[PaulHoule]

If Amory Lovins had designed a nuclear reactor that would be unaffordable to build it would be

https://en.wikipedia.org/wiki/EPR_(nuclear_reactor)

You can make the case that regulation inflates the cost of nuclear power plants, and that's somewhat true, but the deep problem is the cost of the steam turbine and other facilities (e.g. heat exchangers) to accept energy at the low temperatures that the LWR works at.

All of that is so big and expensive it would be hard to make the economics work even if you got the heat for free.

A liquid metal fast reactor or a molten salt reactor or a high temperature gas cooled reactor could power a closed-cycle gas turbine

https://www.osti.gov/servlets/purl/1221819

which would fit in the employee break room of the turbine house at a nuclear plant. Such a "fourth-generation" nuclear power plant might have compelling economics to build, but it's hard to believe anybody is going to start and finish an LWR outside of China.

It's little appreciated that the cost of the steam turbine is what killed coal circa 1980. Once GE adapted aerospace turbines for low-capital cost power plants on the ground, it made no sense to build more thermal coal plants.

In the late 1970s you see various attempts to save the coal industry, plausibly you could have gotten better capital costs pyrolyzing the coal and running the gas through a gas turbine. This kind of technology is making a comeback because it can be coupled with carbon storage to make CO2 free or CO2 negative energy.

[lazide]

Eh, the basic economics of a PWR or even BWR are quite sound and you don’t need fancy tech to change that. Even with very expensive uranium and very expensive turbines, it doesn’t change that (depending on the number of orders of magnitude we’re talking about of course). And if you’re making 10x-100x of the things in a few years, it actually gets cheaper for both, since you can build a series of turbines, or reopen a sizable mine and just do it, instead of what we do now.

And now, instead of it taking a couple years to build with predictable timelines and approvals, you end up in decades long and impossible to predict legal fights that drag out construction; ruin any sort of economies of scale; and put everyone into a ‘meh’ state when it comes to actually getting anything done on a timeline. I know folks in Nuclear Engineering for some of the plants that literally have spent a decade plus generating paperwork and going in circles. Very, very, very well paid folks I might add.

A steam turbine doesn’t cost $5 billion dollars and 5 years per plant like these things do.

[cinntaile]

Nuclear is very expensive, that's why even countries very positive to nuclear aren't happily replacing their old reactors. France did the math recently, 100 billion euros for 10 new reactors. The old ones are better from an economical point of view so it's much better to try and keep them going.

[PaulHoule]

There are two problems.

(1) If you could build a nuclear reactor for the sticker price, there's the problem that other energy sources got cheaper, specifically natural gas fired Brayton cycle turbines. To justify nuclear power at the sticker price you need to price carbon emissions.

(2) Nuclear power plants cost many more times to build than the sticker price. Some people blame delays on opposition to nuclear power, but the delays seem intrinsic to the process in industry. AP1000 construction was hung up in the U.S. because it was hung up in China (where environmentalists get shot) and it was hung up there because the factory had trouble make a pump that was supposed to be easier to make.

On one hand you could make the case for a real accounting of the type (2) problem (which I suspect is a game of "Poker" where suppliers quote a lowball price because they know buyers will keep putting chips in the pot.) But I think a more radical approach to the type (1) problem is necessary.

[lazide]

I take it you didn’t read my earlier comment?

There is no engineering reason for those reactors to cost $10bln. Literally zero.

There are lots and lots of other reasons why they will probably cost even more than $10bln/ea though.

Just like there is literally zero engineering reason for the ‘high speed’ rail in California to cost the insane sums it is currently consuming, and will continue to consume.

The reason why the old ones are ‘better’ is because they already are operating under existing approvals, so the tarpits don’t work on them.

[cinntaile]

Life is pretty darn good in lalaland where everything is just a technological problem ready to be solved. I wish I could live there.

[lazide]

Not sure how me pointing out that organizational and political dysfunction, corruption, and general bullshit is the reason why it is 'hard' now (and wasn't as hard 50 years ago when the currently active reactors were built since folks seemed to actually want to build them more than just siphon money out of the system or throw wrenches into the works for ideological reasons), and how it doesn't seem to have anything to do with any of the actual technical or engineering difficulty is living in lalaland - but you do you I guess?

If we wanted to build cost effective and safe reactors, we could, and have many times in the past. Near as I can tell, almost no one does (compared to some cool new idea, or what becomes a one off, or ends up going back to the drawing board 50 times - all while getting paid), so we don't.

Same with high speed rail (and a bunch of other pork projects in CA), same with subways in many big cities, etc.

[cinntaile]

There's nothing wrong with pointing out what you think is the problem. It's just that you can't ignore reality, in the actual world it takes much longer to build and it's more expensive for whatever reason that may be.

[makomk]

The UK tried building gas cooled reactors that produced more useful and efficient steam temperatures on the output. They worked - in fact, they make up pretty much the entire UK nuclear generation capacity these days - but turned out not to be as practical as boring PWR reactors due to various annoying engineering issues. There are other reactor concepts out there which promise to do better but they're pretty untested and would also likely turn out to be harder to build than they look.

[PaulHoule]

They're still running a steam turbine but it is more compact and efficient.

Fourth-generation reactors won't be easy, but the motivation to develop them is strong.

Arguably there is a lot of experience with liquid metal fast reactors, many of the problems like sodium fires and problems with inspection are probably solved. Think

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

as opposed to

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