Reactors can be made safer, but the problem of nuclear waste remains - and nobody wants that shit in their backyard.
If it was technically feasible (and safe to do), people would send it to the moon or into the sun.
Reducing energy consumption of devices and appliances, improving energy storage capacities - and re-evaluating settlement areas, that's the way to go.
Cities like Las Vegas (practically uninhabitable without air-conditioning) are probably a thing of the past.
New York may turn out the same, though.