@kravietz
such calculation often omit the externalized costs of nuclear energy. A study by the French government concluded that a Fukushima style disaster would cost them €430bn, which is more than plant operators and insurance companies can pay, meaning the state will have to cover it.
https://fr.reuters.com/article/topNews/idFRPAE91601Q20130207
The ecological/social/health impacts of uranium mining and the somewhat unsolved problem of waste disposal have to be considered as well.
http://www.afrol.com/articles/36725
Regarding mining, you are certainly aware that any modern renewable energy technology (solar panels, wind turbines, batteries) requires vast amounts of rare earth metals which are... mined. And since they co-exist with radioactive elements such as uranium, thorium, radium, they result in radioactive mining waste too.