The federal government has agreed to conduct an extensive environmental study of a nuclear weapons production effort that includes a multibillion dollar pit factory at the Savannah River Site in South Carolina.

Sued four years ago by environmentalists, the National Nuclear Security Administration has now agreed to undertake the study as part of a settlement announced Friday. The settlement, which halts some of the proposed construction work at SRS, could delay completion of the pit factory, which was scheduled to begin operation in 2035, according to federal estimates, environmentalists said.

Pits are key components of nuclear weapons. The federal government has said the nation’s existing supply is aging and needs refreshing. Making more pits would provide fresh material for bombs, while also making it possible to develop newer types of nuclear weapons.

According to the government’s plan, pit factories would be developed at SRS near Aiken and at the Los Alamos nuclear site near Santa Fe, N.M. They would collectively produce 80 pits per year, 50 of them at SRS. In South Carolina, the pit plant could result in the creation of about 1,000 jobs, preliminary estimates have shown.

But the government never fully studied the impacts on the nation’s air, land and water when it moved ahead with plans for the pit production program about seven years ago, according to environmental groups who filed a lawsuit in 2021.