The Pacific Proving Grounds was the name given by the United States government to a number of sites in the Marshall Islands and a few other sites in the Pacific Ocean at which it conducted nuclear testing between 1946 and 1962. The U.S. tested a nuclear weapon (codenamed Able) on Bikini Atoll on June 30, 1946. This was followed by Baker on July 24, 1946 (dates are Universal Time, local dates were July 1 and 25, respectively).

On July 18, 1947, the United States secured an agreement with the United Nations to govern the islands of Micronesia as the Trust Territory of the Pacific Islands, a strategic trusteeship territory. This is the only such trusteeship ever granted by the United Nations.


The Trust Territory comprised about 2,000 islands spread over 3,000,000 square miles (7,800,000 km2) of the North Pacific Ocean. Five days later, the United States Atomic Energy Commission established the Pacific Proving Grounds.



The United States conducted 105 atmospheric and underwater (i.e., not undergroundnuclear tests in the Pacific, many of which were of extremely high yield. While the Marshall Islands testing composed 14% of all U.S. tests, it composed 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.

Many of the islands which were part of the Pacific Proving Grounds are still contaminated from the nuclear fallout, and many of those who were living on the islands at the time of testing have suffered from an increased incidence of various health problems. Through the Radiation Exposure Compensation Act of 1990, at least $759 million has been paid to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident, the U.S. paid $15.3 million to Japan.

Scientists have calculated that the residents of the Marshall Islands during their lifetimes will be diagnosed with an added 1.6% (with 90% uncertainty range 0.4% to 3.4%) cancers attributable to fallout-related radiation exposures. The cancers are the consequence of exposure to ionizing radiation from weapons test fallout deposited during the testing period (1948-1958) and from residual radioactive sources during the subsequent 12 years (1959-1970).


On July 18, 1947, the United States convinced the United Nations to designate the islands of Micronesia as the Strategic Trust Territory. This was the only trust ever granted by the U.N. The directive stated that the United States should "promote the economic advancement and self-sufficiency of the inhabitants, and to this end shall... protect the inhabitants against the loss of their lands and resources..."

The United States Navy controlled the Trust from a headquarters in Guam until 1951, when the United States Department of the Interior took over control, administering the territory from a base in Saipan.

Despite the promise to "protect the inhabitants", from July 1946 through July 1947, the residents of Bikini Atoll who had been relocated to Rongerik Atoll were starving for lack of food. A team of U.S. investigators concluded in late 1947 that the islanders must be moved immediately. Press from around the world harshly criticized the U.S. Navy for ignoring the people. Harold Ickes, a syndicated columnist, wrote "The natives are actually and literally starving to death." The islanders were later moved again to Kili Island, which is not surrounded by a reef. The island does not support the inhabitants' traditional way of life.


Because of the large amount of atmospheric testing, and especially the Castle Bravo accident of 1954, many of the islands which were part of the Pacific Proving Grounds are still contaminated by nuclear fallout.

Scientists calculated in 2010 that during the lifetimes of members of the Marshall Islands population, potentially exposed to ionizing radiation from weapons test fallout deposited during the testing period (1948-1958) and from residual radioactive sources during the subsequent 12 years (1959-1970), perhaps 1.6% (with 90% uncertainty range 0.4% to 3.4%) of all cancers might be attributable to fallout-related radiation exposures.


By sub-population, the projected proportion of cancers attributable to radiation from fallout from all nuclear tests conducted in the Marshall Islands is 55% (with a 28% to 69% uncertainty range) among 82 persons exposed in 1954 on Rongelap Atoll and Ailinginae Atoll, 10% (2.4% to 22%) for 157 persons exposed on Utirik Atoll, and 2.2% (0.5% to 4.8%) and 0.8% (0.2% to 1.8%), respectively, for the much larger populations exposed in mid-latitude locations including Kwajalein and in southern locations including Majuro


Since 1956, the U.S. has paid at least $759 million to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident on March 1, 1954, the U.S. paid $15.3 million to Japan.[4]

In June 1983, the U.S. and the Marshall islanders signed the Compact of Free Association, which gave the Marshall Islands independence. The Compact became effective in 1986 and was subsequently modified by the Amended Compact that became effective in 2004. It also established the Nuclear Claims Tribunal, which was given the task of adjudicating compensation for victims and families affected by the nuclear testing program. Section 177 of the compact provided for reparations to the Bikini islanders and other northern atolls for damages.


It included $150 million to be paid over a 15-year period ending in 2001. During that time, payments averaging about $18 million per year were made to the peoples of Bikini, Enewetak, Rongelap, and Utrik for medical and radiological monitoring, and in response to claims. The payments began in 1987 with $2.4 million paid annually to the entire Bikini population, while the remaining $2.6 million is paid into The Bikini Claims Trust Fund. This trust is intended to exist in perpetuity and to provide the islanders a 5% payment from the trust annually.

The United States also passed the Radiation Exposure Compensation Act in 1990 to allow individuals to file claims for compensation in relation to testing as well as those employed at nuclear weapons facilities.

On March 5, 2001, the Nuclear Claims Tribunal ruled against the United States for damages done to the islands and its people.[6] The Nuclear Claims Tribunal awarded the islanders a total of $563,315,500 after deducting past awards. However, the U.S. Congress has failed to fund the settlement.


The only recourse is for the Bikini people to petition the U.S. Congress to fund the payment and fulfill this award. The United States Supreme Court turned down the islanders' appeal of the United States courts of appeals decision that refused to compel the government to fund their claim.

As of 2012, trusts remaining from the settlement produced about USD$6 to $8 million annually in investment income, and the trusts paid out about USD$15,000 per family each year in benefits.