Pacific Proving Grounds
Encyclopedia
The Pacific Proving Grounds was the name used to describe a number of sites in the Marshall Islands
and a few other sites in the Pacific Ocean
, used by the United States
to conduct nuclear testing
at various times between 1946 and 1962. In July 1947, after the first atomic weapons testing at Bikini Atoll
, the United States entered into an agreement with the United Nations
to govern the Trust Territory of the Pacific Islands
as a strategic trusteeship territory. The Trust Territory is composed of 2,000 islands spread over 3000000 square miles (7,769,964.3 km²) of the North Pacific Ocean. On July 23, 1947, the United States Atomic Energy Commission
announced the establishment of the Pacific Proving Grounds.
105 atmospheric (i.e., not underground) nuclear tests were conducted there, many of which were of extremely high yield. While the Marshall Islands testing comprised 14% of all U.S. tests, it comprised nearly 80% of the total yields of those detonated by the U.S., with an estimated total yield of around 210 megatons
, with the largest being the 15 Mt Castle Bravo
shot of 1954 which spread considerable nuclear fallout
on many of the islands, including several which were inhabited, and some that had not been evacuated..
The first use of the Pacific Proving Grounds was during Operation Crossroads
, the first nuclear testing done after the atomic bombing of Hiroshima and Nagasaki. Two fission bombs, both with a yield of 21 kilotons, were detonated at the Bikini Atoll
, one ("Able") from an altitude of 520 ft (158 m) on July 1, 1946, and another ("Baker") was detonated a depth of 90 ft (27 m) underwater on July 25. Both tests used a flotilla (a fleet usually made up of small boats) of obsolete vessels from World War II
with the intent of learning the effects of atomic weapons on naval fleets. The "Baker" shot created a large condensation cloud and spread much more radioactive
water onto the ships than was expected; many of the surviving ships became too "hot" to be used or decontaminated and eventually had to be sunk.
in 1948.
in 1951. Two are of particular note: Greenhouse "Item" was the first use of a boosted fission weapon
, and "George" was a thermonuclear experiment designed to prove the feasibility of the Teller-Ulam design
for the possibility of developing hydrogen bombs.
Two weapons were detonated at the Enewetak Atoll as part of Operation Ivy
in 1952. One of them, Ivy King
, was the largest pure-fission bomb ever detonated, with a yield of 500 kilotons, and the other, Ivy Mike
, was the first hydrogen bomb device (it was too large to be an actual weapon), with a yield of 10.4 Mt
.
Six very large nuclear tests were conducted at the Bikini Atoll
and the Enewetak Atoll as part of Operation Castle
in 1954. The most notable was Castle Bravo
, which was the first deployable (dry fuel) hydrogen bomb developed by the United States. Its yield, at 15 Mt was over twice as powerful as was predicted, and was the largest weapon ever detonated by the United States. It spread nuclear fallout
over a wide area, including the Enewetak Atoll, Rongerik Atoll
, Ailinginae Atoll
, and Rongelap Atoll
. An evacuation ensued, but many of the natives exposed suffered from cancers and a high incidence of birth defects. A Japanese fishing boat, the Daigo Fukuryu Maru
, was additionally exposed and resulted in one death from radiation sickness
, which gained considerable international attention.
in 1956. Many of them were designed to prove the feasibility of numerous thermonuclear weapon designs, with yields ranging from around 2 to 5 Mt.
in 1958.
and Johnston Atoll
as part of Operation Dominic I
. Though these tests were not conducted in the Marshall Islands, they are officially considered part of the Pacific Proving Grounds. The portion of the Dominic series of tests that were high altitude nuclear explosion
s were known as Operation Fishbowl
, though not all were successful (one detonated on launchpad and resulted in a substantial plutonium
contamination). Two of the tests were of operational weapons systems—the ASROC
anti-submarine rocket and the Polaris
SLBM (the latter test, Frigate Bird, was the only operational submarine-launched ballistic missile test with a live warhead ever undertaken by the USA).
in 1963 forbade atmospheric and underwater nuclear weapons, and so no further U.S. tests were conducted at the Pacific Proving Grounds, with all but ten occurring at the Nevada Test Site
until the end of testing in 1992.
accident of 1954, many of the islands which were part of the Pacific Proving Grounds continue to be contaminated by nuclear fallout
, and many of those who were living on the islands at the time of testing have suffered from increased incidence of various types of cancer
s and birth defects. The passing of the Radiation Exposure Compensation Act
of 1990 allowed for a systematic filing of compensation claims in relation to testing as well as those employed at nuclear weapons facilities. Since 1956, at least $759 million USD has been paid to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident, $15.3 million was paid to Japan
.
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...
and a few other sites in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, used by the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
to conduct nuclear testing
Nuclear testing
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them...
at various times between 1946 and 1962. In July 1947, after the first atomic weapons testing at Bikini Atoll
Bikini Atoll
Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands....
, the United States entered into an agreement with the United Nations
United Nations
The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...
to govern the Trust Territory of the Pacific Islands
Trust Territory of the Pacific Islands
The Trust Territory of the Pacific Islands was a United Nations trust territory in Micronesia administered by the United States from 1947 to 1986.-History:...
as a strategic trusteeship territory. The Trust Territory is composed of 2,000 islands spread over 3000000 square miles (7,769,964.3 km²) of the North Pacific Ocean. On July 23, 1947, the United States Atomic Energy Commission
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...
announced the establishment of the Pacific Proving Grounds.
105 atmospheric (i.e., not underground) nuclear tests were conducted there, many of which were of extremely high yield. While the Marshall Islands testing comprised 14% of all U.S. tests, it comprised nearly 80% of the total yields of those detonated by the U.S., with an estimated total yield of around 210 megatons
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
, with the largest being the 15 Mt Castle Bravo
Castle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...
shot of 1954 which spread considerable nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
on many of the islands, including several which were inhabited, and some that had not been evacuated..
Operation Crossroads (1946)
The first use of the Pacific Proving Grounds was during Operation Crossroads
Operation Crossroads
Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. It was the first test of a nuclear weapon after the Trinity nuclear test in July 1945...
, the first nuclear testing done after the atomic bombing of Hiroshima and Nagasaki. Two fission bombs, both with a yield of 21 kilotons, were detonated at the Bikini Atoll
Bikini Atoll
Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands....
, one ("Able") from an altitude of 520 ft (158 m) on July 1, 1946, and another ("Baker") was detonated a depth of 90 ft (27 m) underwater on July 25. Both tests used a flotilla (a fleet usually made up of small boats) of obsolete vessels from World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
with the intent of learning the effects of atomic weapons on naval fleets. The "Baker" shot created a large condensation cloud and spread much more radioactive
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...
water onto the ships than was expected; many of the surviving ships became too "hot" to be used or decontaminated and eventually had to be sunk.
Operation Sandstone (1948)
Three weapons were detonated on the Enewetak Atoll as part of Operation SandstoneOperation Sandstone
Operation Sandstone was a series of nuclear weapon tests in 1948. It was the third series of American tests, following Crossroads and preceding Ranger...
in 1948.
Operation Greenhouse (1951)
Four weapons were detonated on the Enewetak Atoll as part of Operation GreenhouseOperation Greenhouse
Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test principles that would lead to developing thermonuclear weapons . Conducted at the new Pacific Proving Ground, all of the devices were mounted in large steel towers, to simulate air...
in 1951. Two are of particular note: Greenhouse "Item" was the first use of a boosted fission weapon
Boosted fission weapon
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released in the fission, as well as inducing the fission reactions...
, and "George" was a thermonuclear experiment designed to prove the feasibility of the Teller-Ulam design
Teller-Ulam design
The Teller–Ulam design is the nuclear weapon design concept used in most of the world's nuclear weapons. It is colloquially referred to as "the secret of the hydrogen bomb" because it employs hydrogen fusion, though in most applications the bulk of its destructive energy comes from uranium fission,...
for the possibility of developing hydrogen bombs.
Operation Ivy (1952)
Operation Ivy
Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot-Knothole. Its purpose was to help upgrade the U.S. arsenal of nuclear weapons in response to the Soviet nuclear weapons program...
in 1952. One of them, Ivy King
Ivy King
Ivy King was the largest pure fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy...
, was the largest pure-fission bomb ever detonated, with a yield of 500 kilotons, and the other, Ivy Mike
Ivy Mike
Ivy Mike was the codename given to the first United States test of a thermonuclear weapon, in which a major part of the explosive yield came from nuclear fusion. It was detonated on November 1, 1952 by the United States at on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy...
, was the first hydrogen bomb device (it was too large to be an actual weapon), with a yield of 10.4 Mt
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
.
Operation Castle (1954)
Bikini Atoll
Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands....
and the Enewetak Atoll as part of Operation Castle
Operation Castle
Operation Castle was a United States series of high-energy nuclear tests by Joint Task Force SEVEN at Bikini Atoll beginning in March 1954...
in 1954. The most notable was Castle Bravo
Castle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...
, which was the first deployable (dry fuel) hydrogen bomb developed by the United States. Its yield, at 15 Mt was over twice as powerful as was predicted, and was the largest weapon ever detonated by the United States. It spread nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
over a wide area, including the Enewetak Atoll, Rongerik Atoll
Rongerik Atoll
Rongerik Atoll or Rongdrik Atoll is a coral atoll of 17 islands in the Pacific Ocean, and is located in the Ralik Chain of the Marshall Islands, approximately east of Bikini Atoll. Its total land area is only , but it encloses a lagoon of .-History:Rongerik Atoll was claimed by the Empire of...
, Ailinginae Atoll
Ailinginae Atoll
Ailinginae Atoll is a coral atoll of 25 islands in the Pacific Ocean, on the northern end of the Ralik Chain of the Marshall Islands. Its total land area is only , but it encloses a lagoon of . It is located approximately west of Rongelap Atoll. The landscape is low-lying with only the top few...
, and Rongelap Atoll
Rongelap Atoll
Rongelap Atoll or Namorik Atoll is a coral atoll of 61 islands in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its total land area is only , but it encloses a lagoon with an area of...
. An evacuation ensued, but many of the natives exposed suffered from cancers and a high incidence of birth defects. A Japanese fishing boat, the Daigo Fukuryu Maru
Daigo Fukuryu Maru
was a Japanese tuna fishing boat, which was exposed to and contaminated by nuclear fallout from the United States' Castle Bravo thermonuclear device test on Bikini Atoll, on 1 March 1954....
, was additionally exposed and resulted in one death from radiation sickness
Radiation Sickness
Radiation Sickness is a VHS by the thrash metal band Nuclear Assault. The video is a recording of a concert at the Hammersmith Odeon, London in 1988. It was released in 1991...
, which gained considerable international attention.
Operation Redwing (1956)
Seventeen nuclear weapons were detonated on the Bikini and Enewetak Atolls as part of Operation RedwingOperation Redwing
Operation Redwing was a United States series of 17 nuclear test detonations from May to July 1956. They were conducted at Bikini and Enewetak atolls. The entire operation followed Operation Wigwam and preceded Operation Plumbbob. The primary intention was to test new, second-generation...
in 1956. Many of them were designed to prove the feasibility of numerous thermonuclear weapon designs, with yields ranging from around 2 to 5 Mt.
Operation Hardtack I (1958)
Thirty-five weapons were detonated at the Bikini Atoll, Enewetak Atoll, and Johnston Island as part of Operation Hardtack IOperation Hardtack I
Operation Hardtack I was a series of 35 nuclear tests conducted by the United States in 1958 in the Pacific Ocean.Operation Newsreel was a series of three high-altitude nuclear tests conducted as part of Hardtack I. The individual tests in the series were Orange, Teak and Yucca.-Test Blasts:-...
in 1958.
Operation Dominic (1962)
Thirty-six weapons were detonated at sites in the Pacific Ocean in the vicinity of Christmas IslandKiritimati
Kiritimati or Christmas Island is a Pacific Ocean raised coral atoll in the northern Line Islands, and part of the Republic of Kiribati....
and Johnston Atoll
Johnston Atoll
Johnston Atoll is a atoll in the North Pacific Ocean about west of Hawaii. There are four islands located on the coral reef platform, two natural islands, Johnston Island and Sand Island, which have been expanded by coral dredging, as well as North Island and East Island , an additional two...
as part of Operation Dominic I
Operation Dominic I and II
Operation Dominic was a series of 105 nuclear test explosions conducted in 1962 by the United States. Those conducted in the Pacific are sometimes called Dominic I. The blasts in Nevada are known as Dominic II. This test series was scheduled quickly, in order to respond in kind to the Soviet...
. Though these tests were not conducted in the Marshall Islands, they are officially considered part of the Pacific Proving Grounds. The portion of the Dominic series of tests that were high altitude nuclear explosion
High altitude nuclear explosion
High-altitude nuclear explosions have historically been nuclear explosions which take place above altitudes of 30 km, still inside the Earth's atmosphere. Such explosions have been tests of nuclear weapons, used to determine the effects of the blast and radiation in the exoatmospheric...
s were known as Operation Fishbowl
Operation Fishbowl
Operation Fishbowl was a series of high altitude nuclear tests in 1962 that were carried out by the United States as a part of the larger Operation Dominic nuclear test program.-Introduction:...
, though not all were successful (one detonated on launchpad and resulted in a substantial plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
contamination). Two of the tests were of operational weapons systems—the ASROC
ASROC
ASROC is an all-weather, all sea-conditions anti-submarine missile system. Developed by the United States Navy in the 1950s, it was deployed in the 1960s, updated in the 1990s, and eventually installed on over 200 USN surface ships, specifically cruisers, destroyers, and frigates...
anti-submarine rocket and the Polaris
UGM-27 Polaris
The Polaris missile was a two-stage solid-fuel nuclear-armed submarine-launched ballistic missile built during the Cold War by Lockheed Corporation of California for the United States Navy....
SLBM (the latter test, Frigate Bird, was the only operational submarine-launched ballistic missile test with a live warhead ever undertaken by the USA).
Partial Test Ban Treaty (1963)
The signing of the Partial Test Ban TreatyPartial Test Ban Treaty
The treaty banning nuclear weapon tests in the atmosphere, in outer space and under water, often abbreviated as the Partial Test Ban Treaty , Limited Test Ban Treaty , or Nuclear Test Ban Treaty is a treaty prohibiting all test detonations of nuclear weapons...
in 1963 forbade atmospheric and underwater nuclear weapons, and so no further U.S. tests were conducted at the Pacific Proving Grounds, with all but ten occurring at the Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...
until the end of testing in 1992.
Remediation and compensation
Because of the large amount of atmospheric testing, and especially the Castle BravoCastle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...
accident of 1954, many of the islands which were part of the Pacific Proving Grounds continue to be contaminated by nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
, and many of those who were living on the islands at the time of testing have suffered from increased incidence of various types of cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
s and birth defects. The passing of the Radiation Exposure Compensation Act
Radiation Exposure Compensation Act
The United States Radiation Exposure Compensation Act is a federal statute providing for the monetary compensation of people, including atomic veterans, who contracted cancer and a number of other specified diseases as a direct result of their exposure to atmospheric nuclear testing undertaken by...
of 1990 allowed for a systematic filing of compensation claims in relation to testing as well as those employed at nuclear weapons facilities. Since 1956, at least $759 million USD has been paid to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident, $15.3 million was paid to Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
External links
- "Gallery of U.S. Nuclear Tests" at Carey Sublette's NuclearWeaponArchive.org
- Bikini Atoll official website
- Republic of the Marshall Islands Nuclear Claims Tribunal