British nuclear testing in the United States

NTS series
Information
Country	United Kingdom
Test site	NTS Area 19, 20, Pahute Mesa; NTS, Areas 1-4, 6-10, Yucca Flat
Period	1962-1991
Number of tests	24
Test type	underground shaft
Max. yield	140 kilotonnes of TNT (590 TJ)
Navigation
Previous test series	Operation Vixen

Following the success of the Grapple X/Round C experiment and joining the club of thermonuclear nations (the US and the USSR at the time), Britain launched negotiations with the US to join the US in a treaty situation in which both nations could share information and material to design, test and maintain their nuclear weapons. This effort culminated in the 1958 US–UK Mutual Defence Agreement. One of the results of that treaty was that Britain was allowed to use United States' Nevada Test Site for testing their designs and ideas, and received full support from the personnel there, in exchange for the data "take" from the experiment, a mutual condition. In effect the NTS became Britain's test ground, subject only to advanced planning and integrating their testing into that of the United States. This resulted in 24 tests with 24 devices tested underground at the NTS from 1958 through the end of nuclear testing in the US in September 1992.

United Kingdom's NTS series tests and detonations

Name [note 1]	Date time (UT)	Local time zone [note 2][1]	Location [note 3]	Elevation + height [note 4]	Delivery, [note 5] Purpose [note 6]	Device [note 7]	Yield [note 8]	Fallout [note 9]	References	Notes
Nougat/Pampas	1 March 1962 19:10:00.09	PST (-8 hrs)	NTS Area U3al 37°02′28″N 116°01′46″W / 37.04118°N 116.02952°W	1,196 m (3,924 ft) - 363.14 m (1,191.4 ft)	underground shaft,		9.5 kt	Venting detected off site, 2 kCi (74 TBq)	[2][3][4][5][6][7]
Storax/Tendrac	7 December 1962 19:00:00.1	PST (-8 hrs)	NTS Area U3ba 37°03′06″N 116°01′48″W / 37.05174°N 116.03002°W	1,202 m (3,944 ft) - 302.67 m (993.0 ft)	underground shaft,		10 kt		[3][4][5][6][7]	Possible test of using fuel grade plutonium, a non-proliferation test. See wiki Reactor-grade plutonium.
Whetstone/Cormorant	17 July 1964 17:18:30.03	PST (-8 hrs)	NTS Area U3df 37°01′03″N 116°01′46″W / 37.01761°N 116.02956°W	1,184 m (3,885 ft) - 271.64 m (891.2 ft)	underground shaft,		2 kt	Venting detected on site, 11 Ci (410 GBq)	[2][4][5][6][7][8]
Whetstone/Courser	25 September 1964 17:02:00.03	PST (-8 hrs)	NTS Area U3do 37°04′21″N 116°00′58″W / 37.07245°N 116.01614°W	1,237 m (4,058 ft) - 358.99 m (1,177.8 ft)	underground shaft,		no yield		[4][6][7]
Flintlock/Charcoal	10 September 1965 17:12:00.03	PST (-8 hrs)	NTS Area U7g 37°04′41″N 116°01′03″W / 37.07797°N 116.01745°W	1,245 m (4,085 ft) - 455.44 m (1,494.2 ft)	underground shaft, weapons development	Polaris warhead?	29 kt		[4][5][6][7][9]
Arbor/Fallon	23 May 1974 13:38:30.164	PST (-8 hrs)	NTS Area U2dv 37°07′28″N 116°04′47″W / 37.12455°N 116.07975°W	1,276 m (4,186 ft) - 466.04 m (1,529.0 ft)	underground shaft, weapons development	Chevaline warhead?	20 kt	Venting detected, 72 Ci (2,700 GBq)	[2][4][5][6][7]
Anvil/Banon	26 August 1976 14:30:00.168	PST (-8 hrs)	NTS Area U2dz 37°07′31″N 116°04′59″W / 37.125199°N 116.083193°W	1,275 m (4,183 ft) - 536.4 m (1,760 ft)	underground shaft, weapons development	Chevaline warhead?	51 kt	Venting detected, 6 Ci (220 GBq)	[2][4][5][6][7][9]
Cresset/Fondutta	11 April 1978 15:30:00.161	PST (-8 hrs)	NTS Area U19zs 37°17′59″N 116°19′36″W / 37.29963°N 116.3267°W	2,072 m (6,798 ft) - 633.07 m (2,077.0 ft)	underground shaft, weapons development	Chevaline warhead?	67 kt		[4][5][6][7][9]
Quicksilver/Quargel	18 November 1978 19:00:00.166	PST (-8 hrs)	NTS Area U2fb 37°07′36″N 116°05′05″W / 37.12675°N 116.08484°W	1,275 m (4,183 ft) - 542 m (1,778 ft)	underground shaft,	Chevaline warhead?	38 kt	Venting detected, 7 Ci (260 GBq)	[2][4][5][6][7][9]
Quicksilver/Nessel	29 August 1979 15:08:00.171	PST (-8 hrs)	NTS Area U2ep 37°07′16″N 116°04′00″W / 37.12122°N 116.06659°W	1,260 m (4,130 ft) - 464 m (1,522 ft)	underground shaft,	Chevaline warhead?	20 kt	Venting detected	[4][5][6][7][9]
Tinderbox/Colwick	26 April 1980 17:00:00.083	PST (-8 hrs)	NTS Area U20ac 37°14′54″N 116°25′23″W / 37.24838°N 116.42311°W	1,946 m (6,385 ft) - 633 m (2,077 ft)	underground shaft,	Chevaline warhead?	140 kt	Venting detected	[4][5][6][7][9]
Guardian/Dutchess	24 October 1980 19:15:00.116	PST (-8 hrs)	NTS Area U7bm 37°04′28″N 116°00′00″W / 37.07456°N 116.00003°W	1,265 m (4,150 ft) - 426.72 m (1,400.0 ft)	underground shaft,		10 kt		[4][5][6][7]
Guardian/Serpa	17 December 1980 15:10:00.086	PST (-8 hrs)	NTS Area U19ai 37°19′29″N 116°18′58″W / 37.32476°N 116.31608°W	2,028 m (6,654 ft) - 572.7 m (1,879 ft)	underground shaft,	Chevaline warhead?	35 kt		[4][5][6][7][9]
Praetorian/Rousanne	12 November 1981 15:00:00.1	PST (-8 hrs)	NTS Area U4p 37°06′29″N 116°03′00″W / 37.10805°N 116.04993°W	1,243 m (4,078 ft) - 517.2 m (1,697 ft)	underground shaft,	Chevaline warhead?	77 kt		[4][5][6][7][9]
Praetorian/Gibne	25 April 1982 18:05:00.008	PST (-8 hrs)	NTS Area U20ah 37°15′21″N 116°25′24″W / 37.2558°N 116.42327°W	1,937 m (6,355 ft) - 570 m (1,870 ft)	underground shaft,	Chevaline warhead?	89 kt	Venting detected, 0.1 Ci (3.7 GBq)	[2][4][5][6][7][9]
Phalanx/Armada	22 April 1983 13:53:00.085	PST (-8 hrs)	NTS Area U9cs 37°06′41″N 116°01′23″W / 37.11144°N 116.02319°W	1,296 m (4,252 ft) - 265 m (869 ft)	underground shaft,	Trident warhead?	1.5 kt	I-131 venting detected, 0	[2][4][5][6][7][10]
Fusileer/Mundo	1 May 1984 19:05:00.093	PST (-8 hrs)	NTS Area U7bo 37°06′22″N 116°01′24″W / 37.10612°N 116.02322°W	1,292 m (4,239 ft) - 566 m (1,857 ft)	underground shaft, weapons development	Trident warhead?	77 kt		[4][5][6][7][9]
Grenadier/Egmont	9 December 1984 19:40:00.089	PST (-8 hrs)	NTS Area U20al 37°16′12″N 116°29′55″W / 37.27004°N 116.4985°W	1,839 m (6,033 ft) - 546 m (1,791 ft)	underground shaft, weapons development	Trident warhead?	103 kt		[4][5][6][7][9]
Charioteer/Kinibito	5 December 1985 15:00:00.067	PST (-8 hrs)	NTS Area U3me 37°03′11″N 116°02′47″W / 37.05313°N 116.04628°W	1,208 m (3,963 ft) - 579.42 m (1,901.0 ft)	underground shaft, weapons development	Trident warhead?	110 kt		[4][5][6][7][9]
Charioteer/Darwin	25 June 1986 20:27:45.092	PST (-8 hrs)	NTS Area U20aq 37°15′52″N 116°30′02″W / 37.26451°N 116.50045°W	1,849 m (6,066 ft) - 548.95 m (1,801.0 ft)	underground shaft, weapons development	Trident warhead?	89 kt		[4][5][6][7][9]
Musketeer/Midland	16 July 1987 19:00:00.077	PST (-8 hrs)	NTS Area U7by 37°06′13″N 116°01′27″W / 37.10361°N 116.02413°W	1,284 m (4,213 ft) - 486.77 m (1,597.0 ft)	underground shaft,	Trident warhead?	20 kt		[4][5][6][7][9]
Aqueduct/Barnwell	8 December 1989 15:00:00.087	PST (-8 hrs)	NTS Area U20az 37°13′52″N 116°24′37″W / 37.23115°N 116.41032°W	2,031 m (6,663 ft) - 600.8 m (1,971 ft)	underground shaft, weapons development	Trident warhead?	120 kt	Venting detected, 0.1 Ci (3.7 GBq)	[2][4][5][6][7][9]
Sculpin/Houston	14 November 1990 19:17:00.071	PST (-8 hrs)	NTS Area U19az 37°13′38″N 116°22′20″W / 37.22735°N 116.37217°W	2,031 m (6,663 ft) - 594.4 m (1,950 ft)	underground shaft, weapons development	Trident warhead?	103 kt	Venting detected	[4][5][6][7][9]
Julin/Bristol	26 November 1991 18:35:00.073	PST (-8 hrs)	NTS Area U4av 37°05′47″N 116°04′14″W / 37.09644°N 116.07047°W	1,246 m (4,088 ft) - 457 m (1,499 ft)	underground shaft, weapons development	Trident Low Yield warhead?	11 kt		[4][5][6][7][9]

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 timezone 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. "Timezone Historical Database". iana.com. Retrieved March 8, 2014.
2. "Estimated exposures and thyroid doses received by the American people from Iodine-131 in fallout following Nevada atmospheric nuclear bomb tests, Chapter 2" (PDF). National Cancer Institute. 1997. Retrieved January 5, 2014.
3. Bolt, Bruce A. (1976). Nuclear Explosions and Earthquakes: The Parted Veil. San Francisco, CA: W.H. Freeman and Co.
4. Official list of underground nuclear explosions (Technical report). Sandia National Laboratories. July 1, 1994. Retrieved December 18, 2013.
5. Norris, Robert S.; Burrows, Andrew S.; Fieldhouse, Richard W. (1994). Nuclear Weapons Databook, Vol. 5: British, French, and Chinese Nuclear Weapons. Boulder, CO: Westview Press.
6. United States Nuclear Tests: July 1945 through September 1992 (PDF) (DOE/NV-209 REV15). Las Vegas, NV: Department of Energy, Nevada Operations Office. December 1, 2000. Archived from the original (PDF) on June 15, 2010. Retrieved December 18, 2013.
7. Yang, Xiaoping; North, Robert; Romney, Carl (August 2000). CMR Nuclear Explosion Database (Revision 3) (Technical report). SMDC Monitoring Research.
8. "Nuclear explosion database". SMDC. 2004. Retrieved January 3, 2014.
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 (Technical report). Nuclear Science and Technology Division.
10. Radiological Effluents Released from U.S. Continental Tests 1961 Through 1992 (DOE/NV-317 Rev. 1) (PDF) (Technical report). DOE Nevada Operations Office. August 1996. Retrieved October 31, 2013.