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Operation Nougat

September 1961 to 30 June 1962

Nevada Test Site

Last changed 3 January 2005
In it closing days, the Eisenhower administration initiated negotitations on a nuclear test ban with the Soviet Union (this intention was announced by Eisenhower on 22 August 1958). As an important confidence building measure, Eisenhower also announced a one-year voluntary moratorium on nuclear testing (if the Soviets made a reciprocal commitment) would go into effect on 31 October 1958. This ban was later extended to 13 months (31 December 1959), but on 29 December 1959 the U.S. announced an end to the voluntary moratorium although it also promised not the renew testing without advance public notice. This decision not the extend the formal moratorium commitment may have been due to the status of the negotiations, which were faring very poorly. On 3 January 1960, Khrushchev pledged that the Soviet Union would not conduct nuclear testing unless the Western nations resumed it. The US, the UK and France made no move to resume testing, and so the matter rested for nearly three years.

On 31 August 1961, Khrushchev announced that the Soviet Union was abruptly abandoning the prevailing de facto nuclear testing moratorium, which they (and the United States) had observed for 34 months. The next day, on 1 September 1961, the Soviet Union began an atmospheric test series of unprecedented magnitude with a 16 Kt atmospheric nuclear shot. Two weeks later, the U.S. responded by initiating Operation Nougat.

This series was conducted at the Nevada Test Site, which permitted rapid initiation of tests, but restricted them to low yields (and mostly underground test shots) due to fallout concerns. Although this was still the "era of atmospheric testing", Nougat was actually the first underground test series. Higher yield atmospheric tests followed seven months later with Operation Dominic in the Pacific.

The assignment of tests to individual "operations" between this time and the end of atmospheric testing is confused and complicated by several overlapping operations - Nougat, Dominic (or Dominic I), Sunbeam (or Dominic II), Fishbowl, Storax, and Roller Coaster. The available documentation on these operations is somewhat unclear unclear or confusing, and it may be that in some cases a shot may be officially included in more than one operation. Definitely and unambiguously assigning shots to operations for this period is thus hard or impossible. Some disagreement about which shots should be properly included with a particular operation may occur. According to this account Operation Nougat included a total of 44 shots, exceeding the previous record holder, Operation Hardtack II, with 37 tests.

Nougat generally resembles Hardtack II in the nature of testing that was conducted. Low yield tactical devices were extensively tested. Thermonuclear primaries and radiation imploson mockups were tested. Much attention was paid to simultaneously achieving desired performance and one-point safety in "sealed pit" fission devices, some designs requiring numerous shots.

Since all the tests were fired underground, and only a few of them produced true blast craters (i.e. not subsidence craters caused by blast cavity collapse), there are few pictures available of these tests.

The one test for which any relevant images are available is much publicized Gnome shot.

Test:Gnome
Time:12:10 10 December 1961 (GMT)
Location:Carlsbad, NM
Test Height and Type:Shaft Shot, -1184 ft
Yield:3.1 kt

This Plowshare shot, conducted by Lawrence Radiation Laboratory (later Lawrence Livermore), was fired in an underground salt dome formation. A permanent stable cavity 170 ft. in diameter, and 80 ft. high, was formed. This one of the very few nuclear test cavities (perhaps the only one) to avoid collapse. Some radiation accidentally released as a result of pot shot drilling, and detected off-site.
Gnome cavity
547x412, 67K
Gnome cavity
Gnome diagram
1024x1119, 87K
Gnome diagram


Operation Nougat Summary

Legend:WD=Weapons Development, WE=Weapons Effects, ST=Safety Test, TN= Thermonuclear, LASL=Los Alamos Scientific Laboratory, LRL=Lawrence Radiation Laboratory (later Lawrence Livermore), DOD=Department of Defense, PS=Plowshare, sim.=similar, proto.=prototype, Zipper=neutron initiator,
Test Name Time and Date (GMT) Location Test Type Height (Ft) Yield (Kt) Sponsor Purpose Comments
Antler 17:00.00.12 15-Sep-61 NTS, Area 12e Tunnel -1,318 2.6 LRL WD Possible W-45 test, yield slightly higher than expected
Shrew 19:45.00.12 16-Sep-61 NTS, Area 3ac Shaft -322 0.017 LASL WD Possible XW-54 test, performed as expected
Boomer 22:00 1-Oct-61 NTS, Area 3aa Shaft -330 <0.1 LASL WD Possible XW-54 test, performed as expected
Chena 18:00.00.12 10-Oct-61 NTS, Area 12b Tunnel -838 <20 LRL WD Arrow device, possible W-44 proto., sim. to D-I Swordfish, yield much lower than pred.
Mink 18:00.00.13 29-Oct-61 NTS, Area 3ae Shaft -630 <20 LASL WD Sim. to HT-II Quay, HT-I Linden, fizzle
Fisher 23:04.59.63 3-Dec-61 NTS, Area 3ah Shaft -1191 13.4 LASL WD Repeat of Mink, possible XW-50 primary test, yield below pred. due to Zipper failure
Gnome 19:00.00.00 10-Dec-61 Carlsbad, NM Shaft -1184 3.1 LRL PS Plowshare shot, fired in salt dome, cavity formed was 170 ft. in diameter, and 80 ft. high, some radiation accidentally released and detected off-site
Mad 18:00.00.16 13-Dec-61 NTS, Area 9a Shaft -594 0.5 LASL WD Sim. to Hoosic and Stillwater, yield below pred., attempt to standardize low yield energy source for future experiments
Ringtail 16:35.00.13 17-Dec-61 NTS, Area 3ak Shaft -1,192 <20 LRL WD Possible XW-54 test, sim. to Shrew and Boomer, purpose to optimize small light system for high yield tactical weapon
Feather 16:30.00.13 22-Dec-61 NTS, Area 12b Tunnel -812 0.15 LRL WD "...results quite striking."
Stoat 16:30.00.14 9-Jan-62 NTS, Area 3ap Shaft -992 5.1 LASL WD Performed as expected, 1st in series to develop new multi-point detonation system, sim. to Agouti, Armadillo, Ermine, Chinchilla I/II
Agouti 18:00.00.13 18-Jan-62 NTS, Area 3ao Shaft -856 6.4 LASL WD Develop test for new 10 inch implosion system, sim. Stoat
Dormouse 18:00.00.13 30-Jan-62 NTS, Area 3aq Shaft -1191 <20 LASL WD Configuration optimization test, sim. to Mink, Fisher, Raccoon, Dormouse Prime, Packrat
Stillwater 18:00.00.16 8-Feb-62 NTS, Area 9c Shaft -595 3.07 LRL WD Similar to Mad and Hoosic
Armadillo 16:30.00.13 9-Feb-62 NTS, Area 3ar Shaft -786 7.1 LASL WD Develop test for new 10 inch implosion system, sim. Stoat
Hardhat 18:00.10.16 15-Feb-62 NTS, Area 15a Shaft -943 5.7 DOD WE Test of underground structure hardening
Chinchilla I 16:30.00.13 19-Feb-62 NTS, Area 3ag Shaft -492 1.9 LASL WD Test of new 10" implosion system, performed as expected, showed device not 1-point safe
Codsaw 17:50.00.16 19-Feb-62 NTS, Area 9g Shaft -696 <20 LRL WD Possible W-45 test, sim. to Hoosic, Hudson, Arikaree
Cimarron 18:00.00.16 23-Feb-62 NTS, Area 9h Shaft -1000 11.9 LRL WD Confirmed advanced warhead design, device performed better than expected
Platypus 16:30.00.13 24-Feb-62 NTS, Area 3ad Shaft -190 <20 LASL WD Sim. to Shrew, Boomer, Ringtail
Pampas 19:10.00.09 1-Mar-62 NTS, Area 3al Shaft -1191 9.5 LASL/UK WD First joint Us-UK test at NTS
Danny Boy 18:15.00.12 5-Mar-62 NTS, Area 18 Subsurface -110 0.43 DOD/LRL WE Test of atomic demolition munition (ADM) cratering effects in basalt, crater 265' by 84', design yield 470 tons
Ermine 16:30.00.13 6-Mar-62 NTS, Area 3ab Shaft -240 <20 LASL ST Test of new 10" implosion system, 1-point safety test
Brazos 18:00.00.21 8-Mar-62 NTS, Area 9b Shaft -841 8.4 LRL WD Successful system proof test, possible XW-55 primary test, developmental test of advanced implosion system, design yield 5-10 Kt
Hognose 16:30.00.13 15-Mar-62 NTS, Area 3ai Shaft -784 <20 LASL WD Sim. to Ht-II Mercury and Oberon
Hoosic 18:00.00.16 28-Mar-62 NTS, Area 9j Shaft -614 3.4 LRL WD Test to determine minimum boosted yield for device previously tested in Mad and Stillwater, possible XW-45 test, pred. yield 2-3.5 Kt, sim. to Hudson and Arikaree
Chinchilla II 18:00.00.13 31-Mar-62 "NTS, Area 3as" Shaft -448 <20 LASL WD Retest of Chinchilla I which was not 1-point safe, sim. to Stoat
Dormouse Prime 18:00.00.13 5-Apr-62 NTS, Area 3az Shaft -856 10.6 LASL WD Yield verification test, design yield 10.5 Kt, boron lined shot hole, sim. to Dormouse, Mink, Fisher, Raccoon, Packrat, HT-I Linden, HT-II Quay
Passaic 18:00.00.16 6-Apr-62 NTS, Area 9i Shaft -766 <20 LRL WD Verification test
Hudson 18:00.00.16 12-Apr-62 NTS, Area 9h Shaft -495 <20 LRL WD Sim. to Arikaree, Hoosic, Codsaw; possible W-45 test
Platte 18:00.00.13 14-Apr-62 NTS, Area 12k Tunnel -628 1.85 LRL WD Yield reproducibility test, failed, retested in Des Moines
Dead 18:40.00.16 21-Apr-62 NTS, Area 9k Shaft -634 <20 LRL WD
Black 18:00.00.16 27-Apr-62 NTS, Area 9p Shaft -714 <20 LRL WD XW-55 primary in TN mockup
Paca 19:33.00.0 7-May-62 NTS, Area 3ax Shaft -848 <20 LASL WD Test of "100 lb/100 Kt" class device
Arikaree 15:00 10-May-62 NTS Shaft -549 <20 LRL WD Sim. to Hudson, Hoosic, Codsaw; possible W-45 test
Aardvark 19:00.00.10 12-May-62 NTS, Area 3 Shaft -1424 40 LASL WD Test of improved TX-33Y2 AFAP
Eel 15:00.00.16 19-May-62 NTS, Area 9m Shaft -714 4.9 LRL WD Successful
White 15:00.00.15 25-May-62 NTS, Area 9b Shaft -635 <20 LRL WD Probable XW-58 primary test, sim. to Sacramento
Racoon 17:00.00.14 1-Jun-62 NTS, Area 3a Shaft -539 <20 LASL WD Successful, sim. to Dormouse, Dormouse Prime, Mink, Fisher, Packrat, HT-I Linden, HT-II Quay
Packrat 17:00.00.12 6-Jun-62 NTS, Area 3aw Shaft -860 <20 LASL WD Successful (see above for similarities), investigated internal initiator to improve safety, increase yield, reduce weight 10 lb.
Des Moines 21:00.00.12 13-Jun-62 NTS, Area 12j Tunnel -660 2.9 LRL WD Sim. to Platte
Daman I 17:00.00.13 21-Jun-62 NTS, Area 3be Shaft -854 <20 LASL WD Successful
Haymaker 18:00.00.12 27-Jun-62 NTS, Area 3aus Shaft -1340 67 LASL WD Possible Mocassin device (tested in Project 58 #2, HT-II Hidalgo)
Marshmallow 17:00 28-Jun-62 NTS, Area 16a Tunnel -1050 <20 DOD/LRL WE Simulated high altitude effects shot in low pressure chamber, successful, x-ray effects of re-entry vehicles investigated
Sacramento 21:30.00.16 30-Jun-62 NTS, Area 9v Shaft -500 <20 LRL WD Sim. to White device, probable XW-58 test


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