Operation Bedrock

Operation Bedrock
Information
Country	United States
Test site	NTS Area 12, Rainier Mesa; NTS Area 19, 20, Pahute Mesa; NTS, Areas 1-4, 6-10, Yucca Flat
Period	1974-1975
Number of tests	27
Test type	underground shaft, underground tunnel
Max. yield	750 kilotonnes of TNT (3,100 TJ)
Navigation
Previous test series	Operation Arbor
Next test series	Operation Anvil (Nuclear test)

The United States's Bedrock nuclear test series^[1] was a group of 27 nuclear tests conducted in 1974-1975. These tests ^{[note 1]} followed the Operation Arbor series and preceded the Operation Anvil series.

United States' Bedrock series tests and detonations

Name [note 2]	Date time (UT)	Local time zone [note 3][2]	Location [note 4]	Elevation + height [note 5]	Delivery [note 6] Purpose [note 7]	Device [note 8]	Yield [note 9]	Fallout [note 10]	References	Notes
Escabosa	10 July 1974 16:00:00.092	PST (-8 hrs)	NTS Area U7ac 37°04′30″N 116°01′58″W / 37.07498°N 116.03269°W	1,223 m (4,012 ft) - 638.52 m (2,094.9 ft)	underground shaft, weapons development		150 kt	I-131 venting detected, 0	[1][3][4][5][6][7]
Crestlake-Briar - 1	18 July 1974 14:00:01.2	PST (-8 hrs)	NTS Area U2dw 37°07′09″N 116°05′10″W / 37.11928°N 116.08601°W	1,274 m (4,180 ft) - 373.68 m (1,226.0 ft)	underground shaft, weapons development		less than 20 kt	Venting detected	[1][5][6][7]	Simultaneous, same hole.
Crestlake-Tansan - 2	18 July 1974 14:00:01.2	PST (-8 hrs)	NTS Area U2dw 37°07′09″N 116°05′10″W / 37.11928°N 116.08601°W	1,274 m (4,180 ft) - 272 m (892 ft)	underground shaft, weapons development		2 kt	Venting detected, 19 Ci (700 GBq)	[1][5][6][7][8]	Simultaneous, same hole.
Puye	14 August 1974 14:00:00.11	PST (-8 hrs)	NTS Area U3jl 37°01′24″N 116°02′14″W / 37.02342°N 116.03713°W	1,188 m (3,898 ft) - 430.08 m (1,411.0 ft)	underground shaft, weapons development		5 kt	I-131 venting detected, 0.000002 Ci (7.4×10^−5 GBq)	[1][3][4][5][6][7]
Portmanteau	30 August 1974 15:00:00.163	PST (-8 hrs)	NTS Area U2ax 37°09′09″N 116°05′04″W / 37.1524°N 116.08456°W	1,313 m (4,308 ft) - 655.32 m (2,150.0 ft)	underground shaft, weapons development		160 kt		[1][3][6][7][8]
Pratt	25 September 1974 14:00:00.08	PST (-8 hrs)	NTS Area U3hq 37°00′44″N 116°01′52″W / 37.01211°N 116.03103°W	1,183 m (3,881 ft) - 313.96 m (1,030.1 ft)	underground shaft, weapons development		5 kt		[1][6][7]
Trumbull	26 September 1974 14:30:00.164	PST (-8 hrs)	NTS Area U4aa 37°05′35″N 116°05′44″W / 37.09316°N 116.09563°W	1,269 m (4,163 ft) - 262.74 m (862.0 ft)	underground shaft, weapons development		200 t		[1][6][7][9]
Stanyan	26 September 1974 15:05:00.17	PST (-8 hrs)	NTS Area U2aw 37°07′57″N 116°04′09″W / 37.13258°N 116.06926°W	1,275 m (4,183 ft) - 573.02 m (1,880.0 ft)	underground shaft, weapons development		100 kt		[1][3][6][7]
Estaca	17 October 1974 17:13:00.118	PST (-8 hrs)	NTS Area U3ja 37°00′23″N 116°00′56″W / 37.00639°N 116.01559°W	1,180 m (3,870 ft) - 321.05 m (1,053.3 ft)	underground shaft, weapons development		less than 20 kt		[1][6][7]
Hybla Fair	28 October 1974 15:00:00.168	PST (-8 hrs)	NTS Area U12n.09 37°12′04″N 116°12′17″W / 37.20108°N 116.20482°W	2,227 m (7,306 ft) - 404.47 m (1,327.0 ft)	underground tunnel, weapon effect		less than 20 kt	Venting detected, 500 Ci (18,000 GBq)	[1][4][5][6][7]	Test of a new line-of-sight pipe configuration for tunnel testing, basic measurements of blast parameters. The configuration proved to be inadequate for effects testing of warheads.
Temescal	2 November 1974 15:30:00.164	PST (-8 hrs)	NTS Area U4ab 37°05′35″N 116°05′33″W / 37.09314°N 116.09254°W	1,263 m (4,144 ft) - 262.74 m (862.0 ft)	underground shaft, weapons development		less than 20 kt	Venting detected, 2 Ci (74 GBq)	[1][5][6][7]
Puddle	26 November 1974 15:00:00.9	PST (-8 hrs)	NTS Area U3kg 37°00′04″N 116°00′43″W / 37.00098°N 116.01207°W	1,169 m (3,835 ft) - 183.97 m (603.6 ft)	underground shaft, safety experiment		less than 20 kt		[1][6][7]
Keel	16 December 1974 17:30:00.088	PST (-8 hrs)	NTS Area U3hu 37°00′41″N 116°01′06″W / 37.01136°N 116.01833°W	1,182 m (3,878 ft) - 304.72 m (999.7 ft)	underground shaft, weapons development		4 kt		[1][3][6][7][9]
Portola - 1	6 February 1975 15:30:00.165	PST (-8 hrs)	NTS Area U10bb 37°10′42″N 116°03′09″W / 37.17836°N 116.05243°W	1,285 m (4,216 ft) - 198.12 m (650.0 ft)	underground shaft, weapons development		350 t	Venting detected, 10 Ci (370 GBq)	[1][5][6][7][9]	Simultaneous, same hole.
Portola-Larkin - 2	6 February 1975 15:30:00.16	PST (-8 hrs)	NTS Area U10bb 37°10′42″N 116°03′09″W / 37.17836°N 116.05243°W	1,285 m (4,216 ft) - 274 m (899 ft)	underground shaft, weapons development		less than 20 kt	Venting detected	[1][5][6][7]	Simultaneous, same hole.
Teleme	6 February 1975 16:13:00.17	PST (-8 hrs)	NTS Area U9cl 37°06′51″N 116°01′18″W / 37.11422°N 116.02166°W	1,300 m (4,300 ft) - 304.8 m (1,000 ft)	underground shaft, weapons development		6 kt		[1][6][7][8][9]
Bilge	19 February 1975 20:10:00.224	PST (-8 hrs)	NTS Area U3kc 37°00′08″N 116°01′31″W / 37.00219°N 116.02527°W	1,179 m (3,868 ft) - 318.35 m (1,044.5 ft)	underground shaft, weapons development		less than 20 kt	Venting detected	[1][5][6][7]
Topgallant	28 February 1975 16:15:00.09	PST (-8 hrs)	NTS Area U4e 37°06′22″N 116°03′26″W / 37.10615°N 116.05712°W	1,245 m (4,085 ft) - 713.37 m (2,340.5 ft)	underground shaft, weapons development		160 kt		[1][3][6][7][8]
Cabrillo	7 March 1975 16:00:00.169	PST (-8 hrs)	NTS Area U2dr 37°08′02″N 116°05′07″W / 37.13402°N 116.0852°W	1,288 m (4,226 ft) - 600.46 m (1,970.0 ft)	underground shaft, weapons development		89 kt	Venting detected, 11 Ci (410 GBq)	[1][3][4][5][6][7]
Dining Car	5 April 1975 19:45:00.187	PST (-8 hrs)	NTS Area U12e.18 37°11′16″N 116°12′53″W / 37.18787°N 116.21476°W	2,238 m (7,343 ft) - 383.01 m (1,256.6 ft)	underground tunnel, weapon effect		20 kt		[1][3][6][7][9]
Edam	24 April 1975 14:10:00.17	PST (-8 hrs)	NTS Area U2dy 37°06′56″N 116°05′17″W / 37.11569°N 116.08811°W	1,272 m (4,173 ft) - 411.48 m (1,350.0 ft)	underground shaft, weapons development		20 kt		[1][3][6][7][9]
Obar	30 April 1975 15:00:00.9	PST (-8 hrs)	NTS Area U7ag 37°06′32″N 116°01′47″W / 37.10881°N 116.02967°W	1,279 m (4,196 ft) - 568.8 m (1,866 ft)	underground shaft, weapons development		38 kt		[1][3][6][7]
Tybo	14 May 1975 14:00:00.16	PST (-8 hrs)	NTS Area U20y 37°13′15″N 116°28′31″W / 37.22071°N 116.47527°W	1,880 m (6,170 ft) - 765.05 m (2,510.0 ft)	underground shaft, weapons development		380 kt		[1][3][6][7][9]
Stilton	3 June 1975 14:20:00.17	PST (-8 hrs)	NTS Area U20p 37°20′24″N 116°31′26″W / 37.34°N 116.52377°W	1,667 m (5,469 ft) - 731.52 m (2,400.0 ft)	underground shaft, weapons development		200 kt		[1][3][6][7][9]
Mizzen	3 June 1975 14:40:00.106	PST (-8 hrs)	NTS Area U7ah 37°05′41″N 116°02′13″W / 37.09478°N 116.03697°W	1,247 m (4,091 ft) - 637.18 m (2,090.5 ft)	underground shaft, weapons development		140 kt		[1][3][6][7][8]
Alviso	11 June 1975 13:00:00.167	PST (-8 hrs)	NTS Area U2du 37°06′42″N 116°04′28″W / 37.11173°N 116.07457°W	1,261 m (4,137 ft) - 183 m (600 ft)	underground shaft, safety experiment		less than 20 kt		[1][6][7]
Futtock	18 June 1975 11:49:00.092	PST (-8 hrs)	NTS Area U3eh 37°03′56″N 116°01′22″W / 37.06562°N 116.02271°W	1,221 m (4,006 ft) - 186.56 m (612.1 ft)	underground shaft, safety experiment		less than 20 kt		[1][6][7]
Mast	19 June 1975 13:00:00.09	PST (-8 hrs)	NTS Area U19u 37°21′01″N 116°19′16″W / 37.35029°N 116.3211°W	2,068 m (6,785 ft) - 910.7 m (2,988 ft)	underground shaft, weapons development		520 kt		[1][3][6][7][9]
Camembert	26 June 1975 12:30:00.161	PST (-8 hrs)	NTS Area U19q 37°16′44″N 116°22′10″W / 37.27887°N 116.36947°W	2,033 m (6,670 ft) - 1,310.64 m (4,300.0 ft)	underground shaft, weapons development		750 kt		[1][3][6][7][9]

1. A bomb test may be a salvo test, defined as two or more explosions "where a period of time between successive individual explosions does not exceed 5 seconds and where the burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points and does not exceed 40 kilometers in length". Mikhailov, V. N., Editor in Chief. "Catalog of World Wide Nuclear Testing". Begell-Atom, LLC.
2. 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.
3. 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:
4. 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.
5. 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.
6. 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.
7. Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
8. 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.
9. Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
10. 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. "Timezone Historical Database". iana.com. Retrieved March 8, 2014.
3. Hechanova, Anthony E.; O'Donnell, James E. (1998-09-25), Estimates of yield for nuclear tests impacting the groundwater at the Nevada Test Site, Nuclear Science and Technology Division
4. 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 2014-01-05
5. Radiological Effluents Released from U.S. Continental Tests 1961 Through 1992 (DOE/NV-317 Rev. 1) (PDF), DOE Nevada Operations Office, August 1996, retrieved 2013-10-31
6. Official list of underground nuclear explosions, Sandia National Laboratories, 1994-07-01, retrieved 2013-12-18
7. United States Nuclear Tests: July 1945 through September 1992 (PDF) (DOE/NV-209 REV15), Las Vegas, NV: Department of Energy, Nevada Operations Office, 2000-12-01, retrieved 2013-12-18
8. Operation Argus, 1958 (DNA6039F), Washington, DC: Defense Nuclear Agency, Department of Defense, retrieved 26 November 2013
9. Norris, Robert Standish; Cochran, Thomas B. (1 February 1994), "United States nuclear tests, July 1945 to 31 December 1992 (NWD 94-1)" (PDF), Nuclear Weapons Databook Working Paper, Washington, DC: Natural Resources Defense Council, retrieved 2013-10-26