Upshot–Knothole Harry (UK#9) was a

nuclear weapons test Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by ...

conducted by the United States as part of

Operation Upshot–Knothole Operation Upshot–Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site. It followed ''Operation Ivy'' and preceded ''Operation Castle''. Over 21,000 soldiers took part in the ground exercise Desert Roc ...

. It took place at the recorded time of 04:05 (05:05 hrs ) hours, on the May the 19th, 1953 in

Yucca Flat 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, ...

, in the

Nevada Test Site The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of th ...

. The sponsor of the test was the National Laboratory of the United States of America located at Los Alamos.

Device

The test device, codenamed ''Hamlet'', was detonated atop a tower, the device produced a yield of 32 kilotonnes. The device had a diameter of 56

inches Measuring tape with inches The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelfth"), ...

and a length of 66 inches. Its weight was 4

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

s. The device was designed by Ted Taylor at the Los Alamos National Laboratory of the United States of America, and is distinguished from all others because it was the most efficient pure fission design with a yield below 100 kt ever tested. The design utilized a new hollow core concept. The concept was termed as "radical implosion system" aiming towards reducing the amount of fissionable materials present in the weapon's core while generating moderately high yield.

Detonation

The device was detonated in Area 3 of the test site.

Deposition

Of the 11 Upshot–Knothole tests, the so-called Harry test deposited the 3rd highest amount of

Caesium-137 Caesium-137 (), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nucl ...

Niobium-95 Naturally occurring niobium (41Nb) is composed of one stable isotope (93Nb). The most stable radioisotope is 92Nb with a half-life of 34.7 million years. The next longest-lived niobium isotopes are 94Nb (half-life: 20,300 years) and 91Nb with a ...

Strontium-90 Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and i ...

, Zirconium-95, the fourth highest deposit for Niobium-95m, Praseodymium-144, fifth for Uranium-240,

Ruthenium-106 Naturally occurring ruthenium (44Ru) is composed of seven stable isotopes. Additionally, 27 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are 106Ru, with a half-life of 373.59 days; 103Ru, with a half-life of 3 ...

, sixth for

Iodine-131 Iodine-131 (131I, I-131) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nuc ...

, Tellurium-127m, eighth for deposition of

Cobalt-60 Cobalt-60 (60Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2713 years. It is produced artificially in nuclear reactors. Deliberate industrial production depends on neutron activation of bulk samples of the monoisoto ...

, tenth for deposition of Europium-155, thirteenth for

Strontium-89 Strontium-89 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 50.57 days. It undergoes β− decay into yttrium-89. Strontium-89 has an application in medicine. History It was used for the first time b ...

Yttrium-90 Yttrium-90 () is an isotope of yttrium. Yttrium-90 has found a wide range of uses in radiation therapy to treat some forms of cancer. Decay undergoes β− decay to zirconium-90 with a half-life of 64.1 hours and a decay energy of 2.28 ...

, and sixteenth for Beryllium-7, (the source lists Sr-90 twice, at 3rd and thirteenth, thirteenth was omitted here). The deposition pattern was most similar to test name CLIMAX. Monitoring personnel including United States of America Atomic Energy Commission personnel monitored the resultant

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...

in areas including

St.George Saint George (Greek: Γεώργιος (Geórgios), Latin: Georgius, Arabic: القديس جرجس; died 23 April 303), also George of Lydda, was a Christian who is venerated as a saint in Christianity. According to tradition he was a soldier ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

. Fallout from the test fell on 3046 counties of the United States. Due to a miscalculation and change in wind-direction, this Upshot–Knothole test released an unusually large amount of fallout (the highest of any test in the continental U.S.), much of which later accumulated in the vicinity of St. George, Utah. Because of this, the shot would become known as "Dirty Harry" in the press when details were released publicly. It would be among the most controversial of the U.S.

nuclear weapon tests Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected b ...

. Two years after the blast,

Howard Hughes Howard Robard Hughes Jr. (December 24, 1905 – April 5, 1976) was an American business magnate, record-setting pilot, engineer, film producer, and philanthropist, known during his lifetime as one of the most influential and richest people in th ...

filmed the motion picture '' The Conqueror'' near St. George. The cast and crew totaled 220 people. By the end of 1980, as ascertained by

People magazine ''People'' is an American weekly magazine that specializes in celebrity news and human-interest stories. It is published by Dotdash Meredith, a subsidiary of IAC (company), IAC. With a readership of 46.6 million adults in 2009, ''People ...

, 91 of them had developed some form of cancer and 46 had died of the disease, including the main stars

John Wayne Marion Robert Morrison (May 26, 1907 – June 11, 1979), known professionally as John Wayne and nicknamed The Duke or Duke Wayne, was an American actor who became a popular icon through his starring roles in films made during Hollywood's Gol ...

and

Susan Hayward Susan Hayward (born Edythe Marrenner; June 30, 1917 – March 14, 1975) was an American film actress, best known for her film portrayals of women that were based on true stories. After working as a fashion model for the Walter Thornton Model A ...

. Hicks (1981) evaluated the gamma-exposure rates and levels of radionuclides. Within the report by Hicks he was required to omit data of U-233, U-235, U-238 & Pu-239, and Pu-240 in order to make the report unclassified. In measurement of cumulative exposures rates of populations within a 300-mile radius of the test site, of the period 1951 to 1959, the Upshot–Knothole tests was found to have produced 50% ( rounded figure) of exposure rate within the population. Of the 50%, 75% ( rounded figure) was due to the test-shot ''Harry''.R.G. Cuddihy, G.J. Newton
report
published by Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute 1985, 162 pages, Original from University of Minnesota, Digitized May 23rd 2009 etrieved 2015-11-29/ref>

References

U.S. Department of Energy / Nevada Operations Office, ''United States Nuclear Tests - July 1945 through September 1992'', December 2000
DOE/NV-209 Rev 15

External links

video of the explosion (black and white)
Published on 9 November 2015 (

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- atomicarchive) *Quinn, V.E.; Urban, V.D.; Kennedy, N.C
radiological and mteorological data
published by

International Atomic Energy Agency The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 1957 ...

{{Nuclear weapons tests of the United States Explosions in 1953 Nevada Test Site nuclear explosive tests May 1953 events in the United States 1953 in Nevada 1953 in military history

Device

Detonation

Deposition

See also

References

External links