Uranium is very power dense. If there is a supply chain disruption, it is problematic but France keeps around at least 5 years worth of nuclear production, which gives it some time to react and adapt. Also, Uranium is not very rare nor expensive, so reliance on one producer is not that worrying I think. Enrichment facilities are rarer, but there is also one in France, so I can see French nuclear tech work on its own.

Canada is a significant producer of uranium and we have a fine relationship with the French, I don't think this is a serious concern at all