Comment by rwcarlsen

Depending on who you talk to and your definitions, nuclear is generally considered dispatchable. The only definitively non-dispatchable sources are e.g. wind and solar where they cannot guarantee power levels and availability during the dispatching window. It is a bit of a spectrum - some sources (i.e. nat gas plants) are considered highly dispatchable because they can be spun up and down and adjust power levels very quickly (i.e. load following).