- NNSA has delivered the first production unit of the Mk4B advanced reentry body for the W76 nuclear warhead ahead of schedule
- The Mk4B is designed to protect submarine-launched ballistic missile warheads during atmospheric reentry
- The W76 warhead supports the sea-based leg of the U.S. nuclear triad
The Department of Energy’s National Nuclear Security Administration has manufactured its first production unit of the Mark 4B, or Mk4B, advanced reentry body for the W76 nuclear warhead three months ahead of schedule.
Developed in partnership with the U.S. Navy, the Mk4B is designed to protect the W76 as the submarine-launched ballistic missile warhead reenters the Earth’s atmosphere, DOE said Wednesday.
“NNSA is making good on our commitment to accelerate production for the nation’s nuclear deterrent and delivering the first W76/Mk4B to the Navy ahead of schedule,” NNSA Administrator Brandon Williams stated.
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How Did NNSA Complete the First Mk4B Production Unit Ahead of Schedule?
NNSA attributed the early completion of the Mk4B’s first production unit to the collective contributions of the nuclear security enterprise.
According to the agency, the Pantex Plant leveraged a previous readiness determination for the W76-1 program to support the Mk4B production. The Kansas City National Security Campus completed key non-nuclear components in an accelerated timeline.
Sandia National Laboratories and Los Alamos National Laboratory also supported the accelerated timeline by issuing qualification evaluation releases.
Kelly Beierschmitt, president and general manager of Pantex, said the effort involved adding new components to improve the existing weapon system, Amarillo Tribune reported. He added that it provided the Navy with greater insight into the mounted warhead.
How Does the W76 Support US Nuclear Deterrence?
According to Pantex, the W76 accounts for the largest share of the U.S. nuclear inventory. It also serves as a key component of the Navy’s Trident II D5 missile system, which is intended to deliver nuclear warheads over intercontinental distances, Interesting Engineering reported. The Trident II D5 missile system will be deployed aboard the Ohio-class and Columbia-class submarines.
The W76 and the Trident II D5 missile system support the sea-based leg of the U.S. nuclear triad.
“As a former nuclear submarine officer, I have a special appreciation for the sea leg of our triad, which is essential to our assured second-strike capability,” Williams commented. “Enhancing the reliability of the W76’s reentry body will help ensure the reliability of the deterrent and strengthen America’s national security more broadly.”
In December, NNSA announced the completion of the last production unit of the W88 Alteration 370, marking the conclusion of a multi-year modernization effort for the nuclear warhead as part of the sea leg of the triad. The W88 is also designed to be deployed on Ohio-class submarines.
