Nuclear is no use for the grid as it can't flex. Sometimes a grid needs 80 units, sometimes 50 units. Nuclear can't provide 80 units all the time as its unaffordable, can't increase or decrease output economically, and only makes sense when they're run 24/7 (except when it has to go offline for maintenence or other issues like heatwaves [0])
[0] https://www.euronews.com/green/2023/07/13/frances-nuclear-po...