The Knolls Atomic Power Laboratory (KAPL)-Knolls Site (also known as KAPL-Schenectady) is engaged solely in research and development for the design and operation of naval nuclear propulsion plants. The Naval Nuclear Propulsion Program is a joint Navy/DOE program responsible for all matters pertaining to Naval nuclear propulsion. This Program is distinct from the remainder of DOE both by Presidential Executive Order and by statute. KAPL is operated by Martin Marietta exclusively for the US Navy and the Department of Energy, and is located in Schenectady NY. The laboratory employs about 2,700 people and has an annual operating budget of approximately $450 million.

The primary site is in Niskayuna, where the mission is the design and development of improved naval propulsion plants and reactor cores. Knolls also operates four land-based prototypes of shipboard pressurized-water reactor plants at the Kenneth A Kesselring site in nearby West Milton and one prototype plant at the Windsor Site in Windsor, Connecticut. Knolls also trains officers and enlisted personnel as reactor operators for the nuclear fleet at the prototype sites.

On May 15, 1946, KAPL began with a contract between General Electric Company and the United States Government. KAPL's purpose in 1946 was to conduct nuclear research and development, including work on the design of a plant that would use nuclear energy -rather than fossil fuel - for generating electricity. In 1950, the nuclear power plant project was converted to a Naval nuclear propulsion project. KAPL was one of the first laboratories to conduct research work on obtaining useable power from nuclear reactors.

In April 1993, General Electric Company transferred GE's Aerospace business segment, GE Government Services, Inc., and an operating component of GE that operated Knolls Atomic Power Laboratory under a contract with the U.S. Department of Energy to a new company controlled by the shareholders of Martin Marietta Corporation in a transaction valued at $3.3 billion.

The General Electric - Martin Marietta merger brought an end to GE's 47-year stewardship of the Knolls Atomic Power Laboratory. GE has taken great pride in playing a key role in the Naval Reactors' program. GE-designed reactors are powering 60% of the ships in the Nuclear Navy. KAPL has developed 10 nuclear propulsion plant designs and trained over 40,000 reactor operators for the U.S. Navy. Recently, KAPL was awarded the lead design responsibility for the next generation submarine propulsion plant.

Activities relating to naval nuclear propulsion systems are performed in accordance with the requirements and authority of the Naval Nuclear Propulsion Program, a joint DOE and US Department of Navy program responsible for all activities relating to naval nuclear propulsion. Facilities at the site include machine shops, waste-handling facilities, a boiler house, and chemistry, physics, and metallurgy laboratories.

The Department used the Separations Process Research Unit, a part of Knolls Atomic Power Laboratory, to develop a process for extracting plutonium and uranium from irradiated fuel. The Knolls Atomic Power Laboratory operated the facility from 1950 to 1953. Once the process was developed, the operation was transferred to Hanford, Washington. The Separations Process Research Unit Facility is located approximately 3.2 kilometers (2 miles) east of the city of Schenectady in the northeastern part of Schenectady County in New York State. The facility occupies approximately 80 hectares (200 acres) of the northwest corner of the 1,640-hectare (4,100-acre) Knolls Atomic Power Laboratory. The Separations Process Research Unit facility consists primarily of two interconnected buildings. Building G-2 housed the separations process systems and Building H-2 housed the liquid waste processing systems. These buildings are approximately 23 meters (75 feet) apart and are connected by an underground pipe tunnel. Additional facilities consist of the tunnel area, tank farm, and waste storage areas.