Abstract We have updated the radiological dose assessment for Rongela Rongelap Atoll using data generated from field trips to the atoll through 1993. The data base used for this dose assessmentis ten fold that available for the 1982 assessment. Details of each data base are presented along with details about the m to calculate the dose from each exposure pathway. The doses are calculated for a resettlement date of January maximum annualeffective dose is 0.26 mSv y-! (26 mrem y-1). ‘50-, and 70-y 1, The es integral effective doses are 0.0059 Sv (0.59 rem), 0.0082 Sv and 0.0097 Sv (0.97 rem), respectively. More than 95% of these estimate due to 137-Cesium (137Cs). About 1.5% of the estimated dose is con 90-Strontium (90Sr), and about the same amount each by 239+240 (239+240Pu), and 241-Americium (241Am). | Introduction On March 1, 1954, a nuclear weapon test, code-named BRAVO, was conducted at Bikini Atoll in the northern Marshall Islands. The explosive yield of the detonation greatly exceeded expectations, with the result that radioactive material in the cloud was three-tofive times what was expected. Thus, despite the attention that was given to meteorology in the operational planning, moderate to heavy fallout was experienced at the Rongerik, Rongelap, Ailinginae, Ailuk, Taka, Mejit, and Utirik Atolls, located to the east of Bikini. Rongelap and Utirik were inhabited by Marshallese. A smail number of Rongelap residents werevisiting . uninhabited Ailinginae, and a small detachment of U.S. military personnel were stationed on Rongerik. These people were removed from ail four atolis as soon as evacuation resources could be deployed. The Rongelap evacuation commenced about 47 hours after the first arrival of fallout and was completed within a few hours. Most. of the acute dose received by these residents was attributable to many short-lived radionuclides. dose.to inhabitants of Rongelap Island from manmade sources. In 1978, in anticipation of the fermination of its role as trustee under the Ugited Nations Trusteeship Agreement, the United States government decided to conduct aerial survey of several atolls east of Bikini Atoll in the direction of the BRAVO fallogt pattern to determine the external gamma-egposure rates. The survey, known as the No Islands Radiological Survey (NM conducted using the USNS helicopters in which the EG&G Enewetak and Bikini Atolis indi terrestrial food chain was potenfi In contrast, by the time they returned to their atoll three years later (June, 1957), many of these radionuclides had decayed. However, some radionuclides with intermediate half-lifes, such as 55-Iron (95Fe), 65-Zinc (65Zn), and 60-Cobalt (69Co), did contribute to the dose people received in the first two or three years (Lessard et al., 1980a) after their return. Currently, the long-lived radionuclides, 137Cs, 90Gr, 239+240Py, and 241Am, contribute most of the possible in the time availablefto (1) provide data for a preliminary dose asfessment at the