Operation Plumbbob

Operation Plumbbob was a series of 29 nuclear tests conducted by the US military between May 28 and October 7, 1957, at the Nevada Test Site. The operation had multiple objectives, including improving tactical weapon design, conducting bio-medical experiments, and understanding the effects of radiation on biological life.

Key Facts About Operation Plumbbob

– *Nuclear Tests*: The operation consisted of 29 explosions, with only two not producing any nuclear yield. The tests included tower shots, balloon-borne devices, and underground shaft detonations. Notably, the “Rainier” shot on September 19, 1957, was the first fully contained underground nuclear test, producing a 1.7-kiloton yield.
– *Bio-Medical Experiments*: Over 1,200 pigs were subjected to bio-medical experiments and blast-effects studies. Some pigs were placed in elevated cages with suits made of different materials to test protection from thermal radiation. During the “Priscilla” shot, 719 pigs were used in various experiments on Frenchman Flat, with many suffering third-degree burns to 80% of their bodies.
– *Troop Exercises*: Approximately 18,000 members of the US Air Force, Army, Navy, and Marines participated in exercises Desert Rock VII and VIII, which involved the largest troop maneuver associated with US nuclear testing. These exercises aimed to understand how average foot-soldiers would perform physically and psychologically under the rigors of a tactical nuclear battlefield.
– *Radiation Release*: The Plumbbob test series released approximately 58,300 kilocuries of radioiodine (I-131) into the atmosphere, producing total civilian radiation exposures amounting to 120 million person-rads of thyroid tissue exposure. The “Smoky” test, in particular, exposed over 3,000 servicemen to relatively high levels of radiation, resulting in significantly elevated rates of leukemia.

Notable Tests and Controversies

– *Smoky Test*: This test exposed over 3,000 servicemen to relatively high levels of radiation, resulting in significantly elevated rates of leukemia, as revealed by a survey of these servicemen in 1980.
– *Pascal-B Test*: A 900 kg steel plate cap was blasted off the top of a test shaft at an unknown speed, potentially reaching six times Earth’s escape velocity. The plate was never found, and scientists believe it may have vaporized due to atmospheric friction.
– *John Shot*: This test involved the only launch of the Air Force’s AIR-2 Genie missile with a nuclear warhead, fired from an F-89 Scorpion fighter over Yucca Flats. A group of five USAF officers volunteered to stand under the blast to demonstrate the weapon’s safety.

Legacy and Impact

Operation Plumbbob’s legacy is marked by controversy due to the significant radiation release and exposure of servicemen. While the project’s findings contributed to the development of warheads for intercontinental and intermediate-range missiles, air defense, and anti-submarine systems, the human cost and environmental impact of the operation remain a topic of discussion and concern.