Nuclear has its own decommissioning and long term disposal problem.
We could fulfill the world's nuclear waste storage needs with a couple landfills if the will was there (though any geologist will tell you are better options than near surface storage).
From an ecological perspective nuclear is the best option by a mile because the amount of stuff you need to pull out of the ground, move around, use and dispose of is so small per energy produced.
Tiny local hydro (with natural dam) is the future, but getting a building permit is near impossible. (I leave it to the reader to guess why)
We need to switch off electricity for everything except (low power) computers and networks. = hand pumped water, wood stove for water heater, earth cellar as fridge!
Mass transports are completely over, grow/breed/preserve your food locally!
Even ignoring the CO2 aspect, the particulate emissions from this would be quite problematic in any sort of dense area. Not to mention what fraction of those particulates would end up inside the house...
Also, you don't mention heating (houses, not water). That is a huge part of energy consumption in many parts of the world.
What has changed such that you could not remake the power grid? Do we lack the raw materials or know how?