if all plutonium holder would form a monopolies on plutonium, then there would be one.
I though free markets prevents forming of monopolies.
If not, then it fails.
and honestly if they are smart enough to purify plutonium, they will also be smart enough to not sell to you.
But i want to produce electricity and i pay well.
You forgot that blowing up the plant is the secret part of plan or can happen as just an accident.