I agree with you, if the Oscar used nuke torpedoes, the damage I received is fair!, and I remarked this from my first post!

and by the way, most of the russians subs have double hull with materials that were a dream in the WWII.
Wiki about Akula:
"The Akula incorporates a double hull system composed of an inner pressure hull and an outer "light" hull. This allows more freedom in the design of the exterior hull shape, resulting in a submarine with more reserve buoyancy than its western analogs. This design requires more power than single-hull submarines[citation needed] because of the greater wetted surface area, which increases drag."