Pantex reaches milestone with W88 Alt 370 LPU

AMARILLO, TX – Officials with the Department of Energy’s National Nuclear Security Administration (DOE/NNSA) and the Pantex Plant, operated by PanTeXas Deterrence, LLC, (PXD), today celebrated the successful completion of the Last Production Unit (LPU) of the W88 Alteration (Alt) 370 nuclear warhead in November 2025.

Under Secretary for Nuclear Security and Administrator of the NNSA Brandon Williams was in attendance for site tours, briefings, and served as keynote speaker for the LPU celebration event. Also in attendance were National Security Enterprise partners in achieving the milestone, representatives of the U.S Navy, and Pantex local stakeholders.

“Reaching this LPU milestone required tremendous effort from all Pantex employees, along with the co-operation and collaboration from thousands of workers at Nuclear Security Enterprise sites across the country, and a close working relationship with the NNSA” PXD President and General Manager Kelly Beierschmitt said. “The success of this program demands the highest standards of safety, security, and quality from all involved. I commend everyone involved for their contributions.”

“Delivering on the W88 LPU is a proud moment and successful enterprise-wide team effort,” said Pantex Field Office Manager Jason Armstrong. “This milestone also exemplifies NNSA’s commitment to provide the nation’s nuclear weapons stockpile to the Department of War in support of national and global security.”

This alteration of the W88 is part of NNSA's multi-faceted strategy to ensure the United States nuclear deterrent continues to be safe, secure, and effective. The W88 is a submarine-launched ballistic missile nuclear warhead that entered the stockpile in late 1988.

The W88 Alt 370 program entered the development engineering phase in 2012 and production engineering began in early 2017. The W88 Alt 370 First Production Unit (FPU) was successfully completed in July 2021, ahead of schedule through outstanding teamwork from the Pantex Plant, Los Alamos National Laboratory, Sandia National Laboratory, Kansas City Nuclear Security Campus, and Y-12 National Security Complex.

The W88 Alt 370 program replaced certain aspects of the weapons system and refreshed the conventional high explosives within the weapon to enhance nuclear safety and support future life extension program options.

PanTeXas Deterrence, LLC (PXD) is the management and operating contractor for the National Nuclear Security Administration’s Pantex Plant located in Carson County near Amarillo, Texas. Pantex maintains the safety, security, and effectiveness of the nation’s nuclear weapons stockpile. PXD is a joint venture led by a BWX Technologies, Inc. (BWXT) subsidiary – it also includes Fluor; SOC, A Day & Zimmermann Company; and The Texas A&M University System.

For more information on Pantex, visit www.pantex.energy.gov. Follow Pantex on Facebook, X, YouTube, Instagram, or LinkedIn.

CONTACT
Steve Myers
Communications
Office (806) 573.0490
Cell (806) 236.2826

Stephen.Myers@pantex.doe.gov