The W88 entered the U.S. nuclear stockpile in 1988, with full production of the upgrade reached in 2022. The programme addressed ageing issues identified through routine surveillance and enhanced the reliability of a key element of the sea-based leg of America’s strategic deterrent.
NNSA Administrator Brandon Williams said: “Completing the W88 Alt 370 is the latest instance of NNSA delivering modernized nuclear weapons to the Department of War at the pace and scale needed to fulfill our deterrence requirements.” He added: “Achieving two LPUs for the B61-12 and W88 and the FPU for the B61-13 all within a single year demonstrates our ability to execute NNSA’s fundamental production mission.”
Williams also stated: “This record of delivery signals to our adversaries and our allies and partners alike that under President Trump’s leadership, the United States has the will and the means to field newer, safer, and more capable warheads for our strategic deterrent.” The W88 Alt 370 work included replacing the arming, fuzing and firing assembly, adding a lightning arrestor connector, refreshing conventional high explosives and replacing limited-life components.
The last upgraded warhead was delivered four years after the First Production Unit was achieved in July 2021, in coordination with the U.S. Navy. The programme involved collaboration across Los Alamos National Laboratory, Sandia National Laboratories, the Pantex Plant, the Y-12 National Security Complex and the Kansas City National Security Campus.
David Hoagland, NNSA Acting Deputy Administrator for Defense Programs, said: “Completion of the last W88 Alt 370 testifies to the successful collaboration we’ve had with our U.S. Navy and Department of War partners.” He added: “The momentum built through the production and delivery of the W88 Alt 370 will continue into our expanding weapons modernization programs and additional stockpile efforts in the coming years.”
Following completion of the final unit, Pantex will continue producing W88 Alt 370 warheads and components to support future surveillance activities. NNSA is continuing modernisation across all three legs of the nuclear triad, including work on the W93 and SLCM-N warheads, with first production units expected in the early to mid-2030s.
Source: United States Department of Energy.
