more so - BWR's You can actually see how France is flexing in the summer on RTE website
France's nuclear operators have been claiming this for years. But recently started claiming that wind and solar are bad because they force nuclear to flex which is too expensive.
> Electricite de France SA said growing solar and wind generation was increasing equipment wear and maintenance costs at its nuclear reactors, which are forced to reduce output when power demand is insufficient.
https://www.bloomberg.com/news/articles/2026-02-16/edf-warns...
"France's nuclear operators have been claiming this for years. But recently started claiming that wind and solar are bad because they force nuclear to flex which is too expensive." - one doesnt disprove the other.
French nuclear is extremely flexible https://www.services-rte.com/en/view-data-published-by-rte/g... but it doesn't mean it's free. Solar and wind without proper bess to support them are creating problems for other generators, acting as grid parasites without offering proper firm generation
The storage problem is home-made, because our problem is intermittent renewables that can't produce on-demand.
With consistent producers like nuclear there is no storage problem.
And of course the Natrium plant has the buffer so it can ramp grid output up and down while maintaining the reactor at consistent power levels.
Nuclear power plants and the electric networks have a big problem when power consumption has sudden big changes, like this
https://www.wsj.com/business/energy-oil/a-new-threat-to-powe...
Storage would mean just to reroute the energy to storage, otherwise you need to lower the power plant‘s output what doesn’t happen fast in nuclear power plants
> With consistent producers like nuclear there is no storage problem.
This tells me you’ve never looked at a demand curve. In for example California the demand swings from 18 GW to 50 GW over the day and seasons.
The problem has always been economical. And this solution is looking like a bandaid to get taxpayer handouts.
Why store expensive nuclear electricity rather than extremely cheap renewable electricity?
France seems to work. They have plenty of nuclear power that is flexible. And you can have other forms of consumption flexibility; otherwise wind and solar are really in trouble.
France is part of the EU power grid and flexibility comes from that not from nuclear power plants. And the government had to rise the subsidies for nuclear energy to prevent higher rises of the energy prices. The costs for the consumers still raised.
And their power plants were in trouble in the last hot summer because the rivers were too hot to be used for cooling. Won‘t be the last time. And that will be a big problem when people turn on their AC in a heat wave but the power plants can’t power up because they don’t have enough cool water.
And that was before drone wars were a thing.
People react nervously when unknown drones fly around airports and power plants.
And didn’t we learn from the internet that centralization is a bad thing? Nuclear power plants are exactly that.
Imagine a grid where every consumer is also a producer who can satisfy their energy needs at least partially for themselves even without the grid. Try to blackout that.
"France is part of the EU power grid and flexibility comes from that not from nuclear power plants." - blatant lie. You can see in generation data they are flexing a lot in the summer. https://www.services-rte.com/en/view-data-published-by-rte/g...
"And their power plants were in trouble in the last hot summer" - blatant lie. Cooling was fine, it's env protection law to avoid damaging the fauna(read - to not boil fish). Yet, it affects about 0.02% of annual generation and valid almost exclusively to NPP without cooling towers. Yet in those exact periods EDF was net exporting about 14GW to neighbors, again, data is public. French nukes can handle ppl's AC's just well, probably EDF even hopes for that to modulate their npp less and get more $
Why people always spread such nonsense without even checking the facts? Like https://www.vie-publique.fr/files/rapport/pdf/288726.pdf
"And didn’t we learn from the internet that centralization is a bad thing? Nuclear power plants are exactly that." France has a combination of centralized and decentralized power - npp's are distributed around the country but each can generate a lot of power. Even more distribution and you start paying a ton for transmission lines and maintenance. That's the reason Germany started subsidizing them from this year, with about 6bn/y. Full decentralization is not a feature and you still can't achieve it since transmission system is centralized, prime example being recent cascade blackout in Spain.
"Imagine a grid where every consumer is also a producer who can satisfy their energy needs at least partially for themselves even without the grid. Try to blackout that." - that'll mean having to need a fully parallel grid for firming. Besides, a lot of home solar are grid followers - if there's a blackout, it'll shut down too unless you have a special invertor+bess which many dont have (yet)
"And that was before drone wars were a thing." - a drone would do nothing to a NPP. Even an airplane impact can be tolerated depending how new is the NPP.
France uses their own and their neighbors fossil capacity to manage nuclear inflexibility.
When a cold spell hits France exports turn to imports.
Now EDF is crying about renewables lowering nuclear earning potential and increasing maintenance costs.
The problem is that they are up against economic incentives. Why should a company or person with solar and storage buy grid based nuclear power? They don’t.
Why should they not sell their excess to their neighbors? They do.
https://www.bloomberg.com/news/articles/2026-02-16/edf-warns...
No it doesn't. You can see it https://www.services-rte.com/en/view-data-published-by-rte/g...
French nuclear is more flexible than coal by design and as flexible as many older gas plants with ALFC system. They can reach up to 0.5%/second modulation (proved by Philipsburg) if the situation requires but it's rarely the case if you have a fleet. It's still not as fast as BWR's that can reach 1%/second but german coal is the slowest load follower and still meets min requirements imposed by the grid.
"When a cold spell hits France exports turn to imports." - was true in the past, a bit, but afaik this and last winter France was net exporting a ton. And with FLA3 reaching full capacity this year it'll be even less of a problem. It's not like they have a problem now, they are the largest net exporter on the continent and it's unlikely to change soon.
"Now EDF is crying about renewables lowering nuclear earning potential and increasing maintenance costs." - yes, because ren generation is acting like a parasitic source without proper BESS deployments - they eat into firm power profits without providing firm power benefits.
"Why should a company or person with solar and storage buy grid based nuclear power? They don’t." - because in many places of the world solar+bess are not sufficient. It's also the reason why Microsoft signed a contract for TMI way above market prices instead of building a fully offgrid ren solution
EDF is selling power to neighbors and makes money from it. It also is modulating it's npp a lot, which will maybe change when AC's will be more widely deployed and EV's will expand. It also is trying to schedule most maintenance works in summer, during lowest demand periods
Construction for the non-nuclear parts started a while ago and is proceeding.
https://www.world-nuclear-news.org/articles/terrapower-break...
The non-nuclear bit is the key there. Site construction is not the challenge. Turning a theoretical reactor design into a working reactor design is.
As far as I can tell, in its 20 years of existence, TerraPower has not built a reactor. nor had one of its designs built by someone else.