Perhaps I'm misreading your comment, but do you have actual insights that these particular power plants are properly maintained, components replaced, and there safety systems being improved in any way ?
There seem to be a generic feeling of "nuclear is fine" in reaction to all the anti-nuclear bashing going on, but few people seem to be really paying attention to the case at hand.
From what I read these reactors are not just old, they are built on an area that can have up to M7 earthquakes. The
seismic risk was taken into account when building the power plants, but after a new security audit following Fukushima, it appears the risk was vastly underestimated, and from there all plans of building replacement plants in the area got nerfed.
Basically these reactors are not actually deemed to be safe, it's just not practical to shut them down now without any alternative plan to cover for the electric needs of the whole country, when there is enough chance of no major earthquakes until they get decommissioned.