8
Responses to Questions in Statement of Task

The statement of task for this study (Appendix B) directed the committee to address eight technical questions concerning the screening process used by the Siting Commission to identify potential sites for a low-level radioactive waste (LLRW) disposal facility. These questions deal with a wide range of issues, including the design and application of technical screening criteria and the adequacy of information used by the Siting Commission to make screening decisions.

The committee did not address these questions explicitly in previous chapters of this report mainly because the questions do not match neatly with the various steps of the screening process. Indeed, the questions are quite variable in technical scope, ranging from queries about individual screening criteria to questions about the entire screening process. The committee found it difficult to answer these questions without reviewing the entire screening process.

The committee's review of the screening process in Chapters 2 through 6 of this report is presented roughly in the chronological order in which the siting process was carried out. The purpose of the present chapter is to pull together information from this review to provide explicit responses to the eight questions in the statement of task. The committee provides brief answers to each question below, and it points out where more detailed discussions can be found elsewhere in the report.

Question 1

Are New York State (NYS) exclusionary criteria based on sound technical principles?



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 141
--> 8 Responses to Questions in Statement of Task The statement of task for this study (Appendix B) directed the committee to address eight technical questions concerning the screening process used by the Siting Commission to identify potential sites for a low-level radioactive waste (LLRW) disposal facility. These questions deal with a wide range of issues, including the design and application of technical screening criteria and the adequacy of information used by the Siting Commission to make screening decisions. The committee did not address these questions explicitly in previous chapters of this report mainly because the questions do not match neatly with the various steps of the screening process. Indeed, the questions are quite variable in technical scope, ranging from queries about individual screening criteria to questions about the entire screening process. The committee found it difficult to answer these questions without reviewing the entire screening process. The committee's review of the screening process in Chapters 2 through 6 of this report is presented roughly in the chronological order in which the siting process was carried out. The purpose of the present chapter is to pull together information from this review to provide explicit responses to the eight questions in the statement of task. The committee provides brief answers to each question below, and it points out where more detailed discussions can be found elsewhere in the report. Question 1 Are New York State (NYS) exclusionary criteria based on sound technical principles?

OCR for page 141
--> Most of the 17 exclusionary criteria developed by the Siting Commission are based on sound principles and address important technical considerations for siting an LLRW disposal facility. As noted in Chapters 5 and 6, however, the committee identified problems with the design or application of three exclusionary criteria. The committee also identified three exclusionary conditions that were not addressed by exclusionary criteria. Criterion 26—air quality nonattainment—appears to have no basis in legislation or existing regulation, and there is no reason to include it as an exclusionary condition. In the committee's judgment, it should have been designated as a preference criterion. Criterion 4—existing mine exclusion and Criterion 44—mineral soil groups—were applied inappropriately. Two preference criteria—Criterion 20 (erosion) and Criterion 3 (subsurface dissolution)—should have been applied as exclusionary criteria. Additionally, there should have been an exclusionary component to Criterion 2—seismic hazards. Question 2 Was the commission's application of exclusionary criteria to volunteered and nonvolunteered lands consistent with good scientific practice? Exclusionary criteria were applied in the following steps of the screening process: Statewide Exclusionary Screening (SES; see Chapter 4), the Exclusionary Screening and Comparative Preference Analysis steps of Candidate Area Identification (CAI, see Chapter 5), and all steps of Potential Sites Identification (PSI) screening (see Chapter 6). The committee reviewed the application of exclusionary criteria in each of these steps and concluded that screening of nonvolunteered and volunteered lands was generally based on good scientific practice with the following three possible exceptions: (1) application of the exclusionary criteria noted above in the response to Question 1; (2) application of the exclusionary criteria in the Field Surveys step of PSI

OCR for page 141
--> (Chapter 6), where not enough information was provided to the committee on how data collected during the surveys were used in site selection; and (3) application of the exclusionary criteria—particularly Criterion 44 (mineral soil groups)—to the offered sites (Chapter 6). Question 3 Were the commission decisions to exclude sites containing existing mines, which were not part of the exclusionary criteria, based on sound technical considerations? The committee believes that it was technically reasonable for the Siting Commission to exclude existing mines even though it was not required by the exclusionary criteria or Department of Environmental Conservation (DEC) regulations. As noted in Chapter 5, however, the committee believes that the Siting Commission's rationale for excluding existing mines based on geologic complexity was inappropriate because geologic complexity could not be evaluated properly using the data available to the Siting Commission at the time this criterion was applied. The committee believes that existing mines should have been excluded for a variety of reasons related to their design and suitability for an LLRW disposal facility rather than for geologic complexity. Question 4 Was the process to select LLRW disposal sites, established by the commission, consistent with good scientific practice? The process established by the Siting Commission to select LLRW disposal sites, which is outlined in the Siting Plan, was problematical for several reasons. The committee believes that the Siting Commission's use of cutoff scores for preference criteria screening is not justified, because sensitivity analyses (Chapters 5 and 6) suggest a weak

OCR for page 141
--> correlation between the numerical score and likely site performance. Indeed, the committee's sensitivity analyses suggest that site selection depends to a great extent on the sequence of screening steps and the combination of criteria applied at each step, rather than the likely performance of a site as an LLRW disposal facility. Additionally, some of the criteria used in screening were not useful for discriminating the desired performance characteristics of sites or were combined with other criteria in inappropriate ways. For example, performance and socioeconomic criteria were combined during CAI and PSI screening. Consequently, a site could receive less than favorable scores on performance criteria and still be selected if it scored highly on socioeconomic criteria. Moreover, many of the performance-related preference criteria were scored using "uncertain" data, that is, data of unknown or uneven accuracy and completeness across the state. The committee concluded that there was insufficient analysis by the Siting Commission to determine the sensitivity of the scoring system to coupling effects among screening criteria or to small changes in scaling and weighting factors. The committee presents examples of such analyses in Chapters 5 and 6. Question 5 Were the decisions made by the commission in selecting or narrowing the range of sites for LLRW disposal based on sound technical considerations? Question 4 addresses the soundness of the screening process used by the Siting Commission to select a site for an LLRW disposal facility. The committee interprets the present question in terms of the manner in which the screening process was applied by the Siting Commission, and particularly the technical soundness of the decisions made by the commission during the various steps of the screening process. In the committee's judgment, Siting Commission decisions during SES were sound. The exclusionary criteria applied during this step of the screening process were applied appropriately, and the criteria used were based on sound regulatory considerations.

OCR for page 141
--> The committee identified several technical problems with Siting Commission decisions during the CAI stage of screening, as described in Chapter 5 of this report. These include the following: The use of a cutoff score for Initial Preference Screening is not justified because there is not a good correlation between a numerical score and the likely performance of a site as an LLRW disposal facility. The results of screening are nonunique in that the candidate areas selected depend to a great extent on the sequence of screening steps and the combination of criteria applied at each step, rather than the likely performance of an area. The sensitivity analysis performed by the Siting Commission was incomplete, poorly documented, and applied to only a small area of the state. The committee also identified several technical problems with Siting Commission decisions during the PSI stage of the screening process, as noted in Chapter 6 of this report. These included the following: The use of a cutoff score in the Geographic Information System (GIS) Screening was not justified because there was not a good correlation between the score and the likely performance of a site. The Qualitative Map Assessment step was not discussed in the Siting Plan but was added later to the process. The primary problem with this step is that preference criteria were applied as exclusionary conditions. The selection of the five final potential sites was based on a poorly documented staff decision. The Siting Commission's decision to include the Taylor North site as one of the five final sites was inconsistent with the commission's requirement that offered sites must be at least as good as other sites. The Taylor North site did not meet the minimum cutoff score applied to other sites at the same stage of screening, and the site contained soils in mineral soil groups 1 through 4, which should have disqualified it from further consideration.

OCR for page 141
--> Question 6 Was the development and application of preference criteria (including weighting and scaling factors) designed to identify sites with geological characteristics adequate to contain radioactive waste? Was the commission's use of criteria unrelated to site performance (including weighting and scaling factors) based on good scientific practice? Four of the 53 preference criteria explicitly address geological characteristics of a disposal site (Appendix I). These are Criterion 1—geologic complexity, Criterion 2—seismic hazards, Criterion 3—subsurface dissolution and Criterion 5—geologic units. The committee identified problems with the design or application of two of these criteria, as noted in its response to Question 1. The committee also found the application of Criterion 1 during CAI screening to be inappropriate without more site-specific data. Twelve preference criteria related to natural resources and hydrology (Appendix I) indirectly address the geological characteristics of a disposal site. The committee identified the following problems in the design or application of these criteria: The application of Criteria 12—primary and principal aquifers—during CAI screening should have accommodated contributed data on aquifer characteristics, well performance, and water usage at the scale of 1-mile-square cells used in CAI screening. Data to apply Criteria 12, 13, and 18—buffers from water resources—were not available during the stage of the screening process (CAI screening) at which these criteria were first applied. Consequently, a single distance standard (1 mile) was applied across the entire state. The design of drainage criteria—particularly Criterion 14—unconsolidated stratigraphic units—was unnecessarily restrictive and may have eliminated many otherwise suitable areas of the state from consideration. Criterion 20—erosion—should have been applied as an exclusionary condition.

OCR for page 141
--> Data to apply Criterion 22—best usage of surface waters—were not available at the stage of the screening process (CAI screening) at which this criterion was first applied. Consequently, a single set of distance standards was applied across the entire state. More detailed discussions of these problems are provided in Chapters 5 and 6 of this report. As noted in the response to Question 4 above, two aspects of the screening process were not well designed to identify sites with geological characteristics adequate to contain radioactive waste: (1) performance and socioeconomic criteria were combined inappropriately for scoring purposes during CAI and PSI screening; consequently, a site could receive less favorable scores on performance criteria and still be selected if it scored highly on socioeconomic criteria; and (2) scoring of preference criteria related to performance of the site relied on "uncertain" data. Because these criteria address performance factors for an LLRW disposal facility, site scores may be correlated only weakly with the likely performance of the sites. Most of the nonperformance criteria addressed the impacts on surrounding populations from a disposal facility. Individually, many of these criteria were reasonable; however, the committee believes that they were not well developed or implemented when viewed as a group. As noted in Chapter 6, many of these criteria describe similar or closely coupled phenomena, and their relative weights shifted dramatically through the various stages of site selection. The sensitivity analyses performed by the Siting Commission were inadequate for elucidating the effects of coupling and scoring on selection decisions. Question 7 Was the commission's application of information obtained through field surveys, site visits, aerial inspections, or any other field investigation used for evaluating potential sites consistent with good scientific practice?

OCR for page 141
--> As noted in Chapter 6, the committee reviewed the plan of the field surveys, the training of staff performing the surveys, and the factors to be evaluated. All appear to be conceptually sound. The windshield surveys conducted during PSI screening were performed over a two-week period. The Report on Potential Sites Identification provides windshield survey results only for those sites that were set aside, not for those that were kept. Thus, it was difficult for the committee to assess how the Siting Commission used this information to make its siting decisions. The data collection forms used in the windshield surveys (see Appendix K) indicate that a broad range of information was to be collected. It is unclear to the committee, however, how this information was actually used in site selection. The committee asked the Siting Commission for, but was never provided, documentation regarding the criteria for the windshield surveys. The use of the windshield surveys during PSI screening was controversial because of county allegations that information was collected that could have been used to exclude two of the final potential sites (Taylor North and Taylor Central). The survey forms for these sites show that newly constructed incompatible structures were observed close to (and within) the site boundaries. The committee's conclusion in Chapter 6 is that the Siting Commission did not adhere to its stated goals (or to good scientific practice) to evaluate the sites ''in light of additional information gained through visual inspection." Question 8 Did the commission seek and/or utilize information from all available sources, including within identified areas? As described in Chapter 4, the initial stages of screening were based on readily available information (e.g., from published maps). As the siting process focused on smaller areas of land, the Siting Commission made a reasonable effort to obtain additional information, including information from local governments. Further, the committee believes that the Siting Commission made a sincere effort to review and

OCR for page 141
--> use this information. Information that was neither used directly nor used to verify information obtained from other sources was deferred for use during independent evaluation of sites rather than for comparison of sites with each other. The committee believes, however, that the Siting Commission's decision to defer consideration of these data, when viewed in hindsight, was not successful from a public relations point of view, primarily because it appeared to local governments that their offered information was being ignored. The Siting Commission did not communicate effectively to local governments and the public why it decided to defer using much of the information until later stages.