B
1994 Letter Report on Systems Engineering



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--> B 1994 Letter Report on Systems Engineering

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--> NATIONAL RESEARCH COUNCIL COMMISSION ON GEOSCIENCES, ENVIRONMENT, AND RESOURCES 2101 Constitution Avenue Washington, D.C. 20418 BOARD ON RADIOACTIVE WASTE MANAGEMENT Office Location: Milton Harris Building (202) 334-3066 Fax: 334-3077 Room 456 2001 Wisconsin Avenue, N.W. 20007 February 3, 1994 Mr. Thomas P. Grumbly Assistant Secretary for Environmental Restoration and Waste Management U.S. Department of Energy Washington, DC 20585 Dear Mr. Grumbly: The National Research Council's Committee on Remediation of Buried and Tank Wastes (Attachment 1) has been in existence since early 1993, sponsored by the Department of Energy (DOE) Office of Environmental Remediation and Waste Management. In mid-August, you suggested to me that our Committee could assist you by evaluating the extent to which systems-analysis methods and perspectives are being used as inputs to the overall tank-remediation program at the Hanford Reservation in Washington. We have been able to respond to you relatively promptly because the issue that you raised fits very nicely into the larger charter of our Committee. We will focus our response on the key elements that should characterize any systems-analysis/systems-engineering approach to a large technical program: articulation of a mission statement, including clear operational objectives; development of an inclusive definition of the system being analyzed; definition of a comprehensive set of alternative approaches to accomplishing the mission; evaluation of the alternatives, prior to selecting the approach to be taken; iterative evaluation of program contingencies, risks, resources, and other external and internal factors; definition of the program strategy, consistent with both the technical and programmatic evaluations; definition of detailed program elements, based on the strategy; and program execution, including feedback.

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--> We have studied the Hanford tank-remediation program to ascertain the extent to which it includes the above elements. A key input to our study has been the newly re-negotiated ''Tentative Agreement on Tri-Party Agreement Negotiations" (U.S. Department of Energy, U.S. Environmental Protection Agency, and Washington State Department of Ecology, 1993), hereafter called the "Tentative TPA", which we have assumed to embody the most up-to-date features of the overall tank-remediation program. (References cited in this letter are listed in Attachment 2.) Another important input has been a letter report (Attachment 3) written by a predecessor to this Committee, the Panel to Review Planned DOE Disposal of Radioactive Waste in Single-Shell Tanks at Hanford (National Research Council, 1992), commenting on a draft systems-engineering study for closure of Hanford single-shell tanks (Boomer et al, 1991—we understand that this draft was never finalized). We believe that many of the concerns expressed by that Panel have yet to be resolved, and indeed in many cases are identical to the concerns expressed herein. Although we have a number of concerns, we also see some positive signs. Our evaluation follows. Articulation of a mission statement, including clear operational objectives The mission statement for the Hanford tank-remediation program appropriately establishes that the broad end point is "to store, treat, and immobilize highly radioactive Hanford waste in an environmentally sound, safe, and cost-effective manner" (U.S. Department of Energy Richland Field Office, 1993). However, to be effective, the mission statement must be translated into clear operational objectives, which seems not to have been done in this case. We observe that the specific program end points (such as specific objectives for public health, worker safety, environmental quality, and interim and ultimate land uses) are not fully defined. In part, they currently await input on future land uses, on how clean will be acceptable as clean enough, and on which desired end-point parameters are most important. Partly, the problem is a lack of comprehensive risk assessments to help guide the program; without them it is difficult to articulate the overall operational objectives clearly, and without well-defined end points, systems analysis becomes ineffectual. The inability to define the specific mission end-point objectives severely handicaps the development of the program strategy and program elements. Given that the end points have changed more than once in the past few years (and are likely to change again, if history is any guide), every aspect of the tank-remediation program is correspondingly affected. The Committee believes that the DOE program strategy should anticipate further instability along these lines and should use systems-analysis/systems-engineering principles to build in resilience and redundancy (see below). Development of an inclusive definition of the system being analyzed The Committee believes that the operational definition of the overall tank-remediation system is seriously deficient. Specifically, the current Hanford tank-remediation system, as embodied in the actions and milestones in the Tentative TPA, concentrates mainly on wastes currently in the tanks. Only limited consideration is given to the leaked wastes and past-practice units, the physical tanks themselves (as distinct

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--> from their contents), and the ultimate fate of the products of the various remediation processes, including any repository to which the waste components are destined. The Committee believes that unless systematic consideration is given to the entire tank-remediation program from now to the completion of all remediation, the analysis of broad program options will inevitably be inadequate, leading to distorted or perhaps erroneous input to decision-makers. For example, the technical approach to remediating the problem of the wastes that have leaked from some of the tanks should be developed together with the technical approach to remediating the tank contents and the tanks themselves. These are linked issues, not separate ones, and the best overall solution may not be "best" for any one of the elements taken singly. One step in the right direction is the "Site-Wide Systems Analysis" described in the Tentative TPA as the basis for determining the requirements for a new "Multi-Function Storage Complex." We will be very interested in following the progress of this initiative. More such broad systems studies are needed. Definition of a comprehensive set of alternative approaches to accomplishing the mission Although the Committee believes that some important technical options have been foreclosed prematurely (see below), we know that DOE has long been aware of a large number of alternative approaches to accomplishing the tank-remediation objectives. In this sense, this third element of systems-analysis/systems-engineering may have been satisfactorily completed. However, the recent decision process seems not to have taken adequate account of the full breadth of available options (see below). Evaluation of the alternatives, prior to selecting the approach to be taken We recognize that the major programmatic choices are influenced by non-technical factors. For example, the recent glass-vs-grout decision about the waste form for the lower-activity fraction of the separated tank wastes took into account the non-technical. aspects of land use, waste volume, and retrievability. Unfortunately, we believe that key program decisions have not benefited sufficiently from analyses of the technical aspects. The Committee believes that technical evaluations have sometimes inadequately explored the possibility that a selected option might not perform as expected. For example, the programmatic uncertainties associated with the new vitrification schedule recently committed to in the Tentative TPA seem not to have been fully understood by—or explained to—the decision-makers. Issues such as possible technical infeasibility, higher costs, schedule delays, and occupational exposures greater than anticipated seem not to have been fully analyzed. In the absence of thorough analyses of these types of technical uncertainties, a decision process will inevitably be handicapped. The Committee urges that major efforts be devoted immediately to exploring all of the significant technical uncertainties associated with today's mainline option and with each of the reasonable alternatives. The interactions between technical and non-technical aspects of alternatives have also not been adequately explored. One example is the key decision to designate all tank wastes as having been "actively managed" after 1980 (as defined under the Resource Conservation and Recovery Act, or RCRA), subjecting them to regulation as hazardous wastes. This decision seems to have been made with little analysis of its technical and

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--> programmatic implications or of alternative approaches available under the law. Its subsequent implementation seems not to have adequately considered the full range of risk management options available under RCRA and CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act). The Committee also believes that the program is seriously handicapped by the lack of comprehensive and credible analyses of the environmental, public-health, and occupational-safety risks associated with all of the feasible options, including the "containment-in-place" option in which the wastes would be left in place, stabilized, protected against migration, and monitored as necessary. Without such analyses, the program cannot determine how much reduction of risk (by full comparison with the "containment-in-place" option) is associated with each of the other tank-remediation alternatives. To the extent that decisions about this program lack information from such analyses, and in light of the fact that the key rationale for the whole effort seems to be the perception among some that the risks of the "containment-in-place" option are unacceptable, the Committee believes that there is inadequate support for decision-makers as they balance the pros and cons of the various options. The Committee calls attention to similar comments put forth in the 1992 report by a predecessor Panel (Attachment 3). Iterative evaluation of program contingencies, risks, resources, and other external and internal factors Any well-executed project must continually evaluate program contingencies, especially those having high probabilities. While this has been done for some of the elements of the tank-remediation program, the Committee believes that in a number of important areas the evaluations are either weak or absent. Among these are the possibility of technical incompatibilities between the high-activity glass waste form and the not-yet-designated geological repository; the possibility of a substantial mismatch between available funding and the planned program, a possibility that could be minimized with a thorough cost-benefit evaluation of alternatives; the possibility that occupational risks may turn out to be far greater than now expected, forcing the expensive, time-consuming re-engineering of one or more of the planned remediation operations; and the previously mentioned possibility that the vitrification technology for the lower-activity fraction may not work out as expected. On this last point, we believe, based on our review of vitrification technology, that there is significant uncertainty as to whether the low-level-waste vitrifier can be obtained commercially with only a small amount of shielding; whether it can operate with contact maintenance; and whether off-gas problems will not become severe as radiation levels rise. Extensive development and demonstration work will likely be needed before the suitability of this technology can be confirmed, and this element of the overall Hanford remediation program seems to lack enough contingency planning to account for potential problems such as those above. The Committee is pleased that in several places the new Tentative TPA allows DOE greater flexibility to continue developing alternative processes as contingencies against the possibility that the planned mainline approaches may not work, and also to propose requisite modifications. We are concerned, however, that there seem to be no similar

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--> provisions for continued evaluation of alternatives to the planned mainline approaches embodied in the new Tentative TPA. We see no apparent evidence that serious attention is being given to technical work on some of the major alternatives—on "hedging one's bets", so to speak. Specifically, the Committee believes that the program has recently foreclosed some important technical options prematurely, by not choosing to carry along certain alternative options in parallel with the selected mainline option. In our opinion, there are several examples of premature foreclosure in the tank-remediation program; among them are the decision to abandon options that would leave much (if not almost all) of the tank wastes stabilized in place, and the recent decision to maintain the grout facility only in a standby condition and to defer further grout technology development in favor of developing a vitrification approach for the lower-activity fraction of the tank waste. In each case, the Committee recommends that DOE carefully evaluate the program uncertainties associated with foreclosing the technical alternatives prematurely, and that where appropriate DOE carry along alternatives at levels sufficient to permit their fuller development, if needed. Definition of the program strategy, consistent with both the technical and programmatic evaluations and definition of detailed program elements, based on the strategy The Committee is pleased to observe that the Tentative TPA seems to tie together the various program elements and to promote the overall program strategy in a more consistent way than had been the case previously. A key example is the new paradigm for waste characterization; we strongly endorse the idea that characterization, which is both an expensive and a pacing element, be driven by the users of the information rather than by an arbitrary schedule as in the earlier version of the Tri-Party Agreement (Washington State Department of Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy, 1992). This is an excellent example of an integrated systems approach, although it can work in practice only if all of the identified users have input to the characterization program plan. Unfortunately, the Committee does not find the same linkage in other major program elements. There is only a weak link, we believe, between the technical aspects which control what is feasible (or practical, or cost-effective, or even possible), and the programmatic aspects, which are driven by such non-technical considerations as the perceived need to get some actual remediation activities underway relatively soon, and the constraints imposed by the RCRA regulatory regime. While it is always appropriate to consider non-technical constraints on the overall strategy of a technical program, the approach that emerges should still be within the range of technical reasonableness, which includes a hedge against technical surprises. Again, what has apparently emerged as the mainline solution—what we were told is the current DOE "planning basis"—seems to our Committee to carry substantial and unnecessary technical risks, as discussed above. These create programmatic uncertainties related to possible schedule delays, budget overruns, potential damage to morale, and loss of public support.

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--> The Committee applauds the way in which the public participation process has been structured and implemented at Hanford. It can serve as a model for other DOE sites. We also applaud the efforts to establish effective communication channels, at several levels, among the three principal parties to the Hanford TPA (DOE, U.S. Environmental Protection Agency, and Washington State Department of Ecology). The likelihood of success for the current program strategy becomes significantly higher with open public information and participation. Program execution, including feedback Given the time available, the Committee did not make a thorough assessment of issues related to program execution. However, we have comments on one particular issue related to the indicated delegation of increased authority to the field offices for the execution of DOE remediation programs. While there are potential benefits to be realized by such delegation, we remain concerned about maintaining at a Department-wide level the overall definition of program missions, goals, budgets, and objectives, particularly as regards overall integration across the DOE complex. Implementing these top-level systems elements will require understanding of and adherence to national program goals by the field offices. In conclusion, the Committee finds that several elements of the current approach use systems-analysis/systems-engineering methods and perspectives appropriately, and recent changes and trends indicate that these would be more fully used in the future. However, in several areas, including the most strategic aspects of the program, there are shortcomings described herein that we believe merit your attention. The Committee hopes that its views on the systems approach with respect to the Hanford tank program are useful. We believe that although many program aspects are proceeding effectively, several key system elements need improvement. If you would like clarification or expansion on any aspect of our review, the Committee would welcome the opportunity to discuss it with you. Sincerely yours, Robert J. Budnitz, Chairman Committee on Remediation of Buried and Tank Wastes attachments (3)

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--> COMMITTEE ON REMEDIATION OF BURIED AND TANK WASTES Robert J. Budnitz, Chairman, Future Resources Associates Thomas A. Burke, The Johns Hopkins University School of Hygiene and Public Health Robert J. Catlin, University of Texas Health Sciences Center at Houston James H. Clarke, Eckenfelder, Inc. Thomas A. Cotton, J.K. Research Associates, Inc. Rodney C. Ewing, University of New Mexico Department of Earth and Planetary Science Donald R. Gibson, Jr., TRW Environmental Safety Systems James H. Johnson, Jr., Howard University Department of Civil Engineering Thomas M. Leschine, University of Washington College of Ocean and Fishery Science W. Hugh O'Riordan, Givens, Pursley, & Huntley Glenn Paulson, Illinois Institute for Technology Benjamin Ross, Disposal Safety Incorporated Paul A. Witherspoon, University of California Department of Material Sciences and Mineral Engineering at Berkeley Raymond G. Wymer, Oak Ridge National Laboratory (retired) Staff Robert Andrews, Senior Staff Officer Terri Jackson, Project Assistant Attachment 1

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--> References Cited Boomer, K.D., S.K. Baker, A.L. Boldt, M.D. Britton, L.E. Engelsman, J.D. Galbraith, J.S. Garfield, K.A. Giese, C.E. Golberg, B.A. Higley, K.J. Hull, L.J. Johnson, R.P. Knight, J.S. Layman, R.S. Marusich, R.J. Parazin, M.G. Piepho, E.J. Slaathaug, T.L. Waldo, and C.E. Worcester. 1992. Systems Engineering Study for the Closure of Single-Shell Tanks, Volume 1-6, Draft A. Westinghouse Hanford Co. Report WHC-EP-0405 - Draft A, Richland, WA. National Research Council. 1992. Comments on Draft Systems Engineering Study for Closure of Hanford Single-Shell Tanks. Panel to Review Planned DOE Disposal of Radioactive Waste in Single-Shell Tanks at Hanford, National Academy of Sciences, Washington, DC. U.S. Department of Energy Richland Field Office. 1993. Tank Waste Remediation System Functions and Requirements. Report DOE/RL-92-60, Richland, WA. U.S. Department of Energy, U.S. Environmental Protection Agency, and Washington State Department of Ecology. 1993. Tentative Agreement on Tri-Party Agreement Negotiations. Richland and Olympia, WA. Washington State Department of Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy. 1992. Hanford Federal Facility Agreement and Consent Order, Volume 1 of 2-First Amendment, August 1990, and Volume 2 of 2-Calendar Year 1992 Annual Update. Document Number 89-10 Rev. 1. Richland and Olympia, WA. Attachment 2

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--> Comments on Draft Systems Engineering Study for Closure of Hanford Single-Shell Tanks Panel to Review Planned DOE Disposal of Radioactive Waste in Single-Shell Tanks at Hanford Board on Radioactive Waste Management National Research Council National Academy of Sciences Washington, DC 28 February 1992 Attachment 3

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--> NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the panel responsible for the report were chosen for their special competences and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Frank Press is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding members, sharing with the National Academy of Sciences the responsibility for advising the federal government. That National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of the appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Frank Press and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council. Support for this project was provided under funds for the Board on Radioactive Waste Management through the U.S. Department of Energy under Contract No. DE-AC01-86DP48039 and DE-AC01-89DP48070. Copies of this report are available from: Board on Radioactive Waste Management National Research Council 2101 Constitution Avenue, N.W. Washington, DC 20418

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--> PANEL TO REVIEW PLANNED DOE DISPOSAL OF RADIOACTIVE WASTE IN SINGLE-SHELL TANKS AT HANFORD Bernd Kahn, Chairman, Georgia Institute of Technology John O. Blomeke, Oak Ridge National Laboratory (retired) Robert J. Catlin, University of Texas Health Sciences Center at Houston James O. Duguid, INTERA Inc. John M. Matuszek, Jr., New York State Department of Health Raymond E. Mesloh, Battelle Memorial Institute Curtis C. Travis, Oak Ridge National Laboratory George Camougis, Consultant, American Reclamation Corporation Staff Robert S. Andrews, Senior Staff Officer Shelly A. Myers, Panel Secretary

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--> Comments on Draft Systems Engineering Study for Closure of Hanford Single-Shell Tanks Panel to Review Planned DOE Disposal of Radioactive Waste in Single-Shell Tanks at Hanford The National Research Council's Panel to Review Planned Department of Energy (DOE) Disposal of Radioactive Waste in Single-Shell Tanks at Hanford (hereafter called the ''Panel'') reviewed a six-volume, yet to be completed draft report by a DOE contractor, Westinghouse Hanford Company, Richland, WA, entitled Systems Engineering Study for the Closure of Single-Shell Tanks (Boomer et al., 1991). Volumes I and 2 constitute the text of the draft Study report, supported by extensive background engineering information in appendices found in the remaining volumes. The following comments provide a preliminary and partial response to a request from R.P. Whitfield, Office of Environmental Restoration, DOE, to provide a review of the initial results of the Systems Engineering Study. The draft Study report provided to the Panel was referred to by its authors as the "60% draft", and it has many sections that have not yet been completed. This report, however, supplemented by presentations by the authors at several Panel meetings, was found to contain adequate details and conclusions for the Panel to provide general commentary at an early enough stage in the Study to influence its course before it becomes final. Upon completion of the Study, the Panel will be prepared to conduct a more extensive review, if requested by DOE. Objectives of a Systems Engineering Study The Panel members, having strongly recommended a systems engineering approach to tank closure at previous meetings, are pleased that the Study has embodied that approach. When first notified, in 1990, of the initiation of the Study, individual members of the Panel suggested the following three objectives. First, the Study should identify reasonable alternatives for managing the waste contained in the Hanford single-shell tanks, and it should present what is known and what must be learned with regard to waste characterization, in situ stabilization, retrieval, treatment, interim storage, site remediation, ultimate disposal, and needed technology to implement these alternatives. Second, the Study should establish the framework for this effort and provide the basis for refining the identified alternatives and other possible alternatives that may be introduced, evaluating the reliability of the required technology, and improving the estimates of cost and risk. Finally, information from the Study will provide a basis for preparing the Supplemental Environmental Impact Statement (SEIS) for closure of single-shell tanks at the Hanford site, and the concepts

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--> and capabilities that are developed may be equally useful for future planning of closure of the Hanford double-shell tanks. The Draft Study Report In the draft Study report, a number of "technology options" for various stages of waste handling and treatment are combined by a number of permutations into 16 "integrated alternatives" for closure. The integrated alternatives are then evaluated with a combination of qualitative and quantitative weighted rating factors. Finally, the draft Study report contains the recommendation that a group of the four integrated alternatives having the highest evaluations, plus two baseline cases [no action or deferred action, and the 1987 Hanford Defense Waste Environmental Impact Statement reference alternative for in situ waste stabilization and disposal (U.S. Department of Energy, 1987)], be included in the SEIS for further evaluation. Findings and Recommendations After reviewing the draft Study report and discussing its highlights as presented by the Westinghouse Hanford Company staff in briefings at the Panel meetings on 25-26 September and 31 October-1 November 1991, the Panel finds that the Study is responsive to most of the objectives set forth above. The report provides a logical and straightforward approach to evaluating technical processes for closure of the Hanford single-shell tanks. Some concerns on the adequacy of identified technology options and resulting integrated alternatives, and of the weight and rating factors used to calculate evaluations are included in the seven recommendations discussed below. The Panel notes a number of specific issues of concern that it anticipates will be addressed as the present draft report is completed. The issues include; (a) adequate emphasis on weight factors related to public and occupational safety risks, especially for alternatives involving retrieval and off-site disposal, and on those factors related to environmental protection and restoration, (b) documentation on the feasibility and costs of technology options as they are developed and tested, (c) plans for presenting the results of the Study to the public for comment, (d) schedule for sampling and analyzing tank contents to characterize waste, and (e) use of absolute rather than comparative risk analysis for performance assessments. The Panel makes the following general recommendations concerning the final report of the Systems Engineering Study: (1)   Explicitly address, at the beginning of the Study report, the cleanup objectives and risk levels to be met by closure of the single-shell tanks at Hanford, and the scientific and technical criteria upon which decisions to retrieve tank waste, or leave the waste

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--> in place, will be based. In addition, state the critical assumptions underlying the rating factors, evaluations, and recommendations. Placement of this information early in the report will guide the reader through the evaluation process. (2)   Devote effort to identifying additional technology options and alternatives for the tank closure process through DOE advisory committees, conferences, public meetings, and invited innovative proposals from industry. For example, during the briefings to the Panel, individuals suggested the use of asphalt for treatment of on-site waste and of the calcining process for treatment of retrieved waste for off-site disposal, two technology options that were not addressed in the draft Study report. Additional feasible combinations of technology options should be more fully explored. Specifically include additional alternatives that combine selective retrieval and in situ treatment technology options. The Panel suggests development of a matrix of technology options that can be easily manipulated to examine the consequences of different combinations. Such a matrix may lead to identification of new, reasonable alternatives and provide a valuable tool for decision making. (3)   Identify and evaluate alternatives for individual tanks or groups of tanks having similar waste compositions. Optimum effectiveness in closure may result from use of several alternatives, no one of which is suitable for every tank. With the above mentioned matrix of technology options, decision makers can test various strategies for each tank or group of tanks. (4)   Do not reduce the number of technology options or alternatives at this early stage in the Study. It is unsuitable to foreclose any technology or alternative before the various benefits, risks, and costs have been thoroughly delineated and carefully reviewed. The Panel has not yet received sufficient evidence to convince it that the four integrated alternatives recommended in the draft Study report are preferable to others that might be considered for tank closure. The completed Study report should contain a summary in which all the integrated alternatives (or groups of alternatives) are assessed for key decision-making factors such as total deaths, total masses of waste to be managed, and total costs. (5)   Sharpen the focus for, and reevaluate the weights assigned to, evaluation categories on critical items by presenting detailed assessments concerning human health and mortality, worker risks, and environmental impacts. The weights and rating factors used as performance measures of the evaluation categories for each integrated alternative are far from definitive, and they are certainly not appropriate for use in deleting integrated alternatives at this time. The cumulation of quantitative rating factors, some based on measurable evaluation criteria and some based on qualitative judgements, is particularly disconcerting. (6)   Be cautious about placing confidence in waste handling and treatment technologies that have not been tested at the pilot-plant stage or that have not been

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--> applied previously at full scale under similar conditions. Three of the four recommended alternatives depend on in situ vitrification (ISV) for treatment of non-retrieved waste and tank farm closure; another group of three of the four recommended alternatives rely on use of transuranic solvent extraction (TRUEX) technology for partitioning of retrieved waste. The Panel believes that neither ISV nor TRUEX have achieved a level of technical development such that their performance can be evaluated with much confidence [a recent independent engineering review raises concerns about the current state of development of the TRUEX process in light of its important role in partitioning the waste stream before vitrification of the high-level components (U.S. Department of Energy, 1991)]. The Panel urges that sufficient effort be devoted to bringing promising technology options through laboratory and pilot-plant development to assure that they would be ready for plant and field application. Early closure activities in single-shell tanks containing low levels of radioactive waste may provide demonstration of such technology options for closure of the more difficult and risky tanks. (7)   Conclude the Study report by listing the information gaps and uncertainties that must be remedied, and state the actions recommended for this purpose. Address the items on this list when developing information for the subsequent Study reports. Conclusions The Panel commends DOE for initiation of the Systems Engineering Study that will become an important management tool for future planning and development. The Panel is concerned that the program for closure of the single-shell tanks at Hanford seems to be driven by schedule constraints rather than by the broad, investigative approach that is appropriate for a program expected to cost tens of billions of dollars and to be conducted over a period of about 30 years. The draft Study report presents analysis from a small group at one organization; the Study needs input and review from a much larger and disparate segment of the scientific and technical community, as well as from the lay public. The Panel understands that the Study is scheduled for completion in February 1992, to be followed by technical evaluation of the four most promising integrated alternatives, plus the two baseline alternatives, during the following 14 months. The Panel recommends that this 14 month period be spent not in focusing on a narrowed list of integrated alternatives, but in using the completed Study report as a framework for identifying other technology options and integrated alternatives, to examine more closely the information base of the efficacy of the technology options, and to improve the methods for evaluating the impacts of the various proposed systems on public health and the environment. It is important to recognize that factors in addition to those based on waste management science and technology may become important considerations for decision making by upper-level DOE managers. Developing an easily understood matrix of technology options and evaluation criteria, as recommended above, should aid in this process.

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--> The Panel wishes to emphasize that the above concerns are not intended to reflect negatively on the quality of this substantial work, but rather to affirm that this Study is in an early stage. The Panel agrees with a goal of achieving single-shell tank closure at the Hanford facility as soon as possible, but it believes that a thorough initial Study effort will justify itself not only by attaining effective closure with the needed public support, but also by avoiding subsequent delays. The Panel looks forward to continuing oversight of the Study as it evolves into a plan of action deserving broad acceptance. References Cited Boomer, K.D., S.K. Baker, A.L. Boldt, M.D. Britton, L.E. Engelsman, J.D. Galbraith, J.S. Garfield, K.A. Giese, C.E. Golberg, B.A. Higley, K.J. Hull, L.J. Johnson, R.P. Knight, J.S. Layman, R.S. Marusich, R.J. Parazin, M.G. Piepho, E.J. Slaathaug, T.L. Waldo, and C.E. Worcester. 1991. Systems Engineering Study for the Closure of Single-Shell Tanks, Volumes 1-6—Draft A. Westinghouse Hanford Co. Report WHC-EP-0405 Draft A, Richland, WA. U.S. Department of Energy. 1987. Final Environmental Impact Statement, Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes, Hanford Site, Richland, Washington. Department of Energy, Assistant Secretary for Defense Programs, Report DOE/ElS-0113 (Volumes 1-5), Washington, DC. U.S. Department of Energy. 1991. Independent Engineering Review of the Hanford Waste Vitrification System. Department of Energy, Office of Environmental Restoration and Waste Management, Report DOE/EM-0056P, Washington, DC.

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