https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...
If other power sources had to factor in the full costs of such contamination they would be uneconomical as well. We need to have power if we want to have nice things, it's purely a question of figuring out how to do it in the most responsible way possible.
For that matter we should probably also factor in upstream contamination - landscape destruction due to large-scale strip mining for coal [1], or pollution from lithium/neodymium refining and silicon fabrication. These are measures where uranium mining has essentially zero pollution but both coal, solar, and wind all have fairly significant pollution footprints.
[1] 1 year's supply of fuel for a 100MW (?) power plant visualized, coal vs nuclear: http://i.imgur.com/Qst8z.gif
Sure, but again you need to compare like with like. How many people relocated per megawatt? The numbers for the alternatives are worse.
In some places, hydro isn't very pretty by this measure.
And if anyone did require power companies to have this insurance, it's likely that nobody would invest.