On 4 January 1995, during testing, the boat reached maximum depth for the first time and made the first firing of a ballistic missile the following month.

On 18 October 2001, the fleet support service notified the DCN that Triomphant was about to take the first period of Unavailability for Maintenance and Repairs (IPER or Indisponibilité pour Entretien et Réparations).

The 150 million Euro contract was granted to DCN, with the IPER starting at Ile Longue on 2 April 2002, scheduled for 29 months in all.

In August 2004 L'Humanité ran a piece with the headline "Pas si Triomphant que ça" reporting that Le Triomphant had suffered a nuclear leak from one of her nuclear warheads by the end of 1997 and from her reactor in 2004, though the FOST downplayed the incidents and stated no radiation had been released since the reactor had been non-operational at the time.

Since 1972, patrols by Submarines forces are conducted 24/7 365/year, embarking each sixteen strategic missiles, which launching can only be authorized by the President of France, and which could destroy 96 targets with an equivalent effect of a hundred times the explosions of Hiroshima and Nagasaki.