The US is significantly more developed and less locally corrupt than Brazil, never mind Brazil in the 1980s.

Practically every time a corporation ends up polluting the environment the government ends up paying for it.

> If it's too diluted, you can purify it with normal chemical processes and then make your bombs. It's not like uranium where you need a monstrously expensive isotope separation process to get the fissionables out.

While technically it is possible to separate plutonium out chemically, it is extremely difficult to do in practice. Plutonium separation plants are more expensive than uranium enrichment plants, and that's the reason states pursuing clandestine nuclear weapons programs choose uranium enrichment over plutonium. Uranium enrichment was much more expensive in the 40s and 50s when the US built up its plutonium production infrastructure, all of which was shut down in the 80s. Modern centrifuges make uranium enrichment cheap and simple, and the only economical source of plutonium is dismantled nuclear weapons.

You are missing that there is weapons grade plutonium with only Pu239 and reactor grade with some Pu240. The Pu240 spoils the fission reaction. Reactor grade might be usuable for bombs, but then all spent fuel is a problem.

Mix some weapons grade and reactor grade plutonium and end up with reactor grade that can't be used. Reactor grade plutonium already gets used in reactors.

PU is toxic, but hardly uniquely toxic. All of the "UPPU" guys from the old days died of natural causes at a ripe old age so clearly mild exposure is no death sentence. As far as proliferation goes I'm not sure how... ransomware gangs are going to switch to presumably armed interdiction and extraction of highly sensitive nuclear material. As a country we manage quite a lot of nuclear material and so far your scenario hasn't come to pass.

So yes there certainly are downsides to anything involving nuclear energy, just like there are downsides to fossil fuels, or the toxic heavy metals so often involved in "green" energy. The upside of nuclear energy is a lack of emissions after the initial construction, minimal mining to support it compared to other options, long working lifetimes and high efficiency.

But people love to focus on Hollywood inspired nightmare scenarios.

But imagine 2D-metamaterialized twisted-angle plutonium! Pure Stargatium!

Bzzzt...…