Project Plowshare was the overall United States program for the development of techniques to use

nuclear explosive A nuclear explosive is an explosive device that derives its energy from nuclear reactions. Almost all nuclear explosive devices that have been designed and produced are nuclear weapons intended for warfare. Other, non-warfare, applications for nuc ...

s for peaceful construction purposes. The program was organized in June 1957 as part of the worldwide

Atoms for Peace "Atoms for Peace" was the title of a speech delivered by U.S. President Dwight D. Eisenhower to the UN General Assembly in New York City on December 8, 1953. The United States then launched an "Atoms for Peace" program that supplied equipment ...

efforts. As part of the program, 31 nuclear warheads were detonated in 27 separate tests. A similar program was carried out in the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

under the name

Nuclear Explosions for the National Economy Nuclear Explosions for the National Economy (russian: Ядерные взрывы для народного хозяйства, Yadernyye vzryvy dlya narodnogo khozyaystva; sometimes referred to as ''Program #7'') was a Soviet program to investiga ...

. Successful demonstrations of non-combat uses for nuclear explosives include

rock blasting Drilling and blasting is the controlled use of explosives and other methods, such as gas pressure blasting pyrotechnics, to break rock (geology), rock for earthworks (engineering), excavation. It is practiced most often in mining, quarrying and ...

, stimulation of

tight gas Tight gas is natural gas produced from reservoir rocks with such low permeability that massive hydraulic fracturing is necessary to produce the well at economic rates. This natural gas is trapped within rocks with very low permeability, in other ...

chemical element A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...

manufacture, unlocking some of the mysteries of the R-process of stellar nucleosynthesis and probing the composition of the Earth's deep crust, creating reflection seismology

vibroseis A seismic source is a device that generates controlled seismic energy used to perform both reflection and refraction seismic surveys. A seismic source can be simple, such as dynamite, or it can use more sophisticated technology, such as a specia ...

data which has helped geologists and follow-on mining company

prospecting Prospecting is the first stage of the geological analysis (followed by exploration) of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking. Traditionally prospecting rel ...

. The project's uncharacteristically large and atmospherically vented Sedan nuclear test also led geologists to determine that Barringer crater was formed as a result of a

meteor impact An impact event is a collision between astronomical objects causing measurable effects. Impact events have physical consequences and have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or me ...

and not from a

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are oft ...

, as had earlier been assumed. This became the first crater on Earth definitely proven to be from an impact event. Negative impacts from Project Plowshare's tests generated significant public opposition, which eventually led to the program's termination in 1977. These consequences included tritiated water (projected to increase by CER Geonuclear Corporation to a level of 2% of the then-maximum level for drinking water) and the deposition of fallout from radioactive material being injected into the atmosphere before underground testing was mandated by treaty.

Rationale

By exploiting the peaceful uses of the "friendly atom" in medical applications, earth removal, and later in nuclear power plants, the nuclear industry and government sought to allay public fears about nuclear technology and promote the acceptance of nuclear weapons. At the peak of the

Atomic Age The Atomic Age, also known as the Atomic Era, is the period of history following the detonation of the first nuclear weapon, The Gadget at the ''Trinity'' test in New Mexico, on July 16, 1945, during World War II. Although nuclear chain reaction ...

, the United States Federal government initiated Project Plowshare, involving "peaceful nuclear explosions". The

United States Atomic Energy Commission The United States Atomic Energy Commission (AEC) was an agency of the United States government established after World War II by U.S. Congress to foster and control the peacetime development of atomic science and technology. President ...

chairman at the time,

Lewis Strauss Lewis Lichtenstein Strauss ( "straws"; January 31, 1896January 21, 1974) was an American businessman, philanthropist, and naval officer who served two terms on the U.S. Atomic Energy Commission (AEC), the second as its chairman. He was a major ...

, announced that the Plowshares project was intended to "highlight the peaceful applications of nuclear explosive devices and thereby create a climate of world opinion that is more favorable to weapons development and tests".

Proposals

Proposed uses for nuclear explosives under Project Plowshare included widening the

Panama Canal The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a condui ...

, constructing a new sea-level waterway through

Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest country in Central America, bordered by Honduras to the north, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the west. Managua is the countr ...

nicknamed the Pan-Atomic Canal, cutting paths through mountainous areas for highways, and connecting inland river systems. Other proposals involved blasting caverns for water, natural gas, and petroleum storage. Serious consideration was also given to using these explosives for various mining operations. One proposal suggested using nuclear blasts to connect underground

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...

s in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

. Another plan involved surface blasting on the western slope of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

's Sacramento Valley for a water transport project. One of the first serious cratering proposals that came close to being carried out was

Project Chariot Project Chariot was a 1958 US 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. History The project o ...

, which would have used several hydrogen bombs to create an artificial harbor at Cape Thompson, Alaska. It was never carried out due to concerns for the native populations and the fact that there was little potential use for the harbor to justify its risk and expense. Project Carryall, proposed in 1963 by the Atomic Energy Commission, the California Division of Highways (now Caltrans), and the Santa Fe Railway, would have used 22 nuclear explosions to excavate a massive roadcut through the

Bristol Mountains The Bristol Mountains are found in the Mojave Desert of California, USA, just west of Mojave National Preserve. The range, which reaches an elevation of 3,874 feet (1,181 m), is located in San Bernardino County, and crosses Interstate 40 between L ...

in the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

, to accommodate construction of

Interstate 40 Interstate 40 (I-40) is a major east–west Interstate Highway running through the south-central portion of the United States. At a length of , it is the third-longest Interstate Highway in the country, after I-90 and I-80. From west to ea ...

and a new rail line. A project proposed in a 1963 memorandum by Lawrence Livermore National Laboratory would have used 520 2-megaton nuclear explosions to excavate a canal through the Negev Desert in Israel at an estimated cost of $575 million ($5 billion in 2021), to serve as an alternative route to the Suez Canal. At the end of the program, a major objective was to develop nuclear explosives, and blast techniques, for stimulating the flow of natural gas in "tight" underground reservoir formations. In the 1960s, a proposal was suggested for a modified ''in situ''

shale oil extraction Shale oil extraction is an industrial process for unconventional oil production. This process converts kerogen in oil shale into shale oil by pyrolysis, hydrogenation, or thermal dissolution. The resultant shale oil is used as fuel oil or up ...

process which involved creation of a

rubble Rubble is broken stone, of irregular size, shape and texture; undressed especially as a filling-in. Rubble naturally found in the soil is known also as 'brash' (compare cornbrash)."Rubble" def. 2., "Brash n. 2. def. 1. ''Oxford English Dictionar ...

chimney (a zone in the oil shale formation created by breaking the rock into fragments) using a

. However, this approach was abandoned for a number of technical reasons.

Plowshare testing

The first Peaceful Nuclear Explosion (PNE) blast was Project Gnome, conducted on December 10, 1961, in a salt bed southeast of

Carlsbad, New Mexico Carlsbad ( ) is a city in and the county seat of Eddy County, New Mexico, United States. As of the 2020 census, the city population was 32,238. Carlsbad is centered at the intersection of U.S. Routes 62/180 and 285, and is the principal city ...

. The explosion released 3.1 kilotons (13 TJ) of energy yield at a depth of which resulted in the formation of a diameter, high cavity. The test had many objectives. The most public of these involved the generation of steam which could then be used to generate electricity. Another objective was the production of useful

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s and their recovery. Another experiment involved

neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons beh ...

time-of-flight Time of flight (ToF) is the measurement of the time taken by an object, particle or wave (be it acoustic, electromagnetic, etc.) to travel a distance through a medium. This information can then be used to measure velocity or path length, or as a w ...

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

. A fourth experiment involved geophysical studies based upon the timed seismic source. Only the last objective was considered a complete success. The blast unintentionally vented radioactive steam while the press watched. The partly developed Project Coach detonation experiment that was to follow adjacent to the Gnome test was then canceled. A number of proof-of-concept cratering blasts were conducted; including the Buggy shot of five 1-kiloton devices for a channel/trench in Area 30 and the largest being 104

kiloton TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a ...

(435

terajoule The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied. ...

) on July 6, 1962, at the north end of

Yucca Flats 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, ...

, within the Atomic Energy Commission's

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 the ...

(NTS) in southern Nevada. The shot, " Sedan", displaced more than of soil and resulted in a radioactive cloud that rose to an altitude of . The

radioactive dust 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 ...

plume headed northeast and then east towards the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it fl ...

. Over the next 11 years 26 more nuclear explosion tests were conducted under the U.S. PNE program. The radioactive blast debris from 839 U.S. underground nuclear test explosions remains buried in-place and has been judged impractical to remove by the DOE's Nevada Site Office. Funding quietly ended in 1977. Costs for the program have been estimated at more than (US) $770 million.

Natural gas stimulation experiment

Three nuclear explosion experiments were intended to stimulate the flow of

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

from "tight" formation gas fields. Industrial participants included

El Paso Natural Gas El Paso Natural Gas (EPNG) is an American company with a system of natural gas pipelines that brings gas from the Permian Basin in Texas and the San Juan Basin in New Mexico and Colorado to West Texas, New Mexico, Nevada, California, and Arizona ...

Company for the Gasbuggy test; CER Geonuclear Corporation and Austral Oil Company for the Rulison test; and CER Geonuclear Corporation for the Rio Blanco test. The final PNE blast took place on May 17, 1973, under Fawn Creek, north of

Grand Junction, Colorado Grand Junction is a home rule municipality that is the county seat and the most populous municipality of Mesa County, Colorado, United States. The city population was 65,560 at the 2020 United States Census, making Grand Junction the 17th mo ...

. Three 30-kiloton detonations took place simultaneously at depths of . If it had been successful, plans called for the use of hundreds of specialized nuclear explosives in the western Rockies gas fields. The previous two tests had indicated that the produced natural gas would be too

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 consi ...

for safe use; the Rio Blanco test found that the three blast cavities had not connected as hoped, and the resulting gas still contained unacceptable levels of

radionuclides A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

. By 1974, approximately $82 million had been invested in the nuclear gas stimulation technology program. It was estimated that even after 25 years of production of all the natural gas deemed recoverable, only 15 to 40% of the investment would be recouped. Also, the concept that stove burners in California might soon emit trace amounts of blast radionuclides into family homes did not sit well with the general public. The contaminated gas was never channeled into commercial supply lines. The situation remained so for the next three decades, but a resurgence in Colorado Western slope natural gas drilling has brought resource development closer and closer to the original underground detonations. By mid-2009, 84 drilling permits had been issued within a radius, with 11 permits within mile of the site.

Impacts, opposition and economics

Operation Plowshare "started with great expectations and high hopes". Planners believed that the projects could be completed safely, but there was less confidence that they could be completed more economically than conventional methods. Moreover, there was insufficient public and Congressional support for the projects. Projects Chariot and Coach were two examples where technical problems and environmental concerns prompted further feasibility studies which took several years, and each project was eventually canceled. Citizen groups voiced concerns and opposition to some of the Plowshare tests. There were concerns that the blast effects from the Schooner explosion could dry up active wells or trigger an earthquake. There was opposition to both Rulison and Rio Blanco tests because of possible radioactive gas flaring operations and other environmental hazards. In a 1973 article, ''

Time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, ...

'' used the term "Project Dubious" to describe Operation Plowshare. There were negative impacts from a select few of Project Plowshare’s 27 nuclear explosions, primarily those conducted in the project's infancy and those that were very high in explosive yield. On Project Gnome and the Sedan test: Project Plowshare shows how something intended to improve national security can unwittingly do the opposite if it fails to fully consider the social, political, and environmental consequences. It also “underscores that public resentment and opposition can stop projects in their tracks”. US and USSR nuclear stockpiles

The

social scientist Social science is one of the branches of science, devoted to the study of societies and the relationships among individuals within those societies. The term was formerly used to refer to the field of sociology, the original "science of socie ...

Benjamin Sovacool contends that the main problem with oil and gas stimulation, which many considered the most promising economic use of nuclear detonations, was that the produced oil and gas was radioactive, which caused consumers to reject it and this was ultimately the program's downfall. Oil and gas are sometimes ''naturally'' radioactive to begin with, however, and the industry is set up to deal with oil and gas that contain radioactive contaminants. Historian Dr. Michael Payne notes that it was primarily changing public opinion, in response to events such as the Cuban Missile Crisis, that drove the protests, court cases and general hostility that ended the oil and gas stimulation efforts. Furthermore, as the years went by without further development and production of nuclear weapons slowed, interest in peaceful applications waned in the 1950s–60s. Cheaper, non-nuclear stimulation techniques suitable for most US gas fields were developed in the following years. As a point of comparison, the most successful and profitable nuclear stimulation effort that did not result in customer product contamination issues was the 1976 Project Neva on the Sredne-Botuobinsk gas field in the

, made possible by multiple cleaner stimulation explosives, favorable rock strata and the possible creation of an underground contaminant storage cavity. The Soviet Union retains the record for the cleanest/lowest fission-fraction nuclear devices so far demonstrated. The public records for devices that produced the highest proportion of their yield via fusion-only reactions, and therefore created orders of magnitude smaller amounts of

long-lived fission products Long-lived fission products (LLFPs) are radioactive materials with a long half-life (more than 200,000 years) produced by nuclear fission of uranium and plutonium. Because of their persistent radiotoxicity it is necessary to isolate them from man ...

as a result, are the USSR's

Peaceful nuclear explosions 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 a ...

of the 1970s, with the three detonations that excavated part of

Pechora–Kama Canal The Pechora–Kama Canal (russian: Канал Печора-Кама), or sometimes the Kama–Pechora Canal, was a proposed canal intended to link up the basin of the Pechora River in the north of European Russia with the basin of the Kama, a trib ...

, being cited as 98% fusion each in the ''Taiga'' test's three 15-

explosive yield devices, that is, a total fission fraction of 0.3

s in a 15 kt device. In comparison, the next three high fusion-yielding devices were all much too high in total explosive yield for oil and gas stimulation: the 50-megaton

Tsar Bomba The Tsar Bomba () ( code name: ''Ivan'' or ''Vanya''), also known by the alphanumerical designation "AN602", was a thermonuclear aerial bomb, and the most powerful nuclear weapon ever created and tested. Overall, the Soviet physicist Andrei ...

achieved a yield 97% derived from fusion, while in the US, the 9.3-megaton Hardtack Poplar test is reported as 95.2%, and the 4.5-megaton Redwing Navajo test as 95% derived from fusion.

Nuclear tests

The U.S. conducted 27 PNE shots in conjunction with other, weapons-related, test series. A report by the Federation of American Scientists includes yields slightly different from those presented below.

Non-nuclear tests

In addition to the nuclear tests, Plowshare executed a number of non-nuclear test projects in an attempt to learn more about how the nuclear explosives could best be used. Several of these projects led to practical utility as well as to furthering knowledge about large explosives. These projects included: {, class="wikitable" , - !Test name !Date !Location !Type !Depth of Burial !Medium !Yield !Note , - !Pre-Gnome , February 10–16, 1959 , Southeast of Carlsbad, New Mexico , seismic experiment (High explosive) , 1,200 ft (365.8 m), each , Bedded salt , 3.65 tons , Three seismic experiments to measure ground shock for the planned GNOME nuclear test. , - !Toboggan , November–December 1959 & April–June 1960 , Nevada Test Site , ditching experiment (High explosive, TNT) , 3 to 20 ft (1 to 6.1 m) , Playa (combination of silt and clay) , Series of 122 detonations of both linear and point HE charges , Study ditching characteristics of both-end detonated and multidetonated HE explosives in preparation for nuclear row charge experiments. , - !Hobo , February–April 1960 , Nevada Test Site , seismic experiment (High explosive, TNT) , Unknown , Tuff , Three explosions, varying from 500 to 1,000 lb. charges each , To study rock fracturing and related phenomena produced by contained explosions. , - !Stagecoach , March 1960 , Nevada Test Site , excavation experiment (High explosive, TNT) , Shot 1 – 80 ft (24.4 m); Shot 2 - 17.1 ft (5.2 m); Shot 3 - 34.2 ft (10.4 m) , Alluvium , Three 40,000 lb. charges , Examine blast, seismic effects and throw out characteristics in preparation for nuclear cratering experiments. , - !Plowboy , March–July 1960 , Winnfield, Louisiana , experiment , Unknown , Unknown , Unknown , Mining operation to examine high explosive- induced fracturing of salt. , - !Buckboard , July–September 1960 , Nevada Test Site , excavation experiment (High explosive, TNT) , 5 to 59.85 ft (1.5 to 18.24 m) , Basalt , Three 40,000 lb. charges and ten 1,000 lb. charges , Establish depth of burst curves for underground explosives in a hard rock medium. , - !Pinot , August 2, 1960 , Rifle, Colorado , tracer experiment (High explosive,

nitromethane Nitromethane, sometimes shortened to simply "nitro", is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a polar liquid commonly used as a solvent in a variety of industrial applications such as in ...

) , 610 ft (185.9 m) , Oil shale , Unknown , To determine how gases in a confined underground explosion migrate. , - !Scooter , 17:17 am, 13 October 1960 , Nevada Test Site , excavation experiment (High explosive, TNT) , 125 ft (38.1 m) , Alluvium , 500 ton charges , To study crater dimension, throw out material distribution,

ground motion Ground motion is the movement of the earth's surface from earthquakes or explosions. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth a ...

, dust cloud growth, and long-range air blast. Initially scheduled for July,{{cite report , author= , author-link= , authors= , date=31 July 1960 , title=TWX TO OBRIEN, ET AL, SUBJECT: HIGH EXPLOSIVE SCOOTER DETONATION HAS BEEN DELAYED , url=https://www.osti.gov/opennet/detail?osti-id=16372937 , publisher=Atomic Energy Commission , page= , docket= , access-date= , quote= the shot was delayed due to the accidental use of dummy detonators. As the detonators had to be placed in the center of the charge, organizers were required to dig down to the TNT charge and then use a steam heated mandrel to melt to its center, an extremely hazardous process.{{cite report , author=Carothers, J , author-link= , authors= , date=June 1995 , title=Caging the dragon: the containment of underground nuclear explosions , url=https://www.osti.gov/biblio/524871 , publisher=USDOE Nevada Operations Office, Las Vegas, NV (United States); Defense Nuclear Agency, Alexandria, VA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States) , page=65-68 , osti= 524871, docket=DOE/NV-388; DNA-TR-95-74; DE98000017 , access-date= , quote= , - !Rowboat , June 1961 , Nevada Test Site , row-charge experiment (High explosive, TNT) , Varied , Alluvium , 8 detonations of series of four 278 lb. charges , To study the effects of depth of burial and charge separation on crater dimensions. , - !Yo-Yo , Summer 1961 , At LRL, near Tracy, California , simulated excavation experiment (High explosive) , Varied , Oil-sand mixture , 100 gm charges , To develop estimates for the quantities of radiation released to the atmosphere by a cratering detonation. , - !Pre-Buggy I , November 1962 – February 1963 , Nevada Test Site , row-charge experiment (High explosive, nitromethane) , 15 to 21.4 ft (4.57 to 6.52 m) for single-charge detonations; all row-charge detonations at 19.8 ft (6.04 m) , Alluvium , Six single-charge detonations, four multiple-charge , U.S. Army Engineer Cratering Group Study of row- charge phenomenology and effects in preparation for nuclear row-charge tests. , - !Pre-Buggy II , June–August 1963 , Nevada Test Site , row-charge experiment (High explosive, nitromethane) , 18.5 to 23 ft (5.64 to 7.0 m) , Alluvium , Five rows of five 1,000 lb. charges , U.S. Army Corps of Engineers study of row-charge phenomenology and effects in preparation for a nuclear row- charge experiment. , - !Pre-Schooner I , February 1964 , Nevada Test Site , cratering experiment (High explosive, nitromethane) , 42 to 66 ft (18.3 to 20.1 m) , Basalt , Four 40,000 lb. spherical charges , U.S. Army Engineer Nuclear Cratering Group study of basic cratering phenomenology in preparation for nuclear cratering experiments. , - !Dugout , June 24,1964 , Nevada Test Site , row charge experiment (High explosive, nitromethane) , 59 ft (18.0 m) , Basalt , simultaneous detonation of a row of five 20 ton charges placed 45 feet (13.7 m) apart (1 crater radius) , Study fundamental processes involved in row charge excavating dense, hard rock. , - !Pre-Schooner II , September 30, 1965 , Owyhee County, southwestern Idaho , cratering experiment (high explosive, nitromethane) , 71 ft (21.6 m) , Rhyolite , 85 ton charge , Obtain data for proposed Schooner nuclear cratering test, particularly cavity growth, seismic effects, and air blast. , - !Pre-Gondola I, II, III , October 1966 – October 1969 , Near Fort Peck Reservoir, Valley County, Montana , excavation experiments (High explosive, nitromethane) , Varied , Saturated Bearclaw shale , Pre-Gondola I, four 20-ton charges; Pre-Gondola II, row of five charges totaling 140 tons; Pre-Gondola III, Phase I, three rows of seven one-ton charges; Phase II, one row of seven 30- ton charges; Phase III, one row of five charges varying from five to 35 tons and totaling 70 tons , U.S. Army Corps of Engineers project to provide seismic calibration test data and cratering characteristics for excavation projects. , - !Tugboat , November 1969 – December 1970 , Kawaihae Bay, Hawaii , excavation experiment (High explosive, TNT) , 4–8 ft (1.2-2.4 m) , Water , Unknown , To study excavation of a small boat harbor in a weak coral medium. , - !Trinidad , July–December 1970 , Trinidad, Colorado (six miles west) , excavation experiment (High explosive) , Unknown , Sandstone/shale , Unknown , Four series of row-charge detonations to study excavation designs. , - !Old Reliable , August 1971 – March 1972 , Galiuro Mountains, 44 miles northeast Tucson, Arizona , fracturing experiment (High explosive, ammonium nitrate) , Unknown , Unknown , 2,002 tons , To promote fracturing and in situ leaching of copper ore.

Proposed nuclear projects

A number of projects were proposed and some planning accomplished, but were not followed through on. A list of these is given here: {, class="wikitable" , - !Name !Date !Location !Type !Purpose , - !Oxcart , 1959 , Nevada Test Site , Nuclear explosive , Investigate excavation efficiency as a function of yield and depth in planning for Project Chariot. , - !Oilsands , 1959 , Athabasca, Canada , Nuclear explosive , Study the feasibility of oil recovery using a nuclear explosive detonation in the Athabascan tar sands. , - !Oil Shale , 1959 , Not determined , Nuclear explosive , Study a nuclear detonation to shatter an oil shale formation to extract oil. , - !Ditchdigger , 1961 , Not determined , Nuclear explosive , A deeply buried clean nuclear explosive detonation excavation experiment , - !Coach , 1963 , Carlsbad, NM (GNOME site) , Nuclear explosive , Produce neutron-rich isotopes of known trans- plutonium elements. , - !Phaeton , 1963 , Not determined , Nuclear explosive , Scaling experiment. , - !Carryall , Nov. 1963 , Bristol Mountains Mojave Desert, CA , Nuclear explosive , Row-charge excavation experiment to cut through the Bristol Mountains for realignment of the Santa Fe railroad and a new highway I-40. , - !Dogsled , 1964 , Colorado Plateau CO or AZ , Nuclear explosive , Study cratering characteristics in dry sandstone; study ground shock and air blast intensities. , - !Tennessee/ Tombigee Waterway , 1964 , Northeast Mississippi , Nuclear explosive , Excavation of three miles of a divide cut through low hills; connect Tennessee and Tombigee rivers; dig 250-mile long canal. , - !Interoceanic Sea-Level Canal Study , 1965–70 , Pan-American Isthmus (Central America) , Nuclear explosive , Commission appointed in 1965 to conduct feasibility studies of several sea-level routes for an Atlantic- Pacific interoceanic canal. Two routes were in Panama and one in northwestern Colombia. The 1970 final report recommended, in part, that no current U.S. canal policy should be made on the basis that nuclear excavation technology will be available for canal construction. AEC deferred in making any decision. , - !Flivver , Mar. 1966 , Nevada Test Site , Nuclear explosive , A low-yield cratering detonation to study basic cratering phenomenology. , - !Dragon Trail , Dec. 1966 , Rio Blanco County, CO , Nuclear explosive , Natural gas stimulation experiment; different geological characteristics than either GASBUGGY or RULISON; geological study completed. , - !Ketch , Aug. 1967 , Renovo, PA (12 miles SW) , Nuclear explosive , Create a large chimney of broken rock with void space to store natural gas under high pressure. , - !Bronco , Oct. 1967 , Rio Blanco County, CO , Nuclear explosive , Break oil shale deposits for in situ retorting; exploratory core holes drilled. , - !Sloop , Oct. 1967 – 1968 , Safford, AZ (11 miles NE) , Nuclear explosive , Fracturing copper ore; extract copper by in situ leaching methods; feasibility study completed. , - !Thunderbird , 1967 , Buffalo, WY (35 miles E) , Nuclear explosive , Coal gasification; fracture rock-containing coal and in situ combustion of the coal would produce low-Btu gas and other products. , - !Galley , 1967–68 , Not determined , Nuclear explosive , A high-yield row charge in hard rock under terrain of varying elevations. , - !Aquarius , 1968–70 , Clear Creek or San Simon, AZ , Nuclear explosive , Water resource management; dam construction, subsurface storage, purification; aquifer modification. , - !Wagon Wheel , Jan. 1968 – 1974 , Pinedale, WY (19 miles S) , Nuclear explosive , Natural gas stimulation; study stimulation at various depths; an exploratory hole and two hydrological wells were drilled. , - !Wasp , Jul. 1969 – 1974 , Pinedale, WY (24 miles NW) , Nuclear explosive , Natural gas stimulation; meteorological observations taken. , - !Utah , 1969 , near Ouray, UT , Nuclear explosive , Oil shale maturation; exploratory hole drilled. , - !Sturtevant , 1969 , Nevada Test Site , Nuclear explosive , Cratering experiment to extend excavation information on yields and rock types relevant to the trans-Isthmian canal. , - !Australian Harbor Project , 1969 , Cape Keraudren (NW coast of Australia) , Nuclear explosive , First discussed with U.S. officials in 1962, the U.S. formally agreed to participate in a joint feasibility study with the Australian government in early 1969 for using nuclear explosives to construct a harbor. The project was stopped in March 1969 when it was determined that there was an insufficient economic basis to proceed. , - !Yawl , 1969–70 , Nevada Test Site , Nuclear explosive , Cratering experiment to extend excavation information on yields and rock types relevant to the trans-Isthmian canal. , - !Geothermal Power Plant , 1971 , Not determined , Nuclear explosive , Geothermal resource experiment; fracturing would allow fluids circulated in fracture zones to be converted to steam to generate electricity.{{cite web, url=https://www.osti.gov/opennet/reports/plowshar.pdf, title=Executive Summary: Plowshare Program, publisher=US Department of Energy, Office of Science and Technical Information, access-date=August 17, 2016 {{PD-notice

Notes

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References

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External links

{{Commons category, Operation Plowshare * {{YouTube, M1k4fbuIOlY , "Plowshare (1961)- US Atomic Energy Commission" * {{Citation , first = Bruce A , last = Bolt , title = Nuclear Explosions and Earthquakes: The Parted Veil , place = San Francisco, CA, US , publisher = WH Freeman & Co , year = 1976 , isbn = 0-7167-0276-2. * {{Citation , first = Chuck , last = Hansen , author-link = Chuck Hansen , title = US Nuclear Weapons: The Secret History , place = Arlington, TX , publisher = Aerofax , year = 1988 , isbn = 0-517-56740-7. * {{Citation , first = Chuck , last = Hansen , author-mask = 3 , url = http://www.uscoldwar.com/ , publisher = US cold war , title = The Swords of Armageddon: US Nuclear Weapons Development Since 1945 , format = CD-ROM , access-date = August 17, 2016. * {{Citation , first = Scott , last = Kirsch , title = Proving Grounds: Project Plowshare and the Unrealized Dream of Nuclear Earthmoving , place = New Brunswick, NJ and London , publisher = Rutgers University Press , year = 2005. * {{Citation , first = Richard L , last = Miller , title = Under the Cloud: The Decades of Nuclear Testing , place = Woodlands, TX , publisher = Two Sixty Press , year = 1999 , isbn = 1-881043-05-3. * {{Citation , editor-first = Stephen I , editor-last = Schwartz , title = Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940 , place = Washington, DC , url = http://www.brookings.edu/ , publisher = Brookings Institution Press , year = 1998 , isbn = 0-8157-7773-6 , access-date = August 17, 2016. * {{cite web, url=http://www.nv.doe.gov/library/publications/historical/DOENV_209_REV15.pdf, archive-url=https://web.archive.org/web/20100615231826/http://www.nv.doe.gov/library/publications/historical/DOENV_209_REV15.pdf, archive-date=June 15, 2010 , title = United States Nuclear Tests, July 1945 through September 1992 , id = DOE/NV-209-REV15 , date=December 2000 , location = US , publisher = Department of Energy Nevada Operations Office * {{Citation , url = http://permanent.access.gpo.gov/websites/osti.gov/www.osti.gov/osti/opennet/plowshar.pdf , title = Plowshare Program , publisher = OSTI , access-date = August 17, 2016. * {{Citation , url = http://www.cancer.gov/i131 , publisher = National Cancer Institute , title = Radioactive I-131 from Fallout , date = December 5, 2014 , contribution = Background. * {{Citation , title = Estimated Exposures and Thyroid Doses Received by the American People from Iodine-131 in Fallout Following Nevada Atmospheric Nuclear Bomb Tests , type = report , publisher = National Cancer Institute , chapter = Executive Summary , year = 1999 , chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK100833/ , quote= Figure 1 – Per capita thyroid doses resulting from all exposure routes from all test. * {{Citation , url = http://www.osti.gov/bridge/servlets/purl/469154-Il8yqP/webviewable/469154.pdf , title = Focused Evaluation of Selected Remedial Alternatives for the Underground Test Area , id = DOE/NV-465 , date=April 1997 , publisher = Environmental Restoration Division, Operations Office, Department of Energy , doi = 10.2172/469154 , place = Nevada, US. * {{Citation , url = http://www.nv.doe.gov/library/publications/historical/plowshare.pdf , title = NV , place = US , publisher = DOE , contribution = Plowshare , quote = Declassification of the yields of 11 nuclear tests conducted as part of the plowshare... program , url-status = dead , archive-url = https://web.archive.org/web/20060907224410/http://www.nv.doe.gov/library/publications/historical/plowshare.pdf , archive-date = September 7, 2006 . * {{Citation , url = http://www.atomictraveler.com/PlowshareProgram.pdf , type = chronology , contribution = Plowshare Program , title = Atomic traveler milestones, including proposed tests and projects conducted. * {{Internet Archive short film , id=Plowshar1961, name=Plowshare (Part I) (ca. 1961) * {{Internet Archive short film , id=Plowshar1961_2, name=Plowshare (Part II) (ca. 1961) * {{Internet Archive short film , id=1961-11-30_New_Mexico, name=New Mexico, 1961/11/30 (1961) * {{Internet Archive short film , id=radiation_safety_1, name=Radiation Safety in Nuclear Energy Explorations (Part I) * {{Internet Archive short film , id=radiation_safety_2, name=Radiation Safety in Nuclear Energy Explorations (Part II) {{US Nuclear Tests {{Authority control

Plowshare In agriculture, a plowshare ( US) or ploughshare ( UK; ) is a component of a plow (or plough). It is the cutting or leading edge of a moldboard which closely follows the coulter (one or more ground-breaking spikes) when plowing. The plowsh ...

Peaceful nuclear explosions