Appendix C
Suggestions from the Committee’s Review #1 and How the FFRDC Responded
Due to the draft and incomplete nature of the Federally Funded Research and Development Center’s (FFRDC’s) working documents presented in mid-February 2018 to the committee, Review #1 did not have required recommendations for the FFRDC’s next draft report. However, Review #1 provided guidance in the form of suggestions to the FFRDC team. This appendix has the purposes of documenting those suggestions and of describing the committee’s observations (shown in italics after each suggestion) of whether and how the FFRDC has responded. The suggestions follow the structure of the tasking in Review #1; see Appendix B for that tasking.
RISK ASSESSMENT METHODOLOGIES
The committee suggests that the FFRDC specify and explain in its forthcoming report what type of probabilistic risk assessment will be used, the parts of the supplemental low-activity waste (SLAW) system to which it will be applied, and the basis for not applying it to other parts of the SLAW system, as well as the basis for selecting the risk analysis techniques applied to other parts of this system.
The committee has not observed a response to this suggestion in the draft report.
It will also be useful for the FFRDC to discuss which risks can be quantified and which can be analyzed using qualitative assessments, e.g., legal and regulatory risks.
On pages 26 and 27 of the Section on “Application of Risk Assessment Techniques,” the FFRDC has some discussion about how it has applied quantitative and qualitative assessments in its analysis and draft report.
The FFRDC has not fully described how it will carry out this [expert] elicitation. As to understanding lines of inquiry, the committee suggests that the forthcoming analytic report discuss more fully how lines of inquiry and associated criteria are determined and defined.
The draft report describes the expert elicitation in Appendix F, which along with Section 3.3.1, provides information about the lines of inquiry and associated criteria used in the elicitation.
The committee also suggests that the FFRDC consider a complete set of risks, including health risks and high-level legal issues, associated with shipping waste forms off the Hanford Site. While the committee notes that political risks will be an important consideration for the U.S. Department of Energy (DOE), the committee understands that there is little, beyond identifying such risks, that can be done within the FFRDC’s scope.
The draft report in Appendix I on “Transportation Considerations” discusses “the programs that will be needed to transport primary and secondary WFs [waste forms] from the Hanford Reservation to
the WCS [Waste Control Specialists] disposal facilities in west Texas.” Also, Appendix H on “Disposal Site Considerations” provides relevant information for both the Integrated Disposal Facility (IDF) and WCS, but the front sections of the draft report concerning “Summary of Disposal Site Considerations” and “Summary of Transportation Considerations” are “TBD.”
COST ESTIMATION
The cost estimation figures based on System Plan 8 are not detailed or precise enough for decision-making. The committee suggests that the FFRDC team in its forthcoming analysis discuss how order of magnitude (which is significantly uncertain) cost estimates could be useful to decision-makers.
The draft report does not discuss “how order of magnitude (which is significantly uncertain) cost estimates could be useful to decision-makers.”
The committee also suggests that the team consider use of DOE’s “Cost Estimating Guide” because it provides guidance on methods and procedures that are to be used in programs at DOE for preparing cost estimates.
Based on the references and text of the draft report, it does not appear that the FFRDC used DOE’s “Cost Estimating Guide.” Appendix G mentions use of “the criteria found in the Association for the Advancement of Cost Engineering, International (AACEI), recommended practices.”
SCHEDULE ASSESSMENTS
Given the importance of schedule as a reason for commissioning the FFRDC study and the increasing danger of tank leakage over time, schedule risk must be a central consideration.… The committee suggests that the FFRDC’s forthcoming analysis examine the important interrelationships among technical and schedule risks as well as safety and costs.
Page 26 of the draft report states that: “The effect [of project risks] is frequently on project costs and schedule. Identifying risks and their potential impact, as well as risk mitigation approaches is important to project planning and execution.” While the draft report has little discussion on these project risks, it does include project risks as part of the criteria in the FFRDC’s data tables for the analytic hierarchy process used in the expert elicitation as included in Appendix F.
In particular, a better understanding of scheduling risks could include considering an incremental approach that would have the SLAW treatment choice be made after the Waste Treatment and Immobilization Plant (WTP) is operational, keeping in mind the WTP’s start date, in order to take advantage of the additional knowledge gained from experience with the actual operation of the waste transport, pre-treatment, and treatment technologies and facilities.
On page 134, the draft report notes that: “Project schedule assumes results of the Analysis of Alternatives (AoA) and a Project Requirements Document (PRD) will be completed in a timely fashion to support completion of technology development, design, construction and startup activities to support a startup of SLAW to support WTP operations schedule.” The committee has not seen in the draft report an explicit discussion of having the SLAW choice be made after the WTP is operational. The committee notes that on page 17, it is mentioned that: “In addition to the potential differences in the feed vector, evaluations are in progress that could change the way Hanford tank waste is processed. Rather than list each of the possible changes, it should be assumed that many aspects of tank waste retrieval and immobilization could change from the current assumptions. These changes have the
potential to minimize the need for a single Supplemental LAW facility tied directly to the WTP facility as assumed in this evaluation and could potentially include smaller, modular systems designed to treat the waste at the individual tank farms or even individual tanks within a farm.”
It is also worth considering performance of a sensitivity analysis of the likely downtimes or failures of essential equipment as well as of the potential for using modular equipment that could be switched out in the event of equipment breakdowns. The sensitivity analysis would include assessment of the optimistic assumption of 70 percent availability for the feed material into the SLAW facility.
As Appendix F shows, the FFRDC performed a sensitivity analysis that was a variance of the weightings of the criteria used in the expert elicitation. As to consideration of equipment breakdowns, page 27 of the draft report notes that the technology readiness level (TRL) and complexity line of inquiry (LOI) include the challenges of major equipment replacement. Appendix F includes these LOIs in the expert elicitation results. On page 17, the draft report mentions: “It was assumed that the throughput through the current WTP LAW is not likely to change dramatically as the models used in the Integrated Flowsheet contain most of the expected improvement in waste loading. The model assumes 70% attainment and operation at nameplate capacity; two conditions that the WTP LAW facility is not likely to exceed. Thus, the throughput through the WTP LAW facility should not be expected to be higher than assumed in the flowsheet and that the amount of feed to Supplemental LAW will not decrease if the LAW mission schedule is not changed.” While the FFRDC has not apparently done a sensitivity analysis of the 70 percent availability assumption, it recognizes that this is an optimistic assumption.
While schedules can be accelerated or delayed depending on the budgetary assumptions and actual receipt of funds to manage a project, the FFRDC team should consider whether it would be helpful to acknowledge the existence of such risks and their impacts on its analysis so that DOE can take them into account in its decision-making.
Page 18 of the draft report states that: “The funding assumptions in the System Plan assume that funding is increased (unconstrained) whenever needed to perform capital projects to construct or upgrade facilities while operating existing facilities. The annual funding needed to support this assumption represents funding increases that could be double or triple the current annual expenditures. If the funding profile remains flat, then the required facilities to perform System Plan 8 will not be available when required. Thus, the mission need for Supplemental LAW could change depending on the actual funding levels provided.”
REGULATORY COMPLIANCE ASSESSMENT
The committee suggests that the FFRDC’s analysis discuss what would be required for the non-vitrified waste forms being assessed to be considered “as good as glass” in the context of the current state of technology for waste forms other than glass from a technical and human health risk perspective.
The committee does not observe this analysis in the draft report.
The committee also suggests that the FFRDC’s analysis discuss how consideration of pre-treatment processing alternatives to remove radionuclides such as technetium-99 and iodine-129 could expand on-site and off-site disposal options, taking into account compliance with applicable laws and regulations, and the extent to which various treatment (immobilization) options affect the need for pre-treatment to remove key radionuclides.
Appendix A of the draft report has an expanded discussion on pre-treatment and shows results of calculations of how strontium removal would affect the waste classification for the three waste forms, which is potentially relevant to disposal at WCS. Appendix A on page 34 also provides information on the removal levels in percentages required for technetium and iodine to meet the U.S. Environmental Protection Agency groundwater protection requirements for the IDF based on the PA that has not yet been released.
The committee suggests that the FFRDC’s analysis discuss differences in requirements concerning time-of-compliance, and the impacts of various assumptions on lines of inquiry such as cost, schedule, and risk.
Appendix J on “Regulatory Compliance” provides much useful information relevant for time-of-compliance but does not give a discussion of “the impacts of various assumptions on lines of inquiry such as cost, schedule, and risk.”
Finally, the committee suggests that the FFRDC’s analysis define the flowsheets that would be compared from the waste receipt tank showing the steps of blending, conditioning, treatment, transportation, and disposal. Also, the committee would like to know the material balances for the key radionuclides in each flowsheet.
Appendixes B, C, and D for the three primary treatment alternatives provide information about the flowsheets developed and considered by the FFRDC. But the data in these appendixes do not fully address the committee’s suggestions such as a comparison from the waste receipt tank showing the steps of blending, conditioning, treatment, transportation, and disposal and the listing of the material balances for the key radionuclides.
WASTE CONDITIONING AND SUPPLEMENTAL TREATMENT APPROACHES
Regarding each of the primary treatment technologies, the committee suggests that the FFRDC clarify the relationship between the low-medium-high TRL levels used in the FFRDC draft report to the traditional nine-level TRL scale and the reason the traditional scale was not used.
Of the technical appendixes on the three primary treatment alternatives, Appendix C on “Steam Reforming” provides a detailed discussion.
The committee suggests that the FFRDC include its assessment of the potential problems and technical challenges of each of these treatment technologies as well as the potential barriers to acceptance of any of these technologies and the resulting waste forms for disposal sites under consideration.
There is some consideration of potential barriers to acceptance, but as discussed in the main text of this review, the committee suggests that the FFRDC perform additional analysis.
Because it was not clear to the committee whether the FFRDC considers these technologies to be major alternatives to the three major SLAW options, or variations within one or more of these three, the committee suggests that the FFRDC clarify whether there are other major alternatives or a variation of or supplement to one of the major three baseline SLAW approaches.
The FFRDC has specified in the draft report which nine variations the FFRDC is considering and has some discussion as to the rationale for these choices.
The committee suggests that it would be useful for the FFRDC to identify promising upstream technologies or processes and use them to perform a sensitivity analysis on their effect on treatment flowsheets.
The draft report does not show that the FFRDC has identified promising upstream technologies or processes and done a sensitivity analysis on their effect on treatment flowsheets.
Consideration can be given to removal of radionuclides of concern, such as technetium-99, iodine-129, and strontium-90, as well as methods of blending tank wastes. The analysis would benefit by having clear explanations of the reasons for such pre-treatment, for example, to remove certain radionuclides and other hazardous chemicals to meet waste acceptance criteria at certain disposal sites or to produce a releasable effluent.
The FFRDC has considered a number of these relevant issues concerning pre-treatment in Appendix A.
The committee also suggests that the team could usefully consider, at least briefly, whether certain combinations of immobilization technologies could confer particular advantages.
The committee does not observe such a consideration in the draft report.
KEY INFORMATION AND DATA SOURCES BEING USED
The committee suggests that the FFRDC explicitly identify, discuss, and document the underlying assumptions in the One System Integrated Flowsheet and System Plan 8 that could impact its analysis.
Page 18 of the draft report has a discussion of several “programmatic challenges with using System Plan 8.” Pages 18 and 19 also have a discussion of other relevant “technical challenges.”
The committee also suggests that the team, if it has not done so, obtain and analyze credible existing studies and data on long-term waste form performance to inform analysis of the “as good as glass” issue.
As mentioned earlier, the draft report does not provide an analysis of the “as good as glass” issue.
GENERAL COMMENTS
The committee suggests that the FFRDC’s forthcoming analytic report include:
- An accessible organizational structure of the analytic approach that presents clear choices and their consequences to decision-makers, with the recognition that the FFRDC will not select a preferred supplemental treatment option.
As discussed earlier in this review, the FFRDC needs to provide an accessible structure for a comparative analysis in its final report.
- A complete and consistent set of supplemental treatment alternatives specifying clearly whether just the major three supplemental treatment approaches are being assessed or whether there are any variations on these three to consider, including the processing, transportation, and disposal options in each alternative. Likewise, the committee suggests that the FFRDC consider identifying and describing opportunities to improve the performance, cost, and rate of implementation of the alternatives through pre-treatment to disposal, even if some are strictly outside the scope of the SLAW facility.
As mentioned earlier, the FFRDC has done this work as shown in the draft report.
- Lines of inquiry to include, among other issues:
- Safety (including nuclear safety, chemical safety, and physical safety of workers and the public)
- Technical readiness of each option
- Waste form performance for each option
- Secondary wastes and effluents produced for each option
- Cost of each option
- Schedule of each option
- Overall regulatory compliance
Appendix F provides relevant information on lines of inquiry.
- A characterization of uncertainties for each line of inquiry.
See the committee’s assessment in Chapter 5 of this review.
- The use of appropriate assessment methodologies implemented using best practices for the comparisons within the lines of inquiry.
See the committee’s assessment in Chapter 5 of this review.
