Editing Nuclear weapons testing (section)

==Alternatives to full-scale testing==
[[File:NTS - LLNL subcritical experiment.jpg|thumb|upright|Subcritical experiment at the [[Nevada National Security Site]] ]]{{See also|Stockpile stewardship}}
Since the 1996 [[Comprehensive Nuclear-Test-Ban Treaty]], "nuclear explosions" of all kinds are banned. Nuclear nations have invested in many alternatives to maintain confidence in weapon capability:

* [[Computer simulation|Computer simulation]] is used extensively to provide as much information as possible without physical testing. Mathematical models for such simulation model scenarios not only of performance but also of [[shelf life]] and [[maintenance]].<ref name="Scoles-2023-04-20">{{cite news |last1=Scoles |first1=Sarah |title=Trust but verify: U.S. labs are overhauling the nuclear stockpile. Can they validate the weapons without bomb tests? |url=https://www.science.org/content/article/trust-verify-can-u-s-certify-new-nuclear-weapons-without-detonating-them |work=Science |date=2023-04-20}}</ref><ref name="Hoffman-2011">{{cite news |last1=Hoffman |first1=David E. |title=Supercomputers offer tools for nuclear testing — and solving nuclear mysteries |url=https://www.washingtonpost.com/national/national-security/supercomputers-offer-tools-for-nuclear-testing--and-solving-nuclear-mysteries/2011/10/03/gIQAjnngdM_story.html |newspaper=Washington Post |date=2011-11-01}}</ref> A theme has generally been that even though simulations cannot fully replace physical testing, they can reduce the amount of it that is necessary.<ref name="AP-2006-10-18">{{cite news |last1=Associated Press |title=Supercomputers can't perfectly simulate nuclear blasts: Experts |url=https://www.cbc.ca/news/science/supercomputers-can-t-perfectly-simulate-nuclear-blasts-experts-1.597887 |work=CBC News |date=2006-10-18}}</ref>

* Physical testing
** Materials testing
*** Subcritical (or cold) tests involving fissile materials and [[high explosives]] that purposely result in no [[nuclear weapon yield|yield]]. The name refers to the lack of creation of a [[critical mass]] of fissile material. Subcritical tests continue to be performed by the United States, Russia, and the People's Republic of China, at least.<ref>{{cite web |date=2012-12-07 |title=US conducts 'subcritical' nuclear test |url=http://zeenews.india.com/news/world/us-conducts-subcritical-nuclear-test_815260.html |access-date=2013-05-28 |website=zeenews.india.com}}</ref><ref>{{cite web |author=Thomas Nilsen |date=2 October 2012 |title=Subcritical nuke tests may be resumed at Novaya Zemlya |url=http://barentsobserver.com/en/security/subcritical-nuke-tests-may-be-resumed-novaya-zemlya-02-10 |access-date=2017-07-13 |website=barentsobserver.com}}</ref> 
*** Proxy isotope testing: high temperature/density/pressure compression testing of non-fissile isotopes such as [[plutonium-242]] or [[uranium-238]], to determine a bomb core's relevant [[equation of state]].
** Fission testing
*** [[Critical mass]] experiments studying fissile material compositions, densities, geometries, and [[Neutron reflector|reflectors]]. They can be subcritical or supercritical, in which case significant radiation fluxes can be produced. This type of test has resulted in several [[criticality accident]]s.
*** Hydronuclear tests (hydrodynamical + nuclear) study nuclear materials under the conditions of explosive shock compression. They can create subcritical conditions, or supercritical conditions with yields ranging from negligible all the way up to a substantial fraction of full weapon yield.<ref>{{Citation |author=Carey Sublette |title=Nuclear Weapons Frequently Asked Questions |date=9 August 2001 |url=http://nuclearweaponarchive.org/Nwfaq/Nfaq4-1.html#Nfaq4.1.9 |access-date=10 April 2011 |at=section 4.1.9}}</ref> Any fission yield is considered banned by the CTBT.
** Fusion testing: [[inertial confinement fusion]] experiments using lasers, like the [[National Ignition Facility]], or magnetized liners, like the [[Z Pulsed Power Facility]], or projectile compression. They study the plasma physics and [[Fusion ignition|ignition]] of deuterium-tritium mixtures. 

Subcritical tests executed by the United States include:<ref>{{cite journal|last1=Papazian|first1=Ghazar R.|last2=Reinovsky|first2=Robert E.|last3=Beatty|first3=Jerry N.|url=https://fas.org/sgp/othergov/doe/lanl/pubs/las28/papazian.pdf|access-date=2013-12-12|title=The New World of the Nevada Test Site|journal=Los Alamos Science|issue=28|year=2003}}</ref><ref>{{cite journal|last1=Thorn|first1=Robert N.|first2=Donald R.|last2=Westervelt|date=February 1, 1987|title=Hydronuclear Experiments|journal=LANL Report LA-10902-MS|url=https://fas.org/sgp/othergov/doe/lanl/docs1/00090266.pdf|access-date=December 9, 2013}}</ref><ref>{{cite journal |last=Conrad |first=David C. |date=July 1, 2000 |title=Underground explosions are music to their ears |journal=Science and Technology Review |url=http://www.llnl.gov/str/Conrad.html |access-date=9 December 2013}}</ref>

{| class="wikitable sortable"
 |+Subcritical Tests
 |-
 !style="background:#efefef;" | Name
 !style="background:#efdead;" | Date Time ([[Universal Time|UT]]{{efn|Universal Time at the [[Nevada National Security Site]] is 8 hours after local time; UT dates are one day after local date for UT times after 16:00.}})
 !style="background:#efefef;" | Location
 !style="background:#efdead;" | Elevation + Height
 !style="background:#efefef;" | Notes
 |-
 ! A series of 50 tests
 | {{dts|1960-1-1}} 
 | [[Los Alamos National Lab]] Test Area 49 {{coord|35.82289|-106.30216|display=inline}}
 | {{sort|002163|}}{{convert|2183|m}} and {{convert|20|m}}
 | Series of 50 tests during US/USSR joint nuclear test ban.<ref>{{Cite report |title=Nevada Test Site: U1a Complex subcritical experiments |url=http://www.nv.doe.gov/news&pubs/dirpdfs/DOENV708_REV1_U1a.pdf |archive-url=https://web.archive.org/web/20030517214406/http://www.nv.doe.gov/news&pubs/dirpdfs/DOENV708_REV1_U1a.pdf |archive-date=17 May 2003 |url-status=dead |publisher=DOE Nevada |date=February 2003 }}</ref>
 |-
 ! ''Odyssey''
 | {{dts|}} 
 | [[Nevada National Security Site|NTS]] Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 |
 |-
 ! ''Trumpet''
 | {{dts|}} 
 | NTS Area U1a-102D {{coord|37.01099|-116.05848|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 |
 |-
 ! ''Kismet''
 | {{dts|1995-03-01}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000929|}}{{convert|1222|m}} and {{convert|293|m}}
 | Kismet was a proof of concept for modern hydronuclear tests; it did not contain any SNM (Special Nuclear Material—plutonium or uranium).
 |-
 ! ''Rebound''
 | {{dts|1997-07-02}} 10:—:—
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000929|}}{{convert|1222|m}} and {{convert|293|m}}
 | Provided information on the behavior of new plutonium alloys compressed by high-pressure shock waves; same as Stagecoach but for the age of the alloys.
 |-
 ! ''Holog''
 | {{dts|1997-09-18}} 
 | NTS Area U1a.101A {{coord|37.01036|-116.05888|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Holog and Clarinet may have switched locations.
 |-
 ! ''Stagecoach''
 | {{dts|1998-03-25}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Provided information on the behavior of aged (up to 40 years) plutonium alloys compressed by high-pressure shock waves.
 |-
 ! ''Bagpipe''
 | {{dts|1998-09-26}} 
 | NTS Area U1a.101B {{coord|37.01021|-116.05886|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Cimarron''
 | {{dts|1998-12-11}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Plutonium surface ejecta studies.
 |-
 ! ''Clarinet''
 | {{dts|1999-02-09}} 
 | NTS Area U1a.101C {{coord|37.01003|-116.05898|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Holog and Clarinet may have switched places on the map.
 |-
 ! ''Oboe''
 | {{dts|1999-09-30}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 2''
 | {{dts|1999-11-09}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 3''
 | {{dts|2000-02-03}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Thoroughbred''
 | {{dts|2000-03-22}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Plutonium surface ejecta studies, followup to Cimarron.
 |-
 ! ''Oboe 4''
 | {{dts|2000-04-06}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 5''
 | {{dts|2000-08-18}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 6''
 | {{dts|2000-12-14}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 8''
 | {{dts|2001-09-26}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 7''
 | {{dts|2001-12-13}} 
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Oboe 9''
 | {{dts|2002-06-07}} 21:46:—
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Mario''
 | {{dts|2002-08-29}} 19:00:—
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Plutonium surface studies (optical analysis of spall). Used wrought plutonium from Rocky Flats.
 |-
 ! ''Rocco''
 | {{dts|2002-09-26}} 19:00:—
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Plutonium surface studies (optical analysis of spall), followup to Mario. Used cast plutonium from Los Alamos.
 |-
 ! ''Piano''
 | {{dts|2003-09-19}} 20:44:—
 | NTS Area U1a.102C {{coord|37.01095|-116.05877|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | 
 |-
 ! ''Armando''
 | {{dts|2004-05-25}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|000932|}}{{convert|1222|m}} and {{convert|290|m}}
 | Plutonium spall measurements using x-ray analysis.{{efn|{{YouTube|EFUUE5shMLc|A video of the ''Armando'' test}}}}
 |-
 ! ''Step Wedge''
 | {{dts|2005-04-01}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | April–May 2005, a series of mini-hydronuclear experiments interpreting Armando results.
 |-
 ! ''Unicorn''
 | {{dts|2006-08-31}} 01:00:—
 | NTS Area U6c {{coord|36.98663|-116.0439|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | "...confirm nuclear performance of the W88 warhead with a newly-manufactured pit."  Early pit studies.
 |-
 ! ''Thermos''
 | {{dts|2007-01-01}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | February 6 – May 3, 2007, 12 mini-hydronuclear experiments in thermos-sized flasks.
 |-
 ! ''Bacchus''
 | {{dts|2010-09-16}} 
 | NTS Area U1a.05? {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | 
 |-
 ! ''Barolo A''
 | {{dts|2010-12-01}} 
 | NTS Area U1a.05? {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | 
 |-
 ! ''Barolo B''
 | {{dts|2011-02-02}} 
 | NTS Area U1a.05? {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | 
 |-
 ! ''Castor''
 | {{dts|2012-09-01}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | Not even a subcritical, contained no plutonium; a dress rehearsal for Pollux.
 |-
 ! ''Pollux''
 | {{dts|2012-12-05}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | A subcritical test with a scaled-down warhead mockup.{{efn|{{YouTube|bGf4-ZOjyVY|A video of the ''Pollux'' test|link=no}}}}
 |-
 ! ''Leda''
 | {{dts|2014-06-15}} 
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | Like ''Castor'', the plutonium was replaced by a surrogate; this is a dress rehearsal for the later ''Lydia''.  The target was a weapons pit mock-up.{{efn|{{YouTube|vmsfgRtxbHg|A video of the ''Leda'' test|link=no}}}}
 |-
 ! ''Lydia''
 | {{dts|2015-01-01|format=hide}}??-??-2015
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | {{sort|001032|}}{{convert|1222|m}} and {{convert|190|m}}
 | Expected to be a plutonium subcritical test with a scaled-down warhead mockup.{{citation needed|date=April 2017}}
 |-
 ! ''Vega''
 | {{dts|2017-12-13}}
 | Nevada test site
 | 
 | Plutonium subcritical test with a scaled down warhead mockup.<ref>{{Cite web |first=Andrew |last=Kishner |date=18 September 2018 |title=U.S. Sneaks in 'Vega,' Its 28th Subcritical Nuclear Test |url=http://andrewkishner.com/vega.htm |access-date=30 October 2019}}</ref>
 |-
 ! ''Ediza''
 | {{dts|2019-02-13}}
 | NTS Area U1a {{coord|37.01139|-116.05983|display=inline}}
 | 
 | Plutonium subcritical test designed to confirm supercomputer simulations for stockpile safety.<ref>{{cite web |last=O'Brien |first=Nolan |url=https://www.llnl.gov/news/subcritical-experiment-captures-scientific-measurements-advance-stockpile-safety |title=Subcritical experiment captures scientific measurements to advance stockpile safety |work=[[Lawrence Livermore National Laboratory|LLNL]] |date=24 May 2019 |access-date=16 January 2021}}</ref>
 |-
 ! ''Nightshade A''
 | {{dts|2020-11}}
 | Nevada test site
 | 
 | Plutonium subcritical test designed to measure ejecta emission.<ref>{{cite web |url=https://www3.nhk.or.jp/nhkworld/en/news/20210116_12/ |title=US conducted subcritical nuclear test in November |work=[[NHK World-Japan]] |date=16 January 2021 |access-date=16 January 2021}}</ref><ref>{{cite report |last1=Danielson |first1=Jeremy |last2=Bauer |first2=Amy L. |title=Nightshade Prototype Experiments (Silverleaf) |work=[[Los Alamos National Laboratory]] |publisher=[[Office of Scientific and Technical Information|OSTI]] |date=September 2016 |doi=10.2172/1338708|osti=1338708 |doi-access=free }}</ref>
 |}