US 18,750-ton submarines' missiles to get modernized nuclear warheads

The National Nuclear Security Administration (NNSA) has completed the final production unit of the W88 Alteration 370 (Alt 370) program, a major modernization effort for the W88 nuclear warhead deployed on Ohio-class ballistic missile submarines. Originally introduced in 1988, the W88 remains a key component of the U.S. sea-based nuclear deterrent. The Alt 370 program addressed aging components identified through routine surveillance by replacing critical parts such as the arming, fuzing, and firing assemblies, adding safety features like a lightning arrestor connector, refreshing conventional high explosives, and updating wear-prone components. Full-rate production began in 2022, and the final unit was delivered roughly four years after the first production unit in 2021, reflecting coordinated efforts across multiple national laboratories and production sites. NNSA officials emphasized that completing the W88 Alt 370 demonstrates the agency’s ability to deliver modernized nuclear systems on schedule, reinforcing U.S. deterrence capabilities amid