A radiological survey of Enewetak was conducted from 1972 to 1973 . In 1977 , the United States military began decontamination of Enewetak and other islands . During the three-year , US$ 100 million cleanup process , the military mixed more than of contaminated soil and debris from the islands with Portland cement and buried it in an atomic blast crater on the northern end of the atoll 's Runit Island . The material was placed in the deep , wide crater created by the May 5 , 1958 , " Cactus " nuclear weapons test . A dome composed of 358 concrete panels , each thick , was constructed over the material . The final cost of the cleanup project was US$ 239 million . The United States government declared the southern and western islands in the atoll safe for habitation in 1980 , and residents of Enewetak returned that same year . The military members who participated in that cleanup mission are suffering from many health issues , but the U.S. Government is refusing to provide health coverage . Section 177 of the 1983 Compact of Free Association between the governments of the United States and the Marshall Islands establishes a process for Marshallese to make a claim against the United States government as a result of damage and injury caused by nuclear testing . That same year , an agreement was signed to implement Section 177 which established a US$ 150 million trust fund . The fund was intended to generate US$ 18 million a year , which would be payable to claimants on an agreed-upon schedule . If the US$ 18 million a year generated by the fund was not enough to cover claims , the principal of the fund could be used . A Marshall Islands Nuclear Claims Tribunal was established to adjudicate claims . In 2000 , the tribunal made a compensation award to the people of Enewetak consisting of US$ 107.8 million for environmental restoration ; US$ 244 million in damages to cover economic losses caused by loss of access and use of the atoll ; and US$ 34 million for hardship and suffering . In addition , as of the end of 2008 , another US$ 96.658 million in individual damage awards were made . Only US$ 73.526 million of the individual claims award has been paid , however , and no new awards were made between the end of 2008 and May 2010 . Due to stock market losses , payments rates that have outstripped fund income , and other issues , the fund was nearly exhausted as of May 2010 and unable to make any additional awards or payments . A lawsuit by Marshallese arguing that " changed circumstances " made Nuclear Claims Tribunal unable to make just compensation was dismissed by the Supreme Court of the United States in April 2010 . The 2000 environmental restoration award included funds for additional cleanup of radioactivity on Enewetak . Rather than scrape the topsoil off , replace it with clean topsoil , and create another radioactive waste repository dome at some site on the atoll ( a project estimated to cost US$ 947 million ) , most areas still contaminated on Enewetak were treated with potassium . Soil that could not be effectively treated for human use was removed and used as fill for a causeway connecting the two main islands of the atoll ( Enewetak and Parry ) . The cost of the potassium decontamination project was US$ 103.3 million
Cactus
Operation Hardtack I
Enewetak Atoll