That hasn't been the case for at least a decade now - not after safety requirements were brought to where they are now.
And that 60-80 year lifetime which is supposed to spread the cost is a myth. Most plants are decommissioned before they turn 40 years of operation:
https://www.statista.com/statistics/272139/age-distribution-...
Also you can't really make meaningful conclusions based on that plot due to obvious reasons. It only includes "Number of nuclear reactors shutdown worldwide". The construction peak was ~1980. The oldest commercial plant was opened only 68 years ago and obviously the early plants much less safe and had a shorter lifetime which introduces another bias...
The ballooning of costs is not even significantly due to changing safety requirements, but often due to compliance and environmental requirements. Those are political requirements that could be removed in one fell swoop.