Enewetak Radiological Survey (Volume-I of 3, Vol. 2 - 5258, Vol. 3 - 5287)

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Introduction (W. Nervik, Lawrence Livermore Laboratory) Enewetak (R. Ray, Nevada Operations Office, USAEC; J. Koranda and K. Marsh, Lawrence Livermore Laboratory; and V. Nelson, University of Survey Plan (W. Nervik, Lawrence Livermore Laboratory) 47 Aerial Radiological and Photographic Survey (T. P. Stuart and Terrestrial Soil Survey (0. D. T. Lynch Jr., Nevada Operations Office, USAEC, and P. H. Gudiksen, Lawrence Livermore Operations Office, USAEC; and T. p. Stuart, EG&G, Inc.) 117 Marine Program (V. Nelson, Laboratory of Radiation Ecology, University of Washington, and V. E. Noshkin, Lawrence Livermore Livermore Laboratory; G. Potter. Environmental Protection Nevada Operations Office, USAEC) . 372 Enewetak Survey Radiological Controls (0. D. T. Lynch, Jr., Nevada Operations Office, USAEC) 486 Dose Assessment and Evaluation . 491 Dietary and Living Patterns (W. L. Robison, Lawrence Livermore Health and Safety Laboratory, USAEC; p. H. Gudiksen and Evaluation of the Inhalation Pathway (D. W. Wilson, Lawrence Appendix A - Relationship Between Resuspended Plutonium in Air and Plutonium in Soil (L. R. Anspaugh, Lawrence

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Dose Estimates for the Marine Food Chain (W, L. Robison, Lawrence Livermore Laboratory) 526 Evaluation of the Dosage from Terrestrial Foods (Y. C. Ng, Thompson, Jr., Lawrence Livermore Laboratory) 542 Summary of Dose Assessment (W. L. Robison, Lawrence IV. Summary of Findings (W. Nervik, Lawrence Livermore Laboratory 626 Appendix I - Planning and Operations Directive (NVO-121) - 1972 Enewetak Atoll Precleanup Radiological Survey 696 Appendix II - Survey Results by Island . Vols. II-III The AEC has conducted a survey of the total radiological environment of Enewetak Atoll in order to provide data for judgments as to whether or not all or any part of the Atoll can be safely reinhabited. More than 4500 samples from all parts of the marine, terrestrial, and atmospheric components of the Atoll environment were analyzed by instrumental and radiochemical methods. In addition, an aerial surducted over all land areas. predominant radioactive isotopes now present, but their distribution is far from uniform. Islands on the southern half of the Atoll from ALVIN to KEITH have levels of contamination comparable to or less than those due to world-wide fallout in the United States. On the northern half, islands ALICE to IRENE are most heavily contaminated, KATE to WILMA are least contaminated, and JANET is at an intermediate level. These radiological data have been combined with the best information currently available on the expected diet of the Enewetak people to estimate potential wholebody and bone doses to the population for six living patterns at 5-, 10-, 30-, and year integral dose estimates for unmodified (i.e., current) conditions are shown Table A. The 30-yr integral dose for six living patterns, assuming unmodified condi30-year integral dose, rem Living Inhalation ~ Terrestrial Marine Total ALVIN through KEITH KATE through WILMA KATE through WILMA ALIC E through IRENE Sou the rn islands

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The mam contribution to the population dose comes through the terrestrial food pathway, followed in decreasing order of significance by the external gamma dose, marine, and inhalation pathways. In the tribution to both whole -body and bone dose is due to pandanus and breadfruit. Percentage contributions to the 30-yr integral dose for each of the terrestrial food items for a population engaged in agriculture on JANET are shown in Corrective actions to reduce popUlation doses will be most beneficial if they are directed at the primary contributors, Le., pandanus and breadfruit in the diet and external gamma dose in the residence areas. Since neither pandanus nor breadfruit are now growing on the Atoll in sufficient amounts to provide a significant dietary component, control of the location and manner in which they are reestablished will have a direct influence on the population doses from these fruits. If their growth were limited to the southern islands, for example, and the population living on JANET were to import them restrial food dose to a population engaged in agriculture on to bone, to whole body, rather than grow them locally, the expected 30-yr bone dose would be reduced from 80 to 25 rem and the whole-body dose from 11 to 6.5 rem. Similar results would be obtained if uncontaminated soil were imported to JANET for the establishment of these plants. Attempts to obtain the same results by removal of JANET would require denuding of the entire island because of the relatively uniform distribution of these isotopes over the land surface. Significant reduction of the external gamma dose may be achieved by placing a 2-in. layer of clean gravel in the village areas and by plOWing the agricultural areas. On JANET, for example, use of these procedures reduces the expected 30-yr external dose from 4.0 to 1.7 rem. Thus, from Table A it is clear that a very broad range of population doses may be expected, depending on Village island, agricultural island, and living pattern. It is equally clear that substantial reductions of the higher doses can be achieved through relatively simple modification of the agricultural practices and of the soil. Table C summarizes the reduction that could be expected from these actions for a population living on JANET. The island of YVONNE presents a unique hazard on Enewetak Atoll. Pure plutonium particles are present on or close to the ground surface, randomly scattered in "hot spots It over n10st of the area from the tower to CACTUS crater. revealed the presence of occasional milligram-size pieces of plutonium metal, as well as smaller pieces whIch are physically IUdistinguishable m size from the r surrounding coral matrix. Given these current conditions, it must be assumed that pure plutonium particles of respirable size are now also present on the surface or may be present in the future as weathering effects oxidize and break down the larger particles. Lung dose assessments for this area, therefore, must be based on inhalation of pure plutonium particles rather than those having the average plutonium content of the The potential health hazard via the inhalation pathway is sufficiently great to dictate two basic alternatives for remedial action for this island: (1) Make the its to all people, or (2) conduct a cleanup campaign which will eliminate the "hotspot" plutonium problem and remove whatever amount of soil is necessary to reduce the soil plutonium concentration to a level comparable to other northern islands. As an indication of the volumes of soil involved, removal of a 10-cm thick layer of topsoil in the area in which "hot spots" have been detected invol ves approximately 17,000 m 3 of material. Further removal of soil to reduce the maximum plutonium contamination levels to 50 pCi!g or less involves an additional 30-yr integral dose, rem a Unmodified soil case Modified soil caseD Enewetak Atoll living Enewetak Atoll living Enewetak Atoll living fined to southe rn Enewetak Atoll living a Sum of all pathways for the Enewetak living patterns (i.e., external, inhaLation, marine, and terrestrial). bSOil modified by placing 2 in. of clean gravel in the village area and plowing the cBased upon background of 100 mrem/yr at sea level.

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Successful completion of the Enewetak Radiological Survey was the result of the effort and cooperation of many organizations. However, organizations are composed of individuals, and it really has been the attitudes and abilities of these people upon which so much has depended. We wish to acknowledge most heartily the efforts of all partic ipants - those who worked in the field, those who worked in the laboratories at home, and those who provided support services so important to an efficient operation. The list is long, but that is indicative only of the size and complexity of the operation. Very likely, in spite of our most diligent efforts, the names of some who participated have been omitted. To them we extend our apologies and our appreciation. All of the following organizations and individuals have made significant contributions to the success of the AEC Enewetak Radiological Survey. To them, collectively and individually, we express deepest thanks for a difficult job done well. This report is long, and it contains an enormous amount of information, but it does not come close to telling the whole story of what happened to all the individuals concerned from September 1972 to October 1973. That is the stuff of which reminiscences are made. For simplicity, and to avoid even the appearance of a pecking order, organizations -and individuals within each organization-are listed in alphabetical order. Lawrence Livermore Laboratory r Argonne National Laboratory (ANL) Atomic Energy Commission Nevada Operations Office Pacific Area Support Office Brookhaven National Laboratory (BNL) Defense Nuclear Agency (DNA) Eberline Instrument Corporation, Santa Fe, N. Mex. IEG&G, Inc., Las Vegas, Nev. Enewetak Marine Biological Laboratory, University of Hawaii P. Helfrich et al.

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Environmental Protection Agency, Las Vegas, Nev. Holmes and Narver, Inc. LFE Environmental (Analysis Laboratories Division), Richmond, Calif. Lawrence Livermore Laboratory (LLL) Los Alamos Scientific Laboratory (LASL) Micronesian Legal Services Oregon State University Pan American World Airways Reynolds Electrical Engineering Company, Communications Department Scripps Institution of Oceanography The Administration of the Trust Territory of the Pacific Islands Ujilang Council (S. Gideon, Magistrate)

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Site Contractor at Enewetak-MATSCo Corp. Kwajalein Missile Range and Site Contractor, Global Associates Sixth Ordnance Detachment U. S. Coast Guard Loran Stations, Enewetak and Kwajalein T. Schmidt et al. Chief Alvarez et al. Chief J. Broyles et al. U. S. Public Health Service, Health and Safety Laboratory University of Washington W. Nervik, Lawrence Livermore Laboratory, Livermore, California On April 18, 1972, Ambassador sentative to the Micronesian Status Talks, and TTPI High Commissioner Edward E. Johnston issued at Saipan a joint announcement which stated that "the United States Government is prepared to release legally the entire (Enewetak) Atoll to the Trust Territory government at the end of 1973, subject to the retention of some minor residual rights." This announcement was welcomed by the Enewetak people, who for many years have sought to obtain a for return of their ancestral homeland to their own jurisdiction. They had been moved from Enewetak in December 1947 in order that the Atoll could be used for the nuclear weapon testing program and ever since have been living on Ujilang, an atoll approximately 125 mi southwest of The announcement went on to state that "prior to the actual settlement of the Atoll, it will be necessary to carry out the same type of survey, cleanup, and rehabilitation procedures that have been utilized for Bikini Atoll. As in Bikini, the schedule for resettlement will depend on the results of the survey and the pace In May 1972 a U. S. Atomic Energy Commission (AP;C) survey team visited Enewetak Atoll to conduct a preliminary radiological reconnaissance. They could not visit all islands in the Atoll in the time available, but of those they visited, they found what they cons ide red to be significant radiological hazards sttl! existing on BELLE, JANET, SALLY, URSULA, itation cost estimates based on data from this survey had, of necessity, to incorporate a wide range of assumptions, due partly to the lack of information on the extent of the radiological contamination, partly to the lack of a detailed analysis of the dose-to-man implications for each isotope comprising that contamination, and partly to uncertainties as to the manner of disposal of radioactive debriS. Acceptability of disposal methods and plans would require detailed consideration of bioenvironmental impact, of political concerns, and of the desires of the Enewetak people. Since estimates based on these assumptions indicated that cleanup costs could run to tens of millions of dollars, it was considered essential that much more comprehensive betical deSignators for all islands will be used in this report. A cross-reference to all names we understand to be in use for each island may be found on p. v of Appendix II. An exception to this approach applies to the name for the Atoll itself. As Dr. Jack Tobin points out, "It is called Enewetak by the Atoll people and the rest of the Marshallese. The people of the Atoll say that it means island (end toward, or pointed toward, the east 01'-- wetak; hence. Enewetak." Since there is acommitment to return the Atoll to TTPI jurisdiction in the near future, this Seems an appropriate time and place to begin using the Marshallese spelling.

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and detailed information on the radiological condition of the Atoll be obtained before the start of cleanup and rehabiliOn September 7, 1972, at an interagency meeting in Washington, the AEC agreed to assume responsibility for Conducting this comprehensive radiological survey; the Department of Defense agreed to assume responsibility fOr conducting such cleanup operations as were required; and the Department of the Interior agreed ity for rehabilitation and resettlement of the native population. This report describes the radiological survey which has been executed by the AEC as a consequence of the September 7 commitment and presents data which have been obtained from that survey. Recomrecti ve action based on these data will be the subject of separate action by the Atomic Energy Commission. [n Section II a fairly detailed description of the Enewetak Atoll and a history of the Enewetak people are presented to set the framework within which the Survey has be conducted. Section III contains a separate chapter for each major component of the Survey, including Plans, Aerial Survey, Terrestrial Soil and Radiation Survey, External Dose Estimation, Marine Survey, Terrestrial Biota Survey, Air Sampling, Engineering Survey, Analysis Program, Radiological Controls, and Dose Section IV contains a Summary of The large number of photographs and figures needed to present the data are contained in the Appendix as Volumes II R. Ray, Nevada Operations Office, U. S. Atomic Energy Commission, Las Vegas, Nevada Lawrence Livermore Laboratory, Livermore, California V. Nelson, University of Washington, Seattle, Washington Portions of this chapter are largely drawn from a working draft of the manuscript which is to become the Draft Environmental Impact Statement for Enewetak cleanup. This statement is being prepared by Holmes and Narver, Inc. under contract to the Department of Defense. We are indebted to the Defense Nuclear Agency for permitting use of the statement and to Dr. Stanley Kaplan of Holmes and Narver for his assistance toward its timely availability. Dr. Jack Tobin, a major contributor to the Kaplan effort, was also consulted extensively on history and anthropology in relation to other sections of this report. The last section of this chapter is drawn from field trip reports of Kenneth Marsh and Enewetak Atoll Island Names Because the native names of most of the islands in the Enewetak Atoll are difficult for English-speaking people to pronounce and spell, male and female first nameS were assigned to the islands during the U. S. occupancy. Site names Were also given to several points in the lagoon and on the reef where scientific structures had been erected. Nearly all documents and maps made subsequent to 1952 include these site names, and in some cases the native nameS are also shown in parentheses. Table 1 presents a correlation of these site names with the native names obtained from the Enewetak people during the Ujilang field trip in August 1973, and from the U. S. Hydrographic Office Charts. …