No, there is currently not much of a debate on this. I am not aware of any poll on the topic either, and I am unable to say what would be the answer if french people were asked about giving up nuclear weapons altogether. The cost argument and the fact that not much is needed for dissuasion would probably make people ok with reducing the stock, though (this is a guess, not a poll).
The reference to history in the other answer is irrelevant, since the suez crisis does not influence current public opinion whatsoever.
The first historical character we should look at is the général de gaulle. Although he left because of interior politics, his foreign policy is still very popular. In short, it consisted in getting the bomb so that France could be independant from both the us and the soviet union. To some, it also ensured that no one could interfere when we (french people older than me) chose to have a socialist president (François Mitterrand) in the 80s.
The second relevant character to look at is Jacques Chirac. Same pattern, he has been blocked time and time again by a socialist prime minister for interior policy reasons. However, he (and Dominique de Villepin) is also remembered for refusing to invade Irak in 2003. Other countries in that case are germany and russia. This decision was very popular and got even more so with time. It was possible (according to the public opinion) because France was not fully dependant on nato for its defense, which meant in part having the bomb. Every nato country besides France and germany did go in Irak.
Recall that the same Chirac was criticised a lot when he made a nuclear test.
Another factor which is hard to measure but could be taken into account is that the argument "we should reduce public spending " is less powerful in the french psyche than in the anglo saxon one.