[rubber_duck]

>Yes, it gains you some of the economics of factory construction and that you can start small and scale a location, but on the other side you lose that again because you lose the economics of scale that traditional PWR gets.

You mean they lose operational efficiency ? Economies of scale come from the ability to mass produce.

You forgot to mention the largest differentiator - eliminates the possibility of a global catastrophe.

[acidburnNSA]

Not in nuclear they haven't historically. Economies of scale drove light water reactor designs from tens of megawatts to hundreds to over a thousand universally from all vendors around the world historically. The big institutional nuclear economics reports all agree that going big improves nuclear economics. The hypothesis that SMRs will somehow overpower this is popular but is very much unproven. This agrees with OECD reports like last month's [1] and all the older ones listed in [2].

[1] http://www.oecd-nea.org/ndd/pubs/2020/7530-reducing-cost-nuc...

[2] https://whatisnuclear.com/economics.html#improving-modern-nu...

[jabl]

> You mean they lose operational efficiency ?

Historically, one of the few successful ways to lower the price per generated power from a nuclear power plant has been to make the reactor larger. So yeah, there's a reason why the latest traditional PWR designs such as the French EPR are huge (1600 MWe).

The gamble with these small reactors like Nuscale is that series production of the reactors in a factory would make up for the loss of the traditional economy of scale due to size. It remains to be seen how well that will work out.

[nickik]

Economics of scale are the reasons modern Gen3+ reactors are so huge.

From AP1000 wikipedia:

> The design traces its history to the System 80 design, which was produced in various locations around the world. Further development of the System 80 initially led to the AP600 concept, with a smaller 600 to 700 MWe output, but this saw limited interest. In order to compete with other designs that were scaling up in size in order to improve capital costs, the design re-emerged as the AP1000 and found a number of design wins at this larger size.

So modern PWR are usually build with 1GWe one location one reactor, huge economics of scale in terms of the size of the power plant. A AP1000 is not much bigger then an AP600.

> You forgot to mention the largest differentiator - eliminates the possibility of a global catastrophe.

I disagree. First of all, I think the possibility of a global catastrophe with a traditional PWR are already incredibly small, and when talking a modern build like an AP1000 the NuScale doesn't have that much better safety characteristics.

PWR are inherently problematic and require tons and tons of complex engineering to make them save and the error potential in such a solution are always there.

[evilos]

If you can pump out standardized large scale reactors like France did, then they are way more efficient than these smaller reactors.

The problem of course is that takes a large government to mandate a huge public project, which is not really likely these days. The advantage of these small reactors for now is that they hopefully prevent expensive,bloated, one-off site designs that go over budget and miss their schedules.