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{{short description|U.S. program examining the peaceful applications of nuclear explosives (1961–77)}}
{{About|proposed peaceful uses of nuclear weapons|the serialized Philip K. Dick novel with the same name|The Zap Gun}}
{{Use mdy dates|date=November 2018}}
[[Image:Sedan Plowshare Crater.jpg|thumb|The 1962 "[[Sedan (nuclear test)|Sedan]]" plowshares shot displaced 12 million tons of earth and created a crater {{convert|320|ft|m}} deep and {{convert|1280|ft|m}} wide.]]

'''Project Plowshare''' was the overall United States program for the development of techniques to use [[nuclear explosive]]s 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<ref>{{Cite book |last=Weinersmith |first=Zach |title=10 Emerging Technologies That'll Improve and/or ruin everything |year= 2017 |isbn=978-0399563829 |pages=154 |language=English}}</ref> 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]], although the Soviet program consisted of 124 tests.

Successful demonstrations of non-combat uses for nuclear explosives include [[rock blasting]], stimulation of [[tight gas]], [[chemical element]] manufacture,{{efn|Test shot Anacostia resulted in [[isotopes of curium|Curium-250]] being discovered.}} unlocking some of the mysteries of the [[R-process]] of [[stellar nucleosynthesis]] and probing the composition of the [[Earth's crust|Earth's deep crust]], creating [[reflection seismology]] [[vibroseis]] data which has helped geologists and follow-on mining company [[prospecting]].<ref name="Executive Summary"/><ref>{{cite web |url=http://www.ociw.edu/ociw/symposia/series/symposium4/ms/becker.ps.gz |title=Archived copy |website=www.ociw.edu |access-date=12 January 2022 |archive-url=https://web.archive.org/web/20060210141005/http://www.ociw.edu/ociw/symposia/series/symposium4/ms/becker.ps.gz |archive-date=10 February 2006 |url-status=dead}}</ref><ref>{{Cite web|url=http://www.ociw.edu/ociw/symposia/series/symposium4/proceedings.html|title=Carnegie Observatories Astrophysics Series |date=February 10, 2006|archive-url=https://web.archive.org/web/20060210141005/http://www.ociw.edu/ociw/symposia/series/symposium4/proceedings.html |archive-date=February 10, 2006 }}</ref>

The project's uncharacteristically large and atmospherically vented [[Sedan (nuclear test)|Sedan nuclear test]] also led geologists to determine that [[Barringer crater]] was formed as a result of a [[impact event|meteor impact]] and not from a [[volcanic eruption]], as had earlier been assumed. This became the first crater on Earth definitely proven to be from an impact event.<ref>{{Cite web|url=http://keyah.asu.edu/lessons/MeteorCrater/KM13.html|title=Keyah Math – Numerical Solutions for Culturally Diverse Geology|website=keyah.asu.edu}}</ref>

Negative impacts from Project Plowshare's tests generated significant public opposition, which eventually led to the program's termination in 1977.<ref name =bks2011 /> 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)<ref>{{cite journal|last1=Jacobsen|first1=Sally|title=Turning up the Gas: AEC Prepares Another Nuclear Gas Stimulation Shot|journal=Bulletin of the Atomic Scientists|date=May 1972|volume=28|issue=5|page=37|url=https://books.google.com/books?id=pwsAAAAAMBAJ&pg=PA37|issn=0096-3402|doi=10.1080/00963402.1972.11457935|url-access=subscription}}</ref> and the deposition of [[fallout]] from radioactive material being injected into the atmosphere before [[Underground nuclear weapons testing|underground testing]] was [[Partial Nuclear Test Ban Treaty|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]].<ref>Stone, Oliver and Kuznick, Peter, ''The Untold History of the United States'' (Gallery Books, 2012), pp. 283–284 {{ISBN?}}</ref> At the peak of the [[Atomic Age]], the United States Federal government initiated Project Plowshare, involving "peaceful nuclear explosions". The [[United States Atomic Energy Commission]] chairman at the time, [[Lewis Strauss]], 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".<ref>{{cite book |last1=Hewlett |first1=Richard G. |last2=Holl |first2=Jack M. |url=https://books.google.com/books?id=0Cv_E3yLHG4C&pg=PA529 |title=Atoms for Peace and War, 1953–1961: Eisenhower and the Atomic Energy Commission |page=529 |date=1989 |publisher=University of California Press |location=Berkeley and Los Angeles, California |quote=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|isbn=978-0520060180 }}</ref><ref>"semiannual report to Congress in January 1958". Other mentions of Strauss making statements in Feb 1958 or hearings being held are on p 447, and 474 it seems. p. 474's quotation: Senate Subcommittee of the Committee on Foreign Relations, Hearings on Control and Reduction of Armaments, Feb. 28 – April 17, 1958, Washington: Government Printing Office, 1958) pp. 1336–1364.</ref>{{request quotation|date=August 2015}} These tests were to demonstrate that atomic bombs can be used for peaceful purposes, that the atomic sword could be beaten into a plowshare.

== Proposals ==
[[Image:Project Chariot plans.jpg|thumb|One of the ''Chariot'' schemes involved chaining five thermonuclear devices to create an artificial harbor.]]{{Multiple image
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| footer            = Artist concepts for Plowshare's proposed road, rail, and canal route excavation.
| align             = left
}}
[[File:Trans-isthmian canal routes (13386826633).jpg|thumb|Plowshare's proposed canals near the Panama Canal.]]
Proposed uses for nuclear explosives under Project Plowshare included widening the [[Panama Canal]], constructing a new sea-level waterway through [[Nicaragua]] 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]]s in [[Arizona]].  Another plan involved surface blasting on the western slope of [[California]]'s [[Sacramento Valley]] for a water transport project.<ref name="bks2011" />

One of the first serious cratering proposals that came close to being carried out was [[Operation Chariot (1958)|Project Chariot]], which would have used several [[hydrogen bomb]]s 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.<ref>{{Citation | last = O'Neill | first = Dan | year = 2007 | orig-year = 1995 | title = The Firecracker Boys: H-Bombs, Inupiat Eskimos, and the Roots of the Environmental Movement | place = New York | publisher = Basic Books | isbn = 978-0-465-00348-8 | url-access = registration | url = https://archive.org/details/unset0000unse_p6n8 }}</ref>

[[Project Carryall]],<ref>{{cite journal | url = http://pubsindex.trb.org/document/view/default.asp?lbid=110048 | title =Preliminary Design Studies In A Nuclear Excavation — Project Carryall | journal =Highway Research Record |publisher= Highway Research Board | year=1964 |issue=50 |pages= 32–39 |access-date= August 17, 2016| last1 =Fry | first1 =J. G. | last2 =Stane | first2 =R. A. | last3 =Crutchfield Jr | first3 =W. H. }}</ref> proposed in 1963 by the [[United States Atomic Energy Commission|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]] in the [[Mojave Desert]], to accommodate construction of [[Interstate 40]] and a new rail line.<ref name=bks2011/>

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]].<ref>{{cite web|url=https://www.osti.gov/opennet/servlets/purl/453701.pdf|title=Use of Nuclear Explosives for Excavation of Sea-Level Canal Across the Negev Desert|last=Maccabee|first=H. D.|publisher=United States Office of Scientific and Technical Information|date=1 July 1963|access-date=2 April 2021}}</ref><ref>{{Cite web|url=https://www.businessinsider.com/us-planned-suez-canal-alternative-israel-blast-with-nuclear-bombs-1960s-2021-3|last=Guenot|first=Marianne|title=The US had a plan in the 1960s to blast an alternative Suez Canal through Israel using 520 nuclear bombs|publisher=Insider|date=25 March 2021|access-date=2 April 2021}}</ref>

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]] process which involved creation of a [[rubble]] chimney (a zone in the [[oil shale formation]] created by breaking the rock into fragments) using a [[nuclear explosive]].<ref name= chimney>{{Cite journal | last1 = Lombard| first1 = DB | last2 =Carpenter|first2=HC |title=Recovering Oil by Retorting a Nuclear Chimney in Oil Shale |journal = Journal of Petroleum Technology | volume = 19 |publisher=Society of Petroleum Engineers |pages= 727–734 |issue= 6 |year = 1967| doi = 10.2118/1669-PA |doi-access = free }}</ref>  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 {{cvt|24|mi|km}} southeast of [[Carlsbad, New Mexico|Carlsbad]], in southeast [[New Mexico]].  The explosion released 3.1&nbsp;kilotons (13&nbsp;TJ) of energy yield at a depth of {{cvt|361|m|ft|order=flip}} which resulted in the formation of a {{cvt|170|ft|m|adj=on}} diameter, {{cvt|80|ft|m|adj=on}} high cavity. The test had many objectives, the most public of which involved the generation of [[steam]] which could then be used to generate electricity.  Another objective was the production of useful [[radioisotope]]s and their recovery.  Yet another experiment involved [[neutron]] [[time-of-flight]] [[Particle physics|physics]], and 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 [[Project Gnome|Gnome test]] was then canceled.

A number of [[proof of concept|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]] (435 [[terajoule]]) on July 6, 1962, at the north end of [[Yucca Flats]], within the [[United States Atomic Energy Commission|Atomic Energy Commission]]'s [[Nevada Test Site]] (NTS) in southern Nevada. The shot, "[[Sedan (nuclear test)|Sedan]]", displaced more than {{convert|12|e6ST|e6kg|abbr=off}} of soil and resulted in a radioactive cloud that rose to an altitude of {{cvt|12000|ft|km}}.  The [[radioactive dust]] plume headed northeast and then east towards the [[Mississippi River]].<ref name=bks2011/>

Over the next 11 years, 26 more nuclear explosion tests were conducted under the United States PNE program. The radioactive blast debris from 839 U.S. underground nuclear test explosions remain buried in-place and have been judged impractical to remove by the DOE's Nevada Site Office. Funding quietly ended in 1997, and costs for the program have been estimated at more than (US) $770 million.<ref name="bks2011" />

===Natural gas stimulation experiment===
Three nuclear explosion experiments were intended to stimulate the flow of [[natural gas]] from "tight" formation gas fields. Industrial participants included [[El Paso Natural Gas]] Company for the [[Gasbuggy]] test near [[Farmington, New Mexico]]; CER Geonuclear Corporation and [[Austral Oil Company]] for the [[Rulison]] test;<ref>{{cite web |url= http://www.library.hbs.edu/hc/lehman/company.html?company=austral_oil_co_inc|title = Austral Oil, Co., Inc. |publisher=Harvard Business School |access-date = November 23, 2014}}</ref> and CER Geonuclear Corporation for the [[Project Rio Blanco|Rio Blanco]] test.

The final PNE blast took place on May 17, 1973, under Fawn Creek, {{cvt|76.4|km|mi|order=flip}} north of [[Grand Junction, Colorado]].  Three 30-kiloton detonations took place simultaneously at depths of {{cvt|1758|, |1875|and|2015|m|ft|order=flip}}.  If it had been successful, plans called for the use of hundreds of specialized nuclear explosives in the [[Rocky Mountains|western Rockies]] gas fields.  The previous two tests had indicated that the produced natural gas would be too [[radioactivity|radioactive]] 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]].<ref name = "Dubious">{{cite news |url = http://www.time.com/time/magazine/article/0,9171,903965,00.html |archive-url = https://web.archive.org/web/20081214071547/http://www.time.com/time/magazine/article/0,9171,903965,00.html |url-status = dead |archive-date = December 14, 2008 |title=Environment: Project Dubious |date=April 9, 1973 |work= Time magazine |access-date= August 17, 2016}}</ref>

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.{{Citation needed|date=March 2025}}

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 {{convert|3|mi|km|adj=on}} radius, with 11 permits within {{cvt|1|mi|km|spell=in}} mile of the site.<ref>{{cite news|first=Mark |last= Jaffe |url= http://www.denverpost.com/2009/07/01/colorado-drilling-rigs-closing-in-on-60s-nuke-site/ |title = Colorado drilling rigs closing in on '60s nuke site |newspaper=The Denver Post |date=July 2, 2009 |access-date = January 30, 2010}}</ref>

==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. [[Operation Chariot (1958)|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.<ref name="Executive Summary"/>

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.<ref name="Executive Summary"/> In a 1973 article, ''[[Time magazine|Time]]'' used the term "Project Dubious" to describe Operation Plowshare.<ref name="Dubious"/>

There were negative impacts from several 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:<ref name=bks2011>{{Citation | first = Benjamin K | last = Sovacool | author-link = Benjamin K. Sovacool | year = 2011 | title = Contesting the Future of Nuclear Power: A Critical Global Assessment of Atomic Energy | publisher= [[World Scientific]] | pages = 171–2}}</ref>
{{Blockquote |Project Gnome vented radioactive steam over the very press gallery that was called to confirm its safety. The next blast, a 104-kiloton detonation at Yucca Flat, Nevada, displaced 12 million tons of soil and resulted in a radioactive dust cloud that rose {{convert|12000|ft|disp=sqbr||}} and plumed toward the Mississippi River. Other consequences – blighted land, relocated communities, tritium-contaminated water, radioactivity, and fallout from debris being hurled high into the atmosphere – were ignored and downplayed until the program was terminated in 1977, due in large part to public opposition.<ref name=bks2011 />}}

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”.<ref name=bks2011/>
[[File:US and USSR nuclear stockpiles.svg|thumb|United States and Soviet Union/Russia nuclear stockpiles. The slow down in the production of nuclear weapons, beginning in the late 1970s in the US, greatly impacted on the economic calculations of peaceful uses of nuclear detonations.]]

The [[social scientist]] [[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.<ref name=bks2011 /> Oil and gas are sometimes [[Naturally occurring radioactive material|''naturally'' radioactive]] to begin with, however, and the industry is set up to deal with oil and gas that contain radioactive contaminants.<ref>{{cite web|url=http://aoghs.org/technology/project-gasbuggy/|title="Gasbuggy" tests Nuclear Fracking – American Oil & Gas Historical Society|date=December 4, 2015}}</ref> 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,<ref>{{cite web|url=http://www.innovationalberta.com/article.php?articleid=92|archive-url=https://web.archive.org/web/20070824172227/http://www.innovationalberta.com/article.php?articleid=92|archive-date=August 24, 2007|title=Innovation Alberta: Article Details|date=August 24, 2007}}</ref> 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.<ref>{{Cite web|url=https://www.osti.gov/opennet/reports/plowshar.pdf|title=Plowshare Program Executive Summary, pp. 4–5}}</ref><ref>{{cite web|url=http://www.elmada.com/wagon/WWS005Projects.htm|archive-url=https://web.archive.org/web/20040706025511/http://www.elmada.com/wagon/WWS005Projects.htm|archive-date=July 6, 2004|title=elmada.com/wagon: Nuclear Stimulation Projects|date=July 6, 2004}}</ref>

As a point of comparison, the most [[Nuclear Explosions for the National Economy|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 [[Soviet Union]], made possible by multiple cleaner stimulation explosives, favorable rock strata and the possible creation of an underground contaminant storage cavity.<ref>{{Cite web|url=https://www.bibliotecapleyades.net/ciencia/ciencia_uranium27.htm|title=The Soviet Program for Peaceful Uses of Nuclear Explosions|website=www.bibliotecapleyades.net}}</ref><ref>{{Cite web |url=https://e-reports-ext.llnl.gov/pdf/238468.pdf |title=Milo D. Nordyke, 2000. peaceful nuclear explosions (PNEs) in the Soviet Union over the period 1965 to 1988. |access-date=July 22, 2016 |archive-url=https://web.archive.org/web/20161223024850/http://e-reports-ext.llnl.gov/pdf/238468.pdf |archive-date=December 23, 2016 |url-status=dead }}</ref> The Soviet Union retains the record for the cleanest/lowest [[Nuclear weapon design|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 [[Fission products|long-lived fission products]] as a result, are the USSR's [[Peaceful nuclear explosions]] of the 1970s, with the three detonations that excavated part of [[Pechora–Kama Canal]], being cited as 98% fusion each in the ''Taiga'' test's three 15-[[kiloton]] explosive yield devices, that is, a total fission fraction of 0.3 [[kiloton]]s in a 15 kt device.<ref>[http://www.bibliotecapleyades.net/ciencia/ciencia_uranium27.htm ''The Soviet Program for Peaceful Uses of Nuclear Explosions''] by Milo D. Nordyke. Science & Global Security, 1998, Volume 7, pp. 1–117</ref> 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]] achieved a yield 97% derived from fusion,<ref>[http://nuclearweaponarchive.org/Nwfaq/Nfaq4-5.html 4.5 Thermonuclear Weapon Designs and Later Subsections]. Nuclearweaponarchive.org. Retrieved on May 1, 2011.</ref> while in the US, the 9.3-megaton [[Operation Hardtack I|Hardtack Poplar]] test is reported as 95.2%,<ref>[http://nuclearweaponarchive.org/Usa/Tests/Hardtack1.html Operation Hardtack I]. Nuclearweaponarchive.org. Retrieved on May 1, 2011.</ref> and the 4.5-megaton [[Operation Redwing|Redwing Navajo]] test as 95% derived from fusion.<ref>[http://nuclearweaponarchive.org/Usa/Tests/Redwing.html Operation Redwing]. Nuclearweaponarchive.org. Retrieved on May 1, 2011.</ref>

== Nuclear tests ==
The U.S. conducted 27 PNE shots in conjunction with other, weapons-related, test series.<ref name="Executive Summary"/> A report by the [[Federation of American Scientists]] includes yields slightly different from those presented below.<ref>{{cite web |url=https://www.fas.org/sgp/othergov/doe/rdd-7.html |title=Restricted Data Declassification Decisions 1946 to the Present, RDD-7, January 1, 2001. |access-date=August 17, 2016}}</ref>

{| class="sortable wikitable" style="margin:auto;"
|+ '''Plowshare nuclear tests'''
|-
! Test name || Date || Location
!Type
!Depth of Burial
!Medium|| Yield (kilotons) || Test series
!Objective
|-
! ''[[Project Gnome|Gnome]]''
| December 10, 1961 || [[Carlsbad, New Mexico]]
|Shaft
|1,185&nbsp;ft (361 m)
|Salt|| 3 || [[Operation Nougat|Nougat]]
|A multipurpose experiment designed to provide data concerning:  (1) heat generated from a nuclear explosion; (2) isotopes production; (3)  neutron physics; (4) seismic measurements in a salt medium; and (5) design  data for developing nuclear devices specifically for peaceful uses.
|-
! ''[[Sedan (nuclear test)|Sedan]]''
| July 6, 1962 || [[Nevada Test Site]]
|Crater
|635&nbsp;ft (194 m)
|Alluvium|| 104
| [[Operation Storax|Storax]]
|An excavation experiment in alluvium to determine feasibility of  using nuclear explosions for large excavation projects, such as harbors and  canals; provide data on crater size, radiological safety, seismic effects,  and air blast.
|-
! ''Anacostia''
| November 27, 1962 || Nevada Test Site
|Shaft
|747&nbsp;ft (227.7 m)
|Tuff|| 5.2 || [[Operation Storax|Storax]]
|A device-development experiment to produce heavy elements and  provide radiochemical analysis data for the planned Coach Project.
|-
! ''Kaweah''
| February 21, 1963 || Nevada Test Site
|Shaft
|745&nbsp;ft (227.1 m)
|Alluvium|| 3 || [[Operation Dominic I and II|Dominic I and II]]
|A device-development experiment to produce heavy elements and  provide technical data for the planned Coach Project.
|-
! ''Tornillo''
| October 11, 1963 || Nevada Test Site
|Shaft
|489&nbsp;ft (149 m)
|Alluvium|| 0.38|| [[Operation Niblick|Niblick]]
|A device-development experiment to produce a clean nuclear  explosive for excavation applications.
|-
! ''Klickitat''
| February 20, 1964 || Nevada Test Site
|Shaft
|1,616&nbsp;ft (492.6 m)
|Tuff|| 70 || [[Operation Niblick|Niblick]]
|A device-development experiment to produce an improved nuclear  explosive for excavation applications.
|-
! ''Ace''
| June 11, 1964 || Nevada Test Site
|Shaft
|862&nbsp;ft (262.7 m)
|Alluvium|| 3|| [[Operation Niblick|Niblick]]
|A device-development experiment to produce an improved nuclear  explosive for excavation applications.
|-
! ''Dub''
| June 30, 1964 || Nevada Test Site
|Shaft
|848&nbsp;ft (258.5 m)
|Alluvium|| 11.7 || [[Operation Niblick|Niblick]]
|A device-development experiment to study emplacement techniques.
|-
! ''Par''
| October 9, 1964 || Nevada Test Site
|Shaft
|1,325&nbsp;ft (403.9 m)
|Alluvium|| 38 || [[Operation Whetstone|Whetstone]]
|A device-development experiment designed to increase the neutron  flux needed for the creation of heavy elements.
|-
! ''Handcar''
| November 5, 1964 || Nevada Test Site
|Shaft
|1,332&nbsp;ft (406 m)
|Dolomite  (carbonate rock)|| 12 || [[Operation Whetstone|Whetstone]]
|An emplacement experiment to study the effects of nuclear  explosions in carbonate rock.
|-
! ''Sulky''
| November 5, 1964 || Nevada Test Site
|Shaft
|90&nbsp;ft (27.4 m)
|Basalt|| 0.9 || [[Operation Whetstone|Whetstone]]
|An excavation experiment to explore cratering mechanics in hard,  dry rock and study dispersion patterns of airborne radionuclides released  under these conditions.
|-
! ''Palanquin''
| April 14, 1965 || Nevada Test Site
|Crater
|280&nbsp;ft (85.3 m)
|Rhyolite|| 4.3 || [[Operation Whetstone|Whetstone]]
|An excavation experiment in hard, dry rock to study dispersion  patterns of airborne radionuclides released under these conditions.
|-
! ''Templar''
| March 24, 1966 || Nevada Test Site
|Shaft
|495&nbsp;ft (150.9 m)
|Tuff|| 0.37 || [[Operation Flintlock (Nuclear test)|Flintlock]]
|To develop an improved nuclear explosive for excavation  applications.
|-
! ''Vulcan''
| June 25, 1966 || Nevada Test Site
|Shaft
|1,057&nbsp;ft (322.2 m)
|Alluvium|| 25 || [[Operation Flintlock (Nuclear test)|Flintlock]]
|A heavy element device-development test to evaluate neutron flux  performance.
|-
! ''Saxon''
| July 11, 1966 || Nevada Test Site
|Shaft
|502&nbsp;ft (153 m)
|Tuff|| 1.2 || [[Operation Latchkey|Latchkey]]
|A device-development experiment to improve nuclear explosives  for excavation applications.
|-
! ''Simms''
| November 6, 1966 || Nevada Test Site
|Shaft
|650&nbsp;ft (198.1 m)
|Alluvium|| 2.3 || [[Operation Latchkey|Latchkey]]
|A device-development experiment to evaluate clean nuclear  explosives for excavation applications.
|-
! ''Switch''
| June 22, 1967 || Nevada Test Site
|Shaft
|990&nbsp;ft (301.8 m)
|Tuff|| 3.1 || [[Operation Latchkey|Latchkey]]
|A device-development experiment to evaluate clean nuclear  explosives for excavation applications.
|-
! ''Marvel''
| September 21, 1967 || Nevada Test Site
|Shaft
|572&nbsp;ft (174.3 m)
|Alluvium|| 2.2 || [[Operation Crosstie|Crosstie]]
|An emplacement experiment to investigate underground  phenomenology related to emplacement techniques.
|-
! ''[[Project Gasbuggy|Gasbuggy]]''
| December 10, 1967 || [[Farmington, New Mexico]]
|Shaft
|4,240&nbsp;ft (1,292 m)
|Sandstone,  gas bearing formation|| 29 || [[Operation Crosstie|Crosstie]]
|A gas stimulation experiment to investigate the feasibility of  using nuclear explosives to stimulate a low-permeability gas field; first  Plowshare joint government-industry nuclear experiment to evaluate an  industrial application.
|-
! ''Cabriolet''
| January 26, 1968 || Nevada Test Site
|Crater
|170&nbsp;ft (51.8 m)
|Rhyolite|| 2.3 || [[Operation Crosstie|Crosstie]]
|An excavation experiment to explore cratering mechanics in hard,  dry rock and study dispersion patterns of airborne radionuclides released  under these conditions.
|-
! ''Buggy''
| March 12, 1968 || Nevada Test Site
|Crater
|135&nbsp;ft (41.1 m)
|Basalt|| data-sort-value="5.5" |5 at 1.1 each|| [[Operation Crosstie|Crosstie]]
|A five-detonation excavation experiment to study the effects and  phenomenology of nuclear row-charge excavation detonations.
|-
! ''Stoddard''
| September 17, 1968 || Nevada Test Site
|Shaft
|1,535&nbsp;ft (467.9 m)
|Tuff|| 31|| [[Operation Bowline|Bowline]]
|A device-development experiment to develop clean nuclear  explosives for excavation applications.
|-
! ''Schooner''
| December 8, 1968 || Nevada Test Site
|Crater
|365&nbsp;ft (111.3 m)
|Tuff|| 30 || [[Operation Bowline|Bowline]]
|An excavation experiment to study the effects and phenomenology  of cratering detonations in hard rock.
|-
! ''[[Rulison]]''
| September 10, 1969 || [[Grand Valley (Colorado-Utah)|Grand Valley]], [[Colorado]]
|Shaft
|8,425&nbsp;ft (2,567.9 m)
|Sandstone|| 43 || [[Operation Mandrel|Mandrel]]
|A gas stimulation experiment to investigate the feasibility of  using nuclear explosives to stimulate a low-permeability gas field; provide  engineering data on the use of nuclear explosions for gas stimulation; on  changes in gas production and recovery rates; and on techniques to reduce the  [[radioactive contamination]] to the gas.
|-
!Flask  -Green, -Yellow, -Red
| May 26, 1970 || Nevada Test Site
|Shaft
|Green,  1736&nbsp;ft (529.2 m); Yellow, 1,099&nbsp;ft (335 m); Red, 499&nbsp;ft (152.1 m)
|Green,  Tuff; Yellow and Red, Alluvium||Green,  105; Yellow, 0.9; Red, 0.4 tons|| [[Operation Mandrel|Mandrel]]
|A three-detonation device development experiment to develop  improved nuclear explosives for excavation applications.
|-
! ''Miniata''
| July 8, 1971 || Nevada Test Site
|Shaft
|1,735&nbsp;ft (528.8 m)
|Tuff|| 83 || [[Operation Grommet|Grommet]]
|To develop a clean nuclear explosive for excavation  applications.
|-
! ''[[Project Rio Blanco|Rio Blanco]]''  -1, -2, -3
| May 17, 1973 || [[Rifle, Colorado]]
|Shaft
|5,840&nbsp;ft (1,780 m); 6,230&nbsp;ft (1,898.9 m); 6,690&nbsp;ft (2,039.1 m)
|Sandstone,  gas-bearing formation|| data-sort-value="99" |3 at 33 each || [[Operation Toggle|Toggle]]
|A gas stimulation experiment to investigate the feasibility of  using nuclear explosives to stimulate a low-permeability gas field; develop  technology for recovering natural gas from reservoirs with very low  permeability.
|}

== 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:<ref name="Executive Summary"/>
{| 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&nbsp;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&nbsp;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&nbsp;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&nbsp;ft (24.4 m); Shot 2  17.1&nbsp;ft (5.2 m); Shot 3 – 34.2&nbsp;ft (10.4 m)
|Alluvium
|Three  40,000&nbsp;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&nbsp;ft (1.5 to 18.24 m)
|Basalt
|Three  40,000&nbsp;lb. charges and ten 1,000&nbsp;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]])
|610&nbsp;ft (185.9 m)
|Oil  shale
|Unknown
|To  determine how gases in a confined underground explosion migrate.
|-
!Scooter
|17:17 am, 13 October 1960<ref>{{cite press release |last= |first= |date=13 October 1960 |title=Press Release, Subject: A Charge of 500 Tons of Chemical High Explosive (Non-Nuclear) was Detonated at 7:17 a.m. Today at the NTS (Plowshare)  |url=https://www.osti.gov/opennet/detail?osti-id=16112563 |url-status= |location= |publisher= |agency=Atomic Energy Commission |archive-url= |archive-date= }}</ref>
|Nevada  Test Site
|excavation  experiment (High explosive, TNT)
|125&nbsp;ft (38.1 m)
|Alluvium
|500 ton charges
|To study crater dimension, throw out material distribution, [[ground motion]], dust cloud growth, and long-range air blast.

Initially scheduled for July,<ref>{{cite report |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=}}</ref> 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.<ref name=dragon>{{cite report |last=Carothers |first=J |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) |pages=65–68 |osti= 524871|docket=DOE/NV-388; DNA-TR-95-74; DE98000017 |access-date= |quote=}}</ref>
|-
!Rowboat
|June 1961
|Nevada  Test Site
|row-charge  experiment (High explosive, TNT)
|Varied
|Alluvium
|8  detonations of series of four 278&nbsp;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&nbsp;ft (4.57 to 6.52 m) for single-charge detonations; all row-charge  detonations at 19.8&nbsp;ft (6.04 m)
|Alluvium
|Six single-charge detonations, four multiple-charge
|U.S. Army Corps of Engineers Nuclear 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&nbsp;ft (5.64 to 7.0 m)
|Alluvium
|Five rows of five 1,000&nbsp;lb. charges
|U.S. Army Corps of Engineers Nuclear Cratering Group 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&nbsp;ft (18.3 to 20.1 m)
|Basalt
|Four 40,000&nbsp;lb. spherical charges
|U.S. Army Corps of Engineers 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&nbsp;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&nbsp;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 Nuclear Cratering Group project to provide seismic calibration test data and  cratering characteristics for excavation projects.
|-
!Tugboat
|November  1969 – December 1970
|[[Kawaihae, Hawaii|Kawaihae Bay, Hawaii]]
|excavation  experiment (High explosive, TNT)
|4–8&nbsp;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:<ref name="Executive Summary"/>
{| class="wikitable"
|-
!Name
!Date
!Location
!Purpose
|-
!Oxcart
|1959
|Nevada  Test Site
|Investigate  excavation efficiency as a function of yield and depth in planning for  Project Chariot.
|-
!''[[Project Oilsand|Oilsand]]''
|1959
|Athabasca,  Canada
|Study  the feasibility of oil recovery using a nuclear explosive detonation in the  Athabascan tar sands.
|-
!Oil Shale
|1959
|Not  determined
|Study  a nuclear detonation to shatter an oil shale formation to extract oil.
|-
!Ditchdigger
|1961
|Not  determined
|A  deeply buried clean nuclear explosive detonation excavation experiment
|-
!Coach
|1963
|Carlsbad,  NM (GNOME site)
|Produce  neutron-rich isotopes of known trans- plutonium elements.
|-
!Phaeton
|1963
|Not  determined
|Scaling  experiment.
|-
!''[[Project Carryall|Carryall]]''
|1963
|Bristol  Mountains Mojave Desert, CA
|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
|Study  cratering characteristics in dry sandstone; study ground shock and air blast  intensities.
|-
![[Tennessee–Tombigbee Waterway#Nuclear excavation study|Tennessee/ Tombigee Waterway]]
|1964
|Northeast  Mississippi
|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)
|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
|A  low-yield cratering detonation to study basic cratering phenomenology.
|-
!Dragon Trail
|Dec. 1966
|Rio  Blanco County, CO
|Natural  gas stimulation experiment; different geological characteristics than either  GASBUGGY or RULISON; geological study completed.
|-
!''[[Project Ketch|Ketch]]''
|Aug. 1967
|Renovo,  PA (12 miles SW)
|Create  a large chimney of broken rock with void space to store natural gas under  high pressure.
|-
!Bronco
|Oct. 1967
|Rio  Blanco County, CO
|Break  oil shale deposits for in situ retorting; exploratory core holes  drilled.
|-
!Sloop
|Oct. 1967 – 1968
|Safford,  AZ (11 miles NE)
|Fracturing  copper ore; extract copper by in situ leaching methods; feasibility study  completed.
|-
!''[[Project Thunderbird|Thunderbird]]
|1967
|Gillette,  WY (20 miles W)
|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
|A  high-yield row charge in hard rock under terrain of varying elevations.
|-
!Aquarius
|1968–70
|Clear  Creek or San Simon, AZ
|Water  resource management; dam construction, subsurface storage, purification;  aquifer modification.
|-
!Wagon Wheel
|Jan.&nbsp;1968&nbsp;–&nbsp;1974
|Pinedale,  WY (19 miles S)
|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)
|Natural  gas stimulation; meteorological observations taken.
|-
!Utah
|1969
|near  Ouray, UT
|Oil  shale maturation; exploratory hole drilled.
|-
!Sturtevant
|1969
|Nevada  Test Site
|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)
|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
|Cratering  experiment to extend excavation information on yields and rock types relevant  to the trans-Isthmian canal.
|-
!Geothermal Power Plant
|1971
|Not  determined
|Geothermal  resource experiment; fracturing would allow fluids circulated in fracture  zones to be converted to steam to generate electricity.<ref name="Executive Summary">{{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}}</ref>
|-
!''[[Project Travois|Travois]]''
|1970
||Various sites in California, New Mexico, Idaho and Oregon
|Several nuclear quarrying projects to create rock fill for dam projects.<ref name=OSTI1>{{Cite report |url=https://www.osti.gov/servlets/purl/1046574 |title=The Off-Site Plowshare and Vela Uniform Programs: Assessing Potential Environmental Liabilities through an Examination of Proposed Nuclear Projects,High Explosive Experiments, and High Explosive Construction Activities |last1=Beck |first1=Colleen M. |last2=Edwards |first2=Susan R. |last3=King |first3=Maureen L. |date=2011-09-01 |issue=Tech Rpt 111 DOE/NV/26383-22, 1046575 |doi=10.2172/1046575 |volume=1 |language=en|section=Project Travois|pages=3–259}}</ref><ref name=Yoman>{{Cite report |url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/36/010/36010774.pdf |author=Yoman, John|title=Symposium on Engineering with Nuclear Explosives  |date=May 1970  |language=en|section=Summary of Nuclear-Excavation Applications|pages=267–268}}</ref>
|}

==See also==
* [[Plowshares movement]]
* [[Atoms for Peace]]
* [[Nuclear Explosions for the National Economy]] – the equivalent Soviet program(s) that achieved "practical application" status.
* [[Atomic age]]
* [[Project Orion (nuclear propulsion)|Project Orion]], a study conducted from the 1950s to the 1960s into propelling spacecraft by detonating nuclear bombs behind them.
* [[Nuclear Cratering Group]], [[United States Army Corps of Engineers|U.S. Army Corps of Engineers]] organization at the [[Lawrence Radiation Laboratory]] focused on the use of nuclear explosives for excavation and quarrying applications

==Notes==
{{Reflist|group=lower-alpha}}

==References==
{{Reflist|22em}}

==Further reading==
* [https://web.archive.org/web/20110908174914/http://www.iaea.org/Publications/Magazines/Bulletin/Bull113/11303580312.pdf IAEA review of the 1968 book: The constructive uses of nuclear explosions by Edward Teller.]
* [http://www.princeton.edu/~ota/disk1/1989/8909/8909.PDF “The Containment of Underground Nuclear Explosions”, Project Director Gregory E van der Vink, U.S. Congress, Office of Technology Assessment, OTA-ISC-414, (Oct 1989).]

==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 | 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)}}

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[[Category:American nuclear weapons testing|Plowshare]]
[[Category:Peaceful nuclear explosions]]
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