The last production unit was completed at the Pantex Plant in Amarillo, Texas, in November. Sandia said the milestone marks the end of production work and the start of the next phase for the W88 Alt 370.
“I remember talking about the Alt 370 when we were just putting together plans,” said Troy Savoie, now a manager at Sandia leading the team that oversees stockpile sustainment of the warhead.
Savoie began his Sandia career working on specification requirements for environmental testing of the W88 Alt 370. The warhead is carried aboard Ohio-class ballistic missile submarines as part of the Trident II D5 strategic weapons system.
Sandia is the design agency for non-nuclear components and the lead systems integrator for nuclear weapon programs. It also served as the production agency for several components within the weapon.
“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,” said NNSA Administrator Brandon Williams.
“Achieving two last production units for the B61-12 and W88 and the first production unit for the B61-13 all within a single year demonstrates our ability to execute NNSA’s fundamental production mission,” Williams said.
The W88 first entered the U.S. nuclear stockpile in 1988. The Alteration 370 modernization program addressed aging-related issues identified through routine surveillance and refreshed key non-nuclear components to extend the warhead’s service life.
The program reached full-rate production in 2022. Sandia said the completion of production closes the modernization phase and moves the warhead fully into stockpile sustainment.
Michael Steward, who served as W88 Alt 370 system production manager, said his team was responsible for the design, development and qualification of the modernization. More recently, the team supported rate production of components and the system as the program moved toward completion.
Steward’s work involved close coordination with NNSA, the Navy, the Kansas City National Security Campus, Los Alamos National Laboratory, the Pantex Plant, Lockheed Martin and other enterprise partners. The goal was to address technical challenges and ensure on-time delivery of warheads to the customer.
“The key to overcoming them was working with subject matter experts here at Sandia, at our peer labs, at the production agencies, NNSA and the Navy,” Steward said.
“Leveraging all the partnerships and relationships across the nuclear security enterprise ensured that we delivered to the customer,” Steward said.
Hundreds of Sandia employees contributed to the W88 Alt 370 modernization. Steward said the warhead remains central to the sea-based component of U.S. nuclear deterrence.
“The W88 is the backbone of the sea-based leg of the U.S. nuclear triad,” Steward said. “It provides the president with a highly survivable strategic deterrent against attacks on the U.S. and its allies.”
Steward’s team worked closely with the sustainment team throughout production to support a smooth transition into the stockpile. The teams were co-located and shared knowledge and lessons learned through daily in-person interactions and formal reviews.
“Sandia’s role in those sustainment activities as the systems integrator will remain just as important,” Savoie said.
Sustainment work will include annual assessments of the W88’s state of health in the stockpile. Sandia will also maintain and extend the technical basis for those assessments while supporting logistics, field operations and production operations for surveillance rebuilds.
Those rebuilds involve units taken out of the stockpile for inspection. Future work will also include assessing compatibility with the next version of the delivery platform and refreshing the surveillance flight test body when it reaches the end of its life.
As production work concludes, Sandia said its teams are preparing for the next chapter of the program. The transition means continued work on the warhead as part of long-term stockpile sustainment.
“It’s not the end. It’s basically the beginning of stockpile life for the W88 Alt 370,” Savoie said. “There’s W88 work at Sandia for years to come.”
