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ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION L. Joe Deal, OES Enclosed is a copy of the report prepared for and submitted to Dr. Liver-manby the group which last week reviwed the Enewetak cleanup criteria and disposal plans, of which you were an observer. Please accept my thanks for all of the effort which you put forth in assisting in this review, and especially for the inconvenience which you and your family experienced as a result of it. Office of Environmental
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for Environment and Safety 0. S. Energy Research and In response to your request of August 11, 1977, plans for the cleanup of Enewetalk Atoll were reviewed at a meeting at the Nevada Operations Office, August 15-17, 1977. A list of participants in the review is Prior to the meeting, the reviewers were provided copies of documents dative to the development of cleanup criteria and preparation of the EIS. Supplemeating these were briefings by Joe Deal, Tommy M&raw, Roger Ray, and members of the Staff of the Defense Nuclear Agency. Mr. Steveus reviewed the Environmental Impact Statement and Major General Shedd and Colonel Hemler described operational plans for soil cleanup and crater disposal. In addition, Mr. M. Wtes, Manager of the&Nevada Operations Office, met with the reviewers discussed points he raised in his letter to you. reviewers addressed two primary issues: The criteria for cleanup of the islands contaminated with The plan for dfsposal of plutonium contaminated soil and other radioactivity contaminated debris in the Cactus Crater. Several other ,relatedissues were addressed during the discussion. was unanimous agreement that the criteria for cleanup of the islands contaninated with plutonium are reasonable in light of present knowledge and their application does not an unacceptable health risk. /
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rAlthough the ,reviewers identified alternatives that may be prefmable, there was unanimous agreement that the planned -lacerPent of plutonium contaminated soil and debris in Concrete in the Cactus Crater does not impose unacceptable arvironmental and health risks. R. Review of Plans for Cleanup of Rnewetak Atoll A. Criteria for removal of contaminated soil T'hereviewers considered the criteria for the relocation of approximately 10 Ci of plutonium from dispersed locations in the terrestrial environment to a central location in the Cactus Crater on Runit Island. The reviewers concurred with the 40 pCi Pu/g soil value adopted in the Environmental Impact Statement as a minimal action level and with 400 pCi/g as the mdatory cleanup level. Using the assumptions in the EIS the reviewers estimated that the lung dose resulting from lifetime inhalation of air containing 8n equivalent concentration (100 ug soil/m3 air or or 1 strad,(year,assuming a quality factor of 10. This compares with the proposed EPA federal guidance value of l mrad/year to the lung from transuranic elements in the environment. The reviewers believe that lung doses from inhaled plutonium will be considerably less than this for persons living and working on the Atoll because of the small land area which minimizes buildup of plutonium concentrations in the air and because of the conservative mssumptioas used in estimating dose; e.g., all contaminated soil was considered respirable, the concentration of soil in air was maintained constantly at the 100 ug/m3 level, etc. The reviewers recommend that more specific guidance for application of the criteria at plutonium levels between 40 and 400 pCi/g be developed for the Task
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&can dumpingkas consideredto be the preferred rolutionby most of the reviewers. Wile the. qusntities-ofsoil and debris are high (75,000225,000 yds3), the plutoniuminventoryis estimated to be only in the order of 20 Cl, an insignificant mount to dump into the Pacific Ocean comparedto that which is alreadypresent in the ocean from ported from the waters of the lagoon to the open ocean each year. We understandthat EPA interpretsPL 92-532 to effectivelyprohibitocean dumping by the U.S. and is signatoryto the internationalagreementon the dumpingof radionuclidesin the ocean under the larger quantitiesthan 20 Ci of plutonium. Advantages of deep ocean dumpingincludethe removalof the plutoniumcompletelyfrom the Atoll environmentand the eliminationof the need for any futuremonitoring have to be reopenedand an oceanographicsurvey Lagoon dumpingas an acceptablealternateto ocean dumping minimizesinternationalramifications. Since . 8oill would be slowly dispensedto the lagoon during the cleanupand only a small fractionof the bound plutoniumwill be remobilized,the actual impact on the lagoonwater concentrationwill be slight. It can be demonstratedby computationthat less than oolutionphase during disposalto the lagoon. The majority of materialwould settle to'the floor of the lagoon. Concentrationsof plutoniumin aquatic organismsmight increase,but since the residence time for sea water in the lagoon is about 150 days, the concentrationswould shortlybe reduced to smbient levels. Again, the EIS would have to be reopenedand permits obtainedfrom the EPA, other Federal agenciesand the Trust Territory.
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Terrestrial disposal on Rtmit Island with a concrete cover would have the least immediate -act: on the local marine environment In that remobilization of the radionuclides from the. rO;llto the groundwater and eventually to -the lagoonis minimized. This method would rarimdze potential occupational exposures during the cleanup operation. . Terrestrial disposal by covering the existing contaminated areas on Runit with contaminated roil removed from other islands, but wlthout concrete cover, was also considered. This vould reduce the average.surface levels of plutonium on Runit, but might require quarantine. Roth terrestrial disposal methods would allow retritevalof the plutonium. Both would require reopening of the EIS. Other methods for disposal of plutonium were proposed. One interesting possibility is the application of mining and milling techniques to separate plutonium from the soil of Enewetak Atoll. The reviewers were not aware of this having been explored. While such a technique could not be available for application to Enewetak Atoll, it might be useful at other sites in the C. Future ERDA Commitments at Enewetak Atoll According to the Environmental Impact Statement, ERDA is committed to long-term monitoring the the Enewetak Atoll. Planning for this responsibility appears to be incomplete. The reviewers offer the following suggestions: 1. The environmental monitoring program should be as inconspicuous as possible-and should be aimed at estimating radiation doses to the inhabitants of 2. Any activities carried out by individuals other than the Enewetakese should be conducted only if it is rscertained that the activity has minimal impact on the inhabitants.
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During the next three years a otudy of c%mxmstaaces typical of those that will occur when the island6 are reinhabited .'_ should be conducted. It is emphasized that tbi6 ehould not be a etudy of resuspension 666ociated vith cleanup activity per se. Information applicable to the Enewetak people will be invaluable in improving tstimates of radiation dose to human beings returning to the islands and will assist ie reaching decisions about future'use of specific Islands. The EPA regards the crater disposal method a6 temporary storage. Under this view, rmsintenanceof the concrete structure may be required. The Defense Nuclear Agency r_egardsthis method as permanent disposal vbich vould imply no maintenance. This could lead to uncertainties of responsibility far future activities at the crater site. A programmatic effort must be initiated to communicate to the Rnewetak people the nature of the risks to which they will be exposed. The potential risks associated wf.thliving and visiting the various islands mt be made comprehensible to the people from their perspective to insure their understanding the need for restricted D. Concern for incomplete cleanup The reviewers were concerned that the cleanup program, as defined in the EIS, could be terminated _ before completion if the funds and other resources appropriated for the effort proved to be insufficient due to underestimates of the magnitude of the amount of roll1that has to be removed.
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In conclusion it should be emphasized that only the adequ&y of the ctiteria and disposal methods were reviewed and that the operational $lans for assuring implementations of the criteria were not examined
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Deputy Directorfor Operationsand Administration Comander, field Comnand girtland AFB, Field Command Col. CharlesJ. Trek, USA