The National Nuclear Security Administration (NNSA) of the US Department of Energy announced a few days ago that the life extension program of the B61-12 nuclear gravity bombs was completed after 17 years.

The last upgraded nuclear warhead was delivered on December 18, 2024, about three years after the production line for modernised gravity nuclear weapons officially started. The NNSA reports that the total cost of the program is about $9 billion.

Technically, these are not new nuclear weapons, but essentially the US took the nuclear warheads from older versions of the B-61-type bombs, such as the B61-3, -4, -7, and -10, and incorporated them into new delivery vehicles with upgraded systems and software to be able to equip modern fighter jets and strategic bombers.

In fact, as part of the modernisation program, the US F-15E and F-16 aircraft, as well as the German Air Force Tornado, have been certified. The F-35A fifth-generation multi-role stealth fighters have also been certified.

On the other hand, the upgraded B61-12 nuclear bombs can be carried by the B-2 strategic bombers and, in the future, by the new generation B-21 bombers. 

Now, the US Agency can move forward with the development and manufacturing of the next-generation nuclear warhead type B61-13, which was announced in October 2023 and is designed to have a higher yield of 360 kilotons. 

The first nuclear warhead of this type is expected to be built in fiscal year 2026.

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