First, nuclear can be extremely inefficient since it's heavily centralized : I have friends working for energy distributors telling me they can lose more than half the energy between the power plant and the client's house.
More importantly, nuclear waste disposal and power plant cleaning costs are heavily underestimated. I've worked for the CEA, the French nuclear agency where they invented the first French atomic bomb and reactor in the sixties, and some experiments aren't still cleaned up yet in 2010's (the current objective is to fully clean up the laboratory in 2025-2040). That is a massive cost which is not factored into the kW price.
I think decentralized technologies are the way to go regarding energy (using local loops and "smart grids") even if they aren't viable now (solar panels cost more in energy to produce than they give back during exploitation for example).
