I'm NO expert either but love to read more from genuine sources and share it here among others. Mindstorm and GarryB are expert people acc. to me.
As of 2015 the Russian fleet three of the six originally constructed Akula subs: the TK-17 Arkhangelsk, the TK-20 Severstal and the TK-208 Dmitry Donskoi exists.
According to the 2014 plans of the Russian Fleet, the submarine will remain in use until 2022, though it is possible that it will then be modernized and continue its service.
Russia announced on12 March 2016 a decision to disarm the nuclear missile system of its Typhoon-class Arkhangelsk submarine – the world's largest – in accordance with the New START treaty between Moscow and Washington. Russia's Zvezdochka shipyard in the northern city of Severodvinsk declared its plan to disarm the missile system on the huge submarine. "We will remove the covers of the submarine's missile launchers and seal them, thus making it impossible to use the vessel's missile weapons," read the press statement. "We are not talking yet about dismantling the submarine itself. The tender for this procedure has not yet been announced."