Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Google to back three new nuclear projects

esgtoday.com

Post reply on HN
Print view View original

351–360 of 365 posts

Re: Google to back three new nuclear projects

#351

Post by ttfkam »

pfdietz wrote: post #286
ttfkam wrote: post #279

Earlier quoted context omitted.

Increasing the heat past a certain threshold reduces the nuclear reactivity. Read up on "passive safety". Teller may have warned about this in 1967, but nuclear technology hasn't been stagnant since 1967. Folks read his stuff and designed systems specifically to fail safe, not run away. Stop fear mongering based upon a 60-year-old supposition. Stop assuming everyone working in the nuclear industry is an idiot that ha…

> Increasing the heat past a certain threshold reduces the nuclear reactivity. Read up on "passive safety". The safety arguments for fast reactors are typically that a serious scenario will not occur, for example that fuel won't melt, not that if it does occur the results won't be bad. Do you trust that sort of argument? I don't.

Nice straw man you've constructed and burnt down.

Those are NOT the safety arguments used within the industry. For example in a molten salt reactor, the fuel is already melted! If it gets too hot, thermal expansion moves the radioactive isotopes further away from one another, reducing reactivity. If heat increases past a certain point, plugs at the bottom of the tanks will melt, allowing gravity to dump the fuel into multiple separated storage vessels sized to prevent further activity.

You do not know what you're talking about. You've read a bunch of fear mongering, and bought it. Do you really believe the entire industry of nuclear engineers and support staff are just blindly YOLOing their way through their jobs, damn the consequences?

I swear, you sound like the power production equivalent of antivaxers convinced the medical industry is trying to poison all of us.

"Passive safety" doesn't mean "stuff shouldn't go wrong."

https://en.wikipedia.org/wiki/Passive_nuclear_safety

It means "we're actively exploring everything that could go wrong and having the worst case scenarios fail to a safe state without requiring human intervention."

Those two positions couldn't be further apart.

Re: Google to back three new nuclear projects

#352

Post by pfdietz »

ttfkam wrote: post #351
pfdietz wrote: post #286

Earlier quoted context omitted.

> Increasing the heat past a certain threshold reduces the nuclear reactivity. Read up on "passive safety". The safety arguments for fast reactors are typically that a serious scenario will not occur, for example that fuel won't melt, not that if it does occur the results won't be bad. Do you trust that sort of argument? I don't.

Nice straw man you've constructed and burnt down. Those are NOT the safety arguments used within the industry. For example in a molten salt reactor, the fuel is already melted! If it gets too hot, thermal expansion moves the radioactive isotopes further away from one another, reducing reactivity. If heat increases past a certain point, plugs at the bottom of the tanks will melt, allowing gravity to dump the fuel into…

So, how exactly do you claim conclusively that molten fuel (in a fast reactor with sold fuel elements) will not flow into a bad configuration? I don't see how one can possibly do that analysis. Teller didn't see how either.

I already said MSRs would be the one kind of fast reactor I could see the analysis work, so thank you for agreeing with me on that.

As a charitable act toward you I will ignore the rest of your comment.

Re: Google to back three new nuclear projects

#353

Post by natmaka »

derriz wrote: post #349
natmaka wrote: post #336

Earlier quoted context omitted.

> Whether your grid has nuclear or renewables, it will also have natural gas capacity. No, turbo-alternators 'burning' hydrogen do exist. And green hydrogen (produced by renewables) is cheaper than pink hydrogen (produced by a nuclear reactor) because the total cost of renewables' electricity is lower than nuclear's.

I don’t see the connection with my comment but hydrogen is irrelevant and contributes less than a rounding error to global electricity generation. The technical components for a hydrogen based energy market do exist but are simply unviable financially. Nuclear also struggles to compete on the basis of price in competitive markets but is a genuinely low-carbon source of electricity. You could argue (I personally would…

The connection is that "it will also have natural gas capacity" seems false to me as backup turbo-alternators can 'burn' hydrogen ( => no natural gas capacity).

> hydrogen > contributes less than a rounding error to global electricity generation

True, however it doesn't imply that it will remain irrelevant.

> unviable financially

For the time being, and less and less. Bloomberg NEF predicts that green hydrogen will cost approximately 1.2€/kg in 2050. Carbon taxes or oil prices may also play a role as nearly all hydrogen is now produced thanks to some fossil fuel.

> nuclear > is a genuinely low-carbon source of electricity

Green hydrogen could also be.

> prone to leakage

This is a major challenge for transportation-related usages, especially in small or not-intensively used vehicles. This isn't in the "gridpower backup" role, as mass and volume of storage isn't a major parameter.

Re: Google to back three new nuclear projects

#354

Post by croes »

Mawr wrote: post #322
croes wrote: post #43

Earlier quoted context omitted.

Nuclear energy was never cheap, it was always heavily subsidized. Just ask Joe Kaeser the former CEO of Siemens. He said no nuclear power plant was ever profitable

Profit is tied to the subsidies, so that statement by the CEO is meaningless. When you say nuclear was never cheap, what are you comparing it to? The impossible to compete with subsidization of coal plants? How can you compete with plants that are allowed to dump toxic radioactive waste into the atmosphere that kills hundreds of thousands annually, but your plants have to go through regulatory hell to prove they're 9…

Cheap isn’t a comparison. If you include the negative side effects coal isn’t cheap either.

Re: Google to back three new nuclear projects

#355

Post by derriz »

natmaka wrote: post #353
derriz wrote: post #349

Earlier quoted context omitted.

I don’t see the connection with my comment but hydrogen is irrelevant and contributes less than a rounding error to global electricity generation. The technical components for a hydrogen based energy market do exist but are simply unviable financially. Nuclear also struggles to compete on the basis of price in competitive markets but is a genuinely low-carbon source of electricity. You could argue (I personally would…

The connection is that "it will also have natural gas capacity" seems false to me as backup turbo-alternators can 'burn' hydrogen ( => no natural gas capacity). > hydrogen > contributes less than a rounding error to global electricity generation True, however it doesn't imply that it will remain irrelevant. > unviable financially For the time being, and less and less. Bloomberg NEF predicts that green hydrogen will c…

I see what you meant now but still see little scope for hydrogen to have a role in the energy sector.

One reason for my skepticism is that I've been hearing optimistic predictions around hydrogen as an energy store for decades at this stage (I'm old) and for a long time believed them but here we are, with little to show for it. In fact, at historical scales, hydrogen's significance as an energy store today is less than it was in the 19th century. As a result, I've adopted "I'll believe it when I see it" approach so I just ignore hydrogen predictions - particularly ones 25 years into the future.

But the main reason is simple physics. It simply has NONE of the physical attributes you'd want in a gas to be used to store energy. It's like if you picked all the attributes you WOULDN'T want in such a gas.

Storage and transport are incredibly expensive and technically difficult. Everything it comes into contact with needs special materials to avoid embrittlement. It's prone to leakage.

It has dreadful energy density. The worst.

It has potent green house gas effects when leaked into the atmosphere.

It's dangerous and highly explosive and burns with such high intensity (and invisibly) that it requires specialist fire-fighting equipment.

Roundtrip efficiency (electricity to H to electricity) is abysmal - a fraction of that of batteries.

In summary, hydrogen as energy store makes no sense to me. And it's completely hypothetical. If we are going to talk about hypothetical approaches to storing energy in the form of a gas, then green methane makes a lot more sense. Not that I'd advocate for either but I see some potential for green methane but none for hydrogen given its physical attributes.

Re: Google to back three new nuclear projects

#356

Post by ttfkam »

natmaka wrote: post #338
ttfkam wrote: post #116

Earlier quoted context omitted.

I love how green hydrogen is assumed to become abundant and trivially easy to retrofit into existing infrastructure but fast neutron reactors are automatically considered infeasible by comparison. Or that by far the easiest way to produce massive amounts hydrogen without emitting carbon into the atmosphere is… wait for it… nuclear power.

Hydrogen is already used in many industrial processes (~1e8 metric tons/year), including turbo-alternators, while there is not a single ready-to-be-built model of industrial breeder reactor.

Not only was a design ready to be built, it was built. Went online 39 years ago. Produced 1.2GWe at peak. Not only produced power on its own but reprocessed spent fuel from other nuclear reactors.

Decommissioned 28 years ago. Because it didn't work? No. Because it wasn't safe? No. Because it wasn't reliable? No, it had a 95% availability rate.

It was taken out of service due to political pressure and legal maneuvering, not technical reasons.

https://en.wikipedia.org/wiki/Superph%C3%A9nix

Re: Google to back three new nuclear projects

#357

Post by ttfkam »

pfdietz wrote: post #352
ttfkam wrote: post #351

Earlier quoted context omitted.

Nice straw man you've constructed and burnt down. Those are NOT the safety arguments used within the industry. For example in a molten salt reactor, the fuel is already melted! If it gets too hot, thermal expansion moves the radioactive isotopes further away from one another, reducing reactivity. If heat increases past a certain point, plugs at the bottom of the tanks will melt, allowing gravity to dump the fuel into…

So, how exactly do you claim conclusively that molten fuel (in a fast reactor with sold fuel elements) will not flow into a bad configuration? I don't see how one can possibly do that analysis. Teller didn't see how either. I already said MSRs would be the one kind of fast reactor I could see the analysis work, so thank you for agreeing with me on that. As a charitable act toward you I will ignore the rest of your co…

> I don't see how one can possibly do that analysis.

Classic argument from ignorance fallacy. Because YOU cannot see how it could be done, no one has ever figured out how it could be done.

Re: Google to back three new nuclear projects

#358

Post by pfdietz »

ttfkam wrote: post #357
pfdietz wrote: post #352

Earlier quoted context omitted.

So, how exactly do you claim conclusively that molten fuel (in a fast reactor with sold fuel elements) will not flow into a bad configuration? I don't see how one can possibly do that analysis. Teller didn't see how either. I already said MSRs would be the one kind of fast reactor I could see the analysis work, so thank you for agreeing with me on that. As a charitable act toward you I will ignore the rest of your co…

> I don't see how one can possibly do that analysis. Classic argument from ignorance fallacy. Because YOU cannot see how it could be done, no one has ever figured out how it could be done.

You didn't answer the question.

All the analyses I've seen for fast reactor safety are about avoiding fuel melting, not what happens if the fuel does melt. The variability in this latter scenario is so great that conclusive analysis ruling out disaster doesn't seem possible. Maybe you could explain the unexpected principle that enables one to do that? Or, lacking that, point me to a paper where such analysis has been performed.

Re: Google to back three new nuclear projects

#359

Post by natmaka »

ttfkam wrote: post #356
natmaka wrote: post #338

Earlier quoted context omitted.

Hydrogen is already used in many industrial processes (~1e8 metric tons/year), including turbo-alternators, while there is not a single ready-to-be-built model of industrial breeder reactor.

Not only was a design ready to be built, it was built. Went online 39 years ago. Produced 1.2GWe at peak. Not only produced power on its own but reprocessed spent fuel from other nuclear reactors. Decommissioned 28 years ago. Because it didn't work? No. Because it wasn't safe? No. Because it wasn't reliable? No, it had a 95% availability rate. It was taken out of service due to political pressure and legal maneuverin…

Facts: Superphénix was a prototype. It didn't reach its goal (reaching the industrial stage). Not a single model of breeder reactor reached it. Mentioning its high availability rate neglects planned shutdowns (planning enough of them improves it). Its load factor in 1996 (just before its shutdown), more relevant, was 0.31, thus well below the minimum viable for an industrial reactor. Some people consider the project to be a success, but no expert or its operator has ever said so (they proclaimed their confidence in their ability to achieve industrial operation by an unspecified date), and its successor, named "ASTRID", launched 12 years later, which was supposed to design and build a reactor for €5 billion, spent more than €700 million on studies alone before being put on hold, so "it worked, but everything has to be redesigned...".

Re: Google to back three new nuclear projects

#360

Post by natmaka »

derriz wrote: post #355
natmaka wrote: post #353

Earlier quoted context omitted.

The connection is that "it will also have natural gas capacity" seems false to me as backup turbo-alternators can 'burn' hydrogen ( => no natural gas capacity). > hydrogen > contributes less than a rounding error to global electricity generation True, however it doesn't imply that it will remain irrelevant. > unviable financially For the time being, and less and less. Bloomberg NEF predicts that green hydrogen will c…

I see what you meant now but still see little scope for hydrogen to have a role in the energy sector. One reason for my skepticism is that I've been hearing optimistic predictions around hydrogen as an energy store for decades at this stage (I'm old) and for a long time believed them but here we are, with little to show for it. In fact, at historical scales, hydrogen's significance as an energy store today is less th…

> I've been hearing optimistic predictions around hydrogen

Fair point, same here (I was born in 1967), however fossil fuels are so effective and adequate as energy sources, as long as we ignored/neglected their dubious effect on the climate, that there was no real attempt to explore other ways.

> Storage and transport are incredibly expensive and technically difficult

For the "gridpower backup" application there is no transport needed, and storage doesn't have to be compact nor mobile (those are a major challenge for hydrogen in transportation).

> dreadful energy density

This is not a show-stopper for the "gridpower backup" application. For huge volumes or very long-term (not sure this will be necessary) it may be stored in salt caverns ( https://en.wikipedia.org/wiki/Hydrogen_storage#Underground_h... )

> potent green house gas effects > dangerous

Granted, however we are used to store huge volumes of dangerous materials, some gaseous at ambiant pressure/temp (methane...), even into salt caverns, albeit when we began to do so (in the 1950's) it was quite a challenge.

> Roundtrip efficiency (electricity to H to electricity) is abysmal

Various new ways to obtain H2 from electricity offer impressive yield in realistic conditions (check SOECs), and other advances are promising ( https://liten.cea.fr/cea-tech/liten/english/Pages/Strategic-... ).

> green methane makes a lot more sense

As does ammonia, in some contexts. There is no one-size-fits-all here!

Post reply on HN