History of Pit Production

During the height of the Cold War, the Rocky Flats Plant in Colorado was the nation’s producer of pits , manufacturing 1,000 to 2,000 pits per year between 1952-1989. Major fires occurred at Rocky Flats in 1957 and 1969, both involving plutonium. The site was raided by the FBI and the U.S. Environmental Protection Agency in 1989 for environmental crimes and permanently closed in 1992. The Los Alamos National Lab (LANL) in New Mexico then produced 29-30 pits between 2007-2011 to end the Rocky Flats production run. The US has tried, and failed, several times to revive plutonium pit production — LANL did not produce another pit until October 2024.

In 2018, the federal government ordered the production of at least 80 pits per year by 2030, including at least 30 pits at LANL and at least 50 at the Savannah River Site (SRS) in South Carolina. In 2021, Nuclear Watch New Mexico, Savannah River Site Watch, Tri-Valley Communities Against a Radioactive Environment (CAREs), and the Gullah/Geechee Sea Island Coalition of coastal Georgia sued the National Nuclear Security Administration (NNSA) for failing to consider the full programmatic impacts of plutonium pit production across sites.

In January 2025, this lawsuit resulted in requiring the NNSA to produce a Programmatic Environmental Impact Statement (PEIS) on plutonium pit production. After scoping hearings in May of 2025, the NNSA released their draft PEIS in April of 2026, kicking off in-person hearings in Livermore, CA, Santa Fe, NM, Aiken, SC, Kansas City, MO, and Washington, DC, as well as a 90-day online public comment period.