Operation Latchkey
CountryUnited States
Test site
  • NTS Area 12, Rainier Mesa
  • NTS Area 19, 20, Pahute Mesa
  • NTS Areas 5, 11, Frenchman Flat
  • NTS, Areas 1–4, 6–10, Yucca Flat
  • Salmon Site, near Lumberton, Mississippi
Period1966–1967
Number of tests38
Max yield870 kilotons of TNT (3,600 TJ)
Previous seriesOperation Flintlock (nuclear test)
Next seriesOperation Crosstie

Operation Latchkey[1] was a series of 38 nuclear tests conducted by the United States in 1966–1967 at the Nevada Test Site. These tests followed the Operation Flintlock series and preceded the Operation Crosstie series.

Nuclear tests

Persimmon

Persimmon included a vertical line-of-sight pipe fitted with a fast-acting closure. At the time of detonation, this vacuum pipe provided a pathway for neutrons from the nuclear device to travel to instruments in a tower located above the shot hole. A few seconds after detonation, these instruments and their samples were dragged out of the tower on a sled, before the subsidence crater formed and destroyed the tower.[2]

List of the nuclear tests

United States' Latchkey series tests and detonations
Name [note 1]Date time (UT)Local time zone[note 2][3]Location[note 3]Elevation + height [note 4]Delivery [note 5]
Purpose [note 6]
Device[note 7]Yield[note 8]Fallout[note 9]ReferencesNotes
SaxonJuly 28, 1966 15:33:30.13PST (–8 hrs)
NTS Area U2cc 37.14044°N 116.13404°W1,411 m (4,629 ft) – 153.04 m (502.1 ft)underground shaft,
peaceful research
1.2 ktVenting detected, 0.5 Ci[1][4][5][6][7]Project Plowshare - excavation device development.
RovenaAugust 10, 1966 13:16:00.07PST (–8 hrs)
NTS Area U10s 37.16864°N 116.04862°W1,278 m (4,193 ft) – 195.25 m (640.6 ft)underground shaft,
weapons development
1 ktVenting detected, 2 Ci[1][4][5][6][7][8]
TangerineAugust 12, 1966 15:36:00.05PST (–8 hrs)
NTS Area U3eb 37.04629°N 116.03007°W1,199 m (3,934 ft) – 87.88 m (288.3 ft)underground shaft,
safety experiment
less than 20 kt[1][6][7]
DerringerSeptember 12, 1966 15:30:00.54PST (–8 hrs)
NTS Area U5i 36.87595°N 115.95136°W1,013 m (3,323 ft) – 255.12 m (837.0 ft)underground shaft,
weapon effect
7.8 ktVenting detected off site, 12 kCi[1][4][5][6][7][9]
DaiquiriSeptember 23, 1966 18:00:00.04PST (–8 hrs)
NTS Area U7o 37.1033°N 116.03657°W1,260 m (4,130 ft) – 561.15 m (1,841.0 ft)underground shaft,
weapons development
less than 20 kt[1][6][7]
NewarkSeptember 29, 1966 14:45:30.09PST (–8 hrs)
NTS Area U10u 37.16862°N 116.04693°W1,279 m (4,196 ft) – 228.63 m (750.1 ft)underground shaft,
weapons development
4 ktVenting detected, 290 Ci[1][4][6][7][8][10]
KhakiOctober 15, 1966 19:00:00.05PST (–8 hrs)
NTS Area U3et 37.04704°N 116.01772°W1,202 m (3,944 ft) – 232.55 m (763.0 ft)underground shaft,
weapons development
less than 20 kt[1][6][7]
SimmsNovember 5, 1966 14:45:00.0PST (–8 hrs)
NTS Area U10w 37.1699°N 116.04809°W1,279 m (4,196 ft) – 198.15 m (650.1 ft)underground shaft,
peaceful research
2.3 ktVenting detected, 11 Ci[1][4][5][6][7][8]Plowshare - evaluate clean nuclear explosives for excavation.
AjaxNovember 11, 1966 12:00:00.14PST (–8 hrs)
NTS Area U9al 37.13449°N 116.05095°W1,254 m (4,114 ft) – 238.45 m (782.3 ft)underground shaft,
weapons development
5 ktVenting detected on site, 1 Ci[1][4][5][6][7][8]
CeriseNovember 18, 1966 15:02:00.04PST (–8 hrs)
NTS Area U3eu 37.04273°N 116.0113°W1,202 m (3,944 ft) – 211.09 m (692.6 ft)underground shaft,
weapons development
7 ktI-131 venting detected, 0[1][4][6][7][8]
VigilNovember 22, 1966 15:00:00.13PST (–8 hrs)
NTS Area U10ad 37.16934°N 116.04918°W1,278 m (4,193 ft) – 93.68 m (307.3 ft)underground shaft,
safety experiment
less than 20 ktVenting detected on site, 0.0014 Ci[1][4][5][6][7]
SterlingDecember 3, 1966 12:15:00.05CST (–6 hrs)
Salmon Site, near Lumberton, Mississippi 31.14229°N 89.57001°W74 m (243 ft) – 830 m (2,720 ft)underground shaft,
joint verification
380 t[1][7]Project Vela Uniform/Dribble. Exploded inside the cavity created by Whetstone/Salmon in Tatum salt dome.
SidecarDecember 13, 1966 17:50:00.04PST (–8 hrs)
NTS Area U3ez 37.03478°N 116.00751°W1,195 m (3,921 ft) – 240.27 m (788.3 ft)underground shaft,
weapons development
1 ktVenting detected on site, 0.041 Ci[1][4][5][6][7][10]
New PointDecember 13, 1966 21:00:00.08PST (–8 hrs)
NTS Area U11c 36.8772°N 115.93875°W1,003 m (3,291 ft) – 243.84 m (800.0 ft)underground shaft,
weapon effect
7 ktVenting detected on site, 3 Ci[1][4][5][6][7][8]
GreeleyDecember 20, 1966 15:30:00.08PST (–8 hrs)
NTS Area U20g - 37.30231°N 116.40966°W1,945 m (6,381 ft) – 1,214.63 m (3,985.0 ft)underground shaft,
weapons development
870 kt[1][6][7][8]Test of Spartan warhead (W71).[11]
Rivet 1January 18, 1967 14:55:00.0PST (–8 hrs)
NTS Area U10aa 37.16507°N 116.04742°W1,276 m (4,186 ft) – 152.1 m (499 ft)underground shaft,
weapons development
150 t[1][4][6][7][10]
NashJanuary 19, 1967 16:45:00.14PST (–8 hrs)
NTS Area U2ce 37.1437°N 116.13619°W1,425 m (4,675 ft) – 363.78 m (1,193.5 ft)underground shaft,
weapons development
39 ktVenting detected off site, 69 kCi[1][4][6][7][8][10]
BourbonJanuary 20, 1967 17:40:04.41PST (–8 hrs)
NTS Area U7n 37.09981°N 116.0047°W1,306 m (4,285 ft) – 559.72 m (1,836.4 ft)underground shaft,
weapons development
41 kt[1][6][7][8][9]
Rivet 2January 26, 1967 16:30:00.0PST (–8 hrs)
NTS Area U10z 37.16475°N 116.04893°W1,274 m (4,180 ft) – 197.78 m (648.9 ft)underground shaft,
weapons development
800 tVenting detected on site, 0.1 Ci[1][4][5][6][7][10]
WardFebruary 8, 1967 15:15:00.13PST (–8 hrs)
NTS Area U10x 37.16748°N 116.04801°W1,277 m (4,190 ft) – 257.25 m (844.0 ft)underground shaft,
weapons development
11 kt[1][6][7][8][10]
PersimmonFebruary 23, 1967 18:34:00.04PST (–8 hrs)
NTS Area U3dn 37.01756°N 116.01662°W1,184 m (3,885 ft) – 299.11 m (981.3 ft)underground shaft,
weapons development
4 kt[1][6][7][8][10]
AgileFebruary 23, 1967 18:50:00.13PST (–8 hrs)
NTS Area U2v 37.12681°N 116.06726°W1,270 m (4,170 ft) – 731.52 m (2,400.0 ft)underground shaft,
weapons development
200 kt[1][6][7][8][9]
Rivet 3March 2, 1967 15:00:00.0PST (–8 hrs)
NTS Area U10y 37.16581°N 116.04957°W1,275 m (4,183 ft) – 271.27 m (890.0 ft)underground shaft,
weapons development
2.5 ktVenting detected[1][5][6][7][8]
MushroomMarch 3, 1967 15:19:00.04PST (–8 hrs)
NTS Area U3ef 37.03946°N 116.01093°W1,198 m (3,930 ft) – 179.55 m (589.1 ft)underground shaft,
weapons development
600 tVenting detected on site, 0.4 Ci[1][4][5][6][7][10]
FizzMarch 10, 1967 15:00:00.04PST (–8 hrs)
NTS Area U3fr 37.04612°N 116.03073°W1,199 m (3,934 ft) – 117.73 m (386.3 ft)underground shaft,
safety experiment
less than 20 kt[1][6][7]
OaklandApril 4, 1967 14:20:00.15PST (–8 hrs)
NTS Area U2bi 37.16195°N 116.08313°W1,321 m (4,334 ft) – 165.35 m (542.5 ft)underground shaft,
weapons development
less than 20 ktVenting detected, 100 Ci[1][5][6][7]
HeilmanApril 6, 1967 15:00:00.12PST (–8 hrs)
NTS Area U2cg 37.13728°N 116.13355°W1,405 m (4,610 ft) – 152.7 m (501 ft)underground shaft,
weapons development
less than 20 ktVenting detected on site, 8 Ci[1][4][5][6][7]
FawnApril 7, 1967 15:00:00.04PST (–8 hrs)
NTS Area U3eo 37.05439°N 116.02296°W1,206 m (3,957 ft) – 271.06 m (889.3 ft)underground shaft,
weapons development
1 kt[1][6][7][8]
ChocolateApril 21, 1967 15:09:00.04PST (–8 hrs)
NTS Area U3es 37.01928°N 116.03818°W1,186 m (3,891 ft) – 240.45 m (788.9 ft)underground shaft,
weapons development
7 kt[1][6][7][8][10]
EffendiApril 27, 1967 14:45:00.0PST (–8 hrs)
NTS Area U2ap 37.13873°N 116.06407°W1,279 m (4,196 ft) – 219.29 m (719.5 ft)underground shaft,
weapons development
800 t[1][6][7][8]
MickeyMay 10, 1967 13:40:00.041PST (–8 hrs)
NTS Area U7m 37.07781°N 115.99617°W1,278 m (4,193 ft) – 499.63 m (1,639.2 ft)underground shaft,
weapons development
22 kt[1][6][7][8][9]
CommodoreMay 20, 1967 15:00:00.2PST (–8 hrs)
NTS Area U2am 37.13011°N 116.0652°W1,271 m (4,170 ft) – 746.46 m (2,449.0 ft)underground shaft,
weapons development
250 ktVenting detected, less than 1 Ci[1][4][5][6][7][8]
ScotchMay 23, 1967 14:00:00.04PST (–8 hrs)
NTS Area U19as 37.27503°N 116.37086°W2,034 m (6,673 ft) – 977.39 m (3,206.7 ft)underground shaft,
weapons development
155 kt[1][6][7]
AbsintheMay 26, 1967 12:30:00.03PST (–8 hrs)
NTS Area U3ep 37.045°N 116.01979°W1,199 m (3,934 ft) – 118.65 m (389.3 ft)underground shaft,
safety experiment
less than 20 kt[1][6][7]
KnickerbockerMay 26, 1967 15:00:01.5PST (–8 hrs)
NTS Area U20d 37.24789°N 116.48106°W1,878 m (6,161 ft) – 630.63 m (2,069.0 ft)underground shaft,
weapons development
76 ktVenting detected, 110 Ci[1][4][5][6][7]
SwitchJune 22, 1967 13:10:00.0PST (–8 hrs)
NTS Area U9bv 37.12551°N 116.02954°W1,277 m (4,190 ft) – 301.75 m (990.0 ft)underground shaft,
peaceful research
3.1 ktVenting detected off site, less than 1 Ci[1][4][5][6][7]Project Plowshare - evaluate clean nuclear explosives for excavation.
Midi MistJune 26, 1967 16:00:00.08PST (–8 hrs)
NTS Area U12n.02 37.20206°N 116.20871°W2,200 m (7,200 ft) – 374.9 m (1,230 ft)tunnel,
weapon effect
20 ktVenting detected, 4.5 kCi[1][4][5][6][7][10]
UmberJune 29, 1967 11:25:00.04PST (–8 hrs)
NTS Area U3em 37.02849°N 116.0233°W1,188 m (3,898 ft) – 310.24 m (1,017.8 ft)underground shaft,
weapon effect
10 ktVenting detected off site, 26 kCi[1][4][6][7][8][10]
  1. ^ The US, France and Great Britain have code-named their test events, while the USSR and China did not, and therefore have only test numbers (with some exceptions – Soviet peaceful explosions were named). Word translations into English in parentheses unless the name is a proper noun. A dash followed by a number indicates a member of a salvo event. The US also sometimes named the individual explosions in such a salvo test, which results in "name1 – 1(with name2)". If test is canceled or aborted, then the row data like date and location discloses the intended plans, where known.
  2. ^ To convert the UT time into standard local, add the number of hours in parentheses to the UT time; for local daylight saving time, add one additional hour. If the result is earlier than 00:00, add 24 hours and subtract 1 from the day; if it is 24:00 or later, subtract 24 hours and add 1 to the day. All historical time zone data are derived from here:
  3. ^ Rough place name and a latitude/longitude reference; for rocket-carried tests, the launch location is specified before the detonation location, if known. Some locations are extremely accurate; others (like airdrops and space blasts) may be quite inaccurate. "~" indicates a likely pro-forma rough location, shared with other tests in that same area.
  4. ^ Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or subtracted by tower, balloon, shaft, tunnel, air drop or other contrivance. For rocket bursts the ground level is "N/A". In some cases it is not clear if the height is absolute or relative to ground, for example, Plumbbob/John. No number or units indicates the value is unknown, while "0" means zero. Sorting on this column is by elevation and height added together.
  5. ^ Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, and barge are all disallowed by the Partial Nuclear Test Ban Treaty. Sealed shaft and tunnel are underground, and remained useful under the PTBT. Intentional cratering tests are borderline; they occurred under the treaty, were sometimes protested, and generally overlooked if the test was declared to be a peaceful use.
  6. ^ Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
  7. ^ Designations for test items where known, "?" indicates some uncertainty about the preceding value, nicknames for particular devices in quotes. This category of information is often not officially disclosed.
  8. ^ Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
  9. ^ Radioactive emission to the atmosphere aside from prompt neutrons, where known. The measured species is only iodine-131 if mentioned, otherwise it is all species. No entry means unknown, probably none if underground and "all" if not; otherwise notation for whether measured on the site only or off the site, where known, and the measured amount of radioactivity released.

References

  1. ^ Yang, Xiaoping; North, Robert; Romney, Carl (August 2000), "CMR Nuclear Explosion Database (Revision 3)", SMDC Monitoring Research
  2. ^ Persimmon: A Nuclear Physics Experiment. Los Alamos Scientific Laboratory. Archived November 9, 2022 at the Wayback Machine. Retrieved 2022-09-25.
  3. ^ "Time Zone Historical Database". iana.com. Archived March 11, 2014 at the Wayback Machine. Retrieved March 8, 2014.
  4. ^ "Estimated exposures and thyroid doses received by the American people from Iodine-131 in fallout following Nevada atmospheric nuclear bomb tests, Chapter 2", National Cancer Institute, 1997, archived from the original on December 21, 2010, retrieved January 5, 2014
  5. ^ "Radiological Effluents Released from U.S. Continental Tests 1961 Through 1992 (DOE/NV-317 Rev. 1)", DOE Nevada Operations Office, August 1996, archived from the original on November 3, 2013, retrieved October 31, 2013
  6. ^ "Official list of underground nuclear explosions", Sandia National Laboratories, July 1, 1994, retrieved December 18, 2013
  7. ^ "United States Nuclear Tests: July 1945 through September 1992" (DOE/NV-209 REV15), Las Vegas, NV: Department of Energy, Nevada Operations Office, December 1, 2000, archived from the original on October 12, 2006, retrieved December 18, 2013
  8. ^ Bolt, Bruce A. (1976), "Nuclear Explosions and Earthquakes: The Parted Veil", San Francisco, CA: W.H. Freeman and Co.
  9. ^ Hechanova, Anthony E. & O'Donnell, James E. (September 25, 1998), "Estimates of yield for nuclear tests impacting the groundwater at the Nevada Test Site", Nuclear Science and Technology Division
  10. ^ Norris, Robert Standish & Cochran, Thomas B. (February 1, 1994), "United States nuclear tests, July 1945 to 31 December 1992 (NWD 94-1)", Nuclear Weapons Databook Working Paper, Washington, DC: Natural Resources Defense Council, archived from the original on October 29, 2013, retrieved October 26, 2013
  11. ^ Robert McNamara (1966-12-02). Production and Deployment of the Nike-X. Secretary of Defense McNamara Memorandum for the President. p. 24. Archived January 21, 2022 at the Wayback Machine. Retrieved 2022-06-24.