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THE NATIONAL ACADEMIES

Advisers to the Nation on Science, Engineering, and Medicine

National Academy of Sciences

National Academy of Engineering

Institute of Medicine

National Research Council

DIVISION ON EARTH AND LIFE STUDIES

Board on Radiation Effects Research

Dr. James M. Smith

Chief, Radiation Studies Branch

Centers for Disease Control and Prevention

4770 Buford Highway, NE

Mailstop F35 Atlanta, Georgia 30341-3742

July 2, 2001

Dear Dr. Smith:

As you are aware, the Centers for Disease Control and Prevention (CDC) asked the National Research Council’s Committee on an Assessment of CDC’s Radiation Studies from DOE Contractor Sites to critically review and comment on a draft report titled Identification and Prioritization of Radionuclide Releases from the Idaho National Engineering and Environmental Laboratory. The draft was submitted to CDC by the Risk Assessment Corporation of South Carolina (RAC) in partial fulfillment of the conditions set forth in a contract 200-95-0927, task order 5 concluded between RAC and the federal government, as represented by CDC. Among its obligations, RAC agreed to deliver “a prioritized list of radionuclides, with the key facilities identified that were the source of the priority radionuclides, the likely chemical forms of the priority radionuclides, and the important release paths for them, indicating the relative completeness of records relevant to a dose reconstruction for each one” (see page 8, contract 200-95-0927, task order 5).

The committee was asked to address the following four questions:

  1. Were the methods and sources of information used in the draft report appropriate?

  2. Are the methods and results clearly presented?

  3. Where stack monitoring data were used, are the methods for correcting the data understandable and acceptable?

  4. Do the results provide sufficient information for selection of the most significant release points and radionuclides for dose reconstruction purposes?

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THE NATIONAL ACADEMIES Advisers to the Nation on Science, Engineering, and Medicine National Academy of Sciences National Academy of Engineering Institute of Medicine National Research Council DIVISION ON EARTH AND LIFE STUDIES Board on Radiation Effects Research Dr. James M. Smith Chief, Radiation Studies Branch Centers for Disease Control and Prevention 4770 Buford Highway, NE Mailstop F35 Atlanta, Georgia 30341-3742 July 2, 2001 Dear Dr. Smith: As you are aware, the Centers for Disease Control and Prevention (CDC) asked the National Research Council’s Committee on an Assessment of CDC’s Radiation Studies from DOE Contractor Sites to critically review and comment on a draft report titled Identification and Prioritization of Radionuclide Releases from the Idaho National Engineering and Environmental Laboratory. The draft was submitted to CDC by the Risk Assessment Corporation of South Carolina (RAC) in partial fulfillment of the conditions set forth in a contract 200-95-0927, task order 5 concluded between RAC and the federal government, as represented by CDC. Among its obligations, RAC agreed to deliver “a prioritized list of radionuclides, with the key facilities identified that were the source of the priority radionuclides, the likely chemical forms of the priority radionuclides, and the important release paths for them, indicating the relative completeness of records relevant to a dose reconstruction for each one” (see page 8, contract 200-95-0927, task order 5). The committee was asked to address the following four questions: Were the methods and sources of information used in the draft report appropriate? Are the methods and results clearly presented? Where stack monitoring data were used, are the methods for correcting the data understandable and acceptable? Do the results provide sufficient information for selection of the most significant release points and radionuclides for dose reconstruction purposes? 2101 Constitution Avenue, NW, Washington, DC 20418 USA 202-334-2232 (telephone) 202-334-1639 (fax) national-academies.org

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At the initial meeting of the committee at the Emory Conference Center in Atlanta on January 30-31, 2001, representatives of RAC—John Till, Kathleen R. Meyer, and Justin Mohler—were present. They enlarged on their draft report and the methods they used in arriving at the conclusions set forth in it, and they responded to questions raised by the committee. Also present at the meeting were six people from the Radiation Studies Branch of CDC: James Smith, chief of the branch; Charles Miller, chief of the Environmental Dosimetry Section of the branch; Judy Qualters, acting chief of the risk analysis and communication section; Marie Spano, health physicist; C. M. Wood, health physicist; and Arthur Robinson, public-health educator. In the pages to follow, the committee sets out its general reactions to the draft report and then turns to the specific questions it was asked to address. General comments: To establish the criteria that the committee should use in judging the draft report, we compared the CDC task order with the work set forth in draft. We note first that the task order does not seem wholly consistent with either the scope of the work or the budget. For example, in sentence 2 (page 2) of the task order, the description does not state “historical releases” only, nor does it state “offsite releases” only. It states “releases to the environment,” which we take to include radioactive materials buried in the ground. In contrast, the penultimate sentence of paragraph 2 (page 3) of the task order clearly limits the scope of the task, as does the last sentence of the first full paragraph on page 5. RAC’s proposed approach on page 5, item 2, does include offsite releases and also promises evaluation of environmental fate, atmospheric dispersion, water dispersion, and other appropriate dilution factors, but these evaluations do not appear to be provided in the draft report. The committee assumes that this full evaluation was not possible with the time and budget allowed. We note also that the last paragraph on page 6 promises to identify data-quality problems, such as sampling-line losses and sampler efficiencies, and sources of bias; such identifications do not appear to be explicitly provided. The draft report does state that only historical releases were analyzed, although, as stated at the committee meeting, the evaluation is limited principally to historical exposures due to past releases.1 This assertion should be clarified and, in our view, highlighted in a box or sidebar (explaining that exposures due to future offsite transport of material from historical releases were not estimated or predicted). It should also be clearly stated that only releases associated with historical offsite transport were analyzed. The committee suggests that the word potential be used sparingly to avoid confusion with the uncertain magnitude of future exposures, which are beyond the scope of the draft report by design. 1   The method adopted used a summary figure that involved dose commitments, so some future doses due to past offsite transport were incorporated. For example, future bone doses due to past inhalation of plutonium are included. In principle, some future exposures (such as to materials deposited on soils) are incorporated, in that the summary figure incorporated such exposures. However, potential exposures due to future transport to the offsite environment of radionuclides currently present onsite were not evaluated.

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The draft report includes a footnote explaining that the ranking accorded a radioisotope is not based on dose even if it is called such. This, too, should be set forth in a box or sidebar where it could be noted that actual exposures of individuals or their radiation doses were not calculated and that the ranking serves only to characterize or predict possible hazards and is not immediately relevant to possible future health risks. RAC used the National Council on Radiation Protection and Measurements (NCRP) Report 123 titled Screening Models for Releases of Radionuclides to Atmosphere, Surface Water, and Ground issued January 22, 1996, for guidance in its work contained in the draft report. In the introduction to the NCRP report three suggestions, recommendations, or admonitions are given to readers: First, the methods were “designed primarily for facilities that handle small quantities of radioactive materials released as point-source emissions. However, these screening techniques can be employed by any facilities releasing radionuclides to the environment, and modifications can be made to the current screening methodology to account for releases from area sources.” Second, “conservative models and parameters are proposed. If compliance with the limits can be demonstrated using these screening models, then more sophisticated modeling techniques are not necessary.” Third, “the models should not be used to evaluate the results of accidental releases.” We recommend that the RAC draft report explicitly address those items with regard to their specific application. Each item should be discussed with emphasis on its effect on the estimation of the results of accidental releases (a type of episodic release) of radionuclides from the Idaho National Engineering and Environmental Laboratory (INEEL). The discussion should include the question of what to use if the NCRP method is not used and the precedent that has already been set on the basis of other release situations (such as the Hanford releases, and the DOE (1991a) report on the INEEL). Many of the discussions of individual facilities and operations on the INEEL are confusing; the reader is assumed to know details that are not discussed or that are referred to with jargon. For example, on page 15, in a discussion of liquid radioactive wastes, the reader is assumed to know that “the Fuel Cycle Facility” and “the laboratory building” were components of the Argonne National Laboratory-West (ANL-W) and that the latter contained “shielded cave areas”. The expert will know what shielded cave areas means in this context, but the public at large might take it to refer to otherwise undisclosed underground facilities. Furthermore, are the “35,000-gallon underground seepage pit,” “a seepage pit,” and “this underground pit” one and the same? It is not possible to tell from the material in the draft report. Another example of confusing descriptions occurs in the discussion of the Aircraft Nuclear Propulsion (ANP) program (pages 69-87), where the discussion refers to Heat Transfer Reactor Experiment (HTRE) assemblies 1, 2, and 3, cores (A2, A-2, A3, and A-3), assemblies (D101A2 and D101A3), a reactor (A3), fuel cartridges, inserts (2B, 1-D, L2A-1, L2A1, L2C-1, and L2E-1), tubes, plates, and other terms. Again, some of these would be understood by experts, but for others (such as “inserts”) and for the precise relationships between and among them (tubes, cartridges, plates, inserts, and cores, for example), one has to know more detail about the HTRE assemblies than is given in the draft report (or even in the Department of Energy, DOE, report, 1991a). Much could be accomplished by simple schematics--for these two

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examples, a map of major areas within each facility (presumably showing just one laboratory and one pit) and a schematic labeled diagram of the three HTRE--and by careful selection of the terms that are introduced. Additional comments are listed in Appendix A and B. Specific issues that the committee was asked to address Were the methods and sources of information used in the draft report appropriate? Methods: Explicit definitions of screening factor and screening units should be included. One should reserve use of screening as a technical term in this document. The more general use of the word to imply sorting or otherwise assessing the relative importance of variables should be avoided. The draft report indicates that the documentation of the methods used is in the spreadsheets (on page 36), but the methods should all be documented in the draft report also and should be consistent between spreadsheets and between spreadsheets and the draft report. While the committee identified some inconsistencies in the methods applied none of these would have any significant effect on the results. Examples of the inconsistencies follow. For routine releases, in Offsite_Air_Screening.xls 13N releases are said to be reported only in 1972, and releases in all other years have been estimated as double that value. This approach was documented in the draft report on page 38. However, in Onsite_Air_Screening.xls that method was not applied: only the reported value for 1972 is included. The half-life of 13N is only 9.97 min, so this approach is more important for evaluating releases to the onsite environment. The manner in which 239,240Pu releases were treated in Offsite_Air_Screening.xls, Onsite Air Screening.xls, and FacilityAirReleases.xls is not the same. In the first spreadsheet, there is a single row for 239,240Pu + 239Pu. The second has three rows, for 239Pu, 239,240Pu, and 239,240Pu + 239Pu; the first two contain reconstructed releases from the Test Reactor Area (TRA) and the Idaho Chemical Processing Plant (ICPP), respectively. The third spreadsheet also has the three rows in the ICPP sheet, for 239Pu, 240Pu, and 239,240Pu; but for early periods the 239Pu row has the 239,240Pu value entered in it. Only by reference to DOE (1991a) can one reconstruct what is intended in the third spreadsheet, despite the notes in it, and it is not clear what happens in later periods without examination of the source documents which the committee has not done. The estimate of 14C emissions is inconsistent. The draft report (page 37) indicates that the lowest 41Ar/14C ratio reported for 1978-1992 was used and gives that minimum as 450. Table 4 and its footnote clearly indicate that the minimum was 420 (attained in

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1978). Offsite_Air_Screening.xls implements this, using the value 420. However, Onsite_Air_Screening.xls uses instead an average value of the 41Ar/14C ratio for 19781992 of 6,680 (to confuse matters further, the explanatory note in the spreadsheet states that the value is 6,800, whereas the actual arithmetic average over that period is 6,646). Some descriptions (in Onsite_Air_Screening.xls, Offsite_Air_Screening.xls, and the draft document) of the methods used for some isotopes appear odd, unjustified, or contradictory or to contain arbitrarily selected, variable, conservative factors. Examples follow (see also Appendix B). 58Co. A notation attached to the row heading of the spreadsheets describes this as follows: “Activation product of stable 55Mn; 58Co releases reported only for 1973. For screening other years, we calculate annual releases of 58Co based on the ratio of the predicted inventory of activation products, 54Mn to 58Co, of 0.5 (Till & Meyer 1983).” That reference is not in the reference list. The method appears plausible, but the prediction presumably depends on reactor or fuel cladding materials. What activation reaction with 55Mn produces 58Co? 58Co is apparently produced through the reaction 58Ni(n,p)58Co, whereas 54Mn is likely to be produced by 54Fe(n,p)54Mn. So the method is apt to depend on a stable relation between Ni and Fe in the claddings of fuels that were reprocessed. However, this discussion might be moot. For each individual year for 58Co, there is another note in the spreadsheets specifying another method, which is the method that appears to have been used: “Activation product; releases only reported in 1973. For release estimates for other years we assumed ten times the ratio of 60Co to 58Co (ratio in 1973 was 1.73) and applied that to reported releases of 60Co. For example, 0.21 Ci 60Co reported in 1952; therefore, releases of 58Co assumed to be 0.21 x 17.3 = 3.7 Ci 58Co for 1952.” No rationale is provided for this method, and it appears that the result is the reciprocal of that intended (58Co/60Co = 1/1.73 = 0.58), so that an additional factor of 3 in addition to the intended factor of 10 has been inadvertently introduced. 54Mn. This is described as follows in the spreadsheet: “Activation product of stable 51Cr; reported releases for 1965, 1973-1975; for other years we assume annual release based on the ratio of releases of 51Cr to 54Mn of 3 (ratio ranged from 3 to 20).” See the proceeding comment. What activation reaction with 51Cr will produce 54Mn? Moreover, the ratios for 1965 and 1973-1975 were 9.81, 5.88, 20.0, and 32.3—a range from 5.88-32.3 (not 3-20 – it appears that 32.3 was misidentified as 3.23). Furthermore, examining the values for 51Cr, we find a note, “Releases reported or [sic] 1952-1969 and 1986-1992; for other years, we assume an annual release equal to twice the average of other years. Average = 0.055 x 2 = 0.10.” So the 54Mn estimates are themselves (except for 1965) based on ratios to other estimated values that have a conservative factor built in. And 0.055 x 2 = 0.11, not 0.10.

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The draft report, in contrast, states (page 39): “Releases of the activation product, 54Mn, were reported from the INEEL for 1965 and 1973-1975. For release estimates during other years, we assumed annual releases based on the ratio of releases of 54Mn to another activation product, 60Co, which was released from routine reactor operations at a similar rate (Eichholz 1983). We calculated a ratio of 3 (ratio ranged from 3 to 20) of 60Co to 54Mn for years when both were reported and applied that ratio to years when 54Mn was not reported.” That was not done. The 60Co/54Mn ratio was 124, 0.15, 0.67, and 1.12 for 1965, 1973, 1974, and 1975, respectively, suggesting a potential problem with this approach if it were to be applied. 238U. Estimated releases for unreported years were taken as 10 times “that reported in 1988 and 1989.” Actually, they were taken as 10 times the higher of the values for those two years. That does not appear to be documented in the draft report. Given the seemingly arbitrary nature of many of the factors cited above, the committee strongly recommends that RAC provide a rationale for each and for the differences that exist. Sources of information: The 1991 DOE Historical Dose Evaluation (HDE) report (DOE, 1991a) appears to have provided an adequate basis for the RAC task group’s starting point. However, the committee recommends that RAC include an explicit justification in the final draft report for its assessment of the lack of potential significance of the lost or destroyed boxes of source material in its conclusions. The other sources of information used appear to be appropriate, although the committee was not in a position to re-examine the many cited source documents. The draft report is not clear in reporting the source documents used for routine releases to air. The committee recommends that RAC identify the source of these latter documents. The HDE report (DOE, 1991a) includes an estimation of the doses resulting from routine and episodic releases based on environmental-transfer models and parameter values appropriate to the INEEL site. It is the view of the committee that it would have been better to review and, if necessary, improve the DOE results rather than to use the NCRP screening method. One drawback of the NCRP screening method, which was not meant to be applied to cases like releases from the INEEL site, is that the degree of conservatism is different between inhalation and ingestion pathways, and between routine and episodic releases. In addition, the results of the NCRP screening method cannot be compared with those based on environmental measurements (such as tritium concentrations in groundwater) or another set of assumptions (such as ingestion of duck meat). Although the committee is not in a position to evaluate the completeness of all of the reports that were evaluated, it is disturbing to note that a series of experiments in 1964 that involved deliberate release of 129I to the atmosphere and that was the subject of

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a 1995 press release from the INEEL (see Appendix D) is not included in the releases examined. Although the release was small, it exceeded the reported routine release in at least 1 year (for example, 1992). If the draft report intended to omit releases that were smaller than some threshold, that should be stated, and the threshold should be given and justified. Pages 17-21 give some details of cross checks on releases from the radioactive lanthanum (RaLa) program, state that reported daily releases of 131I were compiled, and refer to FacilityAirReleases.xls for details. That file, however, does not contain any daily or weekly compilation of releases; it contains a monthly compilation, but gives references (HJM1999070733, HJM1999070739, HJM1999070757, HJM1999070761) that are not identifiable in the draft report. Pages 22-26 discuss routine releases and give examples of the documents consulted (page 22). The section on “Confirmation of Reported Radionuclide Releases” (pages 23-24) discusses compilations of releases and cross checking between these compilations and “annual environmental and effluent release reports, from the Radioactive Waste Management Information System (RWMIS) data, and from HDE (DOE, 1991a) documents.” Several minor discrepancies are noted in ICPP data. However, there is no list of the documents consulted, and the committee could not locate, in the material provided to it, any spreadsheets or other documentation giving details of the compilations and cross checks. The committee recommends that the documents used for the compilations of releases be listed in the report and that the cross checks be documented. The source terms used in the draft report for routine releases are again discussed on pages 34-39. However, the only documentation of source documents in the draft report is on page 35, which indicates that “for annual releases to air for early years of operation, HDE (DOE, 1991a) data proved to be the most complete, because adjustments had been made to the RWMIS data that were the basis for the Historic Dose Evaluation source term data;” it is implied that the HDE values are used, but the period is not specified in the draft report. There does not appear to be any documentation in the draft report on the source documents for total routine releases for any period other than “early years.” For some years, releases are given with no references in the draft report or the supporting spreadsheets. And for some years, no emissions are listed, and there is no reference to indicate documentation for zero emissions (ICPP in 1971-1973, and 1977; ANL-W in 1971-1973, 1975-1977, 1984-1987, and 1989). Low emissions for ANL-W after shutdown of the Fuel Cycle Facility in 1969 (page 15) would be plausible. However, no history of ANL-W after 1969 is provided in the draft document; in fact, the Fuel Cycle Facility was not shut down in 1969, so the source of emissions and the plausibility of years with no emissions are not addressed in the draft report.

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Examination of the source citations indicates that in many instances they are not primary but secondary compilations (e.g. DOE, 1991a; Litteer et al. 1991; Litteer and Reagan 1989; Hoff et al. 1984, 1985, 1986, 1987, 1989, 1990, 1991, 1992, 1993). While DOE (1991a) and some of the corrections made therein are explicitly discussed in the draft report, it would be useful for the report to indicate the nature of each of the references. For example, what was the RWMIS, how was it compiled and maintained, and when did it cease operation? Were the data in it consulted independently of DOE (1991a)? Some mention that DOE (1991a) is based largely on the RWMIS is also warranted. There is no indication that a direct comparison was made between the data in DOE (1991a) and the RWMIS; was such a comparison made to check for errors in compilation of DOE (1991a)? For total sitewide air emissions, as listed in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls, the only documentation the committee could find for the source of the data was in these spreadsheets. They indicate that for 1952-1989 the data came from DOE (1991a, Volume 2) and for 1990-1992 “From PDM1997080611; INEEL Site Environmental Report for CY 1990, 1991, and 1992” which the committee takes to indicate the references Hoff et al. (1991, 1992, 1993) in the draft report. The total emissions are not the sum of the facility emissions tabulated in FacilityAirReleases.xls, although the draft report does not make clear the relationships between the various spreadsheets—or indeed between the various sections of the draft report dealing with routine releases. The relationship between the entries in the spreadsheets FacilityAirReleases.xls and Onsite_Air_Screening.xls, and Offsite_Air_Releases.xls as well as the relationships between the sections of the draft report dealing with routine releases need to be clarified. For routine releases, DOE (1991a) is itself a secondary source, in that it uses and modifies data from another source (the RWMIS). The total site emissions used in the draft report appear to have been obtained principally from Tables A-35 through A-40 of DOE (1991a). The exact sources of the data used in the draft report should be documented. Furthermore, the report needs to indicate any cross checks performed on these tables. For example, were Tables A-35 through A-40 taken directly from DOE (1991a), as indicated by the citation, or were they reconstructed from the RWMIS by using the modifications described in DOE (1991a)? Despite their source reference, the tabulated values in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls are sometimes drastically different from those given in DOE (1991a) Tables A-35 through A-40, apparently because of transcription errors; the most common differences are factors of 10 or 100 or in location in the tables. The largest unexplained difference noted by the committee is a 100-fold difference for 85mKr in 1956; this difference alters the estimated total emissions for that year by a factor of 2 and has more than a 10% effect on the onsite screening estimates for that year. Without consulting the original sources, the committee cannot be certain whether the error is in the draft report or in DOE (1991a), but examination of data on adjacent years suggests that the error is in the draft report. The 10-fold differences noted for 137Cs in 1958 and

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1963 could have a 20% effect on the offsite screening values for those years. Other differences noticed by the committee are listed in Appendix C. The committee recommends that the report list the source documents used for the routine releases, both for individual facilities and for sitewide emissions. In addition, all transcriptions from original documents should be thoroughly proofread and checked for plausibility by comparing between years and between nuclides within years. Are the methods and results clearly presented? For the routine releases, many of the methods are documented only in the spreadsheets and not clearly presented elsewhere. It is impossible to discern the relationship, if any, between the various parts of the document dealing with individual facilities, the RaLa runs, and the overall emissions from the site as a whole. The final report should provide: Better maps of the INEEL to indicate the location of all named places and identify which wells were used for observations and which were used for monitoring. Schematics of facilities or experiments to illustrate the location or function of all named facilities, buildings, and components. A complete chronologic list of all the releases described in the text and associated spreadsheets. A chronologic description of each of the facilities and programs that allows comparison with the emission lists. Separation of the listed emissions into emissions from the various individual facilities would also assist in understanding the relationships. More detailed description of the individual episodic releases. The descriptions given are generally less complete than those of DOE (1991a) although they draw heavily on the descriptions given there. In many places, the draft report is difficult to understand without simultaneous reference to DOE (1991a); where there are statements that the methods of DOE (1991a) are being followed, the methods should be described. Almost all quantitative material is relegated to the spreadsheets. The text for individual episodes should refer explicitly to the spreadsheet that contains relevant material, and the spreadsheets should clearly refer to the text. Otherwise, the reader has trouble in linking the documents effectively.

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Where stack monitoring was used, are the methods for correcting the data understandable and acceptable? The draft report does not include any calculations on stack-monitoring data, or on any methods used for their evaluation. Such data and evaluation clearly must have been used for the routine releases, and for several of the releases treated as episodic (such as the Initial Engine Test (IET) series). One possible reference within the draft report to correction methods was where it agreed with DOE (1991a) that estimates of 132I emissions from the October 16, 1959 ICPP criticality had been miscalculated (draft report, page 97; DOE, 1991a, page A-174). However, there is no further discussion within the draft report, and the values used in the spreadsheet appear to correspond to the erroneously calculated values (see below under "spreadsheets"). The DOE report (1991a) mentions that small corrections were applied to the stack monitoring data from the IET series, but again the draft report does not discuss these corrections or indicate how those monitoring data were used in their evaluation of these events. The committee is thus not in a position to evaluate any "methods for correcting the data" from stack monitoring. Do the results provide sufficient information for selection of the most significant release points and radionuclides? The draft report does not yet provide sufficient information for the selection of the most significant release points. However, it seems unlikely that any radionuclide of dosimetric importance in historical discharges was missed but some radionuclides of less import that probably should not have been included were added. The use of different levels of conservatism for episodic and continued releases leads to the elevation in the rankings of short-lived radionuclides from episodic discharges. For the episodic releases, lack of sufficient documentation of discrepancies (such as in the evaluation of IET 10) leaves the committee unable to conclude that source terms have always been accurately evaluated. Moreover, the variable conservatism between episodic releases for both the source terms and the dispersion estimates introduces sufficient uncertainty that selection according to the ordering in the draft report cannot currently be justified. Accordingly, the committee believes that episodic releases and routine releases should be separated and the rankings reported separately because the ranking methods used are not equally applicable to the two cases. Additional Comments There is a great deal of public concern about issues at INEEL and about the RAC draft report. As it presently exists, the latter report responds only minimally to these citizens’ concerns, particularly those relating to dose considerations. The committee is aware that such considerations were not the main objective of the RAC report, but, given the description by RAC staff of the time and effort spent with the INEEL Health Effects Subcommittee (HES), the report should have given more attention to citizens’ concerns.

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The committee offers the following recommendations to make the report more understandable and meaningful for the public. There should be a public summary, written in easily understood, jargon-free language. It is difficult for a layperson to understand much of what is in the report. There has been considerable public concern about this report, and at least part of it should be understandable to citizens of the region. Major findings should be highlighted and explained in the public summary and in the conclusions of the report. As it stands, the report is difficult for even an educated layperson to distinguish the “wheat from the chaff” and determine what is most important. Did RAC recommend a detailed dose-reconstruction study on the basis of its findings? If a dose-reconstruction is contemplated, there will be a need to identify residential population shifts as a function of time and with respect to site locations. It will also be necessary to identify special groups brought in for short-term work on the site. The last sentence on page 136 of the report is especially weak. It needs to be strengthened to say clearly what RAC recommends—should further studies be done or not? In fact, the summary and conclusions section that starts on page 134 is far more summary than conclusions, and there are no recommendations. That is the substantial weakness of the report for the public and perhaps also for scientists and other interested persons. Public concerns about plutonium and other important issues should be addressed in the report in both the public summary and the main text. Even if there are no positive or negative findings related to these issues, that should be stated. Ignoring issues of public concern diminishes the value of the report. In both the public summary and the text of the report, two important issues should be discussed in more detail. First, the extensive use of the DOE (1991a) report as a basis for describing episodic releases should be explained clearly and justified. Given that there was public opposition to the DOE report, basing this report largely on the findings of the earlier one requires discussion - if for no other reason, to establish public credibility for the new report. Second, as recommended elsewhere in this report, there needs to be serious discussion of and reflection about the impact of the massive destruction of documents. Gathering and analyzing INEEL data were parts of task order 6, which was included in the RAC report. Avoiding discussion of the repercussions of the loss of hundreds of boxes of information means skirting an important question. There should be a section both in the public summary and in the main text that explains what happened to the boxes, what types of information the boxes were supposed to contain, how valuable such information would have been to the RAC study, and what could have changed in the RAC study’s results if the documents had been available. Clearly, the public is aware of the situation; it has been discussed by the Environment Defense Institute in its newsletters. Ignoring the issue will increase public suspicion about the credibility of this report.

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above 200 kW. It reported 2.8 Ci/MW-h, and production can be expected to be nearly proportional to total burnup. These two release rates coincide only at an average nuclear heat production of 20 MW. The draft report apparently unnecessarily overestimates 41Ar production by about 76%. It is difficult to reconcile the descriptions of core damage reported in DOE (1991a) and in the draft report. DOE (1991a) indicates only that minor fuel damage was assumed at the time and that later photographic evidence suggested a loss of 5 g of fuel and associated fission products, whereas the draft report assumes the equivalent of substantial damage to one fuel cartridge and the release of 110 g of uranium. According to DOE (1991a), the measured release rates during IET-6 were less than 3% of those during IET-3, but the draft report suggests a total release of activity of about 50% of that in IET-6. The extra information on which the draft report relies to substantiate the increased release estimates should be noted. The release of uranium given in IET-6.xls is substantially smaller than documented in the draft report or in the accompanying note in the spreadsheet (0.0027 of 37 assemblies of 1100 g would be 110 g, but the activities reported correspond to about 0.6 g). For IET-8 (pages 73-74), it should be pointed out that what was found on the filters was (presumably) radioactive isotopes of Mo and Mn. The sentence suggests that Mo and Mn are necessarily radioactive. For IET-10, the relationship of the spreadsheet pages labeled “IET-10a (total)” and “IET-10b (total)” and the corresponding RSAC-5 documentation to the discussion in the draft report is obscure and needs to be clarified. These might be the initial runs of RSAC-5 (or some of them), but the differences between them are difficult to discern. The page labeled “IET-10c (total)” seems to be what was ultimately used. The description of IET-10 on pages 74-75 is not understandable with the amount of detail given. It is not clear how the election to “assume that the total reactor power was produced by the test insert” is “conservative”. It is physically unreasonable, but the method of calculation used does not appear to make this assumption. (Similarly, it is not clear what is meant by footnote 11 on page 75, in that again the methods of calculation used in the draft report do not necessarily make this assumption.) It is not clear what is meant by the statement that using the DOE (1991a) estimated emission rates “resulted in a fission product release rate that was not conservative by comparison to release rates reported by Foster et al. (1958).” According to DOE (1991a), citing Foster et al. (1958), the values were selected “so that the total fission product release calculated using the RSAC-4 computer code equaled or slightly exceeded the total fission product release estimated for individual runs from the spot sampling data.” The discrepancy should be documented, and the source of any disagreement resolved.

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The release fractions finally used—0.075, 0.1, and 1.0 for solids, halogens, and noble gases—suggest extensive core damage. However, the extent of core damage in IET-10 is described in DOE (1991a) with the statement that “during the disassembly and inspection of the insert following IET #10, some of the fuel tubes in the tenth stage were white in appearance, indicating that the UO2 fuel had been released from the BeO ceramic matrix as a result of operations at temperatures of 3000 to 3200°F (Flagella, 1962, pp. 75-76).” That does not sound like damage equivalent to release of 7.5% of the total core solids, which is what appears to be suggested by the draft report. For IET-11, the relationship of the spreadsheet pages labeled “IET-11a (total)” and “IET-11b (total)” and the corresponding RSAC-5 documentation to the discussion in the draft report is obscure and needs to be clarified. As in the instance of IET-10, these might be the initial runs of RSAC-5 (or some of them), but the differences between them are difficult to discern. The page labeled “IET-11c (total)” seems to be what was ultimately used. The calculation of a core inventory for IET-11 and basing release estimates on it appear to be physically unreasonable. No fuel damage was noted in IET-11, and the fission-product and other emissions were apparently attributed to uranium deposited in the exhaust ducts from the previous IET-10 and still in the neutron flux of the core. The calculation of releases with the method used in the draft report might yield a reasonable estimate of emission, but it should be noted that the uranium emissions, at least, will be double-counted (with IET-10). However, because the uranium responsible for fission-product release was coated as a thin film, it might be more appropriate to model this release with a release fraction of 1 for all fission products (or perhaps 1 for all but solids and 0.5 for solids, to account for decay recoil either out of the uranium film or into it) and to adjust the burnup to match the total emission rate. For SNAPTRAN-3, the header of Table 20 has been copied so faithfully from DOE (1991a) that it also includes the superscript (a). However, in the draft report, this superscript is incorrect: the superscript (a) is used elsewhere in the table for another purpose. No 41Ar is included in the release, although it was included by DOE (1991a); the rationale for that inclusion is not clear, inasmuch as the core apparently was immersed in water to generate the transient. A more detailed explanation of the generation of the transient would greatly enhance the utility of the draft report. For SNAPTRAN-2, DOE (1991a) indicates that the core contained 4.75 kg of total uranium, and that is reflected in Table A-41, although SNAPTRAN-3 is stated to contain 4.75 kg of 235U. The draft report refers to reports 4.75 kg of 235U with 93% enrichment (and implicitly 1% 234U and 6% 238U). The core weight needs to be clarified, and the fractions of 234U and 238U explicitly documented. No 41Ar release is included for SNAPTRAN-2, although DOE (1991a) includes such a release. This test was apparently in air, so such a release is likely. Neutral to light lapse meteorologic conditions were required for this test and it is difficult to see why stability class F was used for the modeling. Was that the observed

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stability condition at the time of the test? The path of the plume was monitored by aircraft out to 30 km downwind. Did it pass over any potentially inhabited offsite area? The release in connection with the blower failure at ICPP (page 113) is included in the wrong section of the draft report. The release was included in DOE (1991a, page A-180; it is omitted from the summary Table A-19). Many of the episodic releases were included in the routine releases reported by DOE (1991a, Table A-19). It would be useful to indicate which of the episodic releases were included in the routine releases in the draft report and to state the fractional contribution of the episodic releases to the routine release estimates and screening-factor estimates. For IET-12 (pages 76-77), it is not clear what is meant by “release fractions . . . in tube 6”. Is “tube 6” equivalent to a “fuel cartridge” that is mentioned. It does not seem conservative to assume only 50% release of noble gases from a fuel cartridge when there is such heavy damage (42% of the fuel unaccounted for). For IET-14 (page 78), the object of this test is stated to be “to measure the fission product release rate”. But, these measurements appear to be disregarded later in favor of the draft report’s own estimate of release, higher by a factor of 5.7 than that reported. In other cases (such as IET-10, for which measurement of the fission-product release rate is not reported as an object of the test), it appears that there was some effort to calibrate the draft report’s estimates against measurements. The approaches appear inconsistent and would introduce arbitrary factors of conservatism in some estimates. For IET-16 (page 79-80), the selection of Cerro Grande as the “nearest offsite location in the general direction of the prevailing winds” seems disingenuous. For “general direction”, Atomic City is somewhat closer to TAN. It appears more likely that Cerro Grande was selected because DOE (1991a) indicated that it was the location with the highest dispersion coefficient. For IET-17, IET-18, IET-22, IET-24, and IET-25, the factors of conservatism between measured and estimated releases appear to be about 2, 18, 125, 181, and 8, respectively. They reinforce the appearance of arbitrary factors of conservatism. For FEBT-A (page 87), a meteorologic lapse does not correspond to “increasing temperature with increasing elevation”, and the previous sentence states that the temperature decreased with elevation (although the sentence is correct in stating that the measured values correspond to a lapse condition). For FPFRT (page 91), the disagreement in tellurium (Te) isotope inventories reported in Table 16 is curious and requires explanation. How was the “reported inventory” obtained? Did contemporary versions of programs like RSAC produce overestimates of Te? The use of the highest value in Table 16 is also curious. One or the other of the inventories should be best. Either RSAC-5 is the best tool for the job, or some factor (known to the original investigators) was not modeled by RSAC.

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More detail on the October 1959 ICPP criticality would be desirable (as is true for most of the release descriptions). The reported energy release is sufficient to vaporize about 280 kg of water; at first sight this seems unlikely for a process designed to operate in critical-safe containers. In Table 19 (page 100), the “stability parameter” needs some explanation, and the relation (if any) to the selected stability categories should be identified. For CERTs (page 105), lists of the tests with the quantities released would improve the presentation. DOE (1991a) reports that CERT No.l was released north of Atomic City, rather than at the Experimental Dairy Farm, and cites Hawley (1966) as a source. The locations of release should be confirmed. For LDTs (page 105), it would improve readers’ understanding to state that these releases were from the ICPP stack under controlled conditions. DOE (1991a) indicates that the quantities of 85Kr were unknown; is this detail provided in the cited references? For the MTR Fuel Melt Incident (page 110), was debris blocking flow in 40% of all fuel-assembly channels in the entire core, as implied here? DOE (1991) indicates two channels of one element. For ETR Fuel Melt Incident (page 110), is De Boisblanc the author of that reference? DOE (1991a) indicates that Covington was the editor. On Appendix A , the inclusion of cooling towers in the table requires explanation. Were there any releases from cooling towers? It is not clear that the list is complete; for example, the IET releases were from a stack that had an “80 ft level”, but the only stack listed for TAN is 40 ft high. Some of the entries in the table might require attention. For example, EBR-II: The circulation rate of 76,000 1/month and blowdown of 100-190 1/month, appear too low. CFSGS: At what time is/was the “monitoring pending”? Power Burst Facility: The listed cooling-tower capacity and maximal flow are not credible. ATR: The listed evaporation rate appears extremely low. ETR: The listed evaporation rate appears extremely low.

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Use of RSAC-5 RSAC-5 was used for many calculations, and this appears to be appropriate. However, the use of RSAC-5 has disadvantages for a report that has to be transparent to the public. The user manual for RSAC-5.2 is freely available at http://ar.inel.gov , and a better copy is available through the Radiation Safety Information Computational Center (RSICC) at Oak Ridge at http://www-rsicc.ornl.gov/rsic.html . The executable code is available from RSICC, apparently at RSICC’s discretion. Obtaining it requires registration, the filling in of several forms, and the prepayment of $630; this is both intrusive and prohibitive for an individual member of the public. The program has been “subjected to extensive independent verification and validation” (see http://www-rsicc.ornl.gov/codes/ccc/ccc1/ccc-125.html ) , or so states the preamble to the user manual obtained from RSICC.

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Appendix C Detailed Comments on Spreadsheets In Offsite_Air_Screening.xls, an inappropriate comment related to 99Tc appears in the 1952 column in the “All years – total” sheet. In the “Sorted all years average” sheet of Offsite_Air_Screening.xls, many (perhaps all) of the comments are in inappropriate cells (they presumably did not get sorted with the rest of the entries). The entry of 2.06E-04 for 238Pu in 1952 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with Table A-40 of DOE (1991a), which assigns that value to 239Pu. The entry of 5.45E+00 for 95Zr in 1955 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 5.45E+01 in Table A-39 of DOE (1991a). The entry of 4.02E+05 for 85mKr in 1956 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 4.02E+03 in Table A-39 of DOE (1991a). The entry of 5.09E+00 for 137Cs in 1958 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 5.09E+01 in Table A-39 of DOE (1991a). For 132I, the entry for 1959 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls is 1.19E+04. An accompanying note states that “an annual total of 1330 Ci of !-132 (sic) was reported in HDE (DOE 1991a). Data from daily and monthly reports give total from ICPP alone of about 11,000 Ci for October 1959 due to a criticality on October 16, 1959. Although this criticality event was treated as an episodic release, too, we assumed that all releases in our assessment were routine for a conservative screening approach.” In fact, DOE (1991a) has an entry of 1.55E+03 Ci, not 1.33E+03, for routine releases (Table A-39 on page A-194). Furthermore, the explanation given in the note is not believable, given that the total inventory of 132I calculated for this criticality according to RSAC-5 at 30-min decay is 9.17 Ci (ICCP_1959_Criticality.xls). DOE (1991a) estimated a release of 11.8 Ci at 0.52-h decay for this criticality (DOE, 1991a, Table A-41 on page A-199 and page A-174) on the basis of a release fraction the same as for 131I, which had a measured release of 3.73 Ci. The committee does not have the RSAC-4-calculated inventory of 131I used by DOE (1991a) to estimate a release fraction, but RSAC-5 apparently produced an inventory of about 4 Ci. As noted in the draft report, DOE (1991a) determined that the initial reports of release of 132I to the environment were in error, and the draft report apparently agrees with that judgment (page 97). However, the

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source of the 1000-fold discrepancy introduced by the note in the spreadsheets requires further elucidation. The entry of 3.06E+00 for 137Cs in 1963 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 3.06E+01 in Table A-38 of DOE (1991a). The entry of 3.41E+00 for 91mY in 1964 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 3.73E+00 in Table A-38 of DOE (1991a). Indeed, the entries for 91mY for the years 1964-1967 all differ from those in DOE (1991a), although they are identical with the entries in DOE (1991a) for 1965-1968. The entries of 5.67E+00 for 136Cs, 6.68E+02 for 137Cs, and 0 for 138Cs in 1968 in the “all-years” sheets of Onsite_Air_Screening.xls and Offsite_Air_Screening.xls do not agree with the values of 0 for 136Cs, 5.67E+00 for 137Cs, and 6.68E+02 for 138Cs 3.06E+01 in Table A-38 of DOE (1991a). These values were propagated to the individual year (1968) in Onsite_Air_Screening.xls, but in Offsite_Air_Screening the values for the individual year agree with DOE (1991a), not with the entries in the “all-years” sheets. The entry of 2.17E-01 for 140Ba in 1968 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of 2.17E-02 in Table A-38 of DOE (1991a). The entry of 6.0E+02 for 133I in 1969 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of zero in Table A-37 of DOE (1991a). Similarly, the entry of zero for 133Xe in 1969 does not agree with the value of 6.0E+02 in DOE (1991a). The entry of 6.23E-03 for 239Pu in 1969 in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls does not agree with the value of zero in Table A-37 of DOE (1991a). It appears to have been transposed from the value for 238Pu, which has the value 6.2E-03 in DOE (1991a) but zero in Onsite_Air_Screening.xls and Offsite_Air_Screening.xls.

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Appendix D INEEL Press Release INEEL Press release at http://www.inel.gov/whats_new/press_releases/1995/hre2.html (at 3/17/2001). FOR IMMEDIATE RELEASE July 31, 1995 RADIATION EXPERIMENT RECORDS MADE AVAILABLE TO THE PUBLIC Historical records found at the Idaho National Engineering Laboratory concerning past radiation experiments are available in the Department of Energy public reading room at University Place, 1776 Science Center Drive in Idaho Falls. The records were found by a special team formed at the INEEL in early 1994 to conduct a thorough and comprehensive search of documents dating to the site’s birth in 1949. The team was formed to support Secretary of Energy Hazel O’Leary’s Openness Initiative, which requires disclosure of all past radiation experiments involving humans at DOE sites, and an Advisory Committee on Human Radiation Experiments established by President Clinton. A summary report, Human Radiation Experiments: The DOE Roadmap to the Story and the Records, was released in February and also is available in the public reading room. This report describes human radiation experiments involving the release of radiation to the environment and records identified by DOE sites throughout the country, including the INEEL. Last year, the team identified five actual or planned human radiation experiments which occurred at the INEEL. They were announced in news releases on Sept. 23, 1994, April 11, 1994 and June 27, 1994. Another study was identified earlier this year involving intentional releases of iodine-129 into the environment. This experiment is being referred to as the Iodine-129 Technology Studies. The experiment involved no intentional exposure of humans to radiation and was not classified. The experiment took place in August, 1964. The Iodine-129 Technology Studies was conducted to examine the atmospheric mixing and dilution of gases and particles containing small amounts of iodine-129. There were a total of five tests: two with particles, one with gases, and two more with particles and gases combined. The first three tests were sampled to distances of about 10 miles over a densely instrumented grid located in the center of the INEEL site. The last two tests were sampled at distances of 25 to 35 miles in off-site area to the north-east of the point of release by use of an environment monitoring network. Less than 1 millicuries of iodine129 were released during the experiment. Although a formal dose calculation has not

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been found, the amount of radioactivity involved was small when compared to current routine operational releases from INEEL facilities. For comparison, 98 millicuries of iodine-129 were released from INEEL facilities in 1993 that produced a hypothetical maximum exposure of an off-site individual to 0.3 percent of the current radiation protection standard established by the Environmental Protection Agency. The studies were a collaborative effort of the U.S. Weather Bureau Research Station at the National Reactor Testing Station and the Nuclear Science and Engineering Corporation of Pittsburgh, Penn. -- INEL -- Media contact: Isabel Valle (208) 526-9906 95-27

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Appendix E Editorial comments Page vii, regarding pages 125, 128, 129, 133, 134, 135, and 140: The correct numbers are 124, 127, 128, 132, 133, 134, and 139, respectively. Page ix: Figure 21 is omitted from the list of figures. Page x, regarding pages 124, 127, 128, 130, 132, 133, 138, and 139: The correct numbers are 123, 126, 127, 129, 131, 132, 137, and 138, respectively. Page 6, first paragraph, line 2: Change the first “was” to “were”. End of page 8 and beginning of page 9: "an ddicharged" should be "and discharged”. Page 9, line 1: “maintined” should be “maintained”. Page 9, line 1: "radation" should be "radiation". Page 9, line 9: "monitorinf" should be "monitoring". Page 12, third paragraph, line 5: “leel” should be “level”. Page 23, last paragraph, line 5: “mullicuries’ should be “millicuries”. Page 25, fifth paragraph, line 6: Change “was” to “were”. Page 29, last paragraph, lines 2-3: Size of the RWMC increased from 13 acres in 1952 to 88 acres in 1988 and 144 acres by 1970? Something wrong? Page 30, line 7: "50-300 feet wide, 250-100 feet long" should be "100-250 feet long or 50-100 feet long"? Page 31, line 2: "as the site" should be "at the site". Page 38, last paragraph, lines 1-2: "releases of 13N twice that reported" Should be "releases of 13N as twice that reported". Page 49, second paragraph: Remove closing parenthesis after “60Co”. Page 49, line 4 from the bottom: “under which they lie” is awkward. Page 56, first paragraph, line 1: “following is some information ..” is awkward. Page 64, line 1: “equation used to address”, equations do not “address” anything!

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Page 64,second paragraph, line 1: “concnetration” should be “concentration”. Page 132, equation 15: Add "x" to the exponential term, that is. “e−µx”. Page 132, equation 17: "2" should be an exponent, that is “ln[(R2 + h2)/h2]”. Page 133, define “X”. Page 133, formula and units: The use of “hr” and “h” for “hour”. Throughout the report, replace "hr" with "h". Change “/” to “(“ in the second line of the calculation. Appendix A, Page 2: The last unit, “16 m s3 s−1”, should be “16 m s−1”.