back
164 comments
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?

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.
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.

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.

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.

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

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.
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.

Never.

Come April, all the production and construction capacity will be commandeered for the war machine.

flip "2" and "3" in that year
Who wants to bet this will be (1) economically viable to operate (2) delivered on time (3) delivered within the stated budget?
I will never, ever understand the HN obsession with presenting nukes as a practical and economically viable technology.

Wind and solar prices are still dropping hard, battery and storage tech is evolving fast, but - let's build monsters that consistently overrun time and budget, and run on fuel that can only be obtained from some of the least stable countries on the planet.

Didn't know canada and Australia are least stable countries on the planet or that US doesn't have own uranium deposits.

Neither did I know regions like Germany (or EU as a whole) can get by on ren alone looking at winter capacity factor data

What happens if a natural (massive volcano eruption) or man made disaster (e.g. nuclear war) darkens the skies for weeks? Don't hitch your energy needs on one technology.
Grids need reliability. Battery tech is not close to providing long enough durations to fulfill load with just renewables. I would much rather have nukes than natural gas filling that role.
So, allow me to say a few things:

Nuclear is about replacing baseload - currently coal basically

Small nuclear agrees you with about "monsters"

Storage at this scale is also not easy

SNR definitely pencil out in today's energy regime.

> presenting nukes as a practical and economically viable technology.

The practicality and economic viability are entirely under our control. We made them impractical and uneconomical here, while they are practical and economical in France and China.

Prediction market?
Fast reactors have an extremely serious potential failure mode.

In a thermal reactor, reactivity is maintained by a carefully designed lattice of fuel elements and moderator. Disrupt this lattice and reactivity goes down. Thermal neutrons are also highly absorbed by certain neutron poisons with resonances that enable neutron capture at low energy; these can be added to shut down any potential reaction.

Fast reactors aren't like that. If fuel rearranges (for example, by melting and flowing into coolant channels) reactivity can increase. A fasts reactor will have ~100 times the "bare core" critical mass of fissionable material in it, so there's plenty of room for serious rearrangement to bring fission material into a prompt fast supercritical configuration.

That by itself could give you an explosion. But if the explosion then compresses some other part of the system beyond supercriticality, one could get an even more serious explosion. The possibility with something with a yield in the kiloton range can't easily be ruled out. This would be far worse than Chernobyl.

The fast reactor concepts I've seen deal with this by saying "our design can't ever melt down". Color me skeptical on that, and defense in depth says you don't believe such claims when failure could be so catastrophic. Even if regulators can be convinced (or be made to say they are convinced), the first experience that indicates the assumption wasn't true will lead to all reactors of that design being permanently shut down. This would be a serious financial risk to anyone thinking of building them.

If I were dead set on a fast reactor I'd look at something like a fast MSR (chloride salt) where such rearrangement could be ruled out.

Not sure about this argument, do you have any references?

In a LWR, if the coolant/moderator boils away, sure, the reactivity goes down. But there is plenty enough decay heat left to melt all the fuel that can then flow into a puddle of suitable geometry and go boom. Hypothetically speaking, at least.

I suppose in practice most LWR's use lightly enriched fuel so it's very hard to get enough material close enough together to make it critical, let alone supercritical, without a moderator of some sort. Of course, plenty of research reactors, naval reactors etc. have operated with very highly enriched fuel (90+%?), but even these have AFAIU so far managed without accidentally turning themselves into nuclear bombs.

Seems most contemporary civilian fast reactor designs are designed to operate with HALEU fuel, where the limit is (somewhat arbitrarily) set at 20%. A lot higher enrichment than your typical LWR, but still much lower than you see in weapons, and you still need quite a lot of it before it can go boom.

It's straightforward. Consider what would happen (for example) if all the fuel in a reactor is compressed into a more compact configuration.

In a thermal reactor, there's no problem, as there's now no moderator. There was massive rearrangement and compaction of melted fuel at the TMI accident, but criticality was not going to be a serious issue for the fundamental reasons I gave above.

In a fast reactor? It can only become more reactive. Anything else there was only absorbing neutrons, not helping, and the geometric change reduces neutron leakage.

Edward Teller somewhat famously warned about the issue in 1967, in a trade magazine named "Nuclear News":

“For the fast breeder to work in its steady state breeding condition, you probably need half a ton of plutonium. In order that it should work economically in a sufficiently big power producing unit, it probably needs more than one ton of plutonium. I do not like the hazard involved. I suggested that nuclear reactors are a blessing because they are clean. They are clean as long as they function as planned, but if they malfunction in a massive manner, which can happen in principle, they can release enough fission products to kill a tremendous number of people.

… But if you put together two tons of plutonium in a breeder, one tenth of one percent of this material could become critical. I have listened to hundreds of analyses of what course a nuclear accident could take. Although I believe it is possible to analyze the immediate consequences of an accident, I do not believe it is possible to analyze and foresee the secondary consequences. In an accident involving plutonium, a couple of tons of plutonium can melt. I don’t think anyone can foresee where one or two or five percent of this plutonium will find itself and how it will get mixed with other material. A small fraction of the original charge can become a great hazard."

(Natrium is not a breeder but the same argument holds.)

That no fast reactors have yet exploded is of course no great argument. How many fast reactors have been built, particularly large ones? Not many. And we've already seen a commercial fast reactor suffer fuel melting (Fermi 1).

They originally were going to build their first plant using this technology starting in 2018 in China, but that got killed by the first Trump administration.
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.
Construction for the non-nuclear parts started a while ago and is proceeding.

https://www.world-nuclear-news.org/articles/terrapower-break...

This is huge, historic even.
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.
Nuscale wasn't a sodium fast reactor. Perhaps you phrased that poorly? Nuscale is a PWR.
They're already building this one. Nuscale didn't break ground AFAIK.
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

Maybe. There is a long road from "approved" to "operational".