The Department of Energy’s National Nuclear Security Administration on Monday formalized its choice to build the Savannah River Plutonium Processing Facility pit factory out of the remains of the partially constructed Mixed Oxide Fuel Fabrication Facility.

The planned pit plant will cost between $6.9 billion and $11.1 billion to build and be ready to annually produce at least 50 pits — fissile plutonium triggers for nuclear weapons — by 2032 or 2035, the civilian nuclear weapons agency wrote in a Monday press release about the facility’s critical decision 1 review.

At that rate, the National Nuclear Security Administration (NNSA) has said it will not meet a legal deadline to produce 80 pits annually by 2030, even though the agency remains confident that another planned pit factory in Los Alamos, N.M., will start producing 30 pits annually by 2026.

Last Friday, the director of the Los Alamos National Laboratory said it would be challenging to make 30 pits in 2026.

Jill Hruby, the Biden administration’s nominee for NNSA administrator, disclosed NNSA’s latest projected cost range for the Savannah River Plutonium Processing Facility (SRPPF) in congressional testimony on May 27. Hruby told Defense Daily then that the figures came from the project’s critical decision one report, supporting documents for which personnel at Savannah River turned over to NNSA headquarters in Washington earlier this year. 

In 2018, NNSA estimated that SRPPF would be ready to make at least 50 pits a year by 2030 and cost around $4.5 billion. The earlier estimate was nowhere near as detailed as the cost range produced for critical decision one, acting NNSA Administrator Charles Verdon said last week in congressional testimony

Verdon has also testified that pairing SRPPF with the smaller Los Alamos pit factory is still the quickest way to produce at least 80 pits annually by next decade. The Los Alamos Plutonium Pit Production Project will cost up to $3.9 billion and begin producing war-usable pits by 2024, the NNSA has said.

The NNSA approved critical decision one for the Los Alamos plant in April. The pits will initially be for W87-1 warheads for the Ground Based Strategic Deterrent: silo-based intercontinental ballistic missiles set to replace the current Minuteman III fleet starting in 2030 or so.