Discussion

josefritzishere: This is huge, historic even.

WorkerBee28474: 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-...

bokohut: 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.

jeffbee: 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.

burnt-resistor: "'streamlined' mandatory hearing process" means "pushed through because TerraPower spent on $645k legitimatized bribery in 2025." [0]"The approval also makes good on a promise by the Trump administration to fast-track the TerraPower project, which comes months ahead of the administration’s target of 18 months. The company says the accelerated approval by the NRC shows the importance of and focus on America advancing nuclear power." [1]The real, unanswered questions are how they got or will get insurance and what the locals think of pedo Bill Gates building an experimental nuclear reactor in their town.0. https://www.opensecrets.org/federal-lobbying/clients/summary...1. https://cowboystatedaily.com/2026/03/04/terrapower-gets-ok-t...

eli_gottlieb: What are the substantive safety or environmental objections to the project that TerraPower is bypassing by allegedly bribing the government?

rgmerk: Their hoped-for completion date is "2031". Anyone want to hazard a guess about what their actual completion date for this plant will be?

willis936: No, but I'm certain the polymarket gamblers do.

tw04: > pedo Bill GatesHuh? You’re going to need a citation to throw those kind of accusations around. A serial philanderer? Absolutely. But all indications are he was interested in adult women, not even young women. I think the Russian call girls that Epstein set him up with were in their 30s?

jfengel: I don't know. I guess we'll find out the hard way.

stinkbeetle: 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.

rgmerk: 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.

mikeyouse: 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.

refulgentis: I guarantee commercial fusion will arrive before this.

amanaplanacanal: 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.

credit_guy: 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.

rgmerk: 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.

mikeyouse: 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...

hunterpayne: There is one, its hard to find. It only has about 19k of volume, so its very thinly traded.

tacticus: > 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.

SoftTalker: 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.

hunterpayne: 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.

testing22321: 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.

mayama: 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

dmix: If there’s more than one approval a decade maybe the odds will be higher it won’t be a bloated mess.

dopa42365: 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

Shitty-kitty: 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.

fulafel: He won't be around long enough.

webXL: 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.

hunterpayne: 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.

conradev: 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.

sgc: We do that in Northern California as well. There are only a couple of options though.

rgmerk: Can you link to it? I'm curious.

stinkbeetle: No.

croes: Our problem isn’t energy production, it’s storage.Nuclear power plants aren’t flexible enough for sudden changes in energy consumption.

croes: Or you just have two bloated messes

jacobn: 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?

fwipsy: 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.

mpweiher: 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.

ViewTrick1002: > 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 usage 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?

chickenbig: 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.

ViewTrick1002: 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...

mpweiher: Westinghouse plans 10 AP-1000 reactors in the USAhttps://www.world-nuclear-news.org/articles/westinghouse-pla...Yes, it would be better if they had already started, but the ship is turning.

croes: Nuclear power plants and the electric networks have a big problem when power consumption has sudden big changes, like thishttps://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

ViewTrick1002: 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 powerThe 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...

Moldoteck: 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

jabl: 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.

evilos: 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.

wombatpm: 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.

Moldoteck: 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

Moldoteck: 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 expansionChina 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

ploxiln: 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.

samarthr1: 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...

GolfPopper: 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.1. https://whatisnuclear.com/rickover.html

croes: 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.

Moldoteck: "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.

mpweiher: Construction for the non-nuclear parts started a while ago and is proceeding.https://www.world-nuclear-news.org/articles/terrapower-break...

GolfPopper: 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.

ZeroGravitas: 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...

AtlasBarfed: 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.

Moldoteck: 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 solutionEDF 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

Moldoteck: "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

croes: > Cooling was fine, it's env protection law to avoid damaging the fauna(read - to not boil fish)You do understand what the point of environmental protection is?If you kill the flora and fauna you are not environment friendly.

hunterpayne: https://polymarket.com/event/us-grants-license-for-new-nucle...

amanaplanacanal: Sorry, I was talking about the fake environmentalists being funded by the fossil fuel industry. And the fossil fuel industry is still successfully killing solar and wind projects in the US.

Moldoteck: Yes, i understand it very wellThe problem is you framed it as1- not being able to cool reactors physically, which is false2- being a major deal, when it affects only 0.2% of generation per year, during a period when EDF is net exporting about 14GW to the neighbors3- being an unfixable issue, which is again false. The problem exista for reactors without cooling towers. EDF can fix it by building them. But there's no financial incentive here. Where would EDF sell extra power when export is already maximized in that same timeframe and market prices in summer are low?

myrmidon: To be fair: grid buildout is quite expensive.A comparison: the giant Dogger Bank offshore wind farm project (multi-GW) cost somewhere in the $10bn range. On the other hand, Germany calculates with >$100bn for grid buildout within the next decade (https://www.netzentwicklungsplan.de/sites/default/files/2023...).Also, having customers that rely on your grid but buy very little of your power is simply unappealing for operators, so I would assume that their pricing tries to disincentivise as much as possible (=> "they gonna overcharge you for the grid connection").

nandomrumber: Lead-bismuth eutectic.A eutectic is an alloy that has a lower melting point than any of its components.Lead-bismuth eutectic or LBE is a eutectic alloy of lead (44.5 at%) and bismuth (55.5 at%) used as a coolant in some nuclear reactors, and is a proposed coolant for the lead-cooled fast reactor, part of the Generation IV reactor initiative. It has a melting point of 123.5 °C/254.3 °F (pure lead melts at 327 °C/621 °F, pure bismuth at 271 °C/520 °F) and a boiling point of 1,670 °C/3,038 °F.https://en.wikipedia.org/wiki/Lead-bismuth_eutectic

stinkbeetle: > 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 dayHave you been looking at "net demand" curves? Total demand variation is not too large over the day. The wind/solar production enormously increases the magnitude of remaining demand difference over the day.https://www.caiso.com/todays-outlook> and seasons.Nobody is talking about batteries to deal with demand swings between seasons though. Capacity has to accommodate whether it's nuclear or fossil or battery or renewable. The issue is day to day variation. And it does not matter how much wind/solar capacity you have, you can't supply demand without storage. That is untrue of other generation types.Other generation might use batteries to take the edge of peaks, but that would only be done if it made total cost cheaper. That's not the case for renewables. If there were no other generation then they would have to use storage, so it's always going to make them more expensive.

muldvarp: The two that came online in 2023 and 2024 are hardly a success story if you look at their history.

treis: 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.

hvb2: 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?

ZeroGravitas: 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.

TheSpiceIsLife: I’m all for burning less gas, it’s too important a resource to simply burn for heat.But we need to build the nuclear reactors first.In the mean time, no: people can’t just freeze in the dark.

TheSpiceIsLife: The not-so-hidden costs of collecting extremely diffuse wind / solar is the elephant in the room 10x bill for the supporting grid infrastructure.Nuclear advocates, like myself, claim drop in replacement nuclear power reactors at existing coal / gas sites would largely obviate this.Even adding new nuclear power reactors at greenfield sites would constitute a significantly reduced grid build cost, as the power is highly concentrated.And nuclear is so say that nuclear power reactors employees are routine exposed to less radiation at work than they are at home in their kitchen with granite bench tops.YIMBY.

ViewTrick1002: Which are paragraph after paragraph agreeing that nuclear power is inflexible, can’t meet a true grid load on its own without flexibility and that renewables craters the earning potential of both existing and new built reactors.As EDF will be able to sell fewer and fewer hours at a profit we will likely see them crying for handouts to even maintain the existing plants. Let alone new builds requiring 18-24 cent/kWh average prices to cover the costs.

Moldoteck: Who is agreeing that nuclear is inflexible? RTE real generation data is a direct proof it's false.EDF needs no handouts for maintenance of their reactors. But I'm eager to see their profits evolution in 2026 H1 after arenh got ditched. There will be some govt loans for EPR2, but the amount is rather tiny if we compare to say German EEG fund.

ViewTrick1002: The net demand curve varies 30 GW over the period you posted?It goes 7 GW negative.The problem with nuclear power is that about all costs are fixed. It costs 18-24 cents/kWh when running at 100% for 40 years excluding backup, transmission, final waste disposal and taxes.Now remove any earning potential from large portions of the day coming from renewables and storage and the economics simply does not pan a out.

bdangubic: flip "2" and "3" in that year

jabl: Yes, some lead cooled reactor designs have used LBE, others pure lead. Though AFAIU so far the only lead cooled reactors that have actually been built and operated in production have used LBE. There is a pure lead cooled reactor under construction that should be started up in a few years if the current schedule holds.

jacquesm: Who wants to bet this will be (1) economically viable to operate (2) delivered on time (3) delivered within the stated budget?

myrmidon: I can see that argument applying to wind, but for solar its the opposite because that is really easy to get closer to consumers than a conventional plant ever could be (i.e. on the rooftop).At this point, I don't believe in a nuclear renaissance, because it seems to me that nuclear power got left behind too far; catching up in cost metrics is already hard enough, but matching growth rates (in "installed TWh/a" of wind/solar) seems virtually impossible by now. The only remaining holdouts (China, US, France, ...) are basically doing it as a hedge and/or to keep/obtain related engineering capabilities (and at the very least an easy path toward weapon-grade material).It is clear to me that no one "actually believes" in nuclear power (by stating clearly: we are solve gonna current and future energy problems by mainly relying on freshly built nuclear power), so I can only see its relevance dwindling (I'd argue that China comes closest, but even they are much more in the hedging/securing capabilities category than anything else).

realityking: Heat pump exists. I’d rather burn gas in the (mostly existing) gas plants than put more gas pipes into the ground.

trhway: >I love the promise of nuclear energyNuclear today isn't that much different from steam engine - the fundamentals make it a technology of the past clearly losing to the today's tech, in this case to the massive solar/wind accompanied by the battery storage.Nuclear will work in space, as it is the only tech feasible beyond the Mars orbit.May be, may be the fundamentals will be sufficiently, to make it feasible on Earth, different for thorium MSRs and hopefully for fusion (my favorite is fusion driven thorium reactor - no need for fusion breakeven and relatively safe as turning off the fusion, the source of neutrons, stops thorium fission)

boringg: Thorium is inefficient. And its related to steam in that steam converts to heat and power. Differentiates considerably on the front end.Nuclear solar and wind are all natural complements. This stupid this or that argument only empowers old oil and gas tech looking to hold on to the future.

TheOtherHobbes: 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.

klysm: 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.

vessenes: So, allow me to say a few things:Nuclear is about replacing baseload - currently coal basicallySmall nuclear agrees you with about "monsters"Storage at this scale is also not easySNR definitely pencil out in today's energy regime.

pfdietz: Nuscale wasn't a sodium fast reactor. Perhaps you phrased that poorly? Nuscale is a PWR.

jacquesm: This is roughly 1980. We are now in 2025. Battery tech has been increasing massively and besides that we now have HVDC tech which can transport very large amounts of energy from end of the country to another without significant losses. The whole 'baseline power' argument is getting really long in the tooth, it is mostly a matter of dogma at this point. It's not 'nukes' or 'natural gas', it's 'what is the best possible mix for this current moment in time.The problem with nuclear power is that it is so expensive to be on standby that you need to buy their output even when you don't need it. So energy market pricing tends to be dominated by the least effective sources rather than by the most effective sources. If nuclear plants were left to fend for themselves they'd be out of business in a year. More so if you consider the cost of decommissioning.

pfdietz: I think storage (transport of energy in time) will beat transmission (transport in space) for users not constrained by population density.

pfdietz: Bismuth leads to the production of polonium, which is extraordinarily dangerous.

pfdietz: > 5 yearsBe careful with these figures. I understand they start the clock later than the west does.

Moldoteck: Do they? Did japan start the clock later too with it's first ABWR?

Moldoteck: 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

jillesvangurp: Batteries work fine right now. Much better than nuclear plants that will take another decade to build. There's probably a few dozens twh of batteries being deployed in between. They retain their charge quite long too.It's more an economical tradeoff than a technical one. But mostly, people doing off grid setups manage fine in some parts of the world. Winter months are challenging at higher latitudes. But there are also wind turbines and cables as alternatives. Cables allow you to import/export power from further south or further west or east. It's one of those things that might be a lot easier than building a lot of new nuclear power plants.The issue with gas (aside from emissions) is that gas turbines are a bit hard to get. The lead time for getting new ones is pretty terrible and companies making them aren't exactly eager to make risky investments in extra production capacity for turbines that may or may not be needed in a 5-10 years. And once you manage to get them, you have to supply them with gas; which is expensive. Gas prices fluctuate a lot.If you look at this through an economic lens, the next ten years will see:- Hundreds of GW of solar deployed. Every year. Still growing. Probably quite a few TW of capacity added. - A bit less wind turbines but still quite a lot. The US seems to have some irrational anti wind mill sentiment currently. But that might change. Huge potential there for upgrading old ones too. And offshore wind obviously. - > 3 twh of battery produced for use in transport, grid, and domestic storage. - Some new gas plants coming online here and there. But not a lot. Gas usage will grow but renewables will out grow it. - Probably growing number of GW of cables and long distance cables. Possibly even cross Atlantic. - Lost of coal plants being decommissioned (just too expensive). Offsetting most of the gw added by gas. - A sprinkling of nuclear plants coming online. Mostly in Asia. If it's not approved yet, there's no way in hell many will come online before 2036 in the US/EU. A few GW per year.The big picture here is that if you need a lot of power, you want low cost and feasibility. Gas is feasible. If you can get the turbines. But it's not cheap. If you want cheap, you mainly need to decide on the number of gw of panels you can afford to buy. And where to put them. Or wind. But the point is it's very feasible and quick to execute once you decide on a budget. Battery is not cheap (but still dropping in price year over year). And you may not actually need infinite buffers. You can fall back to gas when needed but as little as you can get away with (because $$).Any AI/data centers still in business in ten years will probably be competing on energy cost. That's likely not going to be gas or nuclear mostly.

pfdietz: 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.

jabl: 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.

pfdietz: We weren't talking about Japan.

ViewTrick1002: The EU still haven't sanctioned the Russian nuclear industry despite 19 sanction packages.Four years into the war we've almost completely cut out all other parts of the Russian economy. Except the nuclear indutry. We're just too dependent.

naasking: > 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.

TheSpiceIsLife: Heat pumps don’t solve switching away from gas.

Moldoteck: Mostly because many countries still have VVER reactors.It'll happen anyway. Orano and Urenco are expanding while Framatome and Westinghouse learned to manufacture VVER fuel elements

Moldoteck: We were talking about timelines. Chinese timelines are faster than western but slower than Japanese. So maybe you can expand your thought about how China is counting years differently

ViewTrick1002: Again trying to deflect.It is France that is tied to the hip of the Russian nuclear industry, and keeps blocking the sanctions.While continuing to move forward with partnerships with Rosatom and relying on Russian reprocessing for the fuel supply chain .

mpweiher: This is the first one.Before you build the first one, you haven't built one.Are you saying first things can never be built?

GolfPopper: If I go around bragging about my awesome self-built home design for years, and then buy, clear and level a plot of land, while it is a necessary step, it is also largely irrelevant to my ability to actually build the house, much less the quality of the finished building.

stinkbeetle: > The net demand curve varies 30 GW over the period you posted?Right. Due to solar/wind.Gross demand is much flatter. Not completely flat, but it's obvious that it does not require anywhere near the amount of storage or variation that renewables alone would require.

credit_guy: There are.The International Atomic Energy Agency (IAEA) maintains a database of advanced reactor designs, ARIS [1]. It lists 119 reactors. A lot of them are small modular reactors, and the IAEA has published a book with details about them [2]. Some of these reactors have applied for NRC approval, and you can find an enormous amount of details at the NRC website [3].To answer your question: numerous reactor designs are very safe.Let's start with the most techonogically mature: helium cooled gas reactors. Helium is a noble gas, chemically inert, transparent to neutrons (the only substance in the universe to have zero neutron absorption cross-section), and it has a hard-to-believe high heat capacity by mass. The downside is that helium is somewhat expensive and it can leak. China has been operating 2 such reactors for the last 4 years [4]. In the US, there is a reactor design, Xe-100, that is quite similar to the Chinese design. It is quite difficult to come up with a scenario where something bad can happen with such reactors. The only problem is that they are quite expensive to build and operate, compared to water reactors.There is one design that is very similar to the design of helium-cooled gas reactors, the only difference is that the coolant is not helium, it is a molten salt. In the US, the company Kairos is pursuing NRC approval for their reactor Hermes. The molten salt has lower heat capacity than helium by mass, but much higher by volume. There is no need for pressurization. The salt used here is a mixture of lithium fluoride and beryllium fluoride (FLiBe). Fluorine is an extraordinarily corrosive substance, but exactly because it is so, the salts that it forms are extremely stable. Still, stable or not, they can't match the inertness of helium, so such molten salt reactors are a bit more challenging when it comes to the contact between the coolant and the reactor vessel. However, they are extremely far from being a "low grade bomb". These reactors are almost as safe as they can be, albeit a bit below the inherent safety of helium cooled reactors.[1] https://aris.iaea.org/[2] https://aris.iaea.org/publications/SMR_catalogue_2024.pdf[3] https://www.nrc.gov/reactors/new-reactors/advanced/who-were-...[4] https://en.wikipedia.org/wiki/HTR-PM[5] https://x-energy.com/reactors/xe-100[6] https://www.nrc.gov/reactors/non-power/new-facility-licensin...

klysm: I’m not seeing HVDC tech on the interconnection queue. The baseline power problem isn’t going away any time soon.Nuclear just doesn’t go on standby, that’s the point.

mayama: I wanted to emphasise both are untested new designs that are likely to run in to troubles, one is SMR and the other Sodium.

mpweiher: If they had bragged that they had built their design and that is proven in practice, you might have a point. But they haven't. So you don't.They started building, with the non-nuclear bits first, as one does.Now they have regulatory approval.One step after another.

mpweiher: That is incorrect. The profitability floor of even the catastrophic FOAK FV 3 build is 9 cents/kWh for a 2% ROI, with around €130 for 4%. The EPR2 units are lower, around €90/MWh for 4% return and €70-80 for 2% return.Contrast this with French intermittent renewables projects, which are not profitable at all, EDF receives massive subsidies for them.

GolfPopper: Building the actual reactor is the challenging bit.You claimed that building the non-nuclear parts of the construction as evidence that the reactor itself will successfully be built, which is nonsense. That someone builds a launchpad tells you nothing about their ability to build and successfully launch rockets

Moldoteck: France is not that tied. Most reprocessing is done at La Hague. Some tiny part is sent to Russia based on older contracts but it's absolutely irrelevant for french generation in general. Last year France imported from russia the equivalent of 5% of domestic consumption... If you think this is some life changing amount...Up till recently Russia had a higher market share of enrichment market due to megatons to megawatts policy, but as we all know, russia got wild, so now all western companies are ramping up facilities, be it orano or urenco.Consider this, out of 23Bn of energy imports last year from Russia, nuclear related imports were 0.8bn, the rest being from fossils. Out of this 0.8bn, a big chunk was for VVER reactors (Finland, Czechia, Slovenia, Hungary, Bulgaria) - all requiring a very special fuel element. Framatome and Westinghouse started manufacturing it and testing in several facilities, but it'll take time for full replacement.

mpweiher: Where did I claim that all demand was flat?That's right: nowhere!Which is why some solar can be a good addition. But there is a lot that is flat. And for that you need solid, steady generation capacity.

ViewTrick1002: Do you think that demand is willing to pay 18-24 cents per kWh excluding backup, insurance, transmission, final waste disposal etc.?I can tell you they won’t. Which is why there’s currently 0 commercial nuclear reactors under construction in the US.You also have to look at it from incentives. Why should a person or company with solar and storage buy horrifyingly expensive nuclear power from the grid when their own installation delivers?Well, they don’t.Why should their neighbors prefer horrifyingly expensive grid based nuclear electricity to their neighbors excess renewables?Well, they don’t.Do you know what they do instead? These steady consumers. They buy financial instruments like futures and PPAs to ensure steady price and supply.The problem for new built nuclear power is that these financial instruments costs a fraction of the price new built nuclear power requires.New built nuclear power is the fax of the internet age. It is time to let go.

codersfocus: 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.

p forward for advanced nuclear