How familiar are you with the construction arrangement for the Virginia-class boats?
Modules are constructed by both yards. NN builds the bow, stern, sail and selected forward compartments for every Virginia-class boat. In addition, each yard builds their own reactor compartment in order to keep them both nuke-qualified.
http://www.navy.mil/navydata/cno/n87/usw/winter99/virginia_class.htm
"The teaming arrangement between General Dynamics’ Electric Boat Corporation and Newport News Shipbuilding for building this new class allocates major sections of the ship to one yard or the other, so modularity by hull section is inherent from the outset. In addition, large, internal sub-assemblies are fabricated and tested separately before they are “packed” into the hull as Modular Isolated Deck Sections (MIDS). The design process itself incorporates both concurrent engineering design/build teams and an extensive infrastructure for computer-aided design, engineering, and manufacturing (CAD/CAE/CAM). Each design/build team is responsible for a specific aspect of the ship’s structure or mission capability and includes Navy managers, fleet operators, technical personnel, key vendors and suppliers, and the shipyard’s designers and waterfront construction supervisors."