B61-12 bomb reaches major milestone

Los Alamos National Laboratory played a critical role in delivery of first production unit

December 20, 2021

F 35 B61 12
If the B61-12 is ever used, it will be ballistically air delivered in either gravity or guided drop modes. It is being certified for delivery by current strategic and dual-capable aircraft, as well as future aircraft platforms. Here, a U.S. Air Force F-35 Lightning performs a drop test of a B61-12. Credit: DOD's F-35 Joint Program Office

Los Alamos, N.M., Dec. 20, 2021—A major milestone has been achieved with the recent delivery of the first production unit (FPU) of the B61-12, meaning the refurbished bomb is on track for full-scale production in May 2022. The first production unit was built at the Pantex Plant, near Amarillo, Texas. 

The bomb has been undergoing a life extension program for more than nine years. Los Alamos and Sandia National Laboratories are the design agencies for the project, with Los Alamos also being responsible for producing detonators and other classified components.

“The first production unit milestone is the culmination of years of effort across a team that spanned many technical disciplines throughout the Laboratory,” said Bob Webster, deputy director for Weapons at Los Alamos National Laboratory. “’I’m very proud of the exceptional commitment of all involved to reach this point.”

The B61 nuclear gravity bomb, deployed to U.S. Air Force and North Atlantic Treaty Organization bases, has nearly 50 years of service, making it the oldest and most versatile weapon in the enduring U.S. stockpile. Numerous modifications have been made to the B61 since it first entered service in 1968, and four B61 variants remain in the stockpile: the B61-3, -4, -7 and -11.

For the past nine years, the aging weapon system has been undergoing a life extension that consolidates and replaces three current B61 weapon designs (the B61-3, -4, and -7) into one updated design: the B61-12.

In the FPU phase of the nuclear weapons life cycle, all weapons components have been produced through qualified processes; all the necessary qualification testing, engineering analysis and physics certification activities have been completed. In other words, all the processes required to produce the weapon are qualified and exercised.

The life extension program (LEP) refurbishes, reuses, or replaces all of the bomb’s nuclear and nonnuclear components, extending the bomb’s service life by at least 20 years. The LEP addresses all of the bomb’s age-related issues and enhances its reliability, ease of field maintenance, safety and use control.

When fielded, the B61-12 will balance greater accuracy, provided by the modern tail kit, with a substantial reduction in yield, but there will be no overall change in military requirements or capability.

B16 Test
An ultra-high frame-rate x-ray images shows a shock wave move through a test detonation of 9502 high explosives as part of the B61-12 LEP.

About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is managed by Triad, a public service oriented, national security science organization equally owned by its three founding members: Battelle Memorial Institute (Battelle), the Texas A&M University System (TAMUS), and the Regents of the University of California (UC) for the Department of Energy’s National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.