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Westinghouse AP300 Small Module Reactor

westinghousenuclear.com

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Re: Westinghouse AP300 Small Module Reactor

#31

Post by scythe »

gnabgib wrote: post #8

Discussed 9 hours ago, 140 points, 99 comments https://news.ycombinator.com/item?id=35816789

Highlight of the thread, IMHO, from 'beefman:

https://news.ycombinator.com/item?id=35818261

>Not small, modular, or new. But certainly a decent reactor. They clearly want something to slot in against the GE BWRX-300. But they would probably be better served by going all-in on their eVinci reactor, which is small, modular, and new

>https://www.westinghousenuclear.com/energy-systems/evinci-mi...

Re: Westinghouse AP300 Small Module Reactor

#32

Post by p1mrx »

innrautha wrote: post #22
credit_guy wrote: post #16

Earlier quoted context omitted.

> Ramping up and down in response to renewables will be an important function of any nuclear reactor installed today. Realistically, it's not going to happen. PWRs are inherently stable, that's one of their big selling points. If anything goes wrong and the reactor becomes too hot, the water expands, moderates less the neutrons and they don't slow down enough to trigger fission events, so the rate of fission decrease…

That depends on what they mean by load following. While you can load-follow by changing reactor power (like the French do extensively). Westinghouse has long been promoting thermal storage based load following in their other reactor designs [1]. Where instead of perturbing the reactor's power, you divert the thermal output to a molten salt thermal battery when you want to decrease power suddenly, and use the battery…

Light water reactors (like the AP300) don't get hot enough for molten salt storage. That requires one of the high temperature Gen IV reactors.

Re: Westinghouse AP300 Small Module Reactor

#33

Post by acidburnNSA »

rgmerk wrote: post #6

Some history might be worth going in to here. The AP1000 design was an evolution of an earlier design called the AP600. The AP600 conceptual design apparently didn't find any customers because the economics of it were unappealing compared to larger reactors. In a nutshell, if you're going to build a huge containment building etc etc etc, it doesn't cost (in theory) that much more to go even bigger and get more power…

The best way to solve this problem is to build a huge shipyard-based reactor-making gigafactory that makes floating gigawatt scale reactors that are floated to location. You can operate them offshore or on land.

This was actually attempted in the 1970s by Offshore Power Systems (joint venture between Westinghouse and Newport News). They bought and installed the world's largest gantry crane on Blount Island in Jacksonville Florida and got a license from the NRC to build the first 8 of them. Sadly no one bought and they shut it down. Crazy story. Super interesting from a rapid decarbonization perspective.

https://whatisnuclear.com/offshore-nuclear-plants.html

Re: Westinghouse AP300 Small Module Reactor

#34

Post by le-mark »

derefr wrote: post #28

Question about SMRs generally: does the fact that random private companies can apply to buy one of these, mean that nuclear reactors are now basically "state-secret free" as a technology? Or are there still state secrets, but they're all in the e.g. uranium enrichment part of the pipeline — that buying one of these gets you no closer to seeing — rather than in the reactor design?

Unintuitively, the principles nuclear reactors operate on are really very simple. Put enriched uranium rods close together and they get hot, hot enough to create steam and hence electricity. The complexity comes from designing and engineering for the reliability and safety scenarios. So no, no state secrets.

Re: Westinghouse AP300 Small Module Reactor

#35

Post by acidburnNSA »

derefr wrote: post #28

Question about SMRs generally: does the fact that random private companies can apply to buy one of these, mean that nuclear reactors are now basically "state-secret free" as a technology? Or are there still state secrets, but they're all in the e.g. uranium enrichment part of the pipeline — that buying one of these gets you no closer to seeing — rather than in the reactor design?

All power reactors are free of state secrets and owned by private institutions. Some information is required by law to remain secret, such as locations of security hardening features, cameras, guns, etc.

Good old Eisenhower and Atoms for Peace, 1953.

Re: Westinghouse AP300 Small Module Reactor

#37

Post by dirtsoc »

epistasis wrote: post #7
nukeman wrote: post #2

Seriously? I’m insanely pro-nuke, and work in the nuclear sector, but Westinghouse should really focus on their AP1000. They’ve already got deals in place with several countries, and now that they’ve got them running in more than one country, there might be a chance of bringing costs down some. The light water SMR market is getting crowded rather fast. They’re competing with both GE (and their BWRX-300) and NuScale (…

Given the track record of AP1000 construction, who do you think would ever order one? I don't see a future for this. If somebody thought it was a feasible design for construction in Western countries, they could buy the half completed sites at Summer for a song. I also think 300MW is too big. It's not really small enough to get the supposed benefits of small and modular. The entire nuclear industry appears to be off…

What's sad is that it's mainly the US that has problems with this. China has managed to bring multiple of this reactor design to fruition while the US still screws around with building just two. I live in Georgia and the almost decade of overruns and corruption are being about to be paid for by Georgia Power customers via rate hikes.

Re: Westinghouse AP300 Small Module Reactor

#40

Post by innrautha »

p1mrx wrote: post #32
innrautha wrote: post #22

Earlier quoted context omitted.

That depends on what they mean by load following. While you can load-follow by changing reactor power (like the French do extensively). Westinghouse has long been promoting thermal storage based load following in their other reactor designs [1]. Where instead of perturbing the reactor's power, you divert the thermal output to a molten salt thermal battery when you want to decrease power suddenly, and use the battery…

Light water reactors (like the AP300) don't get hot enough for molten salt storage. That requires one of the high temperature Gen IV reactors.

That just means for LWR applications you need to switch the storage media. Any thermal plant could implement heat storage if they identify a medium with a large latent heat of fusion that is around where you want to preheat your working fluid to.

The salt used for energy storage is normally a eutectic mixture of ~60% sodium nitrate and ~40% potassium nitrate (not NaCl) and has a melting temperature of ~260 °C. The secondary on a PWR has a maximum temperature of 275 °C. So within the liquid range of typical thermal storage salts, though I suspect finer tuning of the salt composition would be used to reduce the melting temperature to closer to the feed water temperature of ~220 °C.

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