The Y-12 National Security Complex in Oak Ridge is part of a program to extend the life of B61 bombs, the oldest nuclear weapons in the nation’s active stockpile, federal officials said.

The life extension program, or LEP, for the B61 bombs is the most complex and expensive since the U.S. Department of Energy began stockpile life extension activities in January 1996, according to the U.S. Government Accountability Office.

Critical components of the bombs are reaching the end of their operational lives, and the life extension program will result in a bomb known as B61-12. It will consolidate four versions of the bomb into one. The bombs could be carried on B-2A bomber aircraft and F-15E, F-16, F-35, and PA-200 fighters.

A GAO report described the role of six National Nuclear Security Administration sites and laboratories in the LEP. Besides Y-12, the NNSA sites are Kansas City National Security Campus in Missouri; Los Alamos National Laboratory in New Mexico; Pantex Plant in Amarillo, Texas; Sandia National Laboratories in Albuquerque, New Mexico; and Savannah River Site in Aiken, South Carolina.

Y-12 is designated as the production site for the secondary. All weapons in the U.S. nuclear stockpile are two-stage nuclear weapons, or thermonuclear weapons. The first stage, known as the primary, is a fission device that is the initial source of nuclear energy, the GAO said. The secondary, which is the second stage, is a nuclear stage physically separate from the primary. Together, the primary and secondary are referred to as the weapon’s nuclear explosive package, the GAO said. [Read more…]