Greenpeace was founded to oppose nuclear energy, because it would lead to nuclear war (that was their position at least), which illustrates that, even now, nuclear power is considered not-green.
Greenpeace is a big part of the problem, especially with most of the European left being aligned with them on nuclear hate.
Being "green" is like being "organic" compared to being carbon-neutral which is something you can just calculate.
Germany turned down all of its nuclear plants and is actively demolishing them. Good luck with that.