Sedan (nuclear test)

Last updated
Storax Sedan
Storax Sedan nuke.jpg
Storax Sedan explosion.
Information
CountryUnited States
Test series Operation Storax
Operation Plowshare
Test site Nevada Test Site
DateJuly 6, 1962
Test type Underground
Yield104 kt
Sedan Crater
Sedan Plowshare Crater.jpg
The Sedan crater
USA Nevada location map.svg
Red pog.svg
Location Area 10, Nevada Test Site
Nearest city Mercury, Nevada
Coordinates 37°10′37″N116°02′46″W / 37.17694°N 116.04611°W / 37.17694; -116.04611
NRHP reference No. 94000183
Added to NRHPMarch 21, 1994 [1]

Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on July 6, 1962, as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes. [2] The radioactive fallout from the test contaminated more US residents than any other nuclear test. The Sedan Crater is the largest human-made crater in the United States and is listed on the National Register of Historic Places.

Contents

Effects

Sedan was a thermonuclear device with a fission yield less than 30% and a fusion yield about 70%. [3] [4] According to Carey Sublette, the design of the Sedan device was similar to that used in the Bluestone and Swanee tests of Operation Dominic conducted days and months prior to Sedan respectively, and was therefore not unlike the W56 high yield Minuteman I missile warhead. [5] The device had a diameter of 43 cm (17 in), a length of 96.5 cm (38.0 in), and a weight of 212.2 kg (468 lb). [5]

The timing of the test put it within the Operation Storax fiscal year, but Sedan was functionally part of Operation Plowshare, and the test protocol was sponsored and conducted by Lawrence Livermore National Laboratory with minimal involvement by the United States Department of Defense. The explosive device was lowered into a shaft drilled into the desert alluvium 194 m (636 ft) deep. [4] The fusion-fission blast had a yield equivalent to 104 kilotons of TNT (435 terajoules) and lifted a dome of earth 90 m (300 ft) above the desert floor before it vented at three seconds after detonation, exploding upward and outward displacing more than 11,000,000 t (11,000,000 long tons; 12,000,000 short tons)[ failed verification ] of soil. [6] [3]

Sedan Crater

The resulting crater is 100 m (330 ft) deep with a diameter of about 390 m (1,280 ft). A circular area of the desert floor five miles across was obscured by fast-expanding dust clouds moving out horizontally from the base surge, akin to pyroclastic surge. [7] The blast caused seismic waves equivalent to an earthquake of 4.75 on the Richter scale. [2] The radiation level on the crater lip at 1 hour after the burst was 500 R per hour (130 mC/(kg·h)), [8] but it dropped to 500 mR per hour after 27 days. [8]

Within 7 months (~210 days) of the excavation, the bottom of the crater could be safely walked upon with no protective clothing, [9] with radiation levels at 35 mR per hour after 167 days. [8]

Over 10,000 people per year [10] visit the crater through free monthly tours offered by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office. [11] The crater was listed on the National Register of Historic Places on March 21, 1994. [12]

Russian thistle, also known as tumbleweed, is the primary plant species growing in the crater along with some grasses. Analysis in 1993 observed that the original perennial shrubs once living there had shown no recovery. [13]

Statistics

Observation decks at Sedan Crater Nevada Test Site - Sedan Crater - 10.jpg
Observation decks at Sedan Crater
  • Maximum depth [14] [15]  –320 feet (98 m)
  • Maximum diameter [14] [15]  –1,280 feet (390 m)
  • Volume [16] [15]  –6.6 million cubic yards (5.0×10^6 m3)
  • Weight of material lifted [14] [15]  –12 million short tons (11 Mt)
  • Maximum lip height [16] [15]  –100 feet (30 m)
  • Minimum lip height [16] [15]  –20 feet (6.1 m)
Nevada Test Site - Sedan Crater - 8.jpg
Panorama of the Crater with Russian thistle tumbleweed accumulating at the bottom.

Fallout

US counties that measured the highest levels of radioactive fallout from both Sedan and "Small Boy" of Operation Sunbeam, detonated eight days later. Units are millisieverts. Sedan-Smallboy dose.png
US counties that measured the highest levels of radioactive fallout from both Sedan and "Small Boy" of Operation Sunbeam, detonated eight days later. Units are millisieverts.
The ten highest radiation exposures to residents from US continental nuclear testing US nuclear test exposure.png
The ten highest radiation exposures to residents from US continental nuclear testing

The explosion caused two plumes of radioactive cloud, rising to 3.0 km and 4.9 km (10,000 ft and 16,000 ft). The plumes headed northeast and then east in roughly parallel paths towards the Atlantic Ocean.[ citation needed ] Nuclear fallout was dropped through several counties. [4] Detected radioactivity was especially high in eight counties in Iowa and one county each in Nebraska, South Dakota and Illinois. The most heavily affected counties were Howard, Mitchell and Worth counties in Iowa as well as Washabaugh County in South Dakota. These four counties measured maximum levels higher than 6,000 microcuries per square meter (220 MBq/m2). [17] The explosion created fallout that affected more US residents than any other nuclear test, exposing more than 13 million people to radiation. [18]

Of all the nuclear tests conducted in the United States, Sedan ranked highest in overall activity of radionuclides in fallout. The test released 880,000 curies (33 PBq) of radioactive iodine-131, an agent of thyroid disease, into the atmosphere. [19] Sedan ranked first in percentages of these particular radionuclides detected in fallout: 198Au, 199Au, 7Be, 99Mo, 147Nd, 203Pb, 181W, 185W and 188W. Sedan ranked second in these radionuclides in fallout: 57Co, 60Co and 54Mn. Sedan ranked third in the detected amount of 24Na in fallout. In countrywide deposition of radionuclides, Sedan was highest in the amount of 7Be, 54Mn, 106Ru and 242Cm, and second highest in the amount of deposited 127mTe. [17] While Sedan ranks highest in percentages of 198Au detected, it is not the most prolific generator or gold-heavy design that was tested by the US: due to the explosion being far more well contained, a larger quantity of gold, referred to as "a goldmine", was used extensively in the W71 warhead, [20] that was proof-tested in 1971 within a deep borehole in the Amchitka islands off Alaska.

Sedan's fallout contamination contributed a little under 7% to the total amount of radiation which fell on the US population during all of the nuclear tests at NTS. Sedan's effects were similar to shot "George" of Operation Tumbler–Snapper, detonated on June 1, 1952, which also contributed about 7% to the total radioactive fallout. Uncertainty regarding exact amounts of exposure prevents knowing which of the two nuclear tests caused the most; George is listed as being the highest exposure and Sedan second highest by the United States Department of Health and Human Services, Centers for Disease Control and Prevention, and the National Cancer Institute. [21] [22]

Had this test been conducted after 1965 when improvements in device design were realized, achieving a 100-fold reduction in radiation release is considered feasible. [23]

Conclusions

The Plowshare project developed the Sedan test in order to determine the feasibility of using nuclear detonations to quickly and economically excavate large amounts of earth and rock. Proposed applications included the creation of harbors, canals, open pit mines, railroad and highway cuts through mountainous terrain and the construction of dams. Assessment of the full effects of the Sedan shot showed that the radioactive fallout from such uses would be extensive. Public concerns about the health effects and a lack of political support eventually led to abandonment of the concept. [24] No such nuclear excavation has since been undertaken by the United States, [25] though the Soviet Union continued to pursue the concept through their program Nuclear Explosions for the National Economy, particularly with their 140 kiloton Chagan (nuclear test), which created an artificial lake reservoir (see Lake Chagan).

Diplomatic issue with Sudan

On March 2, 2005, Ellen Tauscher, a Democratic member of the U.S. House of Representatives from California, used Sedan as an example of a test which produced a considerable amount of radioactive fallout while giving congressional testimony on the containment of debris from nuclear testing. However, the name "Sedan" was incorrectly transcribed as "Sudan" in the Congressional Record .

Within days of the error, the international community took notice. Sudanese officials responded by stating that "the Sudanese government takes this issue seriously and with extreme importance". The Chinese Xinhua General News Service published an article claiming that the Sudanese government blamed the U.S. for raising cancer rates among the Sudanese people. [26] Despite the U.S. embassy in Khartoum issuing a statement clarifying that it was a typographic error, Mustafa Osman Ismail, the Sudanese Foreign Minister, stated his government would continue investigating the claims. [27]

See also

Related Research Articles

A cobalt bomb is a type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material, potentially for the purpose of radiological warfare, mutual assured destruction or as doomsday devices.

<span class="mw-page-title-main">Nevada Test Site</span> US Department of Energy reservation in Nevada

The Nevada National Security Sites, popularized as the Nevada Test Site (NTS) until 2010, is a reservation of the Department of Energy of the federal Government of the United States located in the southeastern portion of the Nye County in Nevada, about 65 mi (105 km) northwest of the city of Las Vegas.

<span class="mw-page-title-main">Project Plowshare</span> U.S. program examining the peaceful applications of nuclear explosives (1961–77)

Project Plowshare was the overall United States program for the development of techniques to use nuclear explosives for peaceful construction purposes. The program was organized in June 1957 as part of the worldwide Atoms for Peace efforts. As part of the program, 35 nuclear warheads were detonated in 27 separate tests. A similar program was carried out in the Soviet Union under the name Nuclear Explosions for the National Economy.

<span class="mw-page-title-main">Operation Nougat</span> Series of 1960s US nuclear tests

Operation Nougat was a series of 44 nuclear tests conducted at the Nevada Test Site in 1961 and 1962, immediately after the Soviet Union abrogated a testing moratorium, with the US' Mink test shot taking place the day before the Soviets test-detonated the Tsar Bomba. Most tests were limited-yield underground test shots. New designs would be further developed in atmospheric testing during Operation Dominic I and II.

<span class="mw-page-title-main">Operation Storax</span> Series of 1960s US nuclear tests

Operation Storax was a series of 47 nuclear tests conducted by the United States in 1962–1963 at the Nevada Test Site. These tests followed the Operation Fishbowl series and preceded the Operation Roller Coaster series.

<span class="mw-page-title-main">Nuclear weapons testing</span> Controlled detonation of nuclear weapons for scientific or political purposes

Nuclear weapons tests are experiments carried out to determine the performance, yield, and effects of nuclear weapons. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.

<span class="mw-page-title-main">Project Chariot</span> Proposal to construct an artificial harbor at Cape Thompson, Alaska using nuclear devices

Project Chariot was a 1958 United States Atomic Energy Commission proposal to construct an artificial harbor at Cape Thompson on the North Slope of the U.S. state of Alaska by burying and detonating a string of nuclear devices.

<span class="mw-page-title-main">Semipalatinsk Test Site</span> Nuclear test site for the Soviet Union in northeast Kazakhstan

The Semipalatinsk Test Site, also known as "The Polygon", was the primary testing venue for the Soviet Union's nuclear weapons. It is located on the steppe in northeast Kazakhstan, south of the valley of the Irtysh River. The scientific buildings for the test site were located around 150 km (93 mi) west of the town of Semipalatinsk, later renamed Semey, near the border of East Kazakhstan Region and Pavlodar Region. Most of the nuclear tests taking place at various sites further to the west and the south, some as far as into Karagandy Region.

<span class="mw-page-title-main">Chagan (nuclear test)</span> 1965 Soviet underground nuclear test

Chagan (Чага́н) was a Soviet underground nuclear test conducted at the Semipalatinsk Test Site on January 15, 1965.

<span class="mw-page-title-main">Subsidence crater</span> Hole or depression left on the surface over the site of an underground explosion

A subsidence crater is a hole or depression left on the surface of an area which has had an underground explosion. Many such craters are commonly present at bomb testing areas; one notable example is the Nevada Test Site, which was historically used for nuclear weapons testing over a period of 41 years.

<span class="mw-page-title-main">Lake Chagan</span> Man-made lake in Kazakhstan created by a 1965 nuclear test

Lake Chagan or Lake Shagan, also known as Lake Balapan, is a lake in Kazakhstan created by the Chagan nuclear test on January 15, 1965, which was conducted as part of the Soviet Union's Nuclear Explosions for the National Economy program. A 140 kiloton device was placed in a 178-metre-deep (584 ft) hole in the dry bed at the confluence of the Shagan and Ashchysu rivers. The blast created a crater 400 m (1,300 ft) across and 100 m (330 ft) deep with a lip height of 20 to 38 m ; it is often referred to as "Atomic Lake". The water continues to be radioactive – about 100 times more than the permitted level of radionuclides in the water.

Downwinders were individuals and communities in the intermountain between the Cascade and Rocky Mountain ranges primarily in Arizona, Nevada, New Mexico and Utah but also in Oregon, Washington, and Idaho who were exposed to radioactive contamination or nuclear fallout from atmospheric or underground nuclear weapons testing, and nuclear accidents.

Peaceful nuclear explosions (PNEs) are nuclear explosions conducted for non-military purposes. Proposed uses include excavation for the building of canals and harbours, electrical generation, the use of nuclear explosions to drive spacecraft, and as a form of wide-area fracking. PNEs were an area of some research from the late 1950s into the 1980s, primarily in the United States and Soviet Union.

Nuclear Explosions for the National Economy was a Soviet program to investigate peaceful nuclear explosions (PNEs). It was analogous to the United States program Operation Plowshare.

<span class="mw-page-title-main">Underground nuclear weapons testing</span> Test detonation of nuclear weapons underground

Underground nuclear testing is the test detonation of nuclear weapons that is performed underground. When the device being tested is buried at sufficient depth, the nuclear explosion may be contained, with no release of radioactive materials to the atmosphere.

<span class="mw-page-title-main">Project Gnome (nuclear test)</span> 1961 nuclear test explosion in New Mexico, United States

Project Gnome was the first nuclear test of Project Plowshare and was the first continental nuclear weapon test since Trinity to be conducted outside of the Nevada Test Site, and the second test in the state of New Mexico after Trinity. It was tested in southeastern New Mexico on December 10, 1961, approximately 40 km southeast of Carlsbad, New Mexico.

<span class="mw-page-title-main">Pahute Mesa</span>

Pahute Mesa or Paiute Mesa is one of four major nuclear test regions within the Nevada National Security Site (NNSS). It occupies 243 square miles (630 km2) in the northwest corner of the NNSS in Nevada. The eastern section is known as Area 19 and the western section as Area 20.

The Pechora–Kama Canal, or sometimes the Kama–Pechora Canal, was a proposed canal intended to link the basin of the Pechora River in the north of European Russia with the basin of the Kama, a tributary of the Volga. Completion of this project would integrate the Pechora into the system of waterways of European Russia, centered on the Volga – something that was of importance before the advent of railways, or before the first railway reached the Pechora in the 1940s. Later the project was proposed mostly to transfer Pechora's water to the Volga and further on to the Caspian Sea.

Operation Roller Coaster was a series of four nuclear tests conducted jointly by the United States and the United Kingdom in 1963, at the Nevada Test Site. The tests did not involve the detonation of any nuclear weapons. Instead, their purpose was to evaluate the distribution of radioactive particles in a "dirty bomb" scenario, or an inadvertent, non-nuclear detonation of a nuclear weapon, as well as to evaluate the effectiveness of storage structures in containing the explosion and the particles released. The tests followed the Operation Storax series and preceded the Operation Niblick series.

<span class="mw-page-title-main">Yucca Flat</span> Nuclear test region in Nevada

Yucca Flat is a closed desert drainage basin, one of four major nuclear test regions within the Nevada Test Site (NTS), and is divided into nine test sections: Areas 1 through 4 and 6 through 10. Yucca Flat is located at the eastern edge of NTS, about ten miles (16 km) north of Frenchman Flat, and 65 miles (105 km) from Las Vegas, Nevada. Yucca Flat was the site for 739 nuclear tests – nearly four of every five tests carried out at the NTS.

References

  1. ↑ Furlow, Robert C. (October 5, 1993). "Sedan Crater". National Register of Historic Places Registration Form. National Park Service. Retrieved 2009-05-25.
  2. 1 2 "NTS 50th Anniversary Newsletter – Sedan Tested Use of Nuclear Explosives to Move Earth". US Department of Energy Nevada Site Office. Archived from the original on 1 October 2011. Retrieved 25 September 2011.
  3. 1 2 Information sign at the crater: Nevada Test Site - Sedan Crater - 4.JPG
  4. 1 2 3 United States Nuclear Tests; July 1945 through September 1992, DOE/NV--209-REV 15 December 2000, p. xv. "Archived copy" (PDF). Archived from the original (PDF) on 2006-10-12. Retrieved 2013-12-18.{{cite web}}: CS1 maint: archived copy as title (link)
  5. 1 2 "Operation Storax". nuclearweaponarchive.org. Archived from the original on 17 May 2008. Retrieved 4 August 2017.
  6. ↑ "Operation Storax, Sun Beam, and Roller Coaster". Nuclear Weapons Archive. 20 September 1997. Archived from the original on 17 May 2008. Retrieved 2008-07-14.
  7. ↑ Nevada Test Site Office. Library. Films. Historical Test Films Archived 2008-07-21 at the Wayback Machine
  8. 1 2 3 Information sign at the crater: Nevada Test Site - Sedan Crater - 1.JPG
  9. ↑ "Possibilities for peaceful nuclear explosions. An IAEA review of the 1968 book: The constructive uses of nuclear explosions by Edward Teller" (PDF). Archived from the original (PDF) on 2015-03-20.
  10. ↑ Nevada Test Site History. Sedan Crater Archived November 12, 2008, at the Wayback Machine
  11. ↑ "Nevada Test Site Tours". US Department of Energy. Archived from the original on February 19, 2015. Retrieved January 27, 2015.
  12. ↑ "Photos – Underground Nuclear Testing – Nevada Test Site". Nevada Division of Environmental Protection. Archived from the original on November 16, 2008. Retrieved November 29, 2010.
  13. ↑ Sedan Crater at Nevada Online
  14. 1 2 3 Nevada Test Site History. Sedan Crater Archived November 12, 2008, at the Wayback Machine
  15. 1 2 3 4 5 6 Information sign at the crater: Nevada Test Site - Sedan Crater - 4.JPG
  16. 1 2 3 Project Sedan, On-Site Radiological Safety Report
  17. 1 2 Miller, Richard L. (2002). U.S. Atlas of Nuclear Fallout, 1951–1970. Vol. 1 (Abridged General Reader ed.). Two Sixty Press. p. 340. ISBN   1-881043-13-4 . Retrieved 2008-07-19.
  18. ↑ All Around Nevada – Sedan Crater
  19. ↑ "National Cancer Institute. National Institute of Health. History of the Nevada Test Site and Nuclear Testing Background" (PDF). Archived from the original (PDF) on 2010-12-21. Retrieved 2008-07-22.
  20. ↑ Schwartz, Stephen (2011). Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940. Brookings Institution. p. 332. ISBN   9780815722946.
  21. ↑ "Report on the Feasibility of a Study of the Health Consequences to the American Population from Nuclear Weapons Tests Conducted by the United States and Other Nations, Vol 1. Technical Report" (PDF). Department of Health and Human Services, Centers for Disease Control and Prevention, and the National Cancer Institute. May 2005. Retrieved 4 August 2017.
  22. ↑ "Appendix E, 'External Dose Estimates from NTS Fallout' – Radioactive Decay – Gamma Ray". Scribd. Retrieved 4 August 2017.
  23. ↑ talkingsticktv (7 November 2007). "Declassified U.S. Nuclear Test Film #35". Archived from the original on 2021-12-12. Retrieved 4 August 2017– via YouTube.
  24. ↑ Center for Digital Discourse and Culture, Virginia Tech. U.S. Nuclear Testing from Project Trinity to the Plowshare Program Abby A. Johnson. (1986) Archived 2008-12-06 at the Wayback Machine
  25. ↑ Nevada Test Site Office. Library. Factsheets. Plowshare Program Archived 2008-10-31 at the Wayback Machine
  26. ↑ "Roundup of 2005 news articles and congressional testimony related to the Sedan/Sudan mixup". Federation of American Scientists. March 2005. Retrieved 2008-07-14.
  27. ↑ "Typing error causes nuclear scare". BBC. 11 March 2005. Retrieved 2008-07-14.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.