ABC News has an extensive article about how the lifetimes US nuclear reactors are being extended past the 40 year minimum with very few relicensing requirements. This is very worrying, because the oldest nuclear reactors are also the least safe.
This is why fixed lifetime limits for nuclear reactors are so important. Germany has put a lifetime limit on nuclear reactors since the first nuclear phase-out decision under the Schroeder government. The Merkel government repealed that phase-out decision, only to turn around and now introduce a fixed nuclear phase-out date of 2022. Kernkraftwerk Emsland, the last new nuclear power station to be built in Germany, will be forty years old then.
Thanks to Jay Lake for pointing me to the article.