France have done better than most, largely due to building their fleet before Chernobyl, but even they have long term maintenance and cost overrun problems that led to shortages: https://www.lemonde.fr/en/economy/article/2022/08/26/edf-s-n...

And the EDF reactor project in the UK is of course overrunning on time and budget.

(when is the next French nuclear reactor new build scheduled to come on line?)