Its one of the RN's T class (Trafalgar) - as to which one as RN subs don't carry pennant numbers thats anyones guess.
Originally a class of 7, Trafalgar was retired in 2009 leaving Turbulent, Tireless, Torbay, Trenchant, Tirless & Triumph, so as your photo is 2008 it could be of any of the original 7.