How close are they to commercial implementation

The small nuclear reactor designs by NuScale are commercially viable and are going to be approved by the nuclear regulatory commission rather soon. Thorium isn’t as important as the small and modular aspects. Also Gen IV and breeder reactors are basically perfectly viable commercially if it was held to the same kind of scrutiny as most other power sources whether it’s coal or solar. But politically it’s not viable which is expressed by being so hard to finance with long time scales that investors simply don’t have the patience and nobody can raise the capital worthwhile to bother trying. It’s very much a chicken-egg dynamic impeding its viability similar to what popular renewables faced for different reasons for several decades.

Note that South Korea and France both have large operational nuclear power that is rather cheap to deploy because they basically copy-paste the same proven design and processes again and again. South Korea in particular has been under constant threat of attack by its neighbors for basically over a thousand years now yet went with nuclear decades ago. Comparatively, Switzerland didn’t choose nuclear for reasons I can’t quite remember even though they are fully capable technologically and in terms of process / bureaucracy able to manage the systems perfectly safely. Unsure about France’s reasoning but it’s difficult to compare power costs between France and neighboring Germany in good faith comparisons of energy policy either due to how different their electrical grid needs are.

NuScale is extremely heavily subsidized, both in development (50%) and initial deployments (100%), by US taxpayers.

It is absolutely uncompetitive, without.

There are several that will be deployed in Canada over the next few years [0] and the government seems committed to investing in SMR technology [1]

[0] https://x-energy.com/media/news-releases/x-energy-canada-and...

[1] https://smrroadmap.ca/