Share of the total grid is meaningless comparing solar to nuclear. It’s the wrong metric to optimize for - the metric that actually matters and is the expensive one is reliability.
What matters is “share of the grid when solar literally cannot provide the power at any price”.
In a well designed and functional grid share of nuclear power should be close to 100% of the latter and the lowest percentage of the former you can get away with.
It’s better to think of nuclear as energy storage with a really really long lasting battery that costs the same to run it 24/7 or 1 hour a month.
Ideally it would be replacing close to all baseload/reliable power on the grid outside of hydro - with hydro being your peakers instead of natural gas for topologies amenable to it. The power share graph should look like nuclear at close to 100% at night less wind and battery storage that backs wind unreliability - and that graph remaining flat throughout the peak daytime hours with other energy sources kicking in such as solar, hydro, duck curve sized battery arrays, etc.