The U.S. Nuclear Weapons Cost Study Project was completed in August 1998 and resulted in the book Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940 edited by Stephen I. Schwartz. These project pages should be considered historical.
Three views of a B61 gravity bomb: assembled (background), disassembled into its major subcomponents (middle), and a display of some of the weapon’s 5,919 parts (foreground). The warhead fits inside the blunt-nosed silver canister sitting on the white cloth in front of the partially disassembled bomb.
The B61 is a tactical thermonuclear gravity bomb which can be carried aboard a variety of strategic and tactical aircraft (including the B-52 and B-2A bombers and the F-16 fighter). First deployed in 1968, an estimated 3,000 weapons in nine different versions (designed by Los Alamos National Laboratory) were ultimately built, with yields ranging from 0.3-300 kilotons. Seven of these versions remain operational, including the B61-11, deployed in 1997.
Credit: Department of Energy (courtesy Natural Resources Defense Council)