Right. They will see that it is much more expensive than the tiny fund they have prepared for it. Germany, with way less nuclear power plants, has more money in its decommissioning fund than France.

Generally: The political system in France makes it impossible to demand market prices for electricity. It's all centralized and monopolistic. EDF is the large state owned electricity producer. It has around 80% market share.

Imagine now a steep electricity price rise. This would be highly unpopular and the french president would not be re-elected.