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Rolls-Royce plans mini nuclear reactors by 2029

bbc.co.uk

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Re: Rolls-Royce plans mini nuclear reactors by 2029

#161

Post by 0x4863A0 »

pjc50 wrote: post #143
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…

Plumbing is a problem for hot radioactive molten salt. It's one of the few things that will erode ordinary stainless steel.

Agreed that is a significant gating factor, but the situation is not impossible. Several paths are laid out for moving forward in a 2018 report by a couple of ANL scientists. The report is quite readable, even if you know little about materials science.

[1] https://art.inl.gov/ART%20Document%20Library/High%20Temperat...

Re: Rolls-Royce plans mini nuclear reactors by 2029

#162

Post by chrisco255 »

hannob wrote: post #48
chrisco255 wrote: post #39

Earlier quoted context omitted.

Yep, and nuclear is the only near-infinite source of energy.

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 depends on weather, location and battery storage. Solar cells also require massive amounts of physical area to produce the same amount of energy as a nuclear power plant. And you can't compare a "2 gigawatt" solar installation to an equivalent nuclear installation because nuclear will produce power 24/7 at peak capacity, rain or shine. A solar plant sees a huge amount of variability and only hits peak efficiency for a brief part of the day on clear days.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#163

Post by FiatLuxDave »

missosoup wrote: post #46
Stratoscope wrote: post #40

Earlier quoted context omitted.

When I was five or so, I had a watch with a radium dial. I read in a kid's science book that if you went to bed and waited until your eyes were adjusted to the dark, and then held the watch dial against your closed eyelid, you would be able to see the sparks as individual radium atoms decayed. I did this, and it worked! I could see each spark!

Radium is primarily an alpha emitter. Alpha won't cross through the glass of the watch face, or even your skin. Maybe you were seeing the much more rare beta decays.

I doubt it was from the betas, they are all fairly low energy for typical radium. It was probably from the gammas produced by Ra-226. Ra-226 produces a 186 keV gamma in 3.3% of decays. Cherenkov radiation flashes in the eye are observed by patients undergoing clinical radiation therapy (see this interesting paper where this was explored and tested: https://www.redjournal.org/article/S0360-3016(19)33947-1/ful... ). The test done in the paper was with much higher energy gammas, but it is feasible that the 186 keV lines could cause the same effect.

I've never observed this when working with radium, but then I don't stick it in my eye.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#164

Post by Beltiras »

DrNuke wrote: post #158
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…

> Is it just "this is how we always do these things" or is there something else going on here? That tech is known, well designed, approved and extensively proven through many thousand years manwork experience worldwide. It’s also the most affordable in liberalized markets. Going smaller & modular is the real novelty in the industry, for grid-agnostic coupling and decoupling. FYI: I have been consulting and designing…

I'm just a layman with enthusiastic interest. Can I ask you about one thing in this pipeline of decision making since you are in the field?

Refueling is easier to do in MSRs and nigh takes away an embarrassing long downtime while the solid fuel is loaded. Why is that not a first concern (less downtime means more energy from roughly same capital expenditure)?

Safety is critical. It also costs a lot. With MSRs you need less land and can place the plant closer to the point of use (frozen plug to drain tank makes it so that any runaway is contained without intervention). It's even been suggested that for high-thermal uses like steel plants you could get better efficiency by using a thermal plant instead of making electricity for at least a twofold gain in power use. Is there anything inherently wrong with that idea?

Is the dialysis design as solid as it looks like on paper? Are there operational problems with it that the advocates are not talking about?

I have so many questions.....

Re: Rolls-Royce plans mini nuclear reactors by 2029

#165

Post by mechhacker »

Beltiras wrote: post #151
pjc50 wrote: post #143

Earlier quoted context omitted.

Plumbing is a problem for hot radioactive molten salt. It's one of the few things that will erode ordinary stainless steel.

I haven't researched those issues but apparently it could be done with stone age tech (1960's) compared to the material sciences we have today.

Yes they ran the molten salt reactor.

However, running one and being able to make a cost effective reactor is completely different.

Especially when water is already a very well known and very well understood heat transfer medium.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#166

Post by otabdeveloper4 »

radicalbyte wrote: post #33

We shouldn't be using nuclear energy for power. Solar, wind and batteries will solve that. What we should be doing is using nuclear energy for HEAT. We need a LOT of heat for a variety of chemical and industrial processes, not to mention heating of homes in colder climates. For these uses nuclear fission has massive potential.

> Solar, wind and batteries will solve that.

Pretty sure that's not true if you account for total costs. (Including the energy and materials budget for making solar panels and batteries at scale.)

Re: Rolls-Royce plans mini nuclear reactors by 2029

#167

Post by Beltiras »

mechhacker wrote: post #165
Beltiras wrote: post #151

Earlier quoted context omitted.

I haven't researched those issues but apparently it could be done with stone age tech (1960's) compared to the material sciences we have today.

Yes they ran the molten salt reactor. However, running one and being able to make a cost effective reactor is completely different. Especially when water is already a very well known and very well understood heat transfer medium.

And we understand it to be rather dangerous in failure modes. TMI, Chernobyl and Fukushima all revolved around failure modes with water. The failure mode in Thorium is stopping the reactor. Will take a month or more to restart the reaction.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#168

Post by mortivore »

pjc50 wrote: post #143
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…

Plumbing is a problem for hot radioactive molten salt. It's one of the few things that will erode ordinary stainless steel.

That seems like a pretty major issue. No wonder it hasn't gone forward. Are there any alternatives proposed?

Re: Rolls-Royce plans mini nuclear reactors by 2029

#169

Post by Already__Taken »

chrisco255 wrote: post #154
posix_me_less wrote: post #84

Earlier quoted context omitted.

Loss of power during distribution is not a problem that needs solving, power losses due to transmission in conventional grid are mere 5%. [1] https://en.wikipedia.org/wiki/Electric_power_transmission#Lo... Considering how costly and inflexible all superconductors are, I don't see why they would help.

Those losses are on a per 100 mile basis. 2-5% per 100 miles of line (not as the crow flies mind you). Superconductors would make a huge difference if they could build a room temperature superconductor.

Exactly, when people mention losses saved by superconductors they don't mean to improve the current grid. It's to route power from the always sunny side of the planet.

Re: Rolls-Royce plans mini nuclear reactors by 2029

#170

Post by DrNuke »

Beltiras wrote: post #164
DrNuke wrote: post #158

Earlier quoted context omitted.

> Is it just "this is how we always do these things" or is there something else going on here? That tech is known, well designed, approved and extensively proven through many thousand years manwork experience worldwide. It’s also the most affordable in liberalized markets. Going smaller & modular is the real novelty in the industry, for grid-agnostic coupling and decoupling. FYI: I have been consulting and designing…

I'm just a layman with enthusiastic interest. Can I ask you about one thing in this pipeline of decision making since you are in the field? Refueling is easier to do in MSRs and nigh takes away an embarrassing long downtime while the solid fuel is loaded. Why is that not a first concern (less downtime means more energy from roughly same capital expenditure)? Safety is critical. It also costs a lot. With MSRs you need…

Good to have interested laymen, really, so thanks!

The fundamental point is (in my very humble opinion, mind) you may still have a business case for nuclear in 2020 but no feasible return on investment against non-nuclear sources for decades-long experiments that, all in all, are aimed at marginal improvements in the grand scheme of things and the enormous hassle proponents have to face.

It is fusion or nothing, apart of a couple of Gen IV that are advanced enough already, for the next 20-30 years or such in the West (China or Russia might be more ambitious, but they are not liberal or neoliberal democracies, so they can play a different game to some extent)... until all the PWRs still operating worldwide must be put down for obsolescence.

For a layman computer science comparison, think of the still up-and-running fortran legacy in some sectors (banks?) you won’t really really want to drop if not really forced to... because it works, you need no fix, you do not expect any unheard catastrophic incident or accident anymore.

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