Mainly due to politicians drafting rules to require more safety out of nuclear than any form of other energy solution. Of course it's more expensive if it's 100x more regulated.
> Nuclear waste: Many supposedly safe storage solutions such as in former salt mines have turned out to be unsafe. Gen IV reactors produce less, but not nothing at all
And what damage has these "unsafe" storages caused, especially compared to other forms of energy creation? Coal is basically pumping out the radioactive waste into the air we breathe. It's better to have few concentrated places for the waste rather than spread it all around the air little by little.
You can't just say "nuclear waste" and be done. You have to compare the data between different solutions.
> Security and safety: They're centralized infrastructure, attacking them has catastrophic consequences, unknown unknows like in Fukushima and human errors like in Chernobyl do happen and lead to catastrophes.
Funny you mention Fukushima, where zero people have died or gotten sick due to radiation, and experts say that the toll will probably stay at zero. Overall nuclear has the lowest mortality rate per MWh of any form of energy: http://www.forbes.com/sites/jamesconca/2012/06/10/energys-de...