How much installed capacity of wind or pv would be required to match the output of a 4GW nuclear power plant
Approximately 1,600 square miles of solar panels, perhaps in west Texas to shade the grass and cattle during midday, is enough to supply all the USA with 1,000 watts per person.

Then you need about 4 cubic miles of pumped storage, lifted up 1,000 feet, to store energy for the next 24 hours. Some states (Florida) do not have 1,000 feet or even 500 feet or even 300 feet, of convenient adjacent elevation-change, and must depend o other states for their pumped-storage.