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Comment by lucidguppy | Hacker News Reader

Nuclear should compete with fossil fuels - not renewables. Nuclear power provides 50% of the US's clean energy.

https://www.e-education.psu.edu/ebf301/node/457

We need to replace natural gas with nuke plants. Fossil fuel extraction is the worlds largest source of nuclear waste, not nuclear energy. No one worries about the tons of radon released from fracking. They call it "natural". https://www.resilience.org/stories/2015-04-14/fracking-incre...

I'm all for renewable - don't stop it. But there are many places in the world where a nuke plant would be the right choice. It would be great if we got this amount of resistance to new hydrocarbon vehicles or plants.

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> Nuclear should compete with fossil fuels - not renewables. Nuclear power provides 50% of the US's clean energy.

No, it should compete with both on market terms. If a nuclear plant is built instead of a hydroelectric plant, a wind farm or a gas-fired plant, I’ll be able to sleep just as easily about it so long as it wasn’t built for political reasons.

The market does not price in externalities. That's why they call them that. Nuclear has significantly cheaper externalities than fossil fuels. You should prefer it, and subsidize it in kind.

Subsidizing nuclear is entirely theoretical for me, unless I’m subsidizing it in other States which I wouldn’t be happy to do if it won’t benefit me directly (not indirectly: directly).

California presently has a flat prohibition on new nuclear construction. I would rather keep my dollars for my own utility bill, unless Nevada would like to play host to a nuclear plant built to serve the Bay Area.

I guess the states aren’t so united. Federal Texas are for federal uses which can include state ones.

You’re not wrong but that’s exactly my problem: this isn’t something for the Feds to subsidize. They need to get out of the business of subsidizing industry.

Anything that is capable of negotiating on behalf of society in the case of a transaction that produces externalities is going to be indistinguishable from a government. If you're arguing that no one should advocate for society's interests in these transactions, then you should make that position explicit.

If not for environmental reasons, how about energy security reasons?

Living and human civilization are high energy activities, and becoming higher energy over time. Just the number of electronics I employ in my day-to-day life has made electricity alone more central to my life than it maybe was 20 years ago even.

So plants and energy transmission lines and such are going to be built, especially as more battery-electric vehicles become available in more model lines and at more varied price points for people to buy. If I had a personal preference, I would prefer that electricity to be coming from nuclear and solar plants, but I’m not willing to condemn the poor to raise prices and make those the only options. What gets built will be what makes sense according to the knowledge and expertise of people who build plants, i.e. what is economical in the context of the market which is just trillions of accumulative transactions happening across society made by people; and we’ll make decisions about where to import/export energy from in geopolitical and military contexts where those decisions rightfully belong which can and does inform markets.

The harder we make it to build nuclear though, the less likely nuclear will be chosen. In California for example there is a flat prohibition on new construction, so we’re going to keep building gas-fired plants alongside whatever renewables because that is what we have chosen to do, until we make a different choice.

Maybe we should rebrand away from "nuke plant?" Fission steam boiler sounds better.

The huge problem with nuclear vs. natural gas is, that nuclear power plants have only a limited range, in which the power output can be regulated and they are not too quick in that either. So you need something else you can power switch quickly to maintain grid integrity. Natural gas is great for that, as the plants are very quick in response and can be regulated between 0 and 100% and back.

Nuclear is great to replace coal, but you still need the same amount of e.g. storage to complement changing net load and production (renewables).

Nuclear fuel is cheap enough that it could be economical to simply [0] discard the unneeded production.

[0] It’s not that simple, but dump loads exist, as do mechanisms to intentionally waste power inside a plant without producing electricity. For example: https://www.thermal-engineering.org/what-is-turbine-bypass-s...

The other capital and operational costs stay the same even if you just discard the production you don't need, so just focusing on fuel costs is not very helpful to determine if it's economical to do that.

Financial profitability is not a requirement for infrastructure projects. If it is the best way to supply power in the most sustainable way, it should be subsidized by governments to make it happen. If you want to pretend it balances on paper add eco taxes elsewhere, but again thats not necessary.

It is not that easy, we have privatised the energy markets so there are rules that need to be followed. Ignoring cost is not something governments can or should do, there are many more factors that need to be taken into account and this combination is what should be optimized for instead of just one factor. The most sustainable way to supply power is to reduce the need to supply it in the first place, insulation and other energy saving measures are usually subsidized already.

My point is that, once you’ve paid the capital cost for, say, 1GW of nuclear, the marginal cost of energy produced is low and you can adjust the production on fairly short timescales. I’m not saying you should, but the calculation is different from a natural gas or coal plant in which the marginal cost of energy is much higher.

The OpEx is coal < nuclear < gas [0]. This is for regular nuclear plants, SMRs will have higher OpEx. Not sure how they'll fare against gas exactly. The SMR handbook has some estimations I believe, but I don't recall the numbers.

[0] https://www.e-education.psu.edu/eme801/node/530

This is the actual plan for renewables, because they are just cheap period (though their fuel is pretty darn cheap too). Demand response, simply dumping the excess, storing excess as heat etc.

It's not a good idea for nuclear, because even nuclear that runs all the time can't compete on cost with renewables and any deviation from that schedule destroys the economics conpletely.

A small amount that runs all the time is probably a good idea in places far from the equator, but even then the plummeting costs of renewables opens a few other doors, like shipping green hydrogen around.

24 GW of renewables in my country are not delivering even 1 GW when demanded currently.

That's not demand response. That's failure.

Right, any dollar diverted from renewables + storage to anything else, whether nukes or gas, brings climate disaster ever nearer.

Sounds like a case for Bitcoin ASICs if I've ever heard one . . .

Can machines for extracting CO2 from the atmosphere have how hard they are running be ramped up and down quickly? Or do they just have a rate they work at, where changing how much one is doing would require changing how much machine there is / which ones are active ?

Machines for removing CO2 from the air need consume no power at all. (E.g., a big fabric corral that waves slop into, connected to a fabric tube 10 m across that opens 1000m below.)

Machines to synthesize H2 and NH3 could be ramped up and down, but in practice will run 24/7 except when price peaks and stockpiles are burned for power instead.

> Nuclear fuel is cheap enough that it could be economical to simply [0] discard the unneeded production.

Just run wind turbines backwards, easy!

Small modular reactors may improve on that. Molten salt reactors in particular are supposed to be able to adjust to demand within a minute or so.

Another possibility, for any sort of high-temperature reactor, is to use molten salt as energy storage. Heat the storage salt directly from the reactor, and put the turbine after that, so you don't have conversion losses before storage. Terrapower is working on this with their Natrium project.

>Molten salt reactors in particular are supposed to be able to adjust to demand within a minute or so.

Nobody is making these commercially and the SMR companies out there are making standard pressurized water reactors afaik.

A bunch of companies are developing molten salt reactors commercially, including Terrestrial Energy, Moltex, Elysium, Seaborg, Thorcon, and Terrapower.

Commercially usually means they are actually outputting things.

Lftrs have been hyped since like 2010 and I don't think any new molten salt reactor has made any net power on the grid since then. From what I could tell of the companies you listed not a single one even has a demo reactor and the earliest ones are slated for years from now.

So you wouldn't define pre-release tech startups as commercial? Ok. They have investors who hope for profits, call them what you like.

None of these projects are LFTRs. They're generally uranium-fueled, which retains the safety and cost advantages of MSRs without the radioactive chemical engineering of LFTRs.

Terrestrial Energy, to take one example, has been doing well with regulators in Canada, and plans to operate a 390MW plant in 2028: https://www.powermag.com/terrestrial-energy-launches-390-mw-...

So yes, years away, but not that many years.

Well forgive the pessimism but these claims feel awfully like "Fusion is just 30 years away" which people have been saying for 50 years.

And if a fraction of the funding that was dumped on frivolous "renewables" in the last 20 years (Solara? Ha - tip of the iceberg for waste!) was instead spent on new reactor designs we wouldn't even be having this discussion.

Which is probably why nuclear continues to be demonized. Follow the money...

Solara failed purely because cost for the competition dropped well below theirs. It was an honest business failure, like many others; and ultimately good news for the rest of us. They burned through $1/2 billion. Nukes always burn much more; US subsidies are more, every year, for equal value in the end.

Harping on Solara only calls attention to nukes' overwhelmingly worse performance. Nukes are "demonized" because they cost overwhelming more than alternatives.

The last plant built in the US was the Watts Bar Unit 2, estimated cost around 6.1B USD for ~1.1 GW of output and construction took over 40 years. Average cost for Solar is something like 2-3$/watt. Follow the money indeed.

I've seen non-photovoltaic solar collectors that heat molten salt and then store it for off-peak use. I wonder if they could be hybridized with small modular MSRs.

Those are no longer cost competitive with PV and batteries.

But a lot of that is the cost of concentrated solar.

On the PV side, batteries are not known for being especially cheap. Lazard puts the wholesale cost of PV plus four hours storage at 8 to 14 cents/kWh, as of 2020: https://www.lazard.com/perspective/levelized-cost-of-energy-...

And four hours storage is just what you need to shift peak daytime sun to peak evening demand. You need more to get through a windless night. To cover reduced supply on cloudy winter days you need some combination of overcapacity and long-duration storage, which typically involves some kind of turbine.

Batteries are the most expensive storage. Storage cost is plummeting even faster than solar or wind ever did.

That's handled by grid-scale storage: Batteries, pumped storage, compressed air.

Renewable energy has the same need.

BTW, when I was a teenager I got to go deep inside of a mountain to tour a pumped storage facility built to pair with some early 1970s nuclear power plants. The nuclear plants are long-decommissioned, but the pumped storage is happily running with renewables.

The general preferred choice for energy that can quickly turn on and off (in terms of weather changes that cause low production in wind/solar) is hydro. As long you don't deplete the water reserves it can be turn on and off fairly fast, through there can be considerations downstream. Nuclear can help in keeping those reserves high by reducing demand and letting hydro deal with the peaks.

Using natural gas is non-viable. It funds war as has been fairly obvious lately, and it puts a dependence between those that has the natural resource and those that don't. The climate can also not continue to take the continuous damage that burning/leaking natural gas causes.

The choices that we have is either nuclear, renewables, and batteries. The natural gas plants need to be replaced and so one can either choose nuclear, renewables or batteries.

It’s not really that huge of a problem to have more energy than needed. It just takes additional engineering to put the excess to use. Having a national grid it can be moved around. Or used for energy intensive uses that can be useful elsewhere. Kind of like the flare gas oil rigs burn when those gasses aren’t economic. I’d like to see us have that excess power pull useful gasses out of the atmosphere or sea water, for instance. Done right it could act as a hydrogen source for hydrogen fuel cell vehicles, for instance. Or power a national water grid. Tons of uses for more power than needed.

It's not a huge engineering problem. But it is a huge problem, lower the rates when you have excess power and we will have more uses for the energy. But if the rates are low the revenue is low.

(This would not be so significant a problem if the capital costs weren't so high)

This is not true. Modern nuclear plants can load follow.

The reason they usually don't is because fuel is such a small portion of the cost of operating a nuclear plant. It's comparatively more efficient to run nuclear at 100% and idle fossil plants. But nuclear can absolutely load follow if there's a reason to, such as load sharing with renewables.

You will find further information on this web site: https://en.m.wikipedia.org/wiki/Load-following_power_plant

Only in a very limited way. As we move forward, we are quickly reaching the point where for more and more time, renewables can carry the whole grid load alone. Nuclear power plants would have to be switched off in those times. And while they can follow the load over a large part of their power output, they can't be swithed off and on again. So as the transition to renewables progresses, nuclear power plants are less and less a good counterpart. Gas plants however are. They are very quick and switching them off is possible and saves precious fuel. As the transition progresses, they should use less and less fuel as they are used more rareley and the fuel could be switched to renewable sources (bio, power2gas). The pre-war plans of the current German government included extending the gas infrastructure but with a clear ability for new installations to be also able to use H2 as it becomes available.

If they load follow, their cost per joule produced becomes even worse than it already is.

Anyway there will be no need to load follow, because load producing H2 and NH3, and pumping hydro and compressed air, can follow price, instead.

Seems like a perfect pairing for direct air carbon capture systems, which are primarily energy limited.

No, you just build extra for the peaks and use the low-demand period to drive capture of carbon.

I think the real problem there is carbon capture is very new and often still on the drawing board. But definitely one way to get carbon capture working is to start with whatever we’ve got.

Just need Bitcoin miner’s next door to regulate output

As far as I can tell, the people who are excited about nuclear are mostly people who have fallen for the anti-renewable propaganda.

If they actually wanted nuclear and believed it was better then they'd be in broad agreement with renewables people.

Agreeing timetables to phase out fossil fuels? Check.

Removing fossil subsidies? Check.

Carbon fees? Check.

Pricing in pollution? Check.

Electrifying transport, heating, industry? Check.

Demand response? Check.

Battery storage for short term time shifting? Check.

Efficiency and insulation? Check.

Green hydrogen? Check.

All these things are being done by renewable groups and they are the biggest thing helping keep nuclear plants running.

Does anyone pushing nuclear on HN ever mention any of those things?

Do they mention how renewables don't work, cost too much, it's all the Environmentalists fault, how amazing fossil fuels are?

Yes, they can't see to help themselves for some reason even though it makes their argument for nuclear totally transparent.

I'm sorry but this is just silly, HN threads about non-nuclear renewables are mostly fairly positive. I'm pro nuclear and do in fact agree with most of this list, but also recognize that there is a huge amount of unfair resistance against building nuclear, despite the huge push for renewables.

I didn't say that HN threads were mostly negative about renewables. But the people who comment about nuclear in them are by and large attempting to launder anti-renewable views, and not doing a very good job of it.

I mean it's really not hard to say something positive about nuclear without attacking renewables, or environmentalists or various other basically unrelated issues. But you wouldn't think so from most HN discussions. Feel free to survey the comments here as an example.

Why isn't nuclear considered a renewable source of energy?

Because it produces a kind of pollution that has to be stored permanently. The non-renewable resource is safe places to store the waste for thousands of years.

More importantly it differs from other renewables in its lead-up time. Nuclear plants can take decades to build. There is hope that small modular reactors can fix that problem, but it's not proven yet. And there is the risk of conflict with renewables which are ready right now: "Don't build solar/wind/etc but instead wait indefinitely for this other technology which may not work."

I would welcome successful deployments of SMRs. But I don't expect them soon, and today there remains a lot of opportunities to deploy wind and solar at costs that continue to improve in economies of scale. If SMRs join them as a supplement to reduce greenhouse gases, so much the better, but for the foreseeable future they are not a sole solution.

Current reactors do that - but there are more than a few designs that will burn what we today call waste. And then burn the "waste" from those.

It uses fuel that exists in a limited amount. We call "renewable" things that plug into natural flows of energy, and not things that require artificial flows.

Natural - if there ever was a more misused word! Breeder reactors utilize "natural" processes and create more fissionable material than they consume. Sounds pretty renewable to me.

Are you saying that the flow of energy inside a breeder reactor would be there if people didn't intervene?

I assume for the same reasons that oil is not.

Yup, nuclear fission and burning oil are EXACTLY the same processes. /s

Your response would be hilarious if it wasn't so utterly tragic. Our civilization exists because of cheap, abundant energy - and there is no more cheap or abundant or RENEWABLE energy (ever hear of breeder reactors? Might want to do some reading) then nuclear - if we can ever separate the politics and emotion from this "debate".

I mean from the perspective that both oil and extractable uranium are practically finite. The sun and the wind and gravity are not.

Therefore, if it consumes a finite resource, I would say it isn't renewable.

Uranium isn't only created by mining out of the ground - once again, you might want to look into breeder reactors.

It's not the only substance that can be used in a reactor either - China is racing ahead with Thorium reactors; based on technology that was mature in the US in the 50's but not deployed for purely political reasons.

Uranium mines are a finite resource

Uranium doesn't only come from mines.

Sheesh.

Yes, there is uranium in seawater as a trace element. And there is gold in human blood also as a trace element, but nobody uses corpses yet to make gold.

In any case there is still a finite amount of it, is not uniformly distributed in the planet, most of them in Australia and nuclear converts it into other elements (if I'm not wrong you can't take the opposite path yet), so is not a renewable resource by definition.

Has uranium ever been refined in any quantity from anything but mined ore?

Extracting from seawater, were it cheaper, would surely have been done. Nukes are already way more expensive than renewables; adding on more cost will not make them more attractive.

Because our policies are being construed by environmentalists with a Communist or leftist agenda instead of scientists and pragmatic leaders.

Renewables are much less cost-effective if you take into account the energy storage needed to make them work. And even then they're ineffective because you essentially need 100% backup capacity for an indefinite period of time for when the wind doesn't blow or the sun is obscured by clouds. Current energy storage systems can only provide enough power for two days at the most.

We're being led like Lemmings into the ravine by these environmentalists. It's time we scientists and engineers took charge.

Blaming the commies does not make you seem more sane. And, "taking charge" smells fascist. Maybe try to come up with a legitimate economic argument? Just one?

You have suggested, "every drop of fossil fuel and every pound of coal will be burned" by poorer nations as prices respond to reduced demand. At some level, though, the cost of extracting exceeds that price. As cost for renewables declines, using renewables becomes strictly cheaper than the cost of extraction, and even the poorest people will thus prefer renewables. Anyway, we may expect access to coal and oil under many countries will be forbidden.

In addition, as renewable energy gets cheaper, extracting carbon from the atmosphere to fix in solid form gets cheaper than mining it, so excess atmospheric carbon dioxide can be drawn down. (That, besides extracting carbon to volatiles to be burned and re-emitted.)

The deep ocean has capacity to safely sequester excess carbon already in the atmosphere. It may be moved there cheaply.

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