Components and nuclear power
In very simplified terms, there's one component that is best made as one big casting, I think it's part of the reactor housing. There's something on the order of 4 places in the world big enough to cast it, and naturally there is a big backlog. The same component can be cast in several pieces and welded together. This requires the welds to be inspected regularly. Basically it's slightly higher maintenance. Enough countries (Indonesia, Vietnam, China are the ones I can think of) are building or expanding nuclear programs to the extent that it's pretty clearly a myth.
The World Nuclear Association has a list of available heavy manufacturing places - while there was a pressure vessel backlog in 2007-2009, massive capital expansion now has more than 15 companies capable of 10,000 ton+ forging, and indeed Areva in Virigina have shut down due to lack of orders.
As Gnome Lover pointed out, here it's more of a skills shortage. The USA as an example has a lot of nuclear experts on hand; several universities have their own nuclear power plants, and there are a lot of people who can transition out of jobs running nuclear ships in the Navy to a job running a power plant. We could probably solve some of this with immigration but it'd take time. The last nuclear engineering course at a university here shut down many years ago, though there would be quite a few physicists and guys at ANSTO who would probably have the skills to kickstart it.
That said, NIMBY is a big issue and we're pretty well situated to use alternatives. If I were a country in south-east Asia and solar was less of an option, I'd more seriously consider nuclear. They're talking of damming parts of the Mekong for hydropower which would obviously have a large environmental impact.