Neither nuclear power nor wind/solar is readily ramped up/down economically, but at least nuclear power is consistently available and can be dispatched to some extent.

You can always turn off renewables during periods of overproduction. Whether you build nuclear+renewables or just renewables, you need to overprovision the renewables and be willing to turn them off. You just have to do this more with only renewables.

(Of course, you'd want to use all available strategies to reduce required overprovisioning-- including maximizing use of dispatchable hydroelectric and biogas, some storage, and agreements with utility users to reduce usage during times of critical supply shortages).