Three Mile Island happened in my lifetime, so it's still very relevant
It's not the time period that makes it relevant. It's whether it can happen again. In the United States, at least, I'm fairly confident the answer is no. Nuclear power plants aren't run by cowboys the way they once were.
Let's also not forget that coal power also costs lives every day and nobody seems to be complaining about that.
I hope you're right, but history has a habit of repeating itself especially when ignored. Usually all of the great man-made disasters come off of cutting corners or ignoring safety, then after the inevitable disaster happens the people band together and fix it, but after a while it happens all over again.
The problem with atomic power is 1. waste, and 2. it's very toxic if released by accident or otherwise. Even in the best circumstances a reactor can have an accident, and if a reactor goes into meltdown, (like at Fukushima, which were American made reactors operated in a first-world country), it has consequences that wastes entire regions and affects the entire Earth both in the air and water and can take centuries to clean up if not a millennium before the area is fully restored, unlike if there is an accident at most other types of power generation plants.
For the last century and a half man has acted like resources are infinite and that humanity can endlessly expand, but we are finding out that there are consequences. The truth is instead of playing with something that is not completely controllable for power generation we really need to start looking into conservation rather than endless expansion, as Alexandr Solzhenitsyn said:
"A dozen maggots can’t go on and on gnawing the same apple forever; that if the earth is a finite object, then its expanses and resources are finite also, and the endless, infinite progress dinned into our heads by the dreamers of the Enlightenment cannot be accomplished on it . . . All that ‘endless progress’ turned out to be an insane, ill-considered, furious dash into a blind alley. A civilization greedy for ‘perpetual progress’ has now choked and is on its last legs."