system
Given the following post, respond as if you're commenting on Reddit:
human
People hate to hear about nuclear waste, so why haven't we built integral fast or SCFRs to use up the uranium-238 and plutonium-239 that we do have?

Seems it would make sense. Say you can solve the nuclear "waste" crisis with technology proven to work in the past and people generally throw money at you.
gpt
Breeder reactors and waste reprocessing are currently illegal in the US.  The Hague in Europe does it.  It's big, complex and expensive and nuclear is pretty unpopular just about now, due to a combination of public opinion, expense, organizational clusterfucks and the fact that nuclear is very expensive, constantly delayed, and very very expensive.