[sofixa]

> don't look at these old designs, all these modern designs are 100% safe

This is only said as an answer to all the people screaming "but Chernobyl was horrible". Old designs are pretty safe too ( especially when terrible bugs like the one that caused Chernobyl are fixed), precisely because they keep getting updated to newer norms during refreshes and refits. There are nuclear power plants out there that were constructed in the 1950s that still work.

OP's point is that most nuclear power plants can have their life extended, at some cost, which is negligible compared to the cost of a new plant, and there's rarely a case where that doesn't make sense ( usually when for some reason the retrofit to update to new standards is too expensive). Why waste that? Prolong the life of existing plants, and build new ones to expand production and eventually replace the old ones.

[cycomanic]

Yes and the reasons that they don't get extended indefinitely is because it gets increasingly expensive to modernise and follow the new rules. On top of that is that regulators are becoming more reluctant to extend the lifetime, because the unknown factors increase (cue complaints about regulation). The reason they don't get extended that it is not economical compared to using wind/solar instead. Why do you think coal plants don't get operated indefinitely?