It's not feasible but also it's the same danger as with dams? Which is it? In reality, both nuclear power plants and dams have been attacked many times over the past decades. More decentralized power production has other disadvantages but clearly it can't be targeted as easily. The attacker would take out a single wind turbine or someone's roof PV. The effects would be negligible on a national level.

The cost btw is even higher than most people think considering that energy companies aren't paying for most of it but tax payers do. Some not even born yet. But even without factoring in those future costs, as you suggested we do, nuclear power in its current form is among the most expensive forms of power production. Again, look at the data, not energy company propaganda:

https://en.wikipedia.org/wiki/Levelized_cost_of_electricity