Deliveries of the B61-12 nuclear bomb that eventually will be carried by the Air Force F-35A Joint Strike Fighter are underway, the National Nuclear Security Administration told sister publication Exchange Monitor.

The Nuclear Weapons Council authorized B61-12 Life Extension Program entry into Phase 6.6, which marks full rate production, in June 2022, an NNSA spokesperson said in an email. 

“NNSA is meeting its required B61-12 deliveries to the Department of Defense,” the NNSA said. The spokesperson referred questions about shipment quantities and F-35A aircraft certification to the Air Force.

The Air Force expects to certify the F-35 Joint Strike Fighter to carry nuclear weapons in January, once sufficient numbers of pilots and ground crew are trained to carry out the mission. But jets equipped with the proper avionics and mission systems needed to perform the nuclear mission won’t be ready until several months later

The B61-12, a homogenized version of four Cold War-era variants of the B61 – the oldest active weapon in the U.S. nuclear arsenal – will be built at the NNSA’s Pantex Plant in Amarillo, Texas. The agency plans to deliver the final B61-12 to the Air Force by fiscal year 2026, according to its fiscal year 2024 budget request.

The B61-12 program will extend the life of the bomb for another 20 years and replace all previous versions except the B61-11, which will remain in the stockpile. The NNSA is responsible for certifying the bomb itself before delivering them to the Air Force.