W79 Artillery-Fired Atomic Projectile (AFAP)

A strong continuing interest in improved designs for tactical systems culminated in Livermore's work on the W79 Artillery-Fired Atomic Projectile (AFAP) enhanced- radiation artillery shell in the 1970s. The W79 nuclear warhead design for the Army's 8-inch artillery gun was assigned to the Lab in 1975. The design included an "enhanced radiation" option. The W79 development program led to deployment in 1981. Nuclear artillery shells were part of the US arsenal from the mid-1950s until 1992. Disassembly of the W79 Artillery-Fired Atomic Projectile was completed in FY 2003.

In January 1975, Livermore was assigned the task of developing a new nuclear artillery shell warhead, the W79, for the Army's 8- inch howitzers. Nuclear artillery shells were part of the U. S. arsenal from the mid- 1950s until 1992. They were deployed for both Army and Navy systems and provided a highly accurate, short-range (typically about 10 miles), all-weather capability using delivery systems already deployed with conventional shells.

The W79 and the W70-3 were to be the first battlefield nuclear weapons to include an "enhanced radiation" (ER) capability. ER provided a relatively high fraction of the prompt weapon output in the form of neutrons (hence the nickname "neutron bomb"). ER technology began to be developed at Livermore in the early 1960s and entered the stockpile in 1974 with the deployment of the W66 warhead for the Sprint antiballistic missile interceptor.

ER weapons were also developed for NATO forces. They were far more effective than previously deployed battlefield nuclear weapons for blunting a Soviet armored invasion of Western Europe and hence strengthened deterrence. A lethal radiation dose to enemy troops- likely protected in armored vehicles- could be achieved with the much smaller yield of an ER weapon than with a standard nuclear weapon. ER weapons could be employed to strike enemy units much closer to urban areas while avoiding collateral damage to towns and civilians.

By the time the W70-3 and the W79 were part of NATO forces, they had become the center of an international controversy. A principal concern expressed by opponents was that by virtue of the lower yield and greater utility of ER weapons, their deployment would serve to lower the threshold for nuclear war. This controversy led to a 1985 Congressional order that future W79s be built without the ER capability, and existing units were modified to remove this capability.

Short-range nuclear forces provided visible evidence of NATO's commitment to a forward defense of its territory. In the event of a Warsaw Pact attack, the possibility of these weapons' use would inhibit the Pact from massing its ground forces to break through NATO's conventional defenses. If conventional defenses proved inadequate to stem the aggression, short-range nuclear forces could aid in maintaining a cohesive forward defense. Their widespread deployment enhanced their survivability and contributed materially to the overall effectiveness of NATO's forces.

Modernization programs for the short-range forces center on the replacement of a significant portion of the 30-year-old W33 (8-inch) and 23-year-old W48 (155mm) nuclear artillery projectiles by the early 1990s. The W33 will be replaced by the W79, and the W48 by the W82. These extended-range projectiles -- enhanced for safety, security, and reliability -- would significantly improve short-range nuclear forces. DoD was also evaluating product improvements to ensure the safety and reiiability of those W48s and W33s that would remain in the inventory.

The FY 1987 budget continued development of the W82. All DoD funds required for the W79 program had already been appropriated. Consistent with congressional direction, all W82s, and those W79 rounds produced from FY 1985 on, will not be of the enhanced radiation type.

Eventually, all US battlefield nuclear weapons were retired in accordance with President Bush's September 1991 address to the nation.

The W79 was scheduled for dismantlement. Before beginning the dismantlement process, numerous activities were completed. As final reviewers, the Nuclear Explosives Safety Study review (DOE) and the Safety Evaluation review (Sandia, Lawrence Livermore, and DOE) determined that the process could proceed. The Pilot Lot for the W79 dismantlement program began in mid-1998 with the first dismantlement unit completed the first week of June 1998. The remaining Pilot Lot units were completed by the end of September 1998.