For instance, it is discussed in this press article [1] published in 2016 and available in French. It is mentioned that nuclear power costs 60€/MWh, compared to 80€/MWh for wind power. It is also mentioned quite often in the French press: I have seen it mentioned a few days ago. The source mentioned in the 2016 press article is an official report [2] published in 2014.

However, it is true that the maintenance cost increases as the power plants get older.

[1] https://www.francetvinfo.fr/replay-radio/le-vrai-du-faux/le-... (in French)

[2] https://www.ccomptes.fr/fr/publications/le-cout-de-productio... (in French)