United States, Sept. 26 -- General Dynamics Electric Boat Corp., Groton, Connecticut, is awarded a $642,313,620 cost-plus-fixed-fee modification to a previously awarded contract (N00024-20-C-2120) for Lead Yard Support and development studies and design efforts related to Virginia class submarines. Work will be performed in Groton, Connecticut (94%); McLeansville, North Carolina (3%); Newport News, Virginia (2%); and Newport, and Quonset, Rhode Island (1%), and is expected to be completed by April 2026. Fiscal 2021 shipbuilding and conversion (Navy) funds in the amount of $41,554,263 (34%); fiscal 2024 shipbuilding and conversion (Navy) funds in the amount of $31,236,000 (26%); fiscal 2025 research, development, test and evaluation (Navy) f...