The average time globally is 14 years. The latest point of reference in the west, Vogtle was announced in 2006 and came online in 2025, 19 years later. It took 7 years alone just to start building it.
There's no chance this would take less time in Italy, where you need to also find a suitable place, you don't have the know-how and there's an anti-nuclear referendum that's been voted 3 decades ago. So there is a lot that needs to be changed, starting from having a public voting.
Hinkley Point C, in UK, has ballooned it's cost from the planned 18B pounds to a 43B pounds in the span of a decade. These projects always go overbudget, badly.
Until there’s actual funding talking about nuclear doesn’t really mean anything. Vogal was a boondoggle but it didn’t get construction approval until 2012 and like many projects ran into COVID delays on top of everything else.
> These projects always go overbudget, badly.
Using the worst examples means there’s something very wrong with each of them.
Well there you are, then: projects experience delays in construction approval and run into other unexpected delays, which extends a ~10yr estimate.
You can always pick worse numbers by using a smaller sample of projects, but it isn’t necessarily meaningful to do so. California’s high speed rail has gone far worse than Italy’s projects, America is currently comically bad at large construction projects.
Your 2050’s comment assumes a level of dysfunction that’s presumably exaggerated. Averaging 10 years puts you at 2036 and is itself somewhat pessimistic.
The cost of canceled nuclear projects is generally quite low compared to lifetime subsidies of nuclear. Nuclear may be an inefficient use of government resources, but it’s also offset a staggering amount of emissions and the subsidies tend to end back up in the local economy recuperating some of the expense. IMO, there’s probably dumber things your government is doing that are worth fighting instead.