Figure THAT would be half the cost of building a new boat.
Well, I know back in the 50's, the battleship Wisconsin had to have her bow replaced after she collided with a destroyer. So, they cut the bow off of the unfinished battleship Kentucky, which was later scrapped.
Granted, however, replacing the bow of a battleship is much different from an SSN, because if the repair fails on the battleship (which it hasn't after 45+ years) the worst that will happen is she has to return to port. If the same were to happen to a sub hundreds of feet underwater, the sub would end up in the same conversations as the Thresher and Scorpion.
Yeah, I think this can be considered a "spares restocking" mission for the rest of the fleet.