Staff Report on Bikini Atoll Environmental Levels of Plutonium

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OFFICIAL USE ONLY STAFF REPORT Oill BIKINI ATOLL EXVIRONIGNTAL LEVELS OF PLUTONIUM 1. BscQround of Bikini Program Evacuation and Test Operations. that Bikini Atoll was a suitable site for nuclear weapons tests. The Bikini population, numbering 166, agreed t o leave the atoll. After living some time on Rongerik Atoll and Kvajalein Island, the Bikini people were relocated to Kili Island where they still Early in 1946 it was determined live today. The Bikinians were promised the return of their atoll when it was no longer needed as a testing site. The Bikini field operations and test activities occurred pericdic ally from 1946 through 1958. During t'nis time, areas of the islands were cleared for camp sites and there was construction of housing, docks, towers and instrument bunkers. An gir crc ft runway and parking ramp vas b u i l t on nearby Eneu and another runway was constructed on a string of islands connected by ma-rcade causzways along the southern rim of the reef. A total of 23 devices of both fission and thermonuclear types was detonated during 1946, 1954, 1956, and 1958. Bikini Atoll received fallout porn these tests to varying degrees. of the atoll, were ge pc rally upvind of th8 detonation sites and

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OFFICIAL USE ONLY thus received lesser amounts of fallout debris than some of the other islands. The relative locations of the is lz nds of Bikini Atoll and the test sites are shown i n Figure 1 with the number of tests indicated in the circle. on the enviro1uner.t at Bikini Atoll bras begun shortly after the first An assessment of the impact of test activities two detonations were conducted i n 1946. Survey teams have revisited the atoll between testing periods and since testing was concluded t o obtain samples of marine life,land plants and animals, soil, water and t o spot-check the external radiation levels within the atoll. The most recent surveys were conducted ‘ i n 1964, 1967, and during cleanup operations in 1969. tractors, conducted a field survey of the Eniwetok-Bikini Atolls during The Division of Biology and Kedicine, through i t s COETen scientists from the University of bkshington, Bowling Green University, and Puerto Rico Nuclear Center, led by Dr. Lauren R . Donaldson of t h e University of Washington spent two and one half weeks i n Eniwetok Atoll,ten days in Bikini Atoll, and two and one-half days a t Ror?gelap Atoll. The purpose of this survey was t o issess ,in reconnaissance fashion, the conditions with respect to the effects of nuclear tests and related fallout at these islands. This visit to Bikini Atoll produced a sizeable quantity of data on the OFFICIAL USE OXLY

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OFFICIAL USE ONLY radionuclide content of foods (marine and terrestrial) t h a t would be available to a returning population. Measurements of ex tern el radiation levels were less extensive. Islands were divided into several measurement areas and readings of gamma and beta-gamma were taken at several locations in each area. Results of analyses of en vi ro mental samples collected in 1964 Symposium on Radioecology, Proceedings of t h e Second National Syaposium, Ann &>or, Michigan, May 15-17, 1967, in a report by A . D. Welander entitled " Distribution of Radionuclides inthe Environmect of Eniwetok and Bikini Atolls, August 1964." The value reported for plutonium-239 ' in a single soil sample atthe 1/2" t o 1" depth was 11 pCi/g. 1967 Survey. I n December, 1966,the AEC, i n responding toa request fron the Secretary of the Department of Interior, agreed t o make a determination on whether Bikini and its lagoon were safe for continued habitation and whether the Bikinians could have hazard-free use of the resources of the atoll and its adjacent water areas. Subsequently it was determined that the available survey data were not yet complete and that another team visit was needed t o conduct a nore extensive survey of exterr-a1 radiation levels in Bil in i Atoll. Also needed was a de terni nation of the radionuclides that oontributed to this radi a tim OFFICLAL USE OXLY

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OFFICIAL USE ONLY Planning fora major survey effort by the Division of Biology and Medicine began early in 1967. The emphasis was on delineation of the external radiation fields, particularly at locations of past and future habitation, and on obtaining more measurements on all islands, including the smaller islands near test locations. Dr. Edward Held, University of blashington Marine Radiobiologist was appointed survey team leader. and the U. S . Naval Radiological Defense Laboratory. Four native workers were added tothe team i n Kwajalein. Team membersnip included personnel The survey teem spent 16 days at the atoll in April-May 1967 conciucting an extensive survey of external radiation levels.Except for Adrikon, a very small island in the southwest corner of the atoll,all fourteen islands and the two complexes of islands JoiE et by man-made causeways were surveyed. Seven days were spent w i t h .studies on Bikini fs land.In addition to monitoring e xter cal radistion, samples of food items, vegetation, and soil were collected arid acs1yzt.d for radio nuclide content. External radiation levels and the radio nuclides contributir-6 t o ' those levels were found t o vary from island to island. On is lar As more re note from testing activities such a s Eneu and Bikini,the major contributor to the external g mm field is cesium-137. ?"ne OFFICIAL USE OMLY

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OFFICIAL USE ONLY levels on Bikini were observed t o be highest in the inore heavily vegetated interior and lowest along the shore where there has been external garrms field was observed t o be cobalt-60. On' near test islands,the major contributor to the scrap metal containing cobalt-60 were found on these is lends. Followirg the 1967 survey, the next significant step was taken by Dr.Philip F. Gustafson of the Division of Biology and Medicine, * who collected and sw mri zed the data from all past surveys. in this material were reports from the Trust Territory District Agriculturist and from the Trust Territory District Anthropologist. Dr . Gustafson prepared estimates of potential exposures, both internal and external,for a returning population having living habits and diet that are expected t o apply tothe Bikinians. tat ive recommendations with regard to the basic question of whether Also prepared were tenfrom a radiation exposure viewpoint the Bikinians should be alloved AEC Review. In April 1968, the Division of Biology and Medicine appointed the fol loving --A d Hoc Cormittee t o consider the question of return of the Bikinians : John C . Bugher, Former Director EX, retired Robert A . Conard , Brookhaven Natiohzl Laboratory Charles L. Dunham, Chairnan, Division of Medical Sciences, NRC)rPIAS Shields Warren, Scientific Director, Cancer Rzscarch Institute, ' New Ensland Deaconess Hospital *Uosr a t Argonne National Laboratory , Argonne, Illinois, USA OFFICIAL USE ONLY

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OFFICIAL USE ONLY The Committee members reviewed the survey data,Dr. Gustafson's reports, and consulted with the tem nenbers of the 1967 survey. on this review, the Committee prepared a report stating that, on the basis of infor:nation provided, the exposures to radiation that would result fron? the repatriation of Bikini people do not offer a sign if iczn t threat to their health and safety. Key recomendations for actions to further reduce exposures included restriction of rehabilitation for the present tothe Bikini-Eneu Complex, removal of radioactive scrap, reduction of land crab population, a dietary supplement of calcium, and periodic resurveys of the atoll. There were other recornendations for agricultural and village construction activities expected t o reduce tke radionuclide content of pandznus and reduce ex tern el radiation levels in village and dwelling sites. These reports and analyses formed the basis ford is - cussions between various governmental groups, including AEC, t h e Depzrtment of Interior and DOD on rehabilitation and resettlement of On August 12, 1968, the Presideilt znnounced the decision that the Bikinians were t o be returned to their atoll.Atthe same time AEC issued a press release providing background information relative to the decision and including the Ad Hoc Cozmittee's report. and Department of Defense (DOD) were requested t o work with t h e Deprogram for returning the Bikinians to their home islands. OFFICIAL USE OJTLY

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OFFICIAI; USE ONLY the plznning, High Conunissioner W. R . Nomood of the Trust Territory of the Pacific Islands led a party of Trust Territory officials, nine Bikini natives, AEC and DOD representatives, and members of the press, back to Bikini in late August, 1968. 1969 Operations and Survey. project and this phase was completed i n October 1969. shared the cost of cleanup operations with each agency providing Cleanup operations commenced at Bikini DOD directed the cleanup phase of the rehabilitation DOD and AEC AEC provided monitor iw support during 1969 cleanup operations including guidance for disposal of scrap material. The vegeta t isn removal operations carried out to provide space for replanting coconut groves also provided access to all parts of Bikini and Eneu Islands so that external radi at ibn levels could be mapped in detail(in 1964 and 1967, heavy vegetation placed a limitation on how much mea could During cleanup operations a significant number of additional s aap les of foods, vegetation, soil and sediment, and well water were collected. Separate draft reports containing the external radiation measurements and results of analyses of radio nuclide content of environmental. shmples has been received from the Southwestern Radiological Health Laboratory (SmIL) and fr m the University of Mashingtck. results of analysis for plutonium-238 and plutonium-239 in soil at two locations on Eneman and the University of Washington report contalns OFFICIAL USE ONLY

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OFFICIAL USE ONLY such results for one location on Eneman and tv o loc at is ns OI? Bikini. Except for pluto niu x levels in soll, the measurements of environmental radioactivity in these reports confirmed the results of the 1967 survey. The Department of Interior is presently conducting the agricultural recovery phase of the project and it was recently reported t‘nat housing construction is t o begin about May of 1970. At present there are approximztely 20 native workers and a Trust Territory representative at Bikini Atoll engaged in the agricultural program. 2 . Levels of Alpha bitters in Soil ar.d Ajr March 23, 1970, the levels of plutonium-239 (2nd plutonium-2lcO) intvo As reported in Information Paper AEC 604/124 dated soil sm-ples for Bikini Island appear t o be about a factor of 10 higher than the level reported for a sample collected in 196h. More recent analyses performed by t h e Southwestern Radiological Health Laboratory (SWHL) and the University of Washington have confirmed levels for these two samples enalyzed i n 1969; samples frora other locations on Bikini have proven t o be somewhat lotier. range from 1.3 t o 190 pCi/g, and for Eneu Island, from 0.5 t o < 3 pCi/g The values for Bikini Island of soil,as shown i n Tables 1 and 2. Island, a nearby test island not currently planned for rehabilitation, showed plutonium-239 levels rang iw from 83 t o 410 pCl./g in surface Previous analyses f o r Encmsn OFFICIAL USE orny

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OFFICIAL USE ONLY Rocky Flats.In order t o show possible relationships between soil levels and airborne levels of plutonium-239, data for Rocky Flats and Palomares have been examined. Levels of plutonium-239 in surface soil at1to more than 5 miles from the Rocky Flats plant range from 0.05 to3 pCi/g, with an average of 0.5 pCi/g, a s shown i n Tables 1 and 3. Howe-fer, the air monitoring network around Rocky Flats showed average gross alpha activity in airborne particulates .at various stations ranging f’roln 0.009 t o 0.02 pCi/m 3for the last half of CY 1969, as given i n Tables 1 and 6. Assuming the gross alpha act iv it iy to be of the Concentration Guide value for individuals in the general ;uklfc, or 6$, for a suitable sample of the public.Air samples specifically analyzed for plutonium include a single sample taken by Dotr i n Decesker, 1969, at the east security fence with a level of 0.002 pCi/m ,adS ~ X samples taken by the State of Colorado following the RF fire and procle a wp operations of surface stripping (area 2-1), plowing, etc.,hsve Levels of alpha emitters in soil at Palomares followird ::.e been reported both by Spanish authorities an$ by LASL. Backgr0ur.d soil levels of gross alpha activity in regions of Spain not affected by *.t-.e Palomares incident range fron 3.9 t o 9.5 pCi/g of dry soil and =e d e - OF TIC I AL USE ONLY

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OFFICIAL USE ONLY ' pendent on the type of soil,as shoun i n Table 4. Residual gross alpha activity in surface soil samples taken a t Palomares by Spanish authorities in September 1966, approximately 7 months after the taken inthe same areas and analyzed by LASL for plutonium act iv it iy had levels ranging from 0.05 t o 2,130 pCi/g; areas 2-2 and 3-1 had average plutonium levels of 134 and 156 pCi/g, respectively. data are presented ir, Tables 1 and 5 . range of plutonium in surface soil in control areas at Palomares vas from the incident. It should be noted that the These areas were selected to be free of plutonium This range is comparable to that found a t Rocky Air samplers t o measure gross alpha activity in airborne par - tic u late s were set up in the three areas of initial highest deposition, activity for the period 6 / 6 5 / 6 7 ranged from 0.05 t o 0.14 pCi/m , with an average of about 0.003 pCi/rn . These Palomares levels may be compared with background measurements made a t Madrid during t h e entire content of the sample t o be plutoniuk, the averages for Palomares and for Madrid would be on the order of 0.2 t o 0.4$ of the appropriate For these areas,the maximum gross alpha 8maximum and average gross alpha activity level of

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OFFICIAL USE ONLY Concentrstion Guide for individuals in the general public, or 0.6 t o l.&, for a suitable samsle of the public. Thus, the levels of plutonium i n the to player of soil at Rocky Flats and at Palo m res have not ledto any situations of concern with respect to a possible airborne pathway t o man. As discussed inthe followipg section,the situation is expected t o be even more favorable with respect to possible airborne plutonium at Bikini. 3. Particle.Size in Soil. Determination of the size of individual.particles of plutonium oxide o r plutonium oxide agglomerated with soil is almost impossible after the particle has reached the earth ' s surface and become mixed with other particles. It is the opinion of Dr. John Harley, IIASL, and Dr. Wright Langhan, LASL, that particle size studies of plutoniumbe z ring soil at Bikini or elsewhere would be unprofitable. size determinations …