Nevada Test Site

This handbill was distributed 16 days before the first nuclear device was detonated at the site.

The site was the primary testing location of American nuclear devices from 1951 to 1992; 928 announced nuclear tests occurred there. Of those, 828 were underground.[9] (Sixty-two of the underground tests included multiple, simultaneous nuclear detonations, adding 93 detonations and bringing the total number of NTS nuclear detonations to 1,021, of which 921 were underground.)[10] The site contains many subsidence craters from the testing.

The site was the United States' primary location for tests smaller than 1 Mt (4.2 PJ). 126 tests were conducted elsewhere, including most larger tests. Many of these occurred at the Pacific Proving Grounds in the Marshall Islands.

Mushroom cloud seen from downtown Las Vegas.

During the 1950s, the mushroom clouds from atmospheric tests could be seen for almost 100 mi (160 km). The city of Las Vegas experienced noticeable seismic effects, and the distant mushroom clouds, which could be seen from the downtown hotels, became tourist attractions. The last atmospheric test detonation at the site was "Little Feller I" of Operation Sunbeam, on July 17, 1962.

Although the United States did not ratify the Comprehensive Nuclear-Test-Ban Treaty, it honors the articles of the treaty, and underground testing of weapons ended as of September 23, 1992. Subcritical tests not involving a critical mass continued.

Sedan crater

One notable test shot was the "Sedan" shot of Operation Storax on July 6, 1962, a 104-kiloton-of-TNT (440 TJ) shot for Operation Plowshare, which sought to prove that nuclear weapons could be used for peaceful means in creating bays or canals. It created a crater 1,280 feet (390 m) wide and 320 feet (100 m) deep.

More than 27 subcritical tests have been conducted at the site[11]

In 2018, the State of Nevada sued the federal government to block a plan to ship "more than a metric ton" of plutonium to the site for temporary storage.[12]

In 2022, the government acknowledged that 13,625 cubic meters of radioactive material conforming to its disposal criteria had been shipped to the site for disposal.[13]

Tunnel in the U1a Complex within Area 1

Area 1 held eight nuclear tests for a total of nine detonations.[9] Four early atmospheric tests were conducted above Area 1 in the early 1950s, as well as three underground tests in 1971 and 1990. In 1955, a Civil Defense experiment (called Operation Cue in the press) studied nuclear blast effects on various building types; a few structures still stand.

Heavy drilling equipment and concrete construction facilities are sited in Area 1. Non-destructive X-ray, gamma ray, and subcritical detonation tests continue to be conducted in Area 1.

The radioactivity present on the ground in Area 1 provides a radiologically contaminated environment for the training of first responders.[34]

Area 2 was the site of 144 tests comprising 169 detonations.[9] Shot "Gabbs" was intended for early 1993 but was cancelled in 1992.[35]

Area 3 held 266 nuclear tests for a total of 288 detonations, including Upshot-Knothole 'Harry', more than in any other area of the site.[9]

As part of Operation Tinderbox, on June 24, 1980, a large satellite prototype (DSCS III) was subjected to radioactivity from the "Huron King" shot in a vertical line-of-sight (VLOS) test undertaken in Area 3. This was a program to improve the database on nuclear hardening design techniques for defense satellites.

The final nuclear test detonation at site was Operation Julin's "Divider" on September 23, 1992, just prior to the moratorium ending all nuclear testing.[36] Divider was a safety experiment test shot that was detonated at the bottom of a shaft sunk into Area 3.

In 1995 and 1997, plutonium-contaminated soil from "Double Tracks" and "Clean Slate 1" of Operation Roller Coaster (1963) was picked up from the Tonopah Test Range and brought to the Area 3 Radioactive Waste Management Site as a first step in eventually returning Tonopah Test Range to an environmentally neutral state. Corrective action regarding the contaminated material from the "Clean Slate 2" and "Clean Slate 3" tests has yet to be agreed upon.[37]

Big Explosives Experimental Facility (BEEF) in Area 4

Area 4 held 40 nuclear tests for a total of 44 detonations.[9]

It is home to the Big Explosives Experimental Facility (BEEF).[38]

Area 5 held 19 nuclear tests.[9] Five atmospheric tests were detonated, starting on January 27, 1951, at Area 5 as part of Operation Ranger. These were the first nuclear tests at the site. Further tower detonations were studied at Area 5, and the Grable shot which was fired from a M65 Atomic Cannon located in Area 11 exploded in Area 5. The Priscilla test was conducted at Area 5 on June 24, 1957.

Five underground tests were set up at Area 5; four of those included accidental release of radioactive materials. On March 16, 1968, physicist Glenn T. Seaborg toured the upcoming Milk Shake shot of Operation Crosstie.[39] Milk Shake's radioactive release was not detected outside of the site's boundaries.

Device Assembly Facility in Area 6

Control Point in Area 6

Area 6 held four nuclear tests for a total of six detonations.[9] The area features an asphalt runway, that was constructed on top of a dirt landing strip, that had existed since the 1950s. Some buildings, including a hangar, are situated near the runway.[40]

The Device Assembly Facility (DAF)[38] was originally built to consolidate nuclear explosives assembly operations. It now serves as the Criticality Experiments Facility (CEF).

The Control Point[38] is the communication hub of the site. It was used by controllers to trigger and monitor nuclear test explosions.

In 1982, while a live nuclear bomb was being lowered underground, the base came under attack by armed combatants. The combatants turned out to be a security team conducting an improperly scheduled drill.

Area 7 held 92 nuclear tests.[9]

During Operation Buster, four successful tests were conducted via airdrop, with bomber aircraft releasing nuclear weapons over Area 7.

It is also the site of Matthew Reilly's book called Area 7.

Shot "Icecap" planned for 1993 was abandoned in Area 7 following 1992's testing moratorium. The tower, shaft and wiring remain in place, along with a crane intended to lower the nuclear test package into the shaft.[35]

Radioactive materials were accidentally released from the 1970 Baneberry shot in Area 8.

Area 8 held 13 nuclear tests for a total of 15 detonations.[9]

Area 8 hosted the "Baneberry" shot of Operation Emery on December 18, 1970. The Baneberry 10 kt (42 TJ) test detonated 900 feet (270 m) below the surface but its energy cracked the soil in unexpected ways, causing a fissure near ground zero and the failure of the shaft stemming and cap.[41] A plume of fire and dust was released, raining fallout on workers in different locations within the site. The radioactive plume released 6.7 megacuries (250 PBq) of radioactive material, including 80 kCi (3.0 PBq) of Iodine¹³¹.[42]

Area 9 held 115 nuclear tests for a total of 133 detonations.[9]

In Area 9, the 74 kt (310 TJ) "Hood" test on July 5, 1957, part of Operation Plumbbob, was the largest atmospheric test ever conducted within the continental United States; nearly five times larger in yield than the bomb dropped on Hiroshima. A balloon carried Hood up to 460 meters above the ground where it was detonated. Over 2,000 troops took part in the test in order to train them in conducting operations on the nuclear battlefield. 11 megacuries (410 PBq) of iodine-131 (¹³¹I) were released into the air.[42]

North end of Yucca Flat, where most tests have been conducted.

Area 10 held 57 nuclear tests for a total of 71 detonations.[9]

The first underground test at the site was the "Uncle" shot of Operation Jangle. Uncle detonated on November 29, 1951, within a shaft sunk into Area 10.

The "John" shot of Plumbbob, on July 19, 1957, was the first test firing of the nuclear-tipped AIR-2 Genie air-to-air rocket designed to destroy incoming enemy bombers with a nuclear explosion. The 2 kt (8.4 TJ) warhead exploded approximately three miles above five volunteers and a photographer who stood unprotected at "ground zero" in Area 10 to show the safety of battlefield nuclear weapons to personnel on the ground.[43] The test also demonstrated the ability of a fighter aircraft to deliver a nuclear-tipped rocket and avoid being destroyed in the process. A Northrop F-89J fired the rocket.

The "Sedan" test of Operation Storax on July 6, 1962, a 104 kt (440 TJ) shot for the Operation Plowshare which sought to discover whether nuclear weapons could be used for peaceful means in creating lakes, bays or canals. The explosion displaced 12 million tons of earth, creating the Sedan crater which is 1,280 feet (390 m) wide and 320 feet (100 m) deep.

Area 11 held 9 nuclear tests.[9] Four of the tests were weapons safety experiments conducted as Project 56; they spread so much radioactive material that Area 11 has been called "Plutonium Valley". As is the case with Area 1, background radiation levels make Area 11 suitable for realistic training in methods of radiation detection.[37]

Area 12 held 61 nuclear tests between 1957 and 1992, one of which involved two detonations. All tests were conducted below Rainier and Aqueduct mesas.

Area 12 was the primary location for tunnel tests and used almost exclusively for that purpose. The tunnel complexes mined into Rainier and Aqueduct Mesa include the B-, C-, D-, E-, F-, G-, I-, J-, K-, N-, P-, and T-Tunnel complexes, and the R- and S- shafts.

There is no Area 13 within NNSS, though such a name is attached to a section of Nellis Air Force Range which abuts the northeastern corner of Area 15.[44] Project 57's weapons safety test was conducted here on April 24, 1957, spreading particles emitting alpha radiation over a large area.[45]

Area 14 occupies approximately 26 square miles (67 km²) in the central portion of the NNSS. Various outdoor experiments are conducted in this area.[46] No atmospheric or underground nuclear tests were conducted in Area 14.[9]

EPA farm in Area 15

Three underground detonations took place in area 15 in the 1960s.[9]

Pile Driver was a notable Department of Defense test. A large underground installation was built to study the survivability of hardened underground bunkers undergoing a nuclear attack. Information from the test was used in designing hardened missile silos and the North American Aerospace Defense Command facility in Colorado Springs.[38]

The abandoned Crystal and Climax mines are found in Area 15. Storage tanks hold contaminated materials.[38]

From 1964 to 1981, the Environmental Protection Agency operated a 36-acre (150,000 m²) experimental farm in Area 15. Extensive plant and soil studies evaluated the uptake of pollutants in farm-grown vegetables and from the forage eaten by a dairy herd of some 30 Holstein cows. Scientists also studied horses, pigs, goats, and chickens.[38]

Area 16 held six nuclear tests.[9]

No nuclear tests took place in Area 17.[9]

Area 18 held five nuclear tests[9] and includes the Pahute Mesa Airstrip.[33]

Pahute Mesa is one of four major nuclear test regions within the Nevada National Security Site (NNSS). It occupies 243 square miles (630 km²) in the northwest corner of the NNSS. The eastern section is known as Area 19 and the western section as Area 20.

A total of 85 nuclear tests were conducted in Pahute Mesa between 1965 and 1992. Three of them — Boxcar, Benham and Handley — had a yield of over one megaton. Three tests were conducted as part of Operation Plowshare and one as part of Vela Uniform.

The western section of Pahute Mesa, with a portion of the 85 nuclear tests conducted in the Pahute Mesa occurring in this section.

There is no Area 21 within NNSS, though such a name is attached to a section of Los Alamos National Laboratory.[47]

No nuclear tests took place in Area 22.[9] Area 22 once held Camp Desert Rock, a staging base for troops undergoing atmospheric nuclear blast training; as many as 9,000 troops camped there in 1955. Desert Rock Airport's runway was enlarged to a 7,500 ft (2,300 m) length in 1969 by the Atomic Energy Commission. It is a transport hub for personnel and supplies going to NNSS and also serves as an emergency landing strip.

No nuclear tests took place in Area 23.[9] The town of Mercury, Nevada lies within Area 23. The area is the main pathway to and from NNSS test locations by way of U.S. Route 95. An open sanitary landfill is located to the west of Mercury, and a closed hazardous waste site abuts the landfill. Mercury is also the main management area for the site which includes a bar and large cafeteria, printing plant, medical center, warehousing, fleet management, liquidation and recycling center, engineering offices, dormitories, and other administrative areas for both the O&M contractors, LLNL, LANL, and SNL personnel. At its height in the 1950s and '60s, it also held several restaurants, a bowling alley, a movie theater, and a motel.

There is no Area 24 within NNSS, though such a name is attached to a satellite site of the NNSS referred to as the North Las Vegas Facility.[47]

Mostly abandoned buildings and structures at Port Gaston

No nuclear tests took place in Area 26,[9] the most arid section of the NNSS. An old abandoned mine, the Horn Silver Mine, was used for waste disposal between 1959 and the 1970s; some of the waste is radioactive. Water flow past the shaft could pose a human health risk, so corrective action has been planned.[48]

In 1983 the Department of Defense, the Department of Energy, and the Federal Emergency Management Agency performed the NUWAX-83 tests near Port Gaston in Area 26, simulating the explosion of a nuclear-armed helicopter and the resulting spread of nuclear debris over 65 acres. The radioactive material used to simulate the accident became inert in less than six months.[49]

An eight-square-mile complex was constructed in Area 26 in support of Project Pluto.[46] It consisted of six miles of roads, the critical assembly building, the control building, the assembly and shop buildings, and utilities.[50] Those buildings have been used recently as mock reactor facilities in the training of first responders.

Area 28 no longer exists; it was absorbed into Areas 25 and 27.[38]

No nuclear tests took place in Area 29.[9] The rugged terrain of Area 29 serves as a buffer between other areas of NNSS. A helipad is present at Shoshone Peak.

The Crosstie Buggy test

Area 30 occupies approximately 59 square miles (150 km²) at the center of the western edge of the NNSS. Area 30 has rugged terrain and includes the northern reaches of Fortymile Canyon. It is used primarily for military training and exercises.[46]

Area 30 was the site of a single nuclear test, the Crosstie Buggy row charge experiment, part of Operation Plowshare, which involved five simultaneous detonations.[9]