The Pilgrim Nuclear Power Station is a generating station located in Plymouth, MA, 38 miles south of Boston on the coast of the Atlantic in Cape Cod Bay. It is one of two plants in Massachusetts (the other being Seabrook, north of Boston). Pilgrim Station, operated by Holtec International, is in the process of decommissioning following operation and electrical generation from 1972 until May 2019. Decommissioning is the process to end energy production and safely retire the station and any hazardous materials on site. Owners are accountable to the Nuclear Regulatory Commission.

The single reactor unit with a boiling-water reactor and steam turbine generator uses Cape Cod Bay water for cooling, and this continues through decommissioning as spent nuclear fuel is stored in water pools to cool. Over the life of the Station this water has been released back into the ocean slowly over time.