How long is the season for the National French Union Rugby team?

I'm afraid you are mistaken. The French team also plays in the usual mid and end-of-year tests -- generally against SANZAR, Argentina or Pacific Island squads. This means their work load is much the same as that of any other Tier One nation. All of the French internationals play for elite Eurpopean clubs -- mostly with the French Top 14, although others have played for English and Celtic League clubs -- which means that they play in the Heiniken Cup matches as well. Sebastein Chabal, for example, spent a few years with Sale in the English Premiership. There is currently one member (fly-half Frédéric Michalak) who plays with the Sharks in South Africa. If you look at the wikipedia article on the current French squad, you'll find their club side listed along with each player. See http://en.wikipedia.org/wiki/French_rugby_union_team