Over their lifecycle they are down more like 20-25%.
90%+ capacity factor/uptime is pretty much standard and the better ones reach ~95%
For example TVO in Finland has 93% to 97% depending on the reactor since the early 1990s. Fortum has very similar numbers for their reactors.
edit:
Basically competent operators hit ~90%.
US is around 93%.
Sweden 84%
Switzerland 90%
France would hit that if they could run their plants at 100% when they are on but they run theirs in load following mode due to having so many of them. So they run at around 80%.
World average is 83%.
https://world-nuclear.org/getmedia/891c0cd8-2beb-4acf-bb4b-5...
And yes I know best the numbers about the market I live in because I live here and this stuff effects the price I have to pay for electricity.