W88 Alt 370 development flight test
Development flight test for the W88 Alt 370

Warhead modernization program ensures viability of nuclear deterrent and strengthens America’s security

W88 Alt 370 arming, fuzing, and firing assembly
W88 Alt 370 arming, fuzing, and firing assembly

WASHINGTON – The Department of Energy’s National Nuclear Security Administration (DOE/NNSA) successfully completed the system-level First Production Unit for the W88 Alteration (Alt) 370 at the Pantex Plant July 1, 2021.

The W88 Alt 370 is a major warhead acquisition program that ensures the future viability of the sea-launched ballistic missile strategic deterrent. This major milestone for DOE/NNSA, the Department of Defense (DoD), and the Nation was achieved one month ahead of schedule after more than 11 years of design, development, qualification, and component production.

 Shipping container for the W88 warhead
Shipping container for the W88 warhead

Dr. Charles Verdon, Acting NNSA Administrator, congratulated the program on this impressive achievement. “This accomplishment is the culmination of over a decade of work, featuring contributions from several sites within the NNSA Nuclear Security Enterprise, members of the NNSA federal workforce, and members of the DoD,” said Verdon. “The W88 Alt 370 is a crucial part of Nation’s strategy for the sea-based leg of the nuclear triad, and a testament to the Enterprise’s ability to execute major modernization programs. As we continue to modernize the stockpile, the successes and lessons learned from this program will bolster our future warhead activities to provide a safe, secure, and reliable deterrent.”

The W88/Mk5 strategic warhead entered the stockpile in 1988 and is deployed on the U.S. Navy’s Ohio-class ballistic missile submarines. In late 2009, a joint NNSA and DoD program to refurbish the W88/Mk5 strategic warhead was initiated to address aging issues and to maintain its state of readiness. The program required significant coordination between the NNSA, its Nuclear Security Enterprise, and the Navy Strategic Systems Programs Office and its contractors.