I think it's a pro-nuclear energy meme, joking on people's misplaced worry and minimising the danger of stored nuclear waste

I feel that pro nuclear stuff is trying to make people less interested in renewable energy despite a city being able to add more energy to its grid in weeks with solar and wind backed by batteries compared to two decades for nuclear, but also you need enough because every few decades it needs to shut down for months to be refuelled at enormous expense.

Wind power waste is inert, solar power waste is highly recyclable

They say "keep using coal and oil, because nuclear is the only good electric power supply and will surely come real soon"