SUMMARY

At the request of the U.S. Department of Energy (DOE), the National Research Council formed a committee in 1999 to provide an independent technical review of alternatives selected by the Savannah River Site (SRS) for processing the high-level radioactive waste (HLW) salt solutions stored there. The final report of that committee, Alternatives for High-Level Waste Salt Processing at the Savannah River Site, was issued in August 2000. DOE subsequently asked the National Research Council to provide an assessment of DOE's efforts to select a processing alternative for removal of cesium, strontium, and actinides from high level waste at the Savannah River Site. A new committee was appointed, and it addresses in this interim report the first part of its statement of task—“evaluate the adequacy of the criteria that will be used by DOE to select from among the candidate processes under consideration.”

DOE identified eleven criteria to be used in evaluating three alternatives for processing the HLW in the SRS tanks. Based on information presented by representatives from the SRS, the committee concludes that the eleven criteria are reasonable and appropriate and were developed in a transparent way. However, as described in the body of the report, some of the criteria do not appear to be independent of others, and some criteria appear unlikely to discriminate among the process alternatives.

The methodology for using the evaluation criteria is still evolving, and revisions in the weighting factors may be necessary in consideration of the points raised in the body of this report. Preliminary application of the criteria in three different scoring exercises by DOE has shown little discrimination among the three processes. The committee recommends that the criteria should not be implemented in a way that relies on a single numerical “total score.” Rather than averaging and totaling the scores for each criterion, the various criteria should be seen as relevant to different goals and purposes and should be considered individually. Some of the criteria should be used as “go/no go” gates and some should have thresholds for use that demonstrate a given level of difference between the three processes. Also, the committee recommends that DOE should define what are significant differences in the scoring procedure. The committee finds it difficult to see a path forward for this procedure (e.g., adjustment of weighting factors) without these differences being specified. The objective of the evaluation procedure should be to provide adequate information for making a risk-informed decision evaluating the science, technology, operational aspects, time factors, and costs, as well as policy matters not addressed in this evaluation.

Despite limitations in discriminating among the alternatives, the committee recognizes that research and development currently being conducted for the several alternative processes may result in changes in the scores on the eleven criteria. Additionally, the committee finds that the current scoring system for individual criteria can be useful for identifying and following the progress of the research and development program prior to downselection (i.e., a reduction in the number of process alternatives), thereby assisting in determination of where significant further effort is needed for each process.

INTRODUCTION

The National Research Council (NRC) formed a committee, at the request of the U.S. Department of Energy (DOE), to provide an independent technical review of alternatives



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EVALUATION OF CRITERIA FOR SELECTING A SALT PROCESSING ALTERNATIVE FOR HIGH-LEVEL WASTE AT THE SAVANNAH RIVER SITE: INTERIM REPORT SUMMARY At the request of the U.S. Department of Energy (DOE), the National Research Council formed a committee in 1999 to provide an independent technical review of alternatives selected by the Savannah River Site (SRS) for processing the high-level radioactive waste (HLW) salt solutions stored there. The final report of that committee, Alternatives for High-Level Waste Salt Processing at the Savannah River Site, was issued in August 2000. DOE subsequently asked the National Research Council to provide an assessment of DOE's efforts to select a processing alternative for removal of cesium, strontium, and actinides from high level waste at the Savannah River Site. A new committee was appointed, and it addresses in this interim report the first part of its statement of task—“evaluate the adequacy of the criteria that will be used by DOE to select from among the candidate processes under consideration.” DOE identified eleven criteria to be used in evaluating three alternatives for processing the HLW in the SRS tanks. Based on information presented by representatives from the SRS, the committee concludes that the eleven criteria are reasonable and appropriate and were developed in a transparent way. However, as described in the body of the report, some of the criteria do not appear to be independent of others, and some criteria appear unlikely to discriminate among the process alternatives. The methodology for using the evaluation criteria is still evolving, and revisions in the weighting factors may be necessary in consideration of the points raised in the body of this report. Preliminary application of the criteria in three different scoring exercises by DOE has shown little discrimination among the three processes. The committee recommends that the criteria should not be implemented in a way that relies on a single numerical “total score.” Rather than averaging and totaling the scores for each criterion, the various criteria should be seen as relevant to different goals and purposes and should be considered individually. Some of the criteria should be used as “go/no go” gates and some should have thresholds for use that demonstrate a given level of difference between the three processes. Also, the committee recommends that DOE should define what are significant differences in the scoring procedure. The committee finds it difficult to see a path forward for this procedure (e.g., adjustment of weighting factors) without these differences being specified. The objective of the evaluation procedure should be to provide adequate information for making a risk-informed decision evaluating the science, technology, operational aspects, time factors, and costs, as well as policy matters not addressed in this evaluation. Despite limitations in discriminating among the alternatives, the committee recognizes that research and development currently being conducted for the several alternative processes may result in changes in the scores on the eleven criteria. Additionally, the committee finds that the current scoring system for individual criteria can be useful for identifying and following the progress of the research and development program prior to downselection (i.e., a reduction in the number of process alternatives), thereby assisting in determination of where significant further effort is needed for each process. INTRODUCTION The National Research Council (NRC) formed a committee, at the request of the U.S. Department of Energy (DOE), to provide an independent technical review of alternatives