Operation Enewetak

Original caption: Cactus Crater on Runit island holds 110,000 cubic yards of radioactive contaminated soil and 6,000 cubic yards of contaminated debris. This island is permanently quarantined.

The Atoll

The classic coral atoll of Enewetak and its small population had seen much change during the 20th century as compared to the relatively quiet nine previous centuries since humans first came to the atoll’s islands.  The Germans were the first industrial culture to claim possession of the islands which became part of the Marshalls island group in the 1880s, only to be superseded by the Japanese after that nation’s brief conflict with the Germans in the Pacific early in World War I. The Second World War brought conflict once again to the atoll when the Japanese fortified three of the 40 islands in the atoll (Engebi, Enewetak, and Parry).  A combined U.S. Army/U.S. Marine Corps force assaulted the three islands and overcame the Japanese defenders between 17 and 23 February 1944.  In the wake of the fighting, the natives living on the islands of Enewetak and Enjebi were evacuated first to Meck Island in order to make room for military and naval support facilities.  Thereafter, Enewetak Atoll became a significant anchorage for the U.S. Pacific Fleet, its large central lagoon acted as a safe sanctuary for hundreds of ships on a daily basis.  As the fighting of the Pacific War shifted northward towards the Japanese home islands through the rest of 1944 and early 1945, Enewetak became more of a Navy backwater anchorage providing support to the fleet now steaming many hundreds of miles to the north.

Pacific Proving Ground

Less than two years after the end of World War II, the United Nations awarded the United States a trusteeship over a number of island groups it had captured from the Japanese.  Among the island groups was the Marshalls, which became a part of what became known as the Trust Territory of the Pacific Islands (TTPI).  Initially governed by the United States Navy, TTPI provided isolated and easily controlled lands for a variety of national defense purposes.

In the two years prior to establishment of the TTPI, a new weapon, the atomic bomb, went from being an extremely secret weapon to a very visible symbol of American military superiority.  However, the years leading up to the first uses of the new weapon over the Japanese cities of Hiroshima and Nagasaki saw only one test of a device of which a great deal was not known.  Also, as nuclear weapons technology advanced, new weapon designs were developed, and testing of those designs became necessary.

The first postwar nuclear tests were two weapons effects tests conducted in the summer of 1946, prior to the establishment of the TTPI.  Known as Operation Crossroads, this test operation set the pattern for future nuclear weapons tests.  Conducted on Bikini Atoll several hundred miles due east of Enewetak, the U.S. Navy moved the 167 natives of the various atoll islands to the nearby Rongerik Atoll to ensure their safety.  Unfortunately for the Bikini islanders, the second Crossroads test, Baker, created so much contamination on the land of the atoll that no resettlement seemed possible.

Once the TTPI was established in July of 1947, it was only a matter of days before the newly established Atomic Energy Commission (AEC) designated both Enewetak and Bikini as part of the Pacific Proving Grounds (PPG).  Enewetak quickly became a favored test site, beginning with Operation Sandstone in April and May of 1948.  Between 1948 and 1958, the AEC, supported by the Armed Services, conducted six series of nuclear and thermonuclear weapons tests on the northern and northeastern islands of the atoll.  A total of 43 separate detonations took place over that decade, scattering tons of irradiated material and fission/fusion products on the islands and waters surrounding the atoll.

Enewetak hosted by far the most detonations of any location in the PPG, and many of the 40 islands of the atoll took a pounding from the nuclear and thermonuclear yields.  The small island of Elugelab hosted the detonation of the very first thermonuclear device, the cryogenically-fueled Ivy Mike shot on Halloween 1952.  The 10.4 megaton yield obliterated the island, replacing it with a crater in the coral reef nearly 2 kilometers in diameter and 150 meters deep.  Succeeding tests used the Mike crater or were located close to it, resulting in a near-complete breach of the coral wall surrounding Enewetak.  Still further testing occurred on locations that spanned from the atoll’s northwest to nearly east.  Two detonations took place to the southwest, one inside the reef and one outside.

The Partial Test Ban Treaty of August 1963 eventually led to the end of U.S. above-ground testing in the PPG, and no more nuclear detonations took place on Enewetak Atoll.  However, after the Hardtack series of tests in 1958, the islands of the atoll were either uninhabitable due to radiological hazards or covered with testing infrastructure.  Although difficult to determine from the records, evidently the Johnson Administration’s effort to return the Bikini islanders to their home in the late 1960s inspired a similar effort to repatriate the Enewetak residents who had been away from their native land for more than twenty years.


From a Defense Nuclear Agency (DNA) fact sheet prepared in April of 1980: in April 1972, the United Sates committed to the transfer of the administration of Enewetak to the TTPI and to the cleanup of the aftermath of the weapons tests.  A master plan was developed to serve as a guide for the rehabilitation and resettlement of the atoll.

By mid-1975, the Energy Research and Development Agency (ERDA, the successor to the AEC) along with the DNA conducted a series of surveys to determine the work needed to ready the atoll for the return of all its people.  Although nearly $40 million was requested for the total project in the Fiscal Year 1976 budget, the U.S. Congress only appropriated $20 million as a one-time expenditure for the project.  A separate $12 million program for the resettlement of Enewetak was funded through the Department of the Interior (DOI), who inherited governance of the TTPI from the U.S. Navy. Economy was to be the order of the day in conducting the atoll cleanup and decontamination.  Although the original project proposal looked to use contractors to perform the work, the slashing of the project budget in half meant that American servicemen (often perceived by civilian leaders as “free” labor) would be the ones conducting the restoration project.

In September 1976, while the formal planning of the difficult decontamination and cleanup work progressed, the formal turnover ceremony took place when the atoll was turned over from the Department of Defense (DoD) to the TTPI administration.  In March of 1977, a small party of islanders returned to the uncontaminated island of Japtan, on the southeastern rim of the atoll.  The joint Department of Energy (DOE, the successor to ERDA)/DNA survey of the atoll determined that the radiological contamination that resulted from the extensive weapons tests was confined to the top soil levels on almost all of the affected islands and islets.  The major exception to this analysis was the island of Runit on the eastern rim of the atoll, which hosted no fewer than 17 of the 43 nuclear detonations on the atoll and was heavily contaminated.

The decontamination plan specified that where surveys indicated the presence of radiological contamination, the soil of that location would be scraped up and moved to Runit, which had been chosen as the repository for all the contaminated soil in the atoll.  The cleanup units would use the crater formed by shot Hardtack I Cactus as the disposal site.  The soil would be mixed into a concrete matrix to ensure that it could not be spread and would be covered by an 18-inch-thick concrete dome for further protection from the elements.  The island itself would remain off limits to the islanders indefinitely.

As for resettlement, the surveys determined that the three larger islands in the southeastern corner of the atoll, Enewetak, Medren, and Japtan, would be most suitable for resettlement.  Initially it was also thought that the northern island of Enjebi would be resettled so that its original inhabitants and families could return.  However, further analysis of the data gathered from that island determined that families could not survive on any crops grown there due to the persistence of fission/fusion products in the soils–all returnees would have to live in the south.

Original caption: Army engineers from bases throughout the United States served during the Enewetak operation.  The construction of the dome in the Fall of 1979 culminated the removal and entombment of the contaminated soil and debris.

The cleanup operation began in May of 1977.  Decontamination was scheduled in three phases, with the last phase to be completed by mid-April 1980.  Resettlement preparations occurred simultaneously with decontamination work so as to return the islanders to their atoll as soon as possible.  Typically over 900 men worked on the decontamination project at one time, mostly service personnel with some contractors and civil service employees. Ultimately over 4,000 men worked on the project from 1977 to 1980.

The DNA fact sheet goes on to detail the work completed:

  • 215,000 cubic yards of uncontaminated debris removed
  • 16,000 items of World War II ordnance disposed of
  • 6,000 cubic yards of radiologically contaminated debris removed to Runit Island and mixed with concrete in the Cactus crater
  • 105,000 cubic yards of radiologically contaminated soil removed to Runit Island and mixed with concrete in the Cactus crater
  • 30 atoll islands qualified as residential and subsistence agriculture islands
  • 7 atoll islands qualified  as agriculture islands
  • 2 atoll islands qualified as food-gathering islands
  • Runit Island cleared of high levels of  fission/fusion products
  • Total cost for the project for DoD was $86 million (including pay and subsistence of the servicemen on the project); for DOI the cost was $14 million; and for DOE the cost was $4 million for a total project cost of $104 million

Rehabilitation and Resettlement

While the cleanup activity was proceeding, DOI representatives met with the driEnjebi (People of Enjebi) and driEnewetak (People of Enewetak) about the resettlement of the atoll.  As a result of these discussions, it was determined that the atoll population would require 116 homes: 76 on Enewetak Island; 32 on Medren; and 8 on Japtan.  Six different house types were offered to islanders with differing floor plans.  Community structures such as a council house, church, schoolhouse, dispensary, cooperative store, minister’s residence, teacher’s residence, nursery, recreation building, playing fields, cistern, and sanitary facilities were provided in addition to the residences.  Many of these structures were adapted from the existing military/testing facilities on the three islands.

Original caption: Department of the Interior contractors constructed 116 homes on the three residence islands.  The People of Enewetak selected both the style and the site of each home.

The DOI rehabilitation and resettlement plan also incorporated an agriculture program for the three islands slated to receive the Enjebi and Enewetak people.  A total of more than 25,000 coconut, breadfruit, edible pandanus, and dwarf coconut trees were planted on Enewetak, Medren, and Japtan.  Another 12,000 trees, primarily coconut, were planted on seven other islands in the atoll.

The Records

The documents that spoke about Operation Enewetak are in a recently declassified four-box record series (Record Group 59 (Records of the Department of State), Entry UD-14W 115, Subject Files Relating to Micronesia Status Negotiations).  These records date from early in the first Reagan Administration and are focused on the negotiations for the Compact of Free Association that the United States held with the island governments that had formed the TTPI.  In one of the boxes there appeared a colorful brochure folder labeled Operation Enewetak bearing the seals for the DOI, DoD, and DOE.  The folder contained a number of fact sheets from the DNA and DOE. The folder also contained sheets on the history and cultural background of the people of Enewetak, a Enewetak Atoll fact sheet, a geological/marine biological sheet on the atoll itself, a brief on the World War II Battle of Enewetak, a Marshall Islands chronology, six 8½” X 11″ color photographs, and, finally, a 25-page bilingual (Ebon/English) full color booklet The Enewetak Atoll Today, published by DOE in September 1979.

Page 8 from The Enewetak Atoll Today showing the bilingual Ebon/English text.  The photo in the center shows the Hardtack I Cactus crater being prepared for draining prior to its use as a radioactive debris/soil dump site.
Page 18 from The Enewetak Atoll Today illustrating the best case scenarios for radiation exposure for islanders returning back to the atoll.  There are four pages of this analysis in the booklet.


5 thoughts on “Operation Enewetak

  1. So much untold truth here. Lots of fabrications still be pushed by the government. I did not read about the testing equipment (radiation badges etc) that did not work after 1-2 weeks and gave false readings of radiation. Government says personnel were not exposed to heavy radiation doses – of course not – badge readings were for 1-5 days of exposure. We were there for 180 straight days! Out of 4300 servicemen, less than 300 are alive.

  2. so many lies to the brass make all this story a fairy tale, it makes good reading for people who know absolutely nothing about radiation or fallout, exposure Correlation factors Over all correlation factors, doses faulty film badges. and the real truth about the protective gear.

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