I don't believe in PWR SMR (Pressurized Water Reactor, Small Modular Reactor) will actually solve the problem with nuclear. The only reason to do it, is because the whole regulation is expecting PWRs and to have LITERALLY ANY chance to get a new reactor threw regulation it needs to be a PWR (in the US).

However, while PWR SMR can help you with modular construction and factory mass production, you lose the economics of scale of a larger reactor. I wish NuScale success, but I do not think the technology is very promising to actually reduce cost by the required amount. You need to be competitive with cheap gas prices.

PWR in general are a technological deadend that should never made it past the 70s. Even the inventor of PWR said so in the 60s and that is why he worked on Molten Salt Reactors.

However if you want to know about the future of nuclear, the only place where we see serious development in the Western world, look at Canada. They had a strong program of CANDU reactors and a globally respected regulatory agency. CANDU has now been privatized and the Canadians started to look more into Generation IV reactors (even while I totally dislike this terminology).

This has lead to Canada becoming a hub for nuclear innovation, as the Canadian regulatory system 'only' requires you to prove a safety case that is technology independent. In the US they just say 'show us the secondary pump for the steam', 'my reactor does not have any steam inside of it', 'PLEASE SHOW US THE SECONDARY STEAM PUMP'. facepalm

The company that is most advanced in the regulatory process is Terrestrial Energy (www.terrestrialenergy.com) and another one that is a couple years behind is Moltex Enery (www.moltexenergy.com) an originally British company who moved to Canada because the British regulatory agency is possibly even more disfunctional then the US one.

Both of these reactors are based on the Molten Salt reactors and really nice designs. The are both Fast Burners in their first iteration, while Moltex initially focuses more using Canadian CANDU Waste as fuel, Terrestrial Energy has opted to take the most commercially available fuel, 5% enriched Uranium.

However, both hope to eventually develop a Molten Salt Thorium Breeder design, long consider the holy grail among nuclear fans.

Terrestrial Energy is already working on a project to deploy their first US reactor in Idaho. The hope is that the US Regulatory Agency (who have realized how nonsensical their regulation are) are ready with a improved framework and that much of the work done for Canada will be accepted in the US.

The Moltex Ractor is special because it combines Molten Salt with a more traditional fuel assembly design (reusing well tested materials from Sodium Reactors). Listen here if you are interested: https://www.youtube.com/watch?v=TvXcoSdXYlk

Terrestrial Energy is building a more traditional Molten Salt reactor but instead of switching out fuel assemblies, they just replace the whole core. See here for more on their design: https://www.youtube.com/watch?v=OgTgV3Kq49U

For a more economic focus analysis on their design: https://www.youtube.com/watch?v=zsAfUBzRp3M

One thing that is often missed with this discussion is how irrelevant fusion really is in some ways. Fission has an energy density of 10^12 over chemical, Fusion is much better at 10^15, but really if we are not willing to switch to Fission, a technology we already have, why would be do it for Fusion.