For quite some time now there's been on my computer this sci-fi novel I wrote when I was about 16 years old. For quite some time I've been thinking on how to improve it to make it...readable, at least. The idea is to work on the existing chapters to give them unity, while adding also new chapters on the way to fill in the gaps when necessary. And so, after devising a new storyline, I've started by writing a brand new opening chapter. Cutting to the chase, after completing this new chapter by one third, I'm stuck. The idea I'm struggling with is this: is it plausible for fission nuclear reactors to still exist in the 25th century? Is there any way I can make it plausible, for a novel set in a universe which is pretty much like that of Star Trek tv series? I need a nuclear explosion to occur after an accident with a broken reactor or something, pretty much like what happened when the Chernobyl reactor 4 blew up...but for a fission reactor to still exist and still be flawed in 25th century seems...unlikely. Aww my head's gonna blow!