Operation Plumbbob
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Operation Plumbbob, conducted between May 28 and October 7, 1957, represented the biggest, longest, and most controversial nuclear test series in the history of the Nevada Test Site (NTS). The operation was the sixth test series and consisted of 29 detonations, of which two did not produce any nuclear yield. 21 laboratories and government agencies were involved. While most Operation Plumbbob tests contributed to the development of warheads for intercontinental and intermediate range missiles, they also tested air defense and anti-submarine warheads with small yields. They included 43 military effects tests on civil and military structures, radiation and bio-medical studies, and aircraft structural tests. Operation Plumbbob had the tallest tower tests to date in the U.S. nuclear testing program, as well as high-altitude balloon tests. One nuclear test involved the largest troop maneuver ever associated with U.S. nuclear testing.
Approximately 18,000 members of the U.S. armed forces participated in exercises Desert Rock VII and VIII during Operation Plumbbob. The military was interested in knowing how the average foot-soldier would stand up, physically and psychologically, to the rigors of the tactical nuclear battlefield.
Studies were conducted of radiation contamination and fallout from a simulated accidental detonation of a weapon; and projects concerning earth motion, blast loading and neutron output were carried out.
Nuclear weapons safety experiments were conducted to study the possibility of a nuclear weapon detonation during an accident. On July 26, 1957, a safety experiment, "Pascal-A" was detonated in an unstemmed hole at NTS, becoming the first underground shaft nuclear test. The knowledge gained here would provide data to prevent nuclear yields in case of accidential detonations, for example a plane crash.
The first detonation contained underground, "Rainier", was conducted on September 19, 1957, containing all radioactive products underground, thus producing no fallout. This test of 1.7 kilotons could be detected around the world by seismologists using ordinary seismic instruments. The Rainier test became the prototype for larger and more powerful underground tests. The test also subjected toughened weapons to the fireball underground.
Plumbbob released 58,300 kilocuries (2.16 EBq) of radioiodine (I-131) into the atmosphere. This produced total civilian radiation exposures amounting to 120 million person-rads of thyroid tissue exposure (about 32% of all exposure due to continental nuclear tests). This can be expected to eventually cause or have caused about 38,000 cases of thyroid cancer, leading to some 1900 deaths. [citation needed] In addition, troop exercises conducted near the ground near shot "Smoky" exposed over three thousand servicemen to relatively high levels of radiation.
Note: A study in 1980 found significantly elevated rates of leukemia among the soldiers surveyed (ten cases were found, instead of the baseline expected four).
The tests comprising the 1957 Operation Plumbbob were as follows in TNT equivalent:
- BOLTZMAN, 28 May, tower, weapons related, 12 kilotons (kt)
- FRANKLIN, 2 June, tower, weapons related, 140 tons
- LASSEN, 5 June, balloon, weapons related, 0.5 kt
- WILSON, 18 June, balloon, weapons related, 10 kt
- PRISCILLA, 24 June, balloon, weapons related, 37 kt
- COULOMB-A, 1 July, surface, safety experiment, zero yield
- HOOD, 5 July, balloon, weapons related, 74 kt
- DIABLO, 15 July, tower, weapons related, 17 kt
- JOHN, 19 July, rocket, weapons effects, about 2 kt (live firing of AIR-2 Genie)
- KEPLER, 24 July, tower, weapons related, 10 kt
- OWENS, 25 July, balloon, weapons related, 9.7 kt
- PASCAL-A, 26 July, shaft, safety experiment, slight yield
- STOKES, 7 August, balloon, weapons related, 19 kt
- SATURN, 10 August, tunnel, safety experiment, zero yield
- SHASTA, 18 August, tower, weapons related, 17 kt
- DOPPLER, 23 August, balloon, weapons related, 11 kt
- PASCAL-B, 27 August, shaft, safety experiment, slight yield
- FRANKLIN PRIME, 30 August, balloon, weapons related, 4.7 kilotons
- SMOKY, 31 August, tower, weapons related, 44 kt
- GALILEO, 2 September, tower, weapons related, 11 kt
- WHEELER, 6 September, balloon, weapons related, 197 tons
- COULOMB-B, 6 September, surface, safety experiment, 300 tons
- LAPLACE, 8 September, balloon, weapons related, 1 kt
- FIZEAU, 14 September, tower, weapons related, 11 kt
- NEWTON, 16 September, balloon, weapons related, 12 kt
- RAINIER, 19 September, tunnel, weapons related, 1.7 kt
- WHITNEY, 23 September, tower, weapons related, 19 kt
- CHARLESTON, 28 September, balloon, weapons related, 12 kt
- MORGAN, 7 October, balloon, weapons related, 8 kt
The Air Force, Army, Navy and Marines continued the Desert Rock exercises, number VII and VIII with 13,300 personnel.
[edit] The true first man-made object in space?
According to urban legend, a manhole cover was accidentally launched from its shaft during an underground nuclear test in the 1950s, at great enough speed to leave the solar system. The myth is based on a real incident during the Pascal-B test, where a heavy (900 kg) steel plate cap was blasted off the test shaft at tremendous velocity, never to be seen again, although it is doubtful that it left the atmosphere. It is believed to have been vaporised by atmospheric effects, due to the extreme velocity.
This incident has been used as technical justification for the Orion project.
[edit] References
- Department of Energy of Nevada Original source for test information
- Plumbbob page on the Nuclear Weapons Archive.
- National Cancer Institute Study Estimating Thyroid Doses of I-131 Received by Americans From Nevada Atmospheric Nuclear Bomb Test, 1997
