NNSA “diamond-stamped” first plutonium pit for W87-1 warhead

The National Nuclear Security Administration on Tuesday finished its First Production Unit of a plutonium pit for the planned W87-1 warhead, an agency press release said.

The National Nuclear Security Administration (NNSA) verified, or “diamond stamped,” the pit, the fissile core of a warhead first stage, after it met the requirements for readiness to be deployed to the nuclear stockpile at “war reserve” quality, the press release said.

A newly manufactured warhead based on a previously tested design, W87-1 will be the second of two warheads to tip the Air Force’s silo-based Sentinel intercontinental ballistic missile some time next decade. Sentinel, facing long delays after a cost breach that the Air Force says is mostly unrelated to missile development, will replace Boeing’s Minuteman III.

“This complex effort executed by our mission partners represents an important step on our path to restoring and modernizing NNSA’s capability to produce plutonium pits at the quantities needed to support military requirements set by the Department of Defense,” Marvin Adams, deputy administrator of defense programs for NNSA, said in the release.

A spokesperson for the U.S. Strategic Command told the Monitor in September that the first-production pit was “not impacted” by the three-month stopgap budget Congress passed in the final week of September to keep the government open through Dec. 20. 

However, the Strategic Command spokesperson said, the NNSA would have only enough funding under the continuing resolution to keep pits on schedule for about two months.

NNSA said earlier this year that it would begin producing 30 war-reserve pits annually at Los Alamos in 2028. Air Force Gen. Anthony Cotton, commander of U.S. Strategic Command, said that would meet military needs. Federal law that dates to 2014 requires the NNSA to produce 30 pits annually by 2026. The same law required 10 war-reserve pits in 2024. 

NNSA had long planned to make pits only at Los Alamos. In 2017, however, word leaked that the agency planned to repurpose a plutonium recycling plant to make the warhead cores. That plant, now the Savannah River Plutonium Processing Facility, is still being designed and might open in the mid-2030s, the NNSA has said.

Los Alamos is supposed to make at least 30 pits a year. Savannah River, facing delays and overruns, is supposed to make at least 50, though NNSA has said either plant could make more in a pinch. In 2023, NNSA Administrator Jill Hruby said the Savannah River pit plant would probably have to make more than 50 pits a year as soon as it opens.

Meanwhile, a federal judge this week ruled that the NNSA has yet to do an adequate environmental review of its plan to produce pits in two states. The ruling was part of a lawsuit filed in 2021 by a group of environmentalists. The ruling, first reported by Weapons Complex Morning Briefing, has so far not stopped design or construction of the Savannah River pit plant.