Having flown the 747, and the JFK-CDG route, the center fuel tanks (the one that exploded) would normally be empty. The center tank is the last filled and first emptied. This is the same for all Boeing’s. Paris is a relatively short flight - 7:00 hours. The wing tanks had plenty of room for the necessary fuel.
Since you’re a 747 pilot, what is your opinion of 800?
TWA-800 was flying to Rome via Paris. On that model of 747 going to Paris, the center tank would have had fuel in it?