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

Rolls-Royce plans mini nuclear reactors by 2029

bbc.co.uk

Post reply on HN
Print view View original

241–250 of 353 posts

Re: Rolls-Royce plans mini nuclear reactors by 2029

#241

Post by Lutzb »

jason0597 wrote: post #206
Beltiras wrote: post #137

I'm amazed that the industry is still propagating the mistake made in the early nuclear age of using PWR and solid fuel. The more I read about nuclear the more convinced I become that SMRs for next gen plants are safest and most efficient using the Thorium-U233 fuel cycle and employing molten salt to transfer heat. It's automatically safe since if a runaway reaction takes place the fuel will drain into a tank and rea…

Someone made an excellent post on reddit a while back on why Thorium reactors will never become a reality, it's a really good read: https://old.reddit.com/r/europe/comments/9unimr/dutch_satiri...

Thank you, this was very informative. It seems a lot of thorium reactor proponents never discuss those issues or are not aware of them.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#242

Post by stjohnswarts »

Retric wrote: post #193
koheripbal wrote: post #122

Earlier quoted context omitted.

The important flaw in your argument is the use of the word average. A grid cannot make use of average power generation. It needs consistent power generation. ...and storage needed to make that happen is orders of magnitude higher than what's being factored in here.

Batteries inherently allow for peaking power, it’s nuclear that has issues with fluctuations in demand. So, by average I mean how much are you able to use directly vs how much do you need to store in batteries. To be more clear only using solar with battery backup you can provide 24/7 power that covers demand but at lower costs per kWh than current nuclear numbers operating 24/7 and vastly lower than trying to reach…

Your argument is completely shot down by the mere fact that 75% of France's power is provided by nuclear energy.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#243

Post by cesarb »

koheripbal wrote: post #118
simonblack wrote: post #17

Nuclear reactors' biggest drawback is the cost and danger of dismantling and disposing of them after their working life is finished. Up till then they are clean and cost-effective.

Why does no one ever factor in the cost of dismantling other major projects, like the Hoover Dam, or the Three Gorges Dam? ...or thee solar plants being built, or the wind turbines? Why does nuclear power have this enormous additional requirement that literally no other power source seems to have to account for?

> Why does nuclear power have this enormous additional requirement that literally no other power source seems to have to account for?

Because no other power source has the inner components become radioactive during normal operation. Normally these radioactive parts are fully contained, but that's no longer the case once it's dismantled. That makes dismantling a nuclear power plant not only much more expensive, but also a requirement (you can't just abandon it, otherwise it will gradually break down and lose the containment).

Re: Rolls-Royce plans mini nuclear reactors by 2029

#244

Post by Accujack »

eeZah7Ux wrote: post #65
grabbalacious wrote: post #15

>Environmentalists are divided over nuclear power, with some maintaining it is dangerous and expensive, while others say that to achieve net zero emissions by 2050 all technologies are needed. Yes, a mix of technologies. But there's more to it than that. We're going to need increasing amounts of power in the future to explore the solar system and to solve all kinds of existential problems. Energy usage is not inheren…

> solve all kinds of existential problems ...very few existential problems have anything to do with technology.

If you're human, every existential problem has to do with technology. That's who we are.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#245

Post by Accujack »

Beltiras wrote: post #137

I'm amazed that the industry is still propagating the mistake made in the early nuclear age of using PWR and solid fuel. The more I read about nuclear the more convinced I become that SMRs for next gen plants are safest and most efficient using the Thorium-U233 fuel cycle and employing molten salt to transfer heat. It's automatically safe since if a runaway reaction takes place the fuel will drain into a tank and rea…

The PWR tech was chosen by the US government originally because using that type of reactor supported weapons production. Many countries still want it for that reason.

Newer types aren't used yet in the US because the incredible over-regulation of existing reactors due to the fear involved has made them very un-economical to build and very difficult to get new designs approved... if there's no money in something, corporations won't do it.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#246

Post by kerkeslager »

akiselev wrote: post #187
kerkeslager wrote: post #179

Earlier quoted context omitted.

Does titanium hold up to radioactive molten salt? There are a bunch of places I've found where the difficulty (and therefore cost) of working with titanium is really holding humanity back. If we could find cheaper techniques for working with titanium it would revolutionize a lot of industries, as it's plentiful, light, strong, non-reactive, and melts at high temperatures. But the same attributes that make it hold up…

A radioactive fluoride salt might just be one of the most corrosive substances on the planet. Titanium might hold up a little longer but not by much. Any material that can resist the corrosion will be bombarded by neutrons until it is transmuted into another material that can't, even with "slow" neutrons.

Okay, what's the solution?

The Wikipedia article[1] says, "A 2011 MIT study concluded that although there is little in the way of barriers to a thorium fuel cycle, with current or near term light-water reactor designs there is also little incentive for any significant market penetration to occur. As such they conclude there is little chance of thorium cycles replacing conventional uranium cycles in the current nuclear power market, despite the potential benefits." What did they know at MIT in 2011 that we don't? Or were they just wrong?

If really no material will work for this, I can only imagine some sort of mag-lev design that keeps the molten salt out of contact with other materials, but that seems kind of far-fetched.

[1] https://en.wikipedia.org/wiki/Thorium_fuel_cycle

Re: Rolls-Royce plans mini nuclear reactors by 2029

#247

Post by ameister14 »

dmos62 wrote: post #54
luspr wrote: post #35

Earlier quoted context omitted.

Agree completely. It's a fallacy to believe we will require less energy in the long run. We need much more, if we want to advance as a species.

> we want to advance as a species I'm somewhat weary of people talking of civilization progress as if its definition is obvious and universal.

Or even if it's actually happening - it's a problem that the Hegelian concept of progression has rooted itself so deeply in the west that we think it's universally held, where other countries find a cyclical nature to humanity and history

Re: Rolls-Royce plans mini nuclear reactors by 2029

#248

Post by reallydontask »

luspr wrote: post #35
grabbalacious wrote: post #15

>Environmentalists are divided over nuclear power, with some maintaining it is dangerous and expensive, while others say that to achieve net zero emissions by 2050 all technologies are needed. Yes, a mix of technologies. But there's more to it than that. We're going to need increasing amounts of power in the future to explore the solar system and to solve all kinds of existential problems. Energy usage is not inheren…

Agree completely. It's a fallacy to believe we will require less energy in the long run. We need much more, if we want to advance as a species.

> It's a fallacy to believe we will require less energy in the long run

It's hard to say without knowing your definition of long run so would you care to explain why you believe that less energy is required in your long run?

I see it as exactly the opposite, in the short/medium term we will use more energy but it will eventually go into reverse.

Maybe Jevons Paradox will intervene and you are correct, I don't know

For the record, my long run is 150+ years, if only to make sure that we are all dead.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#249

Post by hanniabu »

mgoetzke wrote: post #212
koheripbal wrote: post #114

Earlier quoted context omitted.

There's also some false equivalency in the quote above. "Environmentalists" is a vague term. If we asked Environmental Energy SCIENTISTS, they overwhelmingly support nuclear power.

Scientists are not always thinking through consequences in the real world though. Just the theoretical aspects of something. Theoretically I find nuclear fission impressive and amazing. Practically I see no desirable outcome without bad effects especially when coordinated by the private sector with their habit of saving money and squeezing out more profits every year.

> private sector with their habit of saving money and squeezing out more profits every year

Bingo. I have no issues with nuclear power. I have an issue with the human component. Safety regulations have been continuously changed and been made more relaxed to keep up with the crumbling nuclear plants that are way past their design life and coming up on another extension.

Have a crack in the concrete? Increase the allowable crack tolerance. Have leaking radioactive water? Change the way the test is performed so it allows you to still pass.

https://www.nytimes.com/2019/07/17/climate/nrc-nuclear-inspe...

https://www.commondreams.org/news/2019/07/17/insanely-bad-mo...

Re: Rolls-Royce plans mini nuclear reactors by 2029

#250

Post by logfromblammo »

erulabs wrote: post #64
hannob wrote: post #48

Earlier quoted context omitted.

I'm always baffled by such statements. Can you explain in which way solar is not a "near-infinite source of energy"? I mean... there are without doubt technical challenges and all that (but arguably less technical challenges than to do the same with nuclear), but there really is no relevant limit to the deployment of solar cells if you include things like large-scale installations in the desert.

Solar power is simply indirect nuclear power anyhow. If we can do what’s happening in the sun in a bottle - then no need to produce panels. If there is material in stars to produce solar power, then there is more potential nuclear power. I’m for both, and solar seems distributed in a way that makes me think it’s better for human society, but since stars are made of fissable materials - by definition there is more “po…

Stellar fusion like that which occurs in our sun is effectively aneutronic, but is also relatively slow, because the limiting step is the combination of two protons into a proton-neutron pair.

You need to keep a lot of hydrogen at plasma-hot temperatures and very high pressures for a long time. So you can't really do it with masses smaller than Jupiter, because smaller bodies can radiate the energy away faster, and produce fewer events from the lesser mass.

So the only technologically effective way to leverage solar is to deconstruct larger stars into red dwarfs between 0.08 and 0.35 solar mass, perhaps with a ferro-platosmiridium core to increase the overall density and make the reactions viable at lower overall mass. Then surround the whole thing with a Dyson shell and Shkadov/Caplan thruster.

It's a bit beyond our means right now.

Post reply on HN