Nuclear power is bad for its consistent output because demand is not constant. You could of course run some energy hungry chemical reaction when there is more power than demand, make hydrogen to use for synthetic fuels for example or build a battery to store the excess power for when the demand is high. But is is of course much cheaper with renewables.
Total demand is not constant, but you can represent total demand as a sum of a given constant demand plus variable demand. Say for instance the average demand varies from 200-350 kWh a year. You could run nuclear power plants to generate 200 kWh worth of electricity, and use solar/wind for the remaining 0-150 kWh demand. It would be fairly efficient to have nuclear provide a base load of some kind while solar and wind vary to meet the full demand.
Hydro is best as a giant battery bank, and pairs quite well with nuclear.