Rink A Fayre 2rVISED Zia sek® a 5/17/73 Introduction Eniwetok Atoll is significant in the nuclear world because it was one of the sites of our atmospheric nuclear testing program during the late 1940's and 1950's. As the Eniwetok Proving Grounds (EPG) and the headquarters of the Pacific Proving Grounds (PPG), the Atoll experienced the effects of some 40 nuclear detonations, including the world's first thermonuclear explosion. The United States' testing program in the Pacific was extensive, involving thousands of personnel. Large complexes were constructed to house these personnel, their experiments and equipment. structures were emplaced throughout the Atoll: Numerous test bunkers, photo and device towers, test stands, experiment holders, etc. During the years of testing, many of these structures were expended in pursuit of the program. As structures were destroyed or rendered use-= less by a test, they were abandoned, pushed aside or buried. New structures took their place. From hindsight we observe that radioactive contamination, resulting from the test detonations and related experiments, was distributed pri- marily as fallout over much of the Atoll. Islands on which surface ground zeros (SGZ) were sited, and those which experienced close-in, intense fallout, received a substantial insult to their environment from each test. Depending on subsequent needs of the program, construction activities--building new or replacing expended test structures--moving earth, "decontaminating" areas--redistributed the radioactivity from the surface of the ground to various depths on several islands or onto the surrounding reef or into the nearby lagoon waters.