The mining and processing of the "fuel" is not. The cost of the plants and the risks neither. That's why nuclear is slowly losing to regenerative.

Btw, from the World Nuclear Industry Status Report 2024 > Key Insights:

Russia is also playing a key role in the supply of fuel services, involving uranium mining, conversion, and fuel assembly manufacturing for Soviet-designed VVER pressurized water reactors, of which there are 19 in the E.U. and 15 in Ukraine. International sanctions have had little effect on the business. On the contrary, the share of Russian supply of natural uranium, conversion, and enrichment services to the E.U. all increased between pre-war year 2021 and 2023; VVER fuel imports doubled.

And you can see all of my points confirmed in that report.