U.S. NUCLEAR TESTING FROM PROJECT TRINITY TO THE PLOWSHARE PROGRAM
U.S. NUCLEAR TESTING FROM PROJECT TRINITY TO THE PLOWSHARE PROGRAM
[From For the Record - A History of the Nuclear Test Personnel Review
Program, 1978-1986, by Abby A. Johnson, et al, Defense Nuclear Agency,
DNA 6041F, 1986.
The United States conducted Project TRINITY, the world's first nuclear
detonation, in 1945. From 1946 to 1963, when the limited nuclear test ban
treaty was signed, the U.S. conducted 18 atmospheric nuclear test series,
identified below as operations, and a program of testing called PLOWSHARE.
In addition, the U.S. staged safety experiments to determine the weapons'
susceptibility to fission due to accidents in storage and transport. This
chapter provides historical summaries of the tests, listed below in the
order in which they occurred and are addressed:
- Project TRINITY, 1945 (CONUS)
- Operation CROSSROADS, 1946 (Oceanic)
- Operation SANDSTONE, 1948 (Oceanic)
- Operation RANGER, 1951 (CONUS)
- Operation GREENHOUSE, 1951 (Oceanic)
- Operation BUSTER-JANGLE, 1951 (CONUS)
- Operation TUMBLER-SNAPPER, 1952 (CONUS)
- Operation IVY, 1952 (Oceanic)
- Operation UPSHOT-KNOTHOLE, 1953 (CONUS)
- Operation CASTLE, 1954 (Oceanic)
- Operation TEAPOT, 1955 (CONUS)
- Operation WIGWAM, 1955 (Oceanic)
- Operation REDWING, 1956 (Oceanic)
- Operation PLUMBBOB, 1957 (CONUS)
- Operation HARDTACK I, 1958 (Oceanic)
- Operation ARGUS, 1958 (Oceanic)
- Operation HARDTACK II, 1958 (CONUS)
- Safety Experiments, 1955-1958 (CONUS)
- Operation DOMINIC I, 1962 (Oceanic)
- Operation DOMINIC II, 1962 (CONUS)
- PLOWSHARE Program, 1961-1962 (CONUS).
Most of the oceanic tests were conducted at the Pacific Proving Ground,
which consisted principally of the Enewetak and Bikini Atolls in the northwestern
Marshall Islands of the Pacific Ocean. The Marshall Islands are in the
easternmost part of Micronesia. The Marshalls spread over about 2 million
km2 of the earth's surface, but the total land area is only
about 180 km2 *. Two parallel chains form the islands: Ratak
(or Sunrise) to the east, and Ralik (or Sunset) to the west; both Enewetak
and Bikini are in the Ralik chain at its northern extreme. Figure 5 shows
these islands in the central Pacific. It also indicates the locations of
the Christmas and Johnston Islands, the sites for most of the DOMINIC I
tests.
* Throughout this chapter, surface distances are given
in metric units. The metric conversion factors include: 1 meter = 3.28
feet; 1 meter = 1.09 yards; and 1 kilometer = 0.62 miles. Vertical distances
are given in feet; altitudes are measured from mean sea level, while heights
are measured from surface level, unless otherwise noted.
Most of the continental U.S. (CONUS) atmospheric tests were conducted
at the Nevada Test Site (NTS). Established by the Atomic Energy Commission
(AEC) in December 1950, the NTS is in the southeastern part of Nevada,
100 kilometers northwest of Las Vegas. Figure 6 shows the current NTS,
an area of high desert and mountain terrain now encompassing approximately
3,500 square kilometers in Nye County. On its eastern, northern, and western
boundaries, the NTS adjoins the Nellis Air Force Range.
The format of this chapter is generally consistent for the following
sections, each of which summarizes a nuclear test series. The section begins
by identifying the nuclear events and continues by discussing relevant
background and objectives, test operations, and radiation doses.
The NTPR teams provided data current as of 1 May 1986 on the radiation
doses. The rest of the material derives from the volumes published by the
Defense Nuclear Agency (DNA) on the nuclear test series. These volumes,
listed in Appendix E, can be consulted for further information.
4.1 Project TRINITY
Project TRINITY was the first detonation of a nuclear weapon. The plutonium-fueled
implosion device was detonated on a 100-foot tower at 0530 hours, 16 July
1945. The test, which occurred on the Alamogordo Bombing Range in south-central
New Mexico, had a nuclear yield equivalent to the energy released by exploding
21 kilotons of TNT. It left a depression in the desert 2.9 meters deep
and 335 meters wide (1: 1,23).
People as far away as Santa Fe and El Paso saw the brilliant light of
the detonation. Windows rattled in the areas immediately surrounding the
test site, waking sleeping ranchers and townspeople. To dispel any rumors
that might compromise the security of this first nuclear test, the Government
announced that an Army munitions dump had exploded. However, immediately
after the bombing of Hiroshima, Japan, on 6 August 1945, the Government
revealed to the public what had actually occurred in the New Mexico desert
(1: 33).
4.1.1 Background and Objectives of Project TRINITY.
The United States' effort to develop a nuclear weapon came during World
War II in response to the potential threat of a German nuclear weapon.
On 6 December 1941, President Roosevelt appointed a committee to determine
if the United States could construct a nuclear weapon. Six months later,
the committee gave the President its report, recommending a fast-paced
program that would cost up to $100 million and that might produce the weapon
by July 1944 (1: 12,13).
The President accepted the committee's recommendation. The effort to
construct the weapon was turned over to the War Department, which assigned
the task to the Army Corps of Engineers. In September 1942, the Corps of
Engineers established the Manhattan Engineer District (MED), under the
command of Major General Leslie Groves, to oversee the development of a
nuclear weapon. This effort was code named the "Manhattan Project"
(1: 13).
During the first 2 years of the Manhattan Project, work proceeded at
a slow but steady pace. Significant technical problems had to be solved,
and difficulties in the concentration of uranium-235 and production of
plutonium, particularly the inability to process large amounts, often frustrated
the scientists. Nonetheless, by 1944 sufficient progress had been made
to persuade the scientists that their efforts might succeed. A test of
the plutonium implosion device was necessary to determine if it would work
and what its effects would be. Led by Dr. J. Robert Oppenheimer, Manhattan
Project scientists at Los Alamos Laboratory (later to become the Los Alamos
National Laboratory) were "to make preparations for a field test in
which blast, earth shock, neutron and gamma radiation would be studied
and complete photographic records made of the explosion and any atmospheric
phenomena connected with the explosion" (1: 13,14).
The planned firing date for the TRINITY device was originally 4 July
1945. On 14 June 1945, Dr. Oppenheimer changed the test date to no earlier
than 13 July and no later than 23 July. On 30 June, the earliest firing
date was moved to 16 July, even though better weather was forecast for
18 and 19 July. The TRINITY test organization adjusted the schedule because
the Allied conference in Potsdam, Germany, was about to begin and the President
needed the results of the test as soon as possible (1: 26).
On 6 August 1945, 3 weeks after the detonation of TRINITY, the first
uranium-fueled nuclear bomb, a gun-type weapon code named LITTLE BOY, was
detonated over Hiroshima. On 9 August, FAT MAN, a plutonium-fueled implosion
weapon with the same design as the TRINITY device, was detonated over another
Japanese city, Nagasaki. Two days later, the Japanese Government informed
the United States of its decision to surrender. On 2 September 1945, Japan
officially surrendered to the Allied Governments, thereby bringing World
War II to an end (1: 11).
4.1.2 TRINITY Test Operations.
From 16 July 1945 through 1946, about 1,000 military and civilian personnel
took part in Project TRINITY or visited the test site. All participants,
civilian as well as military, were under the authority of the MED. Project
activities included scientific studies. Military exercises were not conducted
at TRINITY (1: 1).
The Los Alamos Laboratory, which was staffed and administered by the
University of California (under contract to the MED), conducted diagnostic
experiments. Before the detonation, civilian and military scientists and
technicians, assisted by other military personnel, placed gauges, detectors,
and other instruments around ground zero. Four offsite monitoring posts
were established in the towns of Nogal, Roswell, Socorro, and Fort Sumner,
New Mexico. An evacuation detachment consisting of 144 to 160 enlisted
men and officers was established in case protective measures or evacuation
of civilians living offsite became necessary. Such action was not deemed
necessary, however, and the evacuation detachment was dismissed late on
the day of the detonation for return to Los Alamos (1: 1).
For the detonation, at least 263 DOD participants were at the test site.
Among this group were 99 personnel occupying shelters approximately 9,175
meters north, south, and west of ground zero. No one was closer to ground
zero at shot-time (1: 31).
To determine the extent of the radiation resulting from the detonation,
a network of detectors with remote read-out was installed along routes
between ground zero and each shelter. In addition, trained monitors with
portable radiation survey instruments were assigned to each shelter. No
radiation was detected at the south and west shelters. The remote detectors
north of ground zero indicated that the radioactive cloud was moving in
that direction, and a monitor in the north shelter observed a sharp increase
in the radiation level. The shelter was consequently evacuated shortly
after the detonation. It was learned later that the monitor had inadvertently
changed an adjustment on his instrument, which resulted in a false reading.
Very little contamination occurred at the north shelter (1: 1,2).
A substantial amount of activity took place at the test site during
the first 3 days following the detonation, as scientists entered the ground
zero area to retrieve instruments or to perform experiments. Their entry
into, activities at, and exit from the test site were carefully controlled.
When the itinerary indicated operations in regions of known radiation intensity,
a limit was set on the time spent in the area. Radiation detectors were
provided, when possible, to permit continuous monitoring of the exposure.
Film badges were also provided to each person for subsequent determination
and recording of the doses received. The number of personnel at the TRINITY
test site diminished rapidly after 19 July, as the emphasis shifted to
preparing the devices that were to be used over Japan (1: 38).
4.1.3 Dose Summary for Project TRINITY.
The dose limit for TRINITY participants was 5.0 rem (roentgen equivalent
man) of gamma radiation during a 2-month period (2: 29). The table below
summarizes the available dosimetry information:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
103 |
15 |
30 |
10 |
1 |
1 |
Navy |
2 |
0 |
2 |
0 |
0 |
0 |
4.2 OPERATION CROSSROADS.
Conducted in 1946 at Bikini, CROSSROADS involved approximately 42,000
personnel, 251 ships, and 156 aircraft. The series consisted of an airdrop
detonated at a height of 520 feet and an underwater shot conducted at a
depth of 90 feet:
Event |
Date |
Type |
Yield (kilotons) |
ABLE |
1 July |
Airdrop |
21 |
BAKER |
25 July |
Underwater |
21 |
The nuclear devices were similar to the TRINITY device and to the weapon
detonated over Nagasaki, Japan (3: 17).
Among the numerous observers of these two detonations was an Army doctor
trained as a radiological safety monitor. He made the following observations
of ABLE and BAKER from a Navy aircraft approximately 20 nautical miles
from each detonation:
ABLE: At twenty miles [it] gave us no sound or flash or shock wave.
. . . Then, suddenly we saw it -- a huge column of clouds, dense, white,
boiling up through the strato-cumulus, looking much like any other thunderhead
but climbing as no storm cloud ever could. The evil mushrooming head soon
began to blossom out. It climbed rapidly to 30,000 or 40,000 feet, growing
a tawny-pink from oxides of nitrogen, and seemed to be reaching out in
an expanding umbrella overhead. . . . For minutes the cloud stood solid
and impressive, like some gigantic monument, over Bikini. Then finally
the shearing of the winds at different altitudes began to tear it up into
a weird zigzag pattern (4: 55).
BAKER: This shot in broad day, at fifteen miles, seemed to spring from
all parts of the target fleet at once. A gigantic flash -- then it was
gone. And where it had been now stood a white chimney of water reaching
up and up. Then a huge hemispheric mushroom of vapor appeared like a parachute
suddenly opening. . . . By this time the great geyser had climbed to several
thousand feet. It stood there as if solidifying for many seconds, its head
enshrouded in a tumult of steam. Then slowly the pillar began to fall and
break up. At its base a tidal wave of spray and steam arose, to smother
the fleet and move on toward the islands. All this took only a few seconds,
but the phenomenon was so astounding as to seem to last much longer (4:
93).
Figure 7 shows the BAKER detonation (A). Credits for Figure 7 and the
subsequent photographs follow the references at the end of this chapter.
4.2.1 Background and Objectives of CROSSROADS.
After the atomic bomb attacks on Japan had abruptly ended World War
II, many military leaders felt that military science was at a crossroads.
The admiral who directed CROSSROADS declared that "warfare, perhaps
civilization itself, had been brought to a turning point by this revolutionary
weapon." With this thought in mind, he named the initial postwar test
series (3: 17).
As early as August 1945, the Chairman of the Senate's Special Committee
on Atomic Energy proposed that the effectiveness of atomic bombs be demonstrated
on captured Japanese ships. In September, the Commanding General of the
Army Air Forces put the question of such a test before the Joint Chiefs
of Staff (JCS). The ensuing discussion and recommendations led President
Harry Truman to announce, on 10 December 1945, that the U.S. would further
explore the capabilities of atomic energy in the form of scientific atomic
bomb tests under JCS jurisdiction (3: 18).
CROSSROADS was designed to produce information not available from the
TRINITY test or the Hiroshima and Nagasaki bombings. The primary purpose
was to determine the effects of atomic bombs on naval vessels. The secondary
purposes were to provide training for aircrews in attack techniques using
atomic bombs against ships and to determine atomic bomb effects upon other
military equipment and installations (3: 18).
4.2.2 CROSSROADS Test Operations.
A fleet of more than 90 target vessels was assembled in Bikini Lagoon
for CROSSROADS. The target fleet consisted of older U.S. ships, such as
the aircraft carriers USS Saratoga and the USS Independence,
the battleships USS Nevada, USS Arkansas, USS Pennsylvania,
and USS New York, surplus U.S. cruisers, destroyers, submarines,
and a large number of auxiliary and amphibious vessels. The German cruiser
Prinz Eugen and two major captured Japanese ships, the battleship
Nagato and the cruiser Sakawa, also were targets. The support
fleet comprised more than 150 ships that provided quarters, experimental
stations, and workshops for most of the approximately 42,000 participants,
more than 37,000 of whom were Navy personnel (3: 1,84).
ABLE operations went smoothly. The radioactivity created by the airburst
had only a transient effect. Within a day, radiation intensities in the
lagoon had decayed to less than 0.1 R/24 hours, and nearly all the surviving
target ships had been safely reboarded. The ship inspections, instrument
recoveries, and remooring necessary for the BAKER test proceeded on schedule
(3: 1,217).
BAKER, on the other hand, presented difficulties. The underwater detonation
caused most of the target fleet to be bathed in radioactive water spray
and radioactive debris. With the exception of 12 target vessels in the
lagoon and the landing craft beached on Bikini Island, the surviving target
fleet was too radiologically contaminated for many days for more than brief
on-board activities. During the first week of August, attempts were made
to decontaminate the vessels. By 10 August, upon the advice of the Chief
of the Radiological Safety Division, the Task Force Commander decided to
terminate these efforts and tow most of the remaining target fleet to Kwajalein
Atoll for possible decontamination (3: 2).
In the latter half of August 1946, the surviving target ships were towed
or sailed to Kwajalein Atoll. Eight of the major ships and two submarines
were towed back to the U.S. for radiological inspection. Twelve target
ships were so lightly contaminated that their crews remanned them and sailed
them back to the United States. The remaining target ships were destroyed
by sinking off Bikini Atoll, off Kwajalein Atoll, or near the Hawaiian
Islands during 1946-1948. The support ships were decontaminated as necessary
at U.S. Navy shipyards, primarily in San Francisco and in Bremerton, Washington
(3: 2).
4.2.3 Dose Summary for CROSSROADS.
CROSSROADS operations were undertaken under radiological supervision
intended to keep personnel doses below 0.1 rem of gamma radiation per day.
About 15 percent of the participants were issued film badges. Personnel
anticipated to have the most potential for exposure were badged, and a
percentage of each group working in less radioactive areas were badged
(3: 2,3).
Because radiation dose data are not complete, reconstructions have been
made of personnel doses for unbadged crewmembers of the ships involved.
The calculations relied upon the radiation measurements recorded by radiation
safety personnel in 1946 and used the types of methods discussed in chapter
7. The table below summarizes the available dosimetry information:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
3,250 |
25 |
15 |
10 |
0 |
0 |
Navy |
28,436 |
4,883 |
2,939 |
4 |
0 |
0 |
Marine Corps |
550 |
0 |
0 |
0 |
0 |
0 |
4.3 OPERATION SANDSTONE.
Conducted at the Enewetak Atoll in 1948, Operation SANDSTONE consisted
of three tower shots, all detonated at a height of 200 feet (5: 1):
Event |
Date |
Type |
Yield
(kilotons) |
X-RAY |
15 April |
Tower |
37 |
YOKE |
1 May |
Tower |
49 |
ZEBRA |
15 May |
Tower |
18 |
4.3.1 Background and Objectives of Operation SANDSTONE.
Operation SANDSTONE was the second test series carried out in the Marshall
Islands. It differed from the first, CROSSROADS, in that it was primarily
a scientific series conducted by the Atomic Energy Commission. The AEC
was activated on 1 January 1947 to assume the responsibilities formerly
held by the Manhattan Engineer District, dissolved at the end of 1946.
The Armed Forces had a supporting role in SANDSTONE, whereas they had assumed
a lead role in CROSSROADS (5: 1).
SANDSTONE was a proof-test of second-generation nuclear devices. The
two weapons detonated at CROSSROADS were the same type of weapon dropped
on Nagasaki. On 3 April 1947, the General Advisory Committee to the AEC
recommended development and testing of new weapons. When the President
approved the preliminary SANDSTONE test program on 27 June 1947, the U.S.
apparently had only 13 nuclear weapons in its stockpile. One year later,
despite heavy emphasis on increased production of fissionable material,
the number of weapons was only about 50, far short of the number that military
planners calculated would be required in a war with the Soviet Union. The
great expansion in the U.S. stockpile evident by the end of 1949 was the
direct result of the higher production rates of fissionable material and
the more efficient weapons designs proof-tested at SANDSTONE (5: 17,18).
Meetings were held on 9 July 1947 at Los Alamos, New Mexico, to define
test responsibilities for SANDSTONE. The Los Alamos National Laboratory
(LANL), the organization that had developed the wartime atomic weapons
and that did research and laboratory development of new nuclear weapons
designs, was to provide technical leadership and the military services
were to provide supplies and support (5: 18).
4.3.2 SANDSTONE Test Operations.
Numerous technical experiments were conducted in conjunction with each
of the three detonations. These experiments measured the yield and efficiency
of the devices and attempted to gauge the military effects of the events.
The studies were similar at each of the shots but were carried out more
precisely with YOKE and ZEBRA as collective experience grew (5: 2,102).
Peak DOD numerical strength at SANDSTONE was approximately 11,500 participants,
95 percent of whom were military personnel. The DOD personnel had support
roles and some had duty stations at the AEC weapons design and development
laboratories or were part of units performing separate experiments (5:
1,2).
4.3.3 Dose Summary for Operation SANDSTONE.
The dose limit for SANDSTONE participants was 0.1 rem of gamma radiation
per 24-hour period and a maximum 3.0 rem for certain approved and specific
missions (5: 2). The following table summarizes the available dosimetry
information:
Summary of External Doses for Operation SANDSTONE as of 1 May
1986
Gamma Dose (rem)
Gamma Dose (rem)
| 0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
1,703 |
2 |
7 |
0 |
1 |
0 |
Navy |
7,731 |
17 |
9 |
1 |
1 |
0 |
Air Force |
2,075 |
27 |
8 |
1 |
0 |
0 |
Marine Corps |
180 |
1 |
1 |
0 |
0 |
0 |
Civilian DOD Participants |
17 |
0 |
0 |
0 |
0 |
0 |
4.4 OPERATION RANGER.
Operation RANGER was the first atmospheric nuclear weapons test series
conducted by the Atomic Energy Commission at the Nevada Test Site. This
1951 series consisted of five nuclear events, all of which were airdrops
detonated at heights of about 1,000-1,400 feet. In addition, RANGER included
one nonnuclear high-explosive test detonated 2 days before the first nuclear
event. The following table provides specifics on the nuclear shots (6:
1,4):
Event |
Date |
Type |
Yield (kilotons) |
ABLE |
27 January |
Airdrop |
1 |
BAKER |
28 January |
Airdrop |
8 |
EASY |
1 February |
Airdrop |
1 |
BAKER-2 |
2 February |
Airdrop |
8 |
FOX |
6 February |
Airdrop |
22 |
4.4.1 Background and Objectives of Operation RANGER.
In November 1950, the Los Alamos National Laboratory discovered that
insufficient data were available to determine satisfactory design criteria
for nuclear devices to be tested in Operation GREENHOUSE, a series of AEC
nuclear tests scheduled for the Pacific from 7 April through 24 May 1951.
The LANL scientists believed that variations in the compression of the
critical material could affect the yields of the GREENHOUSE devices. To
confirm this hypothesis, LANL held conferences on 6 and 11 December 1950
and concluded that a series of small nuclear tests should be conducted
to improve the GREENHOUSE design criteria. On 22 December 1950, LANL requested
approval for a continental series from the AEC Division of Military Application
(DMA). DMA approved the request and asked for Presidential approval to
expend the fissionable material required for the series and to use part
of the Las Vegas Bombing and Gunnery Range in Nevada for the tests. The
White House responded affirmatively to both requests on 11 January 1951,
formally creating Operation RANGER (6: 18).
The same day that Operation RANGER was approved by the President, the
AEC distributed its only announcements of the coming tests. Handbills were
circulated in the area of the test site, stating that from 11 January 1951
the Government would be conducting nuclear tests at the Las Vegas Bombing
and Gunnery Range. Figure 8 shows this handbill (6: 18-20).
4.4.2 Establishment of the Nevada Test Site.
Nearly 6 years passed between the detonation of TRINITY at Alamogordo,
New Mexico, on 16 July 1945, and the next CONUS nuclear test, ABLE of the
RANGER series. The AEC had considered establishing a continental test site
in 1948 after SANDSTONE, as a way to reduce construction and logistic costs,
but rejected the idea after concluding that the physical problems and domestic
political concerns would be too complicated. When the Korean War began
in the summer of 1950, however, the AEC doubted that the Pacific could
be used for nuclear weapons testing because of the possibility of the Korean
War expanding throughout the Far East, thus endangering shipping lanes.
On 13 July 1950, the AEC Chairman wrote the Chairman of the Military Liaison
Committee that the possibility of a national emergency required a joint
effort by the AEC and DOD to find a continental test site. The DOD agreed,
and the search began for a suitable site.
The AEC and DOD surveyed six sites within the continental United States
before choosing the Frenchman Flat area of the Las Vegas Bombing and Gunnery
Range, renamed the Nellis Air Force Range in 1956. The Government picked
this site because it best suited AEC criteria for favorable meteorological
conditions, distance from population areas, and proximity to operational
facilities (6: 19-20). Known first as the Nevada Test Site (NTS), then
as the Nevada Proving Ground (NPG) beginning in early 1952, the site since
1955 has again been called the Nevada Test Site, the designation used throughout
this volume.
4.4.3 RANGER Test Operations.
Only about 280 DOD personnel took part in RANGER, which was primarily
an AEC activity. They were engaged in support services, scientific experiments,
weather support, communications security, and observer activities. The
majority participated in the air support services conducted primarily by
Air Force personnel from the Special Weapons Command (SWC) and Headquarters,
Air Force. At each event, air support activities included the airdrop of
the nuclear device, cloud sampling, cloud tracking, aerial surveys of the
terrain, and courier service. Air Force personnel also provided meteorological
services and communications security and monitored worldwide radioactivity
from the RANGER test for the Atomic Energy Detection System. Since RANGER
was only a 13-day operation, the same units and participants performed
the same duties throughout the series (6: 1).
4.4.4 Dose Summary for Operation RANGER.
The summary table given below indicates that four doses exceeded the
3.0-rem limit of gamma radiation per 13-week period (6: 3):
Gamma Dose (rem)
| 0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
8 |
2 |
2 |
2 |
0 |
0 |
Navy |
3 |
1 |
0 |
1 |
1 |
0 |
Air Force |
213 |
0 |
0 |
0 |
0 |
0 |
Marine Corps |
0 |
1 |
0 |
0 |
0 |
0 |
Civilian DOD Participants |
17 |
6 |
9 |
0 |
0 |
0 |
4.5 OPERATION GREENHOUSE.
GREENHOUSE was the fourth postwar atmospheric nuclear weapons test series.
Conducted in 1951 on the northeastern islands of the Enewetak Atoll, the
series consisted of four tower shots, two at 200 feet and two at 300 feet
(7: 1):
Event | Date | Type | Yield (kilotons) |
DOG | 8 April | Tower | 81* |
EASY | 21 April | Tower | 47 |
GEORGE | 9 May | Tower | 225 |
ITEM | 25 May | Tower | 45.5 |
*Some yields marked "Not announced" in the original report
have been declassified since then and are included in this online version.
4.5.1 Background and Objectives of Operation GREENHOUSE.
The purpose of the four GREENHOUSE tests was to continue development
of nuclear weapons for defense. More specifically, work was proceeding
at this time on developing thermonuclear weapons, and the GREENHOUSE tests
were part of this process (7: 1).
In 1949, the Soviet Union detonated its first atomic bomb, providing
the impetus for the United States to proceed with development of a bomb
whose energy would come from the fusion, or joining, of light elements.
Such a weapon is also called a thermonuclear, or hydrogen, bomb. The Atomic
Energy Commission received Presidential approval for work in this area
in January 1950 after lengthy debate in high defense circles over the feasibility
and advisability of such weapons (7: 21).
Although the GREENHOUSE nuclear devices were not thermonuclear devices,
two of them involved thermonuclear experiments, and one test, GEORGE, was
an important step toward thermonuclear devices. GEORGE demonstrated the
initiation of a sustained thermonuclear reaction by use of a fission reaction.
This led directly to the first successful thermonuclear test, MIKE (Operation
IVY), some 16 months later. In addition, ITEM, the fourth test of the series,
involved boosting the efficiency of fission explosions. Development of
this experiment had been planned before the Soviet test in 1949 (7: 21).
4.5.2 GREENHOUSE Test Operations.
The Navy had provided most of the personnel for the earlier Pacific
nuclear test series. It contributed the largest number to GREENHOUSE, too,
but the Army and Air Force were also well represented, as the following
numbers show (7: 1):
Organization | Estimated Number of Participants |
Total | 7,590 |
Army | 1,500 |
Navy | 2,900 |
Air Force | 2,550 |
Marine Corps | 80 |
Civilian DOD Participants | 560 |
Participants supported the eight GREENHOUSE scientific programs, which
consisted of projects recommended by the Army, Navy, Air Force, Armed Forces
Special Weapons Project (AFSWP), and the Atomic Energy Commission. The
programs were of three types: those dealing with the chemistry and physics
of atomic explosions; those dealing with the effects of such explosions
on the natural environment, on man-made objects, and on various plants
and animals; and those designed to help develop means to detect nuclear
detonations at great distances so that U.S. authorities could monitor nuclear
developments in other countries (7: 130).
4.5.3 Dose Summary for Operation GREENHOUSE.
The maximum permissible dose for Operation GREENHOUSE participants was
0.1 rem of gamma radiation per day (0.7 rem per week), not to exceed a
total of 3.9 rem for 13 weeks. A total of up to 3.0 rem on any one day
could be authorized in specific cases. When this authorization was made,
however, individuals were not to exceed 0.1 rem per day during the remainder
of the operation (7: 64).
Film badges were issued to individuals who might be exposed to radiation
while performing their duties. In addition, over 75 film badges for each
test were distributed among the six participating ships, to be worn from
the day of the test to 7 days thereafter. Among the men in the test area
during all or part of the testing operations, 2,416 were badged one or
more times (7: 2).
Fallout occurred on the inhabited islands of Enewetak, Parry, and Japtan
and on the six task force ships after three of the four shots in the series.
Fallout from Shot DOG was approximately twice as great on Parry and Japtan
than it was on Enewetak, where the majority of the island-based participants
were located. Shot EASY fallout was insignificant and affected all residence
islands equally. Shot ITEM fallout, on the other hand, was approximately
twice as great on Enewetak as it was on Japtan (7: 3). Overall, calculated
fallout doses for personnel remaining on the residence islands until the
end of May, when the rollup phase was virtually complete, were nearly equal
on all three of the islands: Enewetak, 2.93 rem; Parry, 3.10 rem; and Japtan,
2.87 rem.
The amount of fallout received by the six ships varied with their locations
and decontamination procedures. Nearly all crewmembers on five of these
ships were assigned a fallout dose immediately after GREENHOUSE, and these
doses were recorded in Navy medical records. The assigned doses ranged
from 0.334 rem on USS LST-859 to 1.1 rem on USS Cabildo (LSD-16)
and USS Sproston (DDE-577). Boat pool doses ranged from 0.700 to
2.1 rem. The fallout exposure was lower aboard ship than on the islands
due to water washdown, shielding, and decontamination of external surfaces
(7: 3).
Gamma Dose (rem) | 0-0.5 | 0.5-1 | 1-3 | 3-5 | 5-10 | 10+ |
Army | 105 | 80 | 115 | 1,174 | 26 | 0 |
Navy | 1,045 | 481 | 1,137 | 180 | 56 | 4 |
Air Force | 721 | 326 | 223 | 1,022 | 214 | 14 |
Marine Corps | 4 | 0 | 41 | 1 | 1 | 0 |
Civilian DOD Participants | 356 | 67 | 96 | 42 | 0 | 0 |
4.6 OPERATION BUSTER-JANGLE.
Conducted from 22 October to 29 November 1951, Operation BUSTER-JANGLE
was the second series of atmospheric nuclear weapons tests at the NTS.
The series consisted of seven nuclear detonations, summarized below:
Event |
Date |
Type |
Yield (kilotons) |
ABLE |
22 October |
Tower |
<0.1 |
BAKER |
28 October |
Airdrop |
3.5 |
CHARLIE |
30 October |
Airdrop |
14 |
DOG |
1 November |
Airdrop |
21 |
EASY |
5 November |
Airdrop |
31 |
SUGAR |
19 November |
Surface |
1.2 |
UNCLE |
29 November |
Underground |
1.2 |
SUGAR was the first surface and UNCLE the first underground (-17 feet)
detonation of a nuclear device (8: 1,6).
4.6.1 Background and Objectives of Operation BUSTER-JANGLE.
This series was originally planned as two separate weapons testing programs:
Operation BUSTER and Operation JANGLE. BUSTER, the plans for which began
in late 1950, was to evaluate new devices developed by the Los Alamos National
Laboratory and to obtain data on the basic phenomena associated with these
devices. Plans for JANGLE originated with Operation CROSSROADS, conducted
at Bikini in 1946. Scientific studies of the underwater CROSSROADS detonation
led to inquiries concerning the effects and possible military value of
an underground nuclear detonation. The Joint Chiefs of Staff accordingly
obtained AEC agreement to conduct tests involving an underground and a
surface nuclear detonation. The general objectives of the tests were to
determine the effects of these detonations and to study the devices for
inclusion in the nuclear arsenal (8: 20-21).
In 1950, AEC and DOD representatives selected Amchitka Island, one of
the Aleutian Islands, as the site for the underground and surface tests,
to be called Operation WINDSTORM and to be conducted from 15 September
to 15 November 1951. During March 1951, they decided that the tests should
be conducted at the NTS and should be coordinated by the Air Force. The
two nuclear events were subsequently renamed Operation JANGLE (8: 21).
Because BUSTER and JANGLE were then both scheduled for the fall of 1951
at the NTS, the Armed Forces Special Weapons Project recommended that the
two series be conducted as consecutive phases of one series, Operation
BUSTERJANGLE. On 19 June 1951, the AEC approved the AFSWP recommendation
(8: 21-22).
4.6.2 BUSTER-JANGLE Test Operations.
Operation BUSTER-JANGLE involved an estimated 7,800 DOD personnel in
observer programs, tactical maneuvers, damage effects tests, scientific
and diagnostic studies, and support activities. Approximately 6,500 of
these participants took part in Exercises Desert Rock I, II, and III, Army
programs involving members from all four armed services. The remaining
DOD personnel provided support for the Desert Rock exercises or participated
in scientific activities (8: 1).
Exercise Desert Rock I was conducted at Shot DOG, and Exercises Desert
Rock II and III at Shots SUGAR and UNCLE, respectively. The troop exercises
were the first staged by the Armed Forces during continental nuclear weapons
testing. The Desert Rock exercises included observer programs, tactical
maneuvers, and damage effects tests. Observer programs, conducted at DOG,
SUGAR, and UNCLE, generally involved briefings on nuclear weapons effects,
observation of the nuclear detonation, and a subsequent tour of a display
of military equipment exposed to the detonation. Tactical maneuvers, conducted
after DOG, were designed both to train troops and to test military tactics.
Damage effects tests, at DOG, SUGAR, and UNCLE, were performed to determine
the effects of a nuclear detonation on military equipment and field fortifications
(8: 1).
4.6.3 Dose Summary for Operation BUSTER-JANGLE.
The AEC established a dose limit of 1.0 rem of gamma radiation for participants
in Exercise Desert Rock I and a limit of 3.0 rem for the following: participants
in Exercises Desert Rock II and III; the test organization, which coordinated
BUSTER-JANGLE; and Special Weapons Command, which provided weather and
air support, among other functions, for the test organization. SWC sampling
pilots and crews were authorized to receive up to 3.9 rem because their
mission required them to penetrate the clouds resulting from the detonations
(8: 4). The following table summarizes the available dosimetry information:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
6,503 |
85 |
33 |
5 |
4 |
0 |
Navy |
156 |
57 |
90 |
16 |
0 |
0 |
Air Force |
502 |
16 |
45 |
18 |
0 |
0 |
Marine Corps |
186 |
0 |
2 |
0 |
0 |
0 |
Civilian DOD Participants |
65 |
4 |
20 |
3 |
0 |
0 |
4.7 OPERATION TUMBLER-SNAPPER.
Operation TUMBLER-SNAPPER, conducted from 1 April to 5 June 1952, was
the third series of nuclear weapons tests at the NTS. The operation consisted
of eight nuclear detonations, identified below:
Event |
Date |
Type |
Yield (kilotons) |
ABLE |
1 April |
Airdrop |
1 |
BAKER |
15 April |
Airdrop |
1 |
CHARLIE |
22 April |
Airdrop |
31 |
DOG |
1 May |
Airdrop |
19 |
EASY |
7 May |
Tower |
12 |
FOX |
25 May |
Tower |
11 |
GEORGE |
1 June |
Tower |
15 |
HOW |
5 June |
Tower |
14 |
The detonations were part of two phases of the series, as explained
in the next section (9: 1,9).
4.7.1 Background and Objectives of Operation TUMBLER-SNAPPER.
As the defense policy evolved in the early 1950s, two particular factors
challenged the ability of U.S. Armed Forces to defend American interests
and to protect its allies during limited hostilities:
- The commitment of U.S. ground forces to the Korean peninsula
- The inability of European allies of the U.S. to develop effective military
capabilities.
In both cases, the United States experienced difficulties because of
limitations in military manpower, which emphasized the need for a new U.S.
policy based not on large standing armies, but on new technological advances,
particularly in nuclear weapons (9: 25).
In 1951, the Chairman of the AEC strongly advocated the development
of nuclear weapons for tactical purposes. "We could," he asserted,
"use an atomic bomb today in a tactical way against enemy troops in
the field, against military concentrations near battle areas and against
other vital military targets without risk to our own troops." TUMBLER-SNAPPER
was accordingly designed both to advance the development of effective nuclear
weapons and to train troops in tactical nuclear warfare (9: 25).
The series, like BUSTER-JANGLE, was originally planned as two separate
testing programs: Operation TUMBLER, to be conducted at the NTS before
1 May 1952; and Operation SNAPPER, scheduled to begin at the NTS on 1 May
1952. Because the programs planned for the two series sometimes overlapped,
they were combined into one operation, TUMBLER-SNAPPER (9: 26-28).
The series consisted of two phases. The TUMBLER phase, of primary concern
to the DOD, featured four weapons effects tests: ABLE, BAKER, CHARLIE,
and DOG. These airdropped devices were detonated to collect information
on the effect of the height of burst on overpressure. Shots CHARLIE and
DOG were also part of the SNAPPER phase, of primary concern to the AEC
and the Los Alamos National Laboratory. The other weapons development tests
in the SNAPPER phase were EASY, FOX, GEORGE, and HOW. The primary purpose
of these four tower shots was to gather information on nuclear phenomena
and to improve the design of nuclear weapons (9: 1).
4.7.2 TUMBLER-SNAPPER Test Operations.
About 7,350 of the estimated 8,700 DOD participants in Operation TUMBLER-SNAPPER
took part in Exercise Desert Rock IV. The remaining DOD personnel assisted
in scientific experiments, air support activities, or administrative and
support activities at the NTS (9: 1).
Exercise Desert Rock IV, an Army training program involving personnel
from the armed services, included observer programs at Shots CHARLIE, DOG,
FOX, and GEORGE and tactical maneuvers after Shots CHARLIE, DOG, and GEORGE.
The tactical maneuvers were designed in part to provide realistic training
for ground units when supported by tactical atomic weapons and to determine
the psychological reactions of troops participating in the exercise. The
DOG tactical maneuver was the first Marine Corps maneuver of the CONUS
tests. In addition to these activities, Exercise Desert Rock IV involved
psychological tests at CHARLIE, FOX, and GEORGE to gauge the troops' reactions
to witnessing a nuclear detonation (9: 1,5).
Figure 9 shows troops advancing into the test area behind a radiological
safety monitor on 2 May 1952, 1 day after the detonation of DOG. The troops
halted as the monitor took measurements with a Geiger Counter (B).
4.7.3 Dose Summary for Operation TUMBLER-SNAPPER.
A dose limit of 3.0 rem of gamma radiation per 13-week period was established
for participants in Exercise Desert Rock IV, the joint AEC-DOD organization
(coordinator of the series), and most of the Air Force Special Weapons
Center (AFSWC) activities (9: 7). The following table presents the available
dosimetry information:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
3,848 |
467 |
61 |
17 |
6 |
1 |
Navy |
446 |
45 |
61 |
4 |
0 |
0 |
Air Force |
1,112 |
35 |
42 |
17 |
3 |
0 |
Marine Corps |
2,033 |
8 |
1 |
0 |
0 |
0 |
Civilian DOD Participants |
368 |
43 |
82 |
10 |
0 |
0 |
4.8 OPERATION IVY.
IVY, conducted at Enewetak Atoll during autumn 1952, consisted of two
detonations. These two detonations, identified in the following table,
were the largest nuclear explosions up to that time:
Event |
Date |
Type |
Yield |
MIKE |
1 November |
Surface |
10.4 megatons |
KING |
16 November |
Airdrop |
500 kilotons |
The description of the MIKE detonation by the author of History--Task
Group 132.1 and reproduced in History of Operation IVY bears
repeating (10: 1,187):
The Shot, as witnessed aboard the various vessels at sea, is not easily
described. Accompanied by a brilliant light, the heat wave was felt immediately
at distances of thirty to thirty-five miles. The tremendous fireball, appearing
on the horizon like the sun when halfrisen, quickly expanded after
a momentary hover time and appeared to be approximately a mile in diameter
before the cloud-chamber effect and scud clouds partially obscured it from
view. A very large cloud-chamber effect was visible shortly after the detonation
and a tremendous conventional mushroom-shaped cloud soon appeared, seemingly
balanced on a wide dirty stem. Apparently, the dirty stem was due to the
coral particles, debris, and water which were sucked high into the air.
Around the base of the stem, there appeared to be a curtain of water which
soon dropped back around the area where the island of Elugelab [Eluklab]
had been.
Figure 10 presents a photograph of the MIKE cloud (C).
4.8.1 Background and Objectives, of Operation IVY.
President Truman made the decision to pursue the development of thermo-nuclear
weapons in 1950. Operation GREENHOUSE was an initial step toward this end,
as section 4.5 explains. Operation IVY considerably extended the GREENHOUSE
advances. MIKE, an experimental device, produced the first thermonuclear
detonation, which means that a substantial portion of its energy was generated
by the fusion, or joining, of hydrogen and other light atoms. KING was
a stockpile weapon, modified to produce a large yield. The energy from
KING was generated by the fission, or splitting, of plutonium atoms (10:
1).
The IVY test program was the result not only of scientific and technical
considerations, but also of an intense controversy within elements of the
U.S. Government concerned with foreign policy and defense matters. During
the early 1950s, various plans rapidly evolved to meet the challenge posed
by the initial Soviet detonation of 1949. Most plans called for increased
development and production of fission weapons and the required delivery
systems. One plan called for the development of fusion, or thermonuclear,
weapons with vastly greater explosive power. Opponents of fusion weapons
argued that the Soviets could be persuaded not to develop these weapons
if the United States would refrain. A further argument, among others, was
that such weapons were not much more effective than high-yield fission
weapons (10: 18).
The advocates of fusion weapons prevailed, and MIKE became the centerpiece
of Operation IVY and the proof-test of the new technology. KING, however,
represented a test of the kind of highyield fission weapon some of
the fusion opponents had in mind. To a degree, the KING device also offered
a backup to help ease the national sense of vulnerability in the event
that the initial attempt at a fusion reaction detonation was unsuccessful
(10: 18-19).
4.8.2 IVY Test Operations.
IVY engaged nearly 11,650 participants, of whom approximately 9,350
were military and about 2,300 were civilians. Most of the civilians and
over 6,600 of the military personnel operated from Enewetak Atoll and from
task force ships based there. These personnel were removed to evacuation
ships before the detonation of MIKE. Most of the additional military were
Air Force personnel who were based at Kwajalein, 350 nautical miles southeast
of Enewetak (10: 2,178-181).
The experimental program for IVY focused primarily on the MIKE experiment
and secondarily on KING. The effort, subdivided into 11 specific programs,
was heavily oriented to weapons development experiments and focused to
a lesser extent on effects experiments (10: 118).
4.8.3 Dose Summary for Operation IVY.
The generally smooth MIKE operations were marred by an accident when
a cloud-sampling pilot was lost at sea after his aircraft ran out of fuel.
A seven-man rescue crew flew their aircraft over a fallout zone to reach
the area of the downed airplane as soon as possible. In the process, the
crewmembers received radiation doses ranging from 10 to 17.8 rem. These
levels considerably exceeded the maximum permissible limit of 3.9 rem of
gamma radiation established for Operation IVY participants (10: 3).
A crew of 12 in a second aircraft was overexposed when caught in fallout
debris while on a photographic mission just after the MIKE shot. The highest
dose for a member of this crew was 11.6 rem. Other than these two events,
no cases exceeded the established limit during IVY (10: 3).
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
1,300 |
1 |
1 |
0 |
0 |
0 |
Navy |
5,191 |
23 |
42 |
2 |
0 |
0 |
Air Force |
2,199 |
325 |
37 |
4 |
9 |
10 |
Marine Corps |
169 |
1 |
8 |
0 |
0 |
0 |
Civilian DOD Participants |
28 |
0 |
3 |
0 |
0 |
0 |
4.9 OPERATION UPSHOT-KNOTHOLE.
Conducted at the NTS from 17 March to 4 June 1953, Operation UPSHOTKNOTHOLE
consisted of 11 nuclear tests, a number exceeding that of any previous
nuclear test series. The following table summarizes these shots:
Event |
Date |
Type |
Yield (Kilotons) |
ANNIE |
17 March |
Tower |
16 |
NANCY |
24 March |
Tower |
24 |
RUTH |
31 March |
Tower |
0.2 |
DIXIE |
6 April |
Airdrop |
11 |
RAY |
11 April |
Tower |
0.2 |
BADGER |
18 April |
Tower |
23 |
SIMON |
25 April |
Tower |
43 |
ENCORE |
8 May |
Airdrop |
27 |
HARRY |
19 May |
Tower |
32 |
GRABLE |
25 May |
Airburst |
15 |
CLIMAX |
4 June |
Airdrop |
61 |
ANNIE, the first device tested, was an "open shot," meaning
that reporters were allowed to view the detonation from News Nob, 11 kilometers
south of the shot-tower. The Government wanted to show the American public
that nuclear weapons could be used defensively, without destroying large
urban centers and populations (11: 1,13,2,30,31).
The firing of GRABLE from a 280 mm cannon, shown in figure 11, marked
the first time an atomic artillery shell was fired and detonated (D). The
Secretary of Defense, the Secretary of the Army, and the Army Chief of
Staff, along with 96 Congressional observers, viewed the detonation from
an area 11 kilometers west of ground zero (12: 120).
4.9.1 Background and Objectives of Operation UPSHOT-KNOTHOLE.
UPSHOT-KNOTHOLE went a step further than the previous CONUS series,
TUMBLERSNAPPER, which had explored the use of nuclear weapons for
tactical purposes. Designed to address both the tactical and strategic
considerations of the U.S. defense policy, UPSHOTKNOTHOLE was designed
to accomplish the following (11: 33):
- Establish military doctrine for the tactical use of nuclear weapons
- Improve the nuclear weapons used for strategic bomber delivery and
those used for tactical battlefield situations.
Like the earlier BUSTER-JANGLE and TUMBLER-SNAPPER series, UPSHOTKNOTHOLE
was initially envisioned as two separate weapons testing programs: Operation
UPSHOT and Operation KNOTHOLE. Plans began in late 1951 for a large military
effects test, later called Operation KNOTHOLE, to be conducted during the
spring of 1953 at the NTS. The objective was to obtain general weapons
effects information to supplement the data obtained from Operation GREENHOUSE,
conducted at the Pacific during spring 1951 (11: 32).
Meanwhile, the AEC was planning Operation UPSHOT, with the earliest
test date set for spring 1953. The DOD consequently accelerated its planning
for Operation KNOTHOLE so that arrangements for the AEC and DOD tests could
be coordinated. In June 1952, the DOD and AEC agreed to conduct the spring
1953 tests as a combined operation, designated UPSHOTKNOTHOLE (11:
32).
4.9.2 UPSHOT-KNOTHOLE Test Operations.
An estimated 18,000 DOD personnel participated at UPSHOT-KNOTHOLE in
observer programs, tactical maneuvers, scientific studies, and support
activities. The largest DOD participation was in Exercise Desert Rock V,
which involved members of all four armed services. Exercise Desert Rock
V included troop orientation and training, a volunteer officer observer
program, tactical troop maneuvers, operational helicopter tests, and damage
effects evaluation. The troop orientation and training included briefings
before the detonation on nuclear weapons characteristics and effects and
on personal protection; figure 12 is a photograph of one such briefing
(E). Troop orientation and training also involved observation of a nuclear
detonation, as did the volunteer officer observer program. For the latter,
trained staff officers calculated the effects of a nuclear detonation to
determine a minimum safe distance for observing the blast; they later watched
the detonation from the calculated position. Among the other activities,
the operational helicopter tests performed by the Marine Corps were designed
to investigate the capability of helicopters and their crews to withstand
a nuclear burst and its effects (11: 1).
4.9.3 Dose Summary for Operation UPSHOT-KNOTHOLE.
The maximum permissible dose for participants in the Joint Test Organization,
which coordinated UPSHOT-KNOTHOLE, and AFSWC was 3.9 rem of gamma radiation
for the series. The limits were higher for Desert Rock V participants,
according to the requirements of their missions. Desert Rock V troops were
restricted to a maximum of 6.0 rem of gamma radiation for the series, with
no more than 3.0 rem of prompt radiation. The volunteer officer observers
were limited to 10.0 rem of gamma radiation, with no more than 5.0 rem
of prompt radiation per test, and a total of no more than 25.0 rem for
the exercise (11: 11).
Dosimetry information is available for the volunteer officer observers,
who participated at Shots NANCY, BADGER, and SIMON. The exposures of seven
of the eight SIMON observers exceeded the 10.0 rem shot limit, with a high
of 17.5 rem. The one volunteer observer who witnessed all three shots had
an exposure of 26.6 rem (11: 12).
The calculated mean neutron doses for the volunteer observers have been
reconstructed as 0.63 rem for Shot NANCY; 2.4 rem for Shot BADGER; and
28 rem for Shot SIMON (11: 12,15).
Summary of External Doses for Operation UPSHOT-KNOTHOLE as of
1 May 1986
Gamma Dose (rem)
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
3,705 |
3,041 |
4,459 |
1,299 |
20 |
10 |
Navy |
402 |
171 |
96 |
87 |
16 |
1 |
Air Force |
1,125 |
226 |
260 |
45 |
17 |
3 |
Marine Corps |
112 |
205 |
330 |
1,611 |
16 |
1 |
Civilian DOD Participants |
98 |
28 |
28 |
2 |
0 |
0 |
4.10 OPERATION CASTLE.
CASTLE was conducted at Enewetak and Bikini Atolls during the spring
of 1954. The first event of this series, Shot BRAVO, had a yield of 15
megatons and was the largest device ever detonated by the U.S. Government
as part of atmospheric nuclear weapons testing. The following table provides
specifics on this detonation, shown in figure 13 (F), as well as the other
five in the series (13: 1):
Event |
Date |
Type |
Yield |
BRAVO |
1 March |
Surface |
15 megatons |
ROMEO |
27 March |
Barge |
11 megatons |
KOON |
7 April |
Surface |
110 kilotons |
UNION |
26 April |
Barge |
6.9 megatons |
YANKEE |
5 May |
Barge |
13.5 megatons |
NECTAR |
14 May |
Barge |
1.69 megatons |
4.10.1 Background and Objectives of Operation CASTLE.
CASTLE was the culmination in the development of the super, or hydrogen,
bomb that began in 1950. Shot GEORGE, a test in the 1951 GREENHOUSE series,
had demonstrated the initiation of a sustained thermonuclear reaction by
use of a fission reaction. Fusion, or thermonuclear, reactions had been
used in 1952 to generate the very powerful detonation of the MIKE device
in Operation IVY, but MIKE was not a deliverable nuclear weapon. In BRAVO,
the first CASTLE test, a device more powerful than MIKE was exploded that,
although not a weapon, was capable of delivery by an aircraft (13: 26).
CASTLE also was the first Pacific series in which the Lawrence Livermore
National Laboratory (LLNL) provided a nuclear device for testing, detonated
as Shot KOON. All previous nuclear test devices had been designed at the
Los Alamos National Laboratory (13: 26).
4.10.2 CASTLE Test Operations.
Numerous technical experiments were carried out in conjunction with
each of the six detonations. These experiments measured the yield and efficiency
of the devices and attempted to gauge the military effects of the explosions.
The approximately 12,700 DOD participants in this series had duty stations
at the AEC design laboratories or were members of units performing separate
experiments or various support roles. Almost all of the Navy support personnel
were at Bikini, where Navy ships provided living quarters for participants
who were evacuated from the islands for the first test and then could not
return to live there because of the potential radiation exposure (13: 2).
4.10.3 Dose Summary for Operation CASTLE.
Among the CASTLE detonations, only BRAVO produced significant, unexpected
personnel radiation exposures. This first shot of the series, which significantly
exceeded its expected yield, released large quantities of radioactive materials
into the atmosphere. These materials were caught up in winds that spread
the particles over a much larger area than had been anticipated. This resulted
in contamination and exposure of Marshall Island residents, Japanese fishermen,
and U.S. personnel on distant atolls or aboard various vessels. Acute radiation
effects were observed among some of these people (13: 3).
Some DOD personnel exceeded the maximum permissible limit of 3.9 rem
of gamma radiation within any 13-week period of the operation. BRAVO fallout
on some Navy ships resulted in personnel who had doses approaching or exceeding
this limit. To allow for completion of the CASTLE tests, it became necessary
to issue a number of waiver authorizations permitting doses of as much
as 7.8 rem. In a limited number of shipboard cases, even this level was
exceeded. Substantial overdoses from BRAVO, the highest for any test series,
were accrued by the 28 Air Force and Army personnel on Rongerik Atoll (13:
3-4) and the 92 crew members of USS Patapsco, a Navy gasoline tanker
that was overtaken by the nuclear cloud on the day following the shot while
en route from Enewetak Atoll to Pearl Harbor (14). Film badge readings
suggest that three members of the U.S. Navy Bikini Boat Pool also may have
received substantial overdoses. Thorough investigation at the time failed,
however, to indicate reasons for these readings (13: 243-244). As a result
of BRAVO, 21 individuals on the USS Philip and 16 on the USS Bairoko
sustained lesions that were classified as beta burns, all of which healed
without complications (13: 3-4).
Summary of External Doses for Operation CASTLE as of 1 May 1986
Gamma Dose (rem)
Gamma Dose (rem)
| 0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
0 |
0 |
1,341 |
47 |
6 |
3 |
Navy |
3,940 |
1,462 |
2,210 |
695 |
211 |
115 |
Air Force |
984 |
193 |
970 |
62 |
30 |
31 |
Marine Corps |
160 |
8 |
101 |
29 |
5 |
0 |
Civilian DOD Participants |
30 |
6 |
13 |
0 |
0 |
0 |
4.11 OPERATION TEAPOT.
Conducted from 18 February to 15 May 1955, Operation TEAPOT was the
fifth series of CONUS tests. Two of the 14 nuclear detonations in the series,
APPLE 1 and WASP PRIME, occurred on the same day although in different
parts of the NTS. ESS, the only TEAPOT subsurface detonation (67 feet),
forced tons of earth upward, thereby creating a crater 88 meters wide and
96 feet deep. Figure 14 shows Exercise Desert Rock VI troops observing
the ESS detonation (G). They were positioned approximately 8 kilometers
from the shot site.
The TEAPOT schedule was continually revised as the AEC waited for appropriate
weather conditions for firing the test shots. The delay in one shot often
resulted in postponing subsequent shots, regardless of the weather. The
many schedule changes, affecting all but the first two shots, caused a
6-week extension of TEAPOT from 1 April to 15 May (15: 29).
The following table provides data on the TEAPOT tests (15: 1,5,9):
Event |
Date |
Type |
Yield (kilotons) |
WASP |
18 February |
Airdrop |
1 |
MOTH |
22 February |
Tower |
2 |
TESLA |
1 March |
Tower |
7 |
TURK |
7 March |
Tower |
43 |
HORNET |
12 March |
Tower |
4 |
BEE |
22 March |
Tower |
8 |
ESS |
23 March |
Crater |
1 |
APPLE 1 |
29 March |
Tower |
14 |
WASP PRIME |
29 March |
Airdrop |
3 |
HA |
6 April |
Airdrop |
3 |
POST |
9 April |
Tower |
2 |
MET |
15 April |
Tower |
22 |
APPLE 2
| 5 May |
Tower |
29 |
ZUCCHINI |
15 May |
Tower |
28 |
4.11.1 Background and Objectives of Operation TEAPOT.
Operation TEAPOT furthered the efforts of the previous CONUS series,
the 1953 Operation UPSHOT-KNOTHOLE, which had studied both the tactical
and strategic uses of nuclear weapons (see section 4.9) (15: 27). Authorized
by President Eisenhower on 30 August 1954, TEAPOT had two primary objectives:
- To establish military doctrine and tactics for the use of ground forces
on a nuclear battlefield
- To improve the nuclear weapons used for strategic bomber delivery and
missile delivery and those used for tactical battlefield situations.
The DOD conducted Exercise Desert Rock VI to achieve the first objective,
and the AEC fielded scientific experiments to achieve the second (15: 27,28).
4.11.2 TEAPOT Test Operations.
Approximately 8,700 DOD personnel participated in TEAPOT observer programs,
tactical maneuvers, scientific studies, and support activities. The largest
number, about 8,000, took part in Exercise Desert Rock VI, which included
observer programs at Shots WASP, MOTH, TESLA, TURK, BEE, ESS, APPLE 1,
and APPLE 2 and troop tests at Shots BEE and APPLE 2. The largest single
TEAPOT activity was the Marine Brigade Exercise at BEE, which involved
about 300 officers and 1,950 enlisted men. The objective of the exercise
was to train personnel and to test the tactics and techniques employed
if a nuclear detonation were used to support an air-ground task force.
The troop test at APPLE 2, involving about 1,000 troops, was designed to
demonstrate the capability of a reinforced tank battalion to seize an objective
immediately after a nuclear detonation. In addition to these activities,
technical studies were conducted at 10 of the shots (15: 1,5-7).
4.11.3 Dose Summary for Operation TEAPOT.
The maximum dose limit for personnel of the Joint Test Organization,
which coordinated Operation TEAPOT, and AFSWC was 3.9 rem of gamma radiation
during the series. The limit for Desert Rock troops was 6.0 rem of gamma
radiation during the series, with no more than 3.0 rem of prompt radiation.
The Desert Rock troops had this higher limit because they, unlike JTO and
some AFSWC technical personnel, were not likely to be exposed to radiation
after the tests (15: 2,3).
The 10 Desert Rock volunteer officer observers at APPLE 2 were authorized
a special limit of 10.0 rem of gamma radiation. Their average film badge
readings were 1.3 rem. Pilots for Project 2.8b, Manned Penetrations of
Atomic Clouds, were authorized a limit of 15 rem. One participant had a
film badge reading of 21.7 rem, and another received 21.8 rem (15: 3).
Gamma Dose (rem)
| 0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
2,280 |
1,088 |
1,234 |
51 |
5 |
0 |
Navy |
287 |
32 |
197 |
21 |
0 |
4 |
Air Force |
842 |
73 |
103 |
55 |
5 |
4 |
Marine Corps |
462 |
1,450 |
4 |
0 |
0 |
0 |
Civilian DOD Participants |
128 |
3 |
1 |
0 |
0 |
0 |
4.12 OPERATION WIGWAM.
Operation WIGWAM consisted of only one nuclear detonation, a deep underwater
test conducted in the Pacific Ocean approximately 500 miles southwest of
San Diego, California. The device was suspended by cable from an unmanned
barge and detonated at a depth of 2,000 feet in water 16,000 feet deep.
The test, which had a yield of 30 kilotons, occurred on 14 May 1955 at
1300 hours Pacific Daylight Time (16: 9).
The test site was chosen after careful deliberation. AT DOD request,
Scripps Institution of Oceanography surveyed various locations in the Pacific,
the Caribbean, and the Atlantic. The site had to be deep enough to contain
the detonation, yet away from undersea or sea bottom perturbations, such
as sea mounts, ridges, and islands. Migratory fishing areas were to be
avoided. In addition, the site was to have fairly well-known currents and
thermal gradients, a predominance of good weather, and isolation from shipping
lanes. The area selected was judged the best to fulfill the requirements
(16: 1-11).
4.12.1 Background and Objectives of Operation WIGWAM.
Prior to WIGWAM, nuclear weapons had been tested in the atmosphere,
on the surface of the earth or water, or at a shallow underwater depth.
Considerable interest developed, particularly within the Navy, in investigating
deep underwater effects by detonating a weapon at sufficient depth to contain
all the initial energy of the nuclear explosion in the water (16: 1-3).
The Navy needed to know how a deep underwater shot would affect naval
forces and, specifically, the answers to two leading questions: (1) What
are the characteristics and lethal ranges of the resulting underwater shock
wave? and (2) What are the effects of the radioactivity, following the
explosion, on naval tactical operations? For example, could a surface vessel
use a nuclear depth charge to destroy submerged enemy submarines without
endangering itself? Specific answers to these questions were required to
plan possible naval use of these weapons (16: 1-3,1-5).
4.12.2 WIGWAM Test Operations.
Approximately 6,800 personnel and 30 ships participated in Operation
WIGWAM. They conducted or supported the three scientific programs designed
to collect the desired data (16: 9,1-3).
A 6-mile towline connected the fleet tug, USS Tawasa, and the
barge from which the nuclear device was suspended. Located at varying distances
along this towline were a variety of pressuremeasuring instruments,
unmanned and specially prepared submerged submarinelike hulls (called
squaws), as well as instrumented and also unmanned surface boats (16: 9).
The ships and personnel conducting the test were positioned 5 miles
upwind from the barge that suspended the nuclear device. The only exceptions
were for USS George Eastman (YAG-39) and USS Granville S. Hall
(YAG-40). These two extensively reconfigured ships, equipped with special
shielding to prevent radiological exposure, were stationed 5 miles downwind
from the barge. Recovery parties later reentered the test area with radiological
safety monitors, and after aerial surveys showed the general location and
size of the contaminated water area and the radiation levels (16: 9).
4.12.3 Dose Summary for Operation WIGWAM.
The maximum dose limit for WIGWAM was 3.9 rem of gamma radiation for
the duration of the operation. The two vessels (YAG-39 and YAG-40) stationed
downwind of the detonation were subjected to contamination by water droplets
of the base surge. Because of the special shielding, however, none of the
YAG personnel exceeded the radiation limit. All doses were low because
most of the radioactivity was confined deep under the surface of the water
(16: 10,11).
WIGWAM was the first series in which nearly all participants were issued
film badges. Personnel whose duties were such that exposure to radiation
was possible (such as sampling radioactive water, recovering equipment
or instruments) were issued additional film badges on a daily basis. One
of the vessels, the USS Wright, contained a film processing center
where badges were read and personnel exposures were recorded. Over the
period of the operation, approximately 10,000 film badges were issued (16:
10).
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
9 |
0 |
0 |
0 |
0 |
0 |
Navy |
6,567 |
1 |
0 |
0 |
0 |
0 |
Air Force |
64 |
0 |
0 |
0 |
0 |
0 |
Marine Corps |
109 |
0 |
1 |
0 |
0 |
0 |
Civilian DOD Participants |
17 |
0 |
1 |
0 |
0 |
0 |
4.13 OPERATION REDWING.
REDWING was conducted in 1956 as the sixth nuclear test series at the
Marshall Islands, specifically at Enewetak and Bikini Atolls. The series
consisted of the 17 detonations identified in the accompanying table. Figure
15 presents a photograph taken during the ERIE detonation, the fifth shot
of the series. It shows a group on Enewetak turned away from the detonation
as it breaks the predawn darkness (H).
Event |
Date |
Type |
Yield |
LACROSSE |
5 May |
Surface |
40 kilotons |
CHEROKEE |
21 May |
Airdrop |
3.8 megatons |
ZUNI |
28 May |
Surface |
3.5 megatons |
YUMA |
28 May |
Tower |
190 tons* |
ERIE |
31 May |
Tower |
14.9 kilotons |
SEMINOLE |
6 June |
Surface |
13.7 kilotons |
FLATHEAD |
12 June |
Barge |
365 kilotons |
BLACKFOOT |
12 June |
Tower |
8 kilotons |
KICKAPOO |
14 June |
Tower |
1.49 kilotons |
OSAGE |
16 June |
Airdrop |
1.7 kilotons |
INCA |
22 June |
Tower |
15.2 kilotons |
DAKOTA |
26 June |
Barge |
1.1 megatons |
MOHAWK |
3 July |
Tower |
360 kilotons |
APACHE |
9 July |
Barge |
1.85 megatons |
NAVAJO |
11 July |
Barge |
4.5 megatons |
TEWA |
21 July |
Barge |
5 megatons |
HURON |
22 July |
Barge |
250 kilotons |
*Some yields marked "Not announced" in the original report
have since been declassified and are included in this online version.
4.13.1 Background and Objectives of Operation REDWING.
The main purpose of Operation REDWING was to test high-yield thermonuclear
devices that could not be tested in Nevada. The only shot of the series
not expressly for weapons development was CHEROKEE, which was airdropped
from a B-52. Its primary purpose was to demonstrate the ability of the
U.S. to deliver large-yield nuclear devices. The event was viewed by 15
press observers, the first such group invited to view a Pacific nuclear
test since the CROSSROADS detonations of 1946. Seventeen invited civil
defense officials also observed the shot (17: 2, 177, 22-23).
During CASTLE, the fifth nuclear test series conducted in the Marshall
Islands, a serious fallout contamination incident from Shot BRAVO had affected
not only U.S. personnel but Marshall Island residents and Japanese fishermen
as well. On 27 April, 8 days before the first REDWING detonation, a joint
DOD-AEC press release identified the safety precautions in effect for the
series. It described the improved fallout prediction capability available
and the extensive monitoring that was to be done both at the Pacific Proving
Ground and beyond. It also described programs for surveying marine life
in the Pacific. Moreover, the release stated that the yields of the devices
to be tested were expected to be lower than the largest of those detonated
as part of Operation CASTLE (17: 21,22).
Press observers were invited to view part of the series. Fifteen members
of the press, the first to observe oceanic tests since the CROSSROADS detonations
of 1946, accordingly witnessed LACROSSE and CHEROKEE. Seventeen invited
civil defense officials also observed the shots (17: 22).
4.13.2 REDWING Test Operations.
Numerous technical experiments were carried out in conjunction with
each of the 17 detonations. These experiments measured the yield and efficiency
of the devices and attempted to gauge the military effects of the explosions.
Approximately 11,350 DOD personnel took part in or supported these activities.
Also present at the tests were several thousand personnel from the AEC
and its contractors, a few from other Government agencies, and some foreign
observers as well (17: 2).
Most of the Navy and Marine Corps personnel were on ships operating
around Bikini providing supply, evacuation capability, and other support
to the tests there. Most of the Army and Air Force personnel were on Enewetak.
All the services had personnel assigned to laboratory organizations whose
operations were conducted on both atolls as well as other locations in
the Pacific (17: 3).
4.13.3 Dose Summary for Operation REDWING.
TEWA, the last REDWING event fired at Bikini, led to an increase in
personnel doses. The edge of the TEWA cloud passed over Enewetak causing
fallout on the Enewetak base camp. Because the incident occurred toward
the end of the series, some personnel had already returned to the U.S.
(17: 3,4). The remaining Enewetak personnel, however, received additional
doses calculated at 2.0 to 3.3 rem from this incident (17: 3,4).
The personnel limit was 3.9 rem of gamma radiation for the series. The
highest doses were received by Air Force flight officers whose missions
required them to penetrate the clouds resulting from the nuclear detonations
(17: 3,4).
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
89 |
262 |
308 |
649 |
144 |
0 |
Navy |
2,987 |
1,843 |
1,581 |
225 |
18 |
0 |
Air Force |
769 |
289 |
938 |
717 |
86 |
12 |
Marine Corps |
59 |
67 |
118 |
9 |
0 |
0 |
Civilian DOD Participants |
62 |
5 |
38 |
1 |
0 |
0 |
4.14 OPERATION PLUMBBOB.
Conducted at the Nevada Test Site from 28 May to 7 October 1957, Operation
PLUMBBOB included the 24 nuclear detonations summarized in the accompanying
table. The series also included six safety experiments, conducted to ensure
that no nuclear reaction would occur if the high explosive components of
the device were accidentally detonated during storage or transport (18:
1,6,7). These tests are discussed with the subsequent safety experiments
in section 4.18.
Event |
Date |
Type |
Yield |
BOLTZMANN |
28 May |
Tower |
12 kilotons |
FRANKLIN |
2 June |
Tower |
140 tons |
LASSEN |
5 June |
Balloon |
0.5 tons |
WILSON |
18 June |
Balloon |
10 kilotons |
PRISCILLA |
24 June |
Balloon |
37 kilotons |
HOOD |
5 July |
Balloon |
74 kilotons |
DIABLO |
15 July |
Tower |
17 kilotons |
JOHN |
19 July |
Air to air missile |
about 2 kilotons |
KEPLER |
24 July |
Tower |
10 kilotons |
OWENS |
25 July |
Balloon |
9.7 kilotons |
STOKES |
7 August |
Balloon |
19 kilotons |
SHASTA |
18 August |
Tower |
17 kilotons |
DOPPLER |
23 August |
Balloon |
11 kilotons |
FRANKLIN PRIME |
30 August |
Balloon |
4.7 kilotons |
SMOKY |
31 August |
Tower |
44 kilotons |
GALILEO |
2 September |
Tower |
11 kilotons |
WHEELER |
6 September |
Balloon |
197 tons |
LAPLACE |
8 September |
Balloon |
1 kilotons |
FIZEAU |
14 September |
Tower |
11 kilotons |
NEWTON |
16 September |
Balloon |
12 kilotons |
RAINIER |
19 September |
Tunnel |
1.7 kilotons |
WHITNEY |
23 September |
Tower |
19 kilotons |
CHARLESTON |
28 September |
Balloon |
12 kilotons |
MORGAN |
7 October |
Balloon |
8 kilotons |
4.14.1 Background and Objectives of Operation PLUMBBOB.
Largely a joint AEC/DOD effort, Operation PLUMBBOB was planned as an
integral part of the continuing U.S. program for developing the means to
conduct nuclear warfare in defense of the Nation. The AEC wanted to test
a number of nuclear devices scheduled for early production for the defense
stockpile or those important to the design of improved weapons. The DOD
used the series to continue its study of military weapons effects and,
with Exercises Desert Rock VII and VIII, its training of personnel in nuclear
operations (18: 34).
4.14.2 PLUMBBOB Test Operations.
About 13,300 DOD personnel participated in observer programs, tactical
maneuvers, and scientific and diagnostic studies during Operation PLUMBBOB.
Exercises Desert Rock VII and VIII, consisting of training programs, tactical
maneuvers, and technical service projects, engaged the largest DOD participation.
At Shot HOOD, approximately 2,150 Marines took part in a maneuver involving
the use of a helicopter-airlift and tactical air support. An estimated
1,144 Army troops (Task Force WARRIOR) participated in an airlift assault
at Shot SMOKY, and about 110 Army troops (Task Force BIG BANG) were interviewed
at Shot GALILEO to determine their psychological reaction to witnessing
a detonation (18: 1,4,5).
4.14.3 Dose Summary for Operation PLUMBBOB.
The maximum dose limit for Desert Rock troops was 5.0 rem of gamma radiation
in any 6-month period, with no more than 2.0 rem to be from prompt radiation.
Participants in activities of the AEC Nevada Test Organization and AFSWC
were limited to 3.0 rem for any 13-week period and 5.0 rem for one calendar
year (18: 2,3).
Gamma Dose (rem)
| 0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
6,242 |
737 |
528 |
55 |
22 |
2 |
Navy |
401 |
36 |
130 |
4 |
2 |
1 |
Air Force |
1,678 |
118 |
102 |
22 |
18 |
4 |
Marine Corps |
726 |
1,244 |
176 |
1 |
1 |
0 |
Civilian DOD Participants |
819 |
22 |
22 |
0 |
0 |
0 |
4.15 OPERATION HARDTACK I.
HARDTACK was the designation for U.S. nuclear testing in both the Pacific
and in Nevada during 1958. Phase I, discussed in this section, consisted
of 34 Pacific nuclear detonations, which was as many as had been fired
in all prior oceanic tests. The series encompassed a wide variety of events,
as indicated in the accompanying table (19: 23,24).
All but two of the detonations were at Enewetak and Bikini Atolls in
the Marshall Islands. TEAK and ORANGE, high-altitude detonations, occurred
42 and 76 kilometers over Johnston Island, which lies about 700 nautical
miles west-southwest of the Hawaiian Islands. A Honolulu resident described
the TEAK burst, which took place 10 minutes before midnight, in a front-page
story for the 1 August Honolulu Star-Bulletin (19: 1,266):
I stepped out on the lanai and saw what must have been the reflection
of the fireball. It turned from light yellow to dark yellow and from orange
to red.
The red spread in a semi-circular manner until it seemed to engulf a
large part of the horizon.
A cloud rose in the center of the circle. It was quite large and clearly
visible. It remained visible for about a half hour.
It looked much closer than Johnston Island. The elevation of the circle
was perhaps 20 above the horizon.
Event |
Date |
Type |
Yield |
YUCCA |
28 April |
High Altitude (Balloon) |
1.7 kilotons* |
CACTUS |
6 May |
Surface |
18 kilotons |
FIR |
12 May |
Barge |
1.36 megatons |
BUTTERNUT |
12 May |
Barge |
81 kilotons |
KOA |
13 May |
Surface |
1.37 megatons |
WAHOO |
16 May |
Underwater |
9 kilotons |
HOLLY |
21 May |
Barge |
5.9 kilotons |
NUTMEG |
22 May |
Barge |
25.1 kilotons |
YELLOWWOOD |
26 May |
Barge |
330 kilotons |
MAGNOLIA |
27 May |
Barge |
57 kilotons |
TOBACCO |
30 May |
Barge |
11.6 kilotons |
SYCAMORE |
31 May |
Barge |
92 kilotons |
ROSE |
3 June |
Barge |
15 kilotons |
UMBRELLA |
9 June |
Underwater |
8 kilotons |
MAPLE |
11 June |
Barge |
213 kilotons |
ASPEN |
15 June |
Barge |
319 kilotons |
WALNUT |
15 June |
Barge |
1.45 megatons |
LINDEN |
18 June |
Barge |
11 kilotons |
REDWOOD |
28 June |
Barge |
412 kilotons |
ELDER |
28 June |
Barge |
880 kilotons |
OAK |
29 June |
Barge |
8.9 megatons |
HICKORY |
29 June |
Barge |
14 kilotons |
SEQUOIA |
2 July |
Barge |
5.2 kilotons |
CEDAR |
3 July |
Barge |
220 kilotons |
DOGWOOD |
6 July |
Barge |
397 kilotons |
POPLAR |
12 July |
Barge |
9.3 megatons |
PISONIA |
18 July |
Barge |
255 kilotons |
JUNIPER |
22 July |
Barge |
65 kilotons |
OLIVE |
23 July |
Barge |
202 kilotons |
PINE |
27 July |
Barge |
2 megatons |
TEAK |
31 July |
High Altitude (Rocket) |
3.8 megatons |
QUINCE |
6 August |
Surface |
zero |
ORANGE |
11 August |
High Altitude (Rocket) |
3.8 megatons |
FIG |
18 August |
Surface |
20 tons |
*Some yields marked "Not announced" in the original report
have since been declassified and are included in this online version.
4.15.1 Background and Objectives of Operation HARDTACK I.
HARDTACK I consisted of three parts. The first, aimed at the development
of nuclear weapons, continued the type of testing that had been conducted
at Enewetak and Bikini during the early and mid-1950s. The AEC weapon development
laboratories (LANL and LLNL) detonated experimental devices, with the DOD
providing support and conducting experiments that did not interfere with
AEC activities (19: 1).
The second part, sponsored by DOD, consisted of the underwater test
shots, WAHOO and UMBRELLA, the first in open ocean and the second within
the lagoon at Enewetak . These tests, which furthered efforts undertaken
with the 1946 CROSSROADS and the 1955 WIGWAM series, were designed to gain
additional data on the effects of underwater explosions on Navy ships and
material (19: 1).
The third part, sponsored by DOD, addressed a military problem that
was newer: nuclear weapons in air and ballistic missile defense. Shots
YUCCA, TEAK, and ORANGE, also called Operation NEWSREEL by DOD, were directed
to this concern (19: 3).
4.15.2 HARDTACK I Test Operations.
The HARDTACK experimental program incorporated two aspects, one being
the development of the weapons and the second being the measurement of
the explosive and radiation effects. The AEC was primarily interested in
weapons development, and the DOD focused on weapons effects, specifically
concerning the military application of the weapons (19: 3).
Approximately 16,000 DOD personnel took part in HARDTACK I. They participated
in the weapons development experiments by providing cloud-sampling aircraft
and crews, along with ship patrols, instrument placement and recovery,
and radioactive sample return. Their primary participation, however, was
in the effects experiments associated with the underwater and the highaltitude
shots (19: 105).
4.15.3 Dose Summary for Operation HARDTACK I.
The maximum permissible dose for HARDTACK I personnel was 3.75 rem of
gamma radiation per consecutive 13-week period, with a maximum of 5.0 rem
for the operation. The crew of airsampling aircraft were authorized
a special limit of 10.0 rem. In case of operational error or emergency,
an additional dose of 10.0 rem would be accepted (19: 3,4).
During the series, one incident involved the exposure of participants
to significantly elevated radiation levels. On 14 May, the base islands
of Enewetak and Parry at Enewetak Atoll received fallout from a test shot
detonated at Bikini 2 days earlier (19: 4,5). According to current calculations,
the period of fallout, which lasted about 60 hours, could have contributed
as much as 1.7 rem through 31 May 1958, 2.2 rem through 30 June 1958, and
2.5 rem through 31 July 1958 to personnel on the Enewetak Atoll.
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
249 |
258 |
1,011 |
54 |
2 |
0 |
Navy |
5,307 |
2,746 |
1,656 |
26 |
1 |
0 |
Air Force |
1,561 |
474 |
1,825 |
183 |
73 |
7 |
Marine Corps |
60 |
99 |
56 |
4 |
0 |
0 |
Civilian DOD Participants |
65 |
34 |
66 |
3 |
0 |
0 |
4.16 OPERATION ARGUS.
ARGUS, the code name for the only atmospheric nuclear test operation
in the Atlantic Ocean, consisted of the three high-altitude, low-yield
detonations identified below. The nuclear devices were lifted to about
a 300-mile altitude by rockets fired from the missile trials ship USS
Norton Sound (AVM-1), one of the nine ships participating in the series
(20: 1).
The operation was based in the Atlantic at about 45 deg south latitude.
The location placed the task force outside regular shipping lanes but kept
the launch well within the range of U.S. military forces required for support
of ARGUS scientific projects (20: 19).
Event |
Date |
Type |
Yield (kilotons) |
ARGUS I |
27 August |
Rocket |
1-2 |
ARGUS II |
30 August |
Rocket |
1-2 |
ARGUS III |
6 September |
Rocket |
1-2 |
4.16.1 Background and Objectives of Operation ARGUS.
ARGUS was unique among U.S. atmospheric nuclear test operations in a
number of respects. It was one of the most expeditiously planned and executed
of all U.S. nuclear tests, requiring just 5 months from inception to execution,
in contrast to the normal period of 1 or more years. Besides TRINITY, it
consisted of the only clandestine tests conducted during the 18-year period
of atmospheric testing. The intentions of all phases of the ARGUS operation
were concealed not only from other nations but also from the majority of
DOD participants in the tests. In addition, ARGUS was the first shipboard
launch of a ballistic missile with a nuclear warhead (20: 11, 18).
Most significant of all, the purpose of ARGUS did not fit the usual
categories: the ARGUS shots, strictly speaking, involved neither diagnostic
tests of a weapon design nor effects tests on military systems. The objective
was to establish the practicability of a theory, postulated by Nicholas
Christofilos, a physicist at LLNL, that a very-high-altitude nuclear detonation
of proper yield would produce phenomena of potentially significant military
importance by interfering with communications and weapon performance. When
the Eisenhower Administration officially announced the occurrence of the
tests on 19 March 1959, the New York Times headlined ARGUS as the
"Greatest Scientific Experiment Ever Conducted" (20: 11,12).
The operation proved the validity of the Christofilos theory. It not
only provided data on military considerations, but also produced a great
mass of geophysical information (20: 2).
4.16.2 ARGUS Test Operations.
The series was conducted by Task Force 88, a naval organization consisting
of nine ships and approximately 4,500 men. Coordinated measurement programs
using satellite, rocket, aircraft, and surface stations were carried out
by the services and other Government agencies and contractors throughout
the world. The ships of Task Force 88, in addition to the USS Norton
Sound, were the antisubmarine carrier USS Tarawa, the destroyers
USS Bearss and USS Warrington, the destroyer escorts USS
Courtney and USS Hammerberg, the fleet oilers USS Neosho
and USS Salamonie, and the seaplane tender USS Albemarle (20:
1).
4.16.3 Dose Summary for Operation ARGUS.
The detonations occurred at such distances above the earth that the
possibilities of personnel exposures to ionizing radiation were considered
remote. The recorded doses were, in fact, so low as to be negligible. The
highest level recorded by the 264 film badges distributed to the task force
was 0.010 rem. The highest level recorded, 0.025 rem, was by a control
film badge, which was not issued to personnel but remained in storage in
a radiation-free area within a ship. Another control badge read 0.020 rem.
These readings were so low that they probably were spurious and the result
of environmental effects on film emulsions (20: 1,2).
4.17 OPERATION HARDTACK II.
HARDTACK II was the continental phase of Operation HARDTACK. The oceanic
phase, HARDTACK I, was conducted in the Pacific from 28 April through 18
August 1958, as noted in section 4.15. Phase II, conducted at the Nevada
Test Site from 12 September through 31 October 1958, consisted of 19 nuclear
weapons tests and 18 safety experiments (21: 1). The next section, 4.18,
discusses the safety experiments. This section concentrates on the weaponsrelated
tests, identified in the accompanying table.
Event |
Date |
Type |
Yield (kilotons) |
EDDY |
19 September |
Balloon |
0.083 |
MORA |
29 September |
Balloon |
2 |
TAMALPAIS |
8 October |
Tunnel |
0.072 |
QUAY |
10 October |
Tower |
0.079 |
LEA |
13 October |
Balloon |
1.4 |
HAMILTON |
15 October |
Tower |
0.0012 |
LOGAN |
16 October |
Tunnel |
5 |
DONA ANA |
16 October |
Balloon |
0.037 |
RIO ARRIBA |
18 October |
Tower |
0.090 |
SOCORRO |
22 October |
Balloon |
6 |
WRANGELL |
22 October |
Balloon |
0.115 |
RUSHMORE |
22 October |
Balloon |
0.188 |
SANFORD |
26 October |
Balloon |
4.9 |
DE BACA |
26 October |
Balloon |
2.2 |
EVANS |
29 October |
Tunnel |
0.055 |
MAZAMA |
29 October |
Tower |
NMY* |
HUMBOLDT |
29 October |
Tower |
0.0078 |
SANTA FE |
30 October |
Balloon |
1.3 |
BLANCA |
30 October |
Tunnel |
22 |
*No measurable yield
4.17.1 Background and Objectives of Operation HARDTACK II.
HARDTACK II was the last nuclear test series before the United States
adopted a nuclear test moratorium, which had originally been intended to
last 1 year but continued until 1961. The nuclear weapons tests were conducted
to evaluate the yield and efficiency of newly developed nuclear devices
(21: 1,7).
Concern about nuclear weapon proliferation intensified throughout the
1950s, particularly after the BRAVO test of Operation CASTLE and the heavy
fallout resulting from this shot. At that time, Prime Minister Nehru of
India proposed a cessation of tests. The call for a test ban figured repeatedly
in disarmament discussions, most importantly, those of the Disarmament
Subcommittee of the U.N. Disarmament Commission, in session from 18 March
to 6 September 1957. Continuing pressure on the nuclear powers to reach
an agreement on limiting testing resulted in the Conference on Discontinuance
of Nuclear Weapons Tests, which began in Geneva on 31 October 1958 and
was attended by U.S., British, and Soviet delegates. On 1 November 1958,
the U.S. unilaterally announced a test moratorium to begin on 1 November
1958, declaring a cessation in nuclear testing if the Soviet Union also
refrained (21: 28).
Because the testing and improvement of various nuclear weapons was crucial
to American defense policy, a number of tests needed to be conducted before
the moratorium began. On 28 August 1958, President Eisenhower approved
an accelerated series of nuclear tests code named Operation MILLRACE to
be completed at the NTS before the start of the moratorium. On 29 August
1958, by AEC directive, the name of the series was changed to Operation
HARDTACK, Phase II (21: 28,29).
4.17.2 HARDTACK II Test Operations.
An estimated 1,650 DOD personnel took part in HARDTACK II. This participation
was relatively small compared with previous nuclear weapons testing series
because of the weapons development emphasis of the program and because
of the substantial DOD involvement (about 16,000 personnel) in HARDTACK
I. The primary DOD involvement in HARDTACK II was at Shots HAMILTON and
HUMBOLDT, the two weapons effects tests cosponsored by the DOD and the
Lawrence Livermore National Laboratory. Projects at these tests were planned
to develop delivery systems for small nuclear devices, to design military
equipment that could withstand the effects of a nuclear detonation, and
to determine the military requirements for future nuclear device designs.
In addition to participation in these projects, DOD personnel at HARDTACK
II provided air and ground support, including radiological safety monitoring,
and administrative staff support (21: 1,29,2).
4.17.3 Dose Summary for Operation HARDTACK II.
HARDTACK II participants, with the exception of AFSWC personnel on cloud-sampling
missions, were limited to a gamma plus neutron dose of 3.0 rem per calendar
quarter or a total of 5.0 rem per year. The AFSWC personnel involved in
cloud sampling were permitted to receive up to 10.0 rem during the series.
Individuals who participated in cloud sampling at HARDTACK II who were
also at HARDTACK I were authorized to receive 15 rem for the total operation
(21: 5,74). The table below summarizes doses for both the weapons-related
events and the safety experiments:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
45 |
64 |
200 |
15 |
5 |
1 |
Navy |
31 |
0 |
1 |
1 |
0 |
0 |
Air Force |
204 |
19 |
27 |
5 |
2 |
0 |
Marine Corps |
2 |
0 |
0 |
0 |
0 |
0 |
Civilian DOD Participants |
952 |
35 |
20 |
2 |
0 |
0 |
4.18 SAFETY EXPERIMENTS.
The nuclear weapons testing program included 33 safety experiments,
conducted at the NTS from 1955 to 1958 (22: 8,9,11,12; 17: 9):
- Four experiments called PROJECT 56 and conducted in November 1955 and
January 1956, after Operation TEAPOT
- Six experiments called PROJECT 57 and conducted in April, July, August,
and September 1957 before and during Operation PLUMBBOB
- Four experiments identified as PROJECT 58 and conducted in December
1957 and February and March 1958, after Operation PLUMBBOB
- Nineteen experiments conducted from July to October 1958 during Operations
HARDTACK I and II.
Eleven of the tests were surface detonations, while nine occurred in
shafts, six in tunnels, and one on a barge. Of the remaining safety experiments,
five were tower detonations and one was a balloon test. Ten of the experiments
had no measurable yield while one, COULOMB C, had 0.5 kiloton, which was
the highest yield of any safety experiment.
4.18.1 Objectives of the Safety Experiments.
Except for one PROJECT 57 test, the safety experiments were conducted
for the same purpose: to determine the weapons' susceptibility to nuclear
detonation during accidents in storage and transportation. High-explosive
portions of these devices were fired to simulate accidental detonation
and to determine the potential for such firings to result in a significant
nuclear yield. The test results were used to develop devices that could
withstand shock, blast, fire, and accidents without initiating a nuclear
chain reaction and producing a nuclear detonation. The initial PROJECT
57 test was conducted to spread alpha-emitting material (plutonium) in
a defined area to study the biological effects of alpha radiation and to
test monitoring and decontamination procedures (22: 23,8).
4.18.2 Test Operations at the Safety Experiments.
DOD personnel participation during these experiments is difficult to
determine. Although most of the employees of LANL and LLNL were civilians,
some DOD personnel also were assigned to these organizations. In addition,
some of the project activities engaged DOD participation. Eight AFSWC personnel
and two participants from the 50th Chemical Service Platoon performed field
work for one of the programs during PROJECT 57, the alpha-dispersion experiment.
Moreover, a DOD effects project was conducted at four of the safety experiments.
Other DOD participation involved cloud-tracking and cloud-sampling missions
(22: 12; 17: 184,185).
4.18.3 Dose Summary for the Safety Experiments.
Section 4.17 presents information on personnel doses at the 18 HARDTACK
II safety experiments. The limited dosimetry information on the other safety
experiments indicates four doses exceeding the 3.9 rem limit at Experiment
4 of PROJECT 56. The readings, which may have resulted from the participants'
having handled hot instrumentation cable, were 28, 18.5, 13.7, and 4.3
rem (22: 21).
4.19 OPERATION DOMINIC I.
Operation DOMINIC, like Operation HARDTACK, consisted of two phases:
DOMINIC I, the oceanic nuclear tests discussed in this section; and DOMINIC
II, the continental tests considered in section 4.20. The DOMINIC shots,
also named Operation SUNBEAM by DOD, were the last atmospheric nuclear
weapons tests conducted by the United States (23: 1).
DOMINIC I consisted of the 36 nuclear tests identified in the accompanying
table. Most of the shots were detonated in the air after having been dropped
from B-52 bombers. Twenty-four of the airdrops took place from 25 April
through 11 July over the ocean just south of Christmas Island, United Kingdom
territory 1,200 nautical miles south of Honolulu. Five more airdrops were
detonated in October over the open ocean in the vicinity of Johnston Island,
U.S. territory 780 nautical miles west-southwest of Honolulu. The five
rocket shots, designated FISHBOWL events, were launched from Johnston Island
and detonated at high altitudes, up to 400 kilometers. The Navy conducted
the other two shots: FRIGATE BIRD, launched by a Polaris missile from the
submarine USS Ethan Allen and detonated east of Christmas Island;
and SWORDFISH, a rocketlaunched antisubmarine nuclear depth charge
detonated 400 miles west of San Diego (23: 1,2). Figure 16 shows the SWORDFISH
spray dome and the USS Agerholm (DD-286), from which the rocket
was fired (I).
4.19.1 Background and Objectives of Operation DOMINIC I.
The U.S. did not conduct any nuclear tests from 30 October 1958, the
date of the last HARDTACK II test, to 15 September 1961, when the U.S.
resumed underground nuclear testing at the NTS. On 1 November 1958, the
U.S. initiated its 1-year suspension of nuclear testing, which was later
extended throughout 1959. On 29 December 1959, the U.S. announced an end
to its moratorium, effective 31 December, but with a promise not to resume
testing without advance public notice (23: 25).
On 3 January 1960, the Soviet Premier pledged that the Soviet Union
would not conduct nuclear tests unless the Western nations resumed their
testing. On 31 August 1961, however, the U.S.S.R. abruptly announced plans
to resume atmospheric testing and then detonated a nuclear device at the
Semipalatinsk test range in Central Asia the next day. This began an extensive
Soviet series that continued into November and included more than 30 nuclear
shots, among which were a 58-megaton detonation (the largest ever) and
high-altitude tests. U.S. testing recommenced with a tunnel shot at the
NTS, 15 September 1961, followed by a series of underground tests. The
President approved planning for atmospheric tests on 10 October 1961 but
did not approve DOMINIC until 2 March 1962 (23: 25).
Operation DOMINIC I was conducted with four primary objectives: to develop
nuclear weapons (the 29 airdrops); to study the effects of nuclear detonations
(the five high-altitude bursts); to test the Polaris weapon system (the
FRIGATE BIRD event); and to test the Navy nuclear antisubmarine rocket
(Shot SWORDFISH) (23: 1).
Event |
Date |
Type |
Yield* |
ADOBE |
25 April |
Airdrop |
190 kilotons |
AZTEC |
27 April |
Airdrop |
410 kilotons |
ARKANSAS |
2 May |
Airdrop |
1.09 megatons |
QUESTA |
4 May |
Airdrop |
670 kilotons |
FRIGATE BIRD |
6 May |
Rocket |
NA** |
YUKON |
8 May |
Airdrop |
100 kilotons |
MESILLA |
9 May |
Airdrop |
100 kilotons |
MUSKEGON |
11 May |
Airdrop |
50 kilotons |
SWORDFISH |
11 May |
Underwater |
Low |
ENCINO |
12 May |
Airdrop |
500 kilotons |
SWANEE |
14 May |
Airdrop |
97 kilotons |
CHETCO |
19 May |
Airdrop |
73 kilotons |
TANANA |
25 May |
Airdrop |
2.6 kilotons |
NAMBE |
27 May |
Airdrop |
43 kilotons |
ALMA |
8 June |
Airdrop |
782 kilotons |
TRUCKEE |
9 June |
Airdrop |
210 kilotons |
YESO |
10 June |
Airdrop |
3 megatons |
HARLEM |
12 June |
Airdrop |
1.2 megatons |
RINCONADA |
15 June |
Airdrop |
800 kilotons |
DULCE |
17 June |
Airdrop |
52 kilotons |
PETIT |
19 June |
Airdrop |
2.2 kilotons |
OTOWI |
22 June |
Airdrop |
81.5 kilotons |
BIGHORN |
27 June |
Airdrop |
7.65 megatons |
BLUESTONE |
30 June |
Airdrop |
1.27 megatons |
STARFISH PRIME |
8 July |
Rocket |
1.4 megatons |
SUNSET |
10 July |
Airdrop |
1 megaton |
PAMLICO |
11 July |
Airdrop |
3.88 megatons |
ANDROSCOGGIN |
2 October |
Airdrop |
75 kilotons |
BUMPING |
6 October |
Airdrop |
11.3 kilotons |
CHAMA |
18 October |
Airdrop |
1.59 megatons |
CHECKMATE |
19 October |
Rocket |
Low |
BLUEGILL 3 PRIME |
25 October |
Rocket |
Submegaton |
CALAMITY |
27 October |
Airdrop |
800 kilotons |
HOUSATONIC |
30 October |
Airdrop |
8.3 megatons |
KINGFISH |
1 November |
Rocket |
Submegaton |
TIGHTROPE |
3 November |
Rocket |
Low |
*Low yield is less than 20 kilotons, and intermediate yield is 20-1,000
kilotons.
**Not announced.
4.19.2 DOMINIC I Test Operations.
The estimated 22,600 participants in DOMINIC I were from all four military
services, as well as from DOD agencies, AEC organizations, DOD and AEC
contractors, and various Federal agencies. The DOD participation was extensive
in all parts of the DOMINIC I experimental program: weapons development,
weapons effects, and operational tests. Even the experimental program for
the weapon development shots at Christmas Island and later at Johnston
Island, conducted by AEC laboratories, involved DOD personnel and units
for device placement, cloud sampling, operation of airborne data recording
stations, and general support. The weapons effects and operational tests
were DOD programs, the former involving a number of experimental projects
(23: 11).
4.19.3 Dose Summary for Operation DOMINIC I.
With exceptions for specified Navy and Air Force participants, the maximum
permissible dose for Operation DOMINIC I personnel was 3.0 rem of gamma
radiation for the series. Navy personnel who were to collect samples of
weapon debris from the radioactive pool of water created by SWORDFISH were
authorized a maximum limit of 7.0 rem. Air Force personnel associated with
cloud sampling (crew, maintenance, sample removal, or decontamination)
could receive up to 20 rem of gamma radiation (23: 3).
The table below summarizes available dosimetry information for DOMINIC
I participants. Existing evidence indicates that some of the film badges
had been defectively sealed or damaged by the environment and that they
gave higher readings than the dose actually received. Nevertheless, all
personnel have been assigned the readings recorded in Navy records (23:
3,4).
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
587 |
8 |
19 |
2 |
0 |
0 |
Navy |
17,604 |
205 |
344 |
9 |
1 |
0 |
Air Force |
2,557 |
83 |
98 |
11 |
19 |
21 |
Marine Corps |
653 |
1 |
5 |
0 |
0 |
0 |
Civilian DOD Participants |
190 |
2 |
1 |
0 |
0 |
0 |
4.20 OPERATION DOMINIC II.
Also known by the DOD code name of Operation SUNBEAM, DOMINIC II was
the continental phase of the DOMINIC nuclear tests. The four shots of this
series were conducted at the NTS from 7 July through 17 July 1962, during
the period of DOMINIC I, the nuclear test series conducted at the Pacific
Proving Ground from 25 April through 3 November 1962 (24: 1).
DOMINIC II consisted of the four low-yield shots identified below.
LITTLE FELLER I, one of the surface shots, was part of Exercise IVY
FLATS, the only military training exercise conducted at DOMINIC II (24:
1,5).
Event |
Date |
Type |
Yield (kilotons) |
LITTLE FELLER II |
7 July |
Surface |
Low |
JOHNIE BOY |
11 July |
Crater |
0.5 |
SMALL BOY |
14 July |
Tower |
Low |
LITTLE FELLER I |
17 July |
Surface |
Low |
4.20.1 Background and Objectives of Operation DOMINIC II.
The United States resumed nuclear weapons testing on 15 September 1961
with a series of underground tests conducted at the NTS: Operation NOUGAT,
15 September 1961 to 30 June 1962. This was followed by another underground
series: Operation STORAX, 6 July 1962 to 25 June 1963. Operation DOMINIC
II was conducted during the period of Operation STORAX but was not a part
of STORAX (24: 19,20).
Operation DOMINIC II, designed to provide information on weapons effects,
originally comprised only Shot SMALL BOY. Subsequent plans were to include
three Little Feller shots, one 3 feet above ground, another 40 feet above
ground, and the third also at a height of 40 feet, having been launched
tactically as part of a military exercise. The third shot was, however,
canceled, and the second, which became LITTLE FELLER I, was changed to
a 3-foot shot to be launched in connection with a tactical maneuver (24:
1,114,73).
Plans for JOHNIE BOY, the last shot added to the series, were not made
until May 1962. Detonated 2 months later, JOHNIE BOY was designed to explore
the cratering effects of a subkiloton nuclear device fired in a shallow
emplacement (24: 94).
4.20.2 DOMINIC II Test Operations.
An estimated 2,900 DOD military and civilian personnel participated
at Operation DOMINIC II in Exercise IVY FLATS (Shot LITTLE FELLER I), scientific
and diagnostic tests, and air support or administrative support activities.
Approximately 1,000 of these participants were Sixth Army military personnel
who took part in Exercise IVY FLATS, which consisted of an observer program
and a troop maneuver. The observers, who wore protective goggles, witnessed
the detonation from bleachers about 3.5 kilometers southwest of ground
zero. Five participants from the IVY FLATS maneuver task force launched
the weapon from a rocket launcher mounted on an armored personnel carrier.
After the initial radiological surveys were completed, the IVY FLATS troops
entered their vehicles and moved into the shot area, where they spent about
50 minutes conducting maneuvers (24: 1,3).
4.20.3 Dose Summary for Operation DOMINIC II.
Most DOMINIC II participants were subject to a quarterly dose limit
of 3.0 rem (gamma plus neutron) and an annual limit of 5 rem (gamma plus
neutron). Cloud-sampling pilots were authorized to receive up to 3.9 rem
per 13-week period because their mission sometimes required them to penetrate
the clouds (24: 3,7).
The following table summarizes the dosimetry data available for DOMINIC
II, as well as for the first two events of the PLOWSHARE Program, GNOME
and SEDAN, which are discussed in section 4.21. GNOME was conducted on
10 December 1961 and SEDAN on 6 July 1962. A number of DOD participants
in these two events also took part in DOMINIC II. In many cases, their
recorded doses were cumulative, covering their participation in both DOMINIC
II and the PLOWSHARE events. For this reason, the combined totals are provided
for DOMINIC II, GNOME, and SEDAN, as is shown below:
Gamma Dose (rem) |
0-0.5 |
0.5-1 |
1-3 |
3-5 |
5-10 |
10+ |
Army |
1,184 |
163 |
101 |
2 |
0 |
0 |
Navy |
61 |
19 |
32 |
0 |
1 |
0 |
Air Force |
235 |
28 |
14 |
1 |
0 |
0 |
Marine Corps |
37 |
8 |
16 |
1 |
0 |
0 |
Civilian DOD Participants |
638 |
21 |
10 |
0 |
0 |
0 |
4.21 PLOWSHARE PROGRAM.
Conducted from 1961 to 1973, the PLOWSHARE Program consisted of 27 nuclear
detonations, four of which occurred before the signing of the 1963 limited
test ban treaty. The detonations, all of which had yields of no more than
200 kilotons, were staged at the NTS and other sites in Colorado and New
Mexico. The tests were all subsurface, being either shaft or cratering
shots (25: 1).
As indicated by the following table, this section discusses only Projects
GNOME and SEDAN, the first two PLOWSHARE events. These two shots were selected
for consideration because they were conducted during the period of U.S.
atmospheric testing and they had documented, although limited, DOD participation.
In addition, the extant sources were sufficient in number and detail to
enable a summation of the events (25: 1).
Event |
Date |
Type |
Yield (kilotons) |
GNOME |
10 December 1961 |
Shaft |
3 |
SEDAN |
6 July 1962 |
Crater |
104 |
4.21.1 Background and Objectives of the PLOWSHARE Program.
From the earliest days of nuclear research and nuclear weapons testing,
scientists were aware of the potential for peaceful applications of nuclear
energy, including nuclear detonations. This recognition became U.S. policy
in the Atomic Energy Act of 1946, which stated that "atomic energy
is capable of application for peaceful as well as military purposes."
The opportunity for American scientists to apply nuclear detonations to
peaceful ends was delayed, however, by several factors, including the greater
priority of developing efficient weapons applications, concern over radioactive
contamination, and international suspicion of the intent of the research.
Nevertheless, the AEC ultimately succeeded in initiating the PLOWSHARE
Program, which had been planned in the late 1950s (25: 19,17,18).
The PLOWSHARE detonations were designed to determine nonmilitary applications
of nuclear explosives. The primary potential use envisioned was in large-scale
geographic engineering, in such projects as canal, harbor, and dam construction,
the stimulation of oil and gas wells, and mining. GNOME was planned in
part to provide information on the characteristics of an underground nuclear
detonation in a salt medium, while SEDAN was to extend knowledge on cratering
effects from detonations with yields of 100 to 200 kilotons. Considering
the peaceful objectives of PLOWSHARE, the AEC took the name of the program
from the Bible: "And they shall beat their swords into plowshares"
(Isaiah 2:4) (25: 1-3).
The ultimate goal of PLOWSHARE, the peaceful applications of nuclear
explosives, was never realized. The limited test ban treaty, signed on
5 August 1963 in Moscow, ended nuclear testing in the atmosphere, on land,
and underwater, although not underground. Hence, a number of the PLOWSHARE
experiments had to be canceled. Other contributing factors were changes
in national priorities, Government and industry disinterest in the program,
public concern over the health and safety aspects of using nuclear detonations
for civil applications, and shortages of funding (25: 26).
4.21.2 PLOWSHARE Test Operations.
The Lawrence Livermore National Laboratory, which provided technical
direction for the PLOWSHARE Program, conducted an extensive series of scientific
projects at GNOME and SEDAN. Given the objectives of PLOWSHARE, the DOD
did not stage military exercises during the program and had limited involvement
in the shots. The primary role of the military was to provide logistical
support. DOD personnel did, however, participate at GNOME and SEDAN in
the VELA UNIFORM program, conducted by the DOD to develop U.S. capabilities
in detecting and identifying underground nuclear detonations. In addition,
the Air Force Special Weapons Center performed cloud-sampling, cloud-tracking,
and support missions at the shots (25: 1-3).
4.21.3 Dose Summary for the PLOWSHARE Program.
PLOWSHARE participants were limited to 3.0 rem of gamma and neutron
radiation per calendar year and not more than 5.0 rem annually. The dosimetry
information available for GNOME and SEDAN participants is included in the
dose summary table given in section 4.20.
SECTION 4 -- REFERENCE LIST
- "Project TRINITY, 1945-1946." Wash., DC.: DNA. DNA-6028F.
Jan 83. 74 p. (A04)AD/A128 035.*/**
- July 16th Nuclear Explosion--Safety and Monitoring of Personnel.
Paul Abersold. Los Alamos, NM.: LASL. LA-616. Jan 47. 170 p.***
- Operation CROSSROADS, 1946. WASH., DC.: DNA. DNA-6032F. May
84. 568 P. (A24)AD/A146 562.*/**
- No Place to Hide, 1946/1984. David Bradley. Hanover, NH.: University
Press of New England. c1983. 217 p.
- Operation SANDSTONE, 1948. Wash., DC.: DNA. DNA-6033F. Dec 83.
222 p. (Al0)AD/A139 151.*/**
- Operation Ranger--Shots ABLE, BAKER, EASY, BAKER-2, FOX-25 January
- 6 February 1951. Wash., DC.: DNA. DNA-6022F. Feb 82. 182 p. (AO9)AD/A118
684.*/**
- Operation GREENHOUSE, 1951. Wash., DC.: DNA. DNA-6034. Jun 83.
334 P. (A15)AD/A134 735.*/**
- Operation BUSTER-JANGLE, 1951. Wash., DC.: DNA. DNA-6023F. Jun
82. 190 p. (A09)AD/A123 441.*/**
- Operation TUMBLER-SNAPPER, 1952. Wash., DC.: DNA. DNA-6019F.
Jun 82. 218 p. (A10)AD/A122 242.*/**
- Operation IVY, 1952. Wash., DC.: DNA. DNA-6036F. Dec 82. 364
p. (A16)AD/A128 082.*/**
- Operation UPSHOT-KNOTHOLE, 1953. Wash., DC.: DNA. DNA-6014F.
Jan 82. 266 p. (A12)AD/A121 624.*/**
- Shots ENCORE - CLIMAX--The Final Four Tests of the UPSHOT-KNOTHOLE
Series, 8 May - 4 June 1953. Wash., DC.: DNA. DNA-6018F. Jan
82. 232 p. (A11)AD/A121 634.***
- CASTLE SERIES, 1954. Wash., DC.: DNA. DNA-6035F. Apr 82. 530
p. (A23)AD/A117 574.*/**
- Memorandum, Subject: Gamma Dose Estimates for Patapsco Crew. R.R. Hammond
and W.W. Perkins. Naval Ocean Systems Center. 19 Jan 1979.
- Operation TEAPOT, 1955. Wash., DC.: DNA. DNA-6009F. Nov 81.
274 p. (A12)AD/A113 537.*/**
- Operation WIGWAM (Series Volume). Wash., DC.: DNA. DNA-6000F.
Sep 81. 262 p. (A12)AD/A105 685.*/**
- Operation REDWING, 1956. Wash., DC.: DNA. DNA-6037F. Aug 82.
442 p. (A19)AD/A134 795.*/**
- PLUMBBOB Series, 1957. Wash., DC.: DNA DNA-6005F. Sep 81. 312
p. (A14)AD/A107 317.*/**
- Operation HARDTACK I, 1958. Wash., DC.: DNA. DNA-6038F. Dec
82. 474 p. (A20)AD/A136 819.*/**
- Operation ARGUS, 1958. Wash., DC.: DNA. DNA-6039F. Apr 82. 138
p. (AO7)AD/A122 341.*/**
- Operation HARDTACK II, 1958. Wash., DC.: DNA. DNA-6026F. Dec
82. 242 p. (A11)AD/A130 929.*/**
- "Safety Experiments, November 1955 - March 1958." Wash.,
DC.: DNA. DNA-6030F. Aug 82. 78 p. (AO5)AD/A123 423.*/**
- Operation DOMINIC I, 1962. Wash., DC.: DNA. DNA-6040. Feb 83.
436 p. (A19)AD/A136 820.*/**
- Operation DOMINIC II--Shots LITTLE FELLER II, JOHNIE BOY, SMALL
BOY, LITTLE FELLER I--7 July-17-July 1962. Wash., DC.: DNA. DNA-6027F.
Jan 83. 218 p. (A1O)AD/A128 367.*/**
- Projects GNOME and SEDAN, the PLOWSHARE Program. Wash., DC.:
DNA. DNA-6029F. Mar 83. 183 p. (A07)AD/A130 165.*/**
See Availability Information page in Appendix E.
*Available from NTIS; price code and order number appear before the
asterisk.
**Available at CIC.