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).

There is not enough geographical locations. Sorry to bust your dream, but not every country in Europe is Switzerland or Austria with useful valleys and rivers in them