> if you'd just let it run without doing anything it would probably run for 30-40 years. Let it run? You mean, presumably, the huge amount of testing and preve

> if you'd just let it run without doing anything it would probably run for 30-40 years. Let it run? You mean, presumably, the huge amount of testing and preventative and planned maintenance that is scheduled in as part of a reactors expected lifetime, plus anything new discovered along the way. That doesn't come for free. > In theory maintain a nuclear power plant to last for 100s of years Sure, given enough effort you can fix anything. But extending a fission plant's lifetime can require massive overhauls, replacing reactor components, replacing materials that have experienced radiation embrittling and activation, etc. Keeping a plant running indefinitely is so complicated and expensive that we haven't managed it so far. Extension is something we should absolutely consider but it's not a magic fix all. Sometimes it's not worth it to keep an old thing running.