Investment in what? The plant is still running, no? Do they need more plants, repairs to existing, or upgrades to existing? How do I dig further?
All of these... but no political will because "nuclear bad, renewables good".
All the while EDF is being nationalized. Should more money have been spent in even deeper pits?
https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...
If we want electricity in a world without less fossil fuels, I'd say yes.
EDIT: renewable can't be the only solution. They are cheap only because they are built on top of existing nuclear/fossil solutions.