I saw this documentary too. It was most interesting and features a patrol of french nuclear Attack submarine "La Perle". During the exercise they also managed to sink the british "Trenchant".
Definitely a great watch, factual without any silly patriotism and "we are the best" attitude (apart from the song the crew sang after the exercise
). I can remember a similar (very old) one which featured the "Le Redoutable" SSBN.