I'm curious why that is. If we know how to build it, it shouldn't take that long. It's not like we need to move a massive amount of earth or pour a humongous amount of concrete or anything like that, which would actually take time. Then why does it take 15 years to build a reactor with a design that is already tried and tested and approved?
When you're the biggest fossil fuel producer in the world, it's vital that you stay laser-focused on regulating nuclear power to death in every imaginable detail while you ignore the vast problems with unchecked carbon emissions and gaslight anyone who points them out.
One of the big issues that have occurred (in the US especially) is, that for 20+ years there were no new plants built. This caused a large void in the talent pool, inside and outside the industry. That fact, along with others has caused many problems with some projects of recent years in the US.