| Commenter | Comment Document No. |
| Inyo County, California, Board of Supervisors | SR330060 |
| Remus, Andrew | SR330051 |
The release of the Preliminary Site Suitability Evaluation, a document which makes conclusory statements regarding the Yucca Mountain site's suitability for development of a deep geologic repository, is premature in light of the fact that the U.S. Department of Energy has yet to complete NEPA proceedings on the Yucca Mountain proposal. Until a Final Environmental Impact Statement has been completed for use by the Department, DOE has no legitimate basis for making a preliminary suitability determination for the site.Response Based on more than 20 years of scientific investigations and analyses described in such documents as the FEIS, the S&ER Rev. 1, and the SSE, the DOE concludes that it has sufficient information to estimate potential impacts from the construction, operation and monitoring, and eventual closure of a repository at Yucca Mountain. The FEIS, which includes the public comments on the DEIS and the SDEIS, and responses to those comments, must be included as part of a comprehensive statement of the basis for any recommendation of the Yucca Mountain Site. In the event of a site recommendation, this comprehensive statement will be submitted to the President and made available to the public. In addition, the DOE has conducted an extensive public comment process for the site recommendation in an effort to ensure consideration of the views of the public. Responses to the comments received during the site recommendation comment period are contained in this CSD, which will be available to support any recommendation of the Yucca Mountain site. 3.2.2 (12371) Remus, Andrew Comment
Release of the PSSE is also premature given the fact that key scientific studies regarding waste package corrosion processes are still underway...Response The DOE has continued testing of Alloy 22 to extend the current database on corrosion rates in repository environments that would address these issues. Testing, which has been underway for over two years, has shown the corrosion rates are very low (much lower than one micrometer per year) and are near the level of detection by the standard methods, such as weight loss measurements. These low values are consistent with data in the literature from both short-term and long-term tests on Alloy 22 and related alloys. Thus, a sufficient database exists to move forward. The degradation of the waste package is detailed in Section 4.2.4 of the S&ER Rev. 1. Corrosion tests of waste package materials have been conducted under conditions expected at Yucca Mountain and at conditions outside of those expected conditions to better understand the material's corrosion susceptibility. This low rate in a humid air or aqueous environment depends on the stability of the passive film on the surface. For the nickel-base Alloy 22, the film is an oxide primarily consisting of chromium with nickel, tungsten and molybdenum. Corrosion testing reported in the literature, as well as that performed by the DOE, shows that this film is stable under conditions expected at Yucca Mountain. These tests have included service-condition testing, as well as accelerated testing. Accelerated testing has included a variety of electrochemical potential tests conducted under aggressive chemistry conditions. The DOE plans to continue laboratory testing throughout the preclosure period to confirm the expected waste package performance. The NRC has also requested additional information for potential licensing and has requested that the DOE: continue testing in the Long Term Corrosion Test Facility; add new 'bounding water' test environments to the Long Term Corrosion Test Facility; install thinner test coupons to decrease measurement error; install high sensitivity corrosion probes; and perform materials corrosion testing during the performance confirmation period. 3.2.2 (12372) Remus, Andrew Comment
...the region's saturated zone, unsaturated zone and alluvial geology is only generally understood.Response Sufficient data and information for the hydrologic setting are available to develop an adequate understanding of the site and regional groundwater flow systems. The DOE, the USGS, and others have been evaluating and assessing the hydrologic setting and associated characteristics at the Yucca Mountain site and nearby region for more than two decades. During this time the DOE has modified its program to reflect new information and assessments and to accommodate reviews by independent parties, both internal and external to The DOE. Nevertheless, the DOE recognizes that additional information would refine its understanding of the regional groundwater flow system, and would reduce uncertainties associated with flow and transport in the alluvial, volcanic, and carbonate aquifers (FEIS, Section 3.1.4.2.1). To obtain additional information, Nye County, in cooperation with the DOE, initiated a program, known as the Early Warning Drilling Program, to further characterize the saturated zone along possible groundwater pathways from Yucca Mountain, as well as the relationships among the volcanic, alluvial, and carbonate aquifers. Information from the site characterization program is being used in conjunction with that of the Early Warning Drilling Program to refine the DOE's understanding of the flow and transport mechanics of the saturated alluvium, valley-fill material, and lower carbonate aquifer south of the proposed repository site (FEIS, Section 3.1.4.2.1). 3.2.2 (12373) Remus, Andrew Comment
Our review of the Science and Engineering Report, the Draft EIS, the Supplemental EIS, and the discussions taking place among DOE, the Nuclear Waste Technical Review Board and the Nuclear Regulatory Commission indicate the persistence of high levels of uncertainty in the behavior of virtually all geologic, hydrologic and proposed engineered systems associated with the proposed repository.Response The DOE approach to handling uncertainty in data and models and compensating for these uncertainties is through a comprehensive evaluation of these uncertainties combined with the probabilistic assessment of performance. Increased confidence in the approach is gained by defense in depth that relies on the natural barriers of the site and the engineered barriers of the preliminary repository design The approach to handling uncertainties would also be used in any license application to demonstrate with reasonable expectation that the licensing regulations in 10 CFR Part 63 (66 FR 55732) would be met. The DOE acknowledges that it is not possible to forecast with complete certainty what would occur thousands of years in the future. The National Academy of Sciences, the EPA, and the NRC also recognize the difficulty of understanding the behavior of complex systems over long time periods. In 10 CFR Part 63 (66 FR 55732) for licensing, the NRC acknowledges that "[P]roof that the geologic repository will conform with the objectives for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the understanding of the evolution of the geologic setting, biosphere, and engineered barrier system. For such long-term performance, what is required for licensing is reasonable expectation." In 40 CFR Part 197, the EPA establishes "reasonable expectation" as a licensing-related test of compliance, with diminished "weight of evidence" with time. The EPA also recognizes expert judgment in assigning scenario probabilities, selecting simulation models, and assigning parameter distributions. Consistent with National Academy of Science observations [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588.], the DOE has designed performance assessments based on a combination of mathematical modeling, site data and information, laboratory and literature data, and natural analogues. The DOE has conducted a comprehensive quantitative analysis of the possible future behavior of a Yucca Mountain repository (TSPA-SR and subsequent supplements). This analysis combined the results of detailed conceptual and numerical models of each of the individual and coupled processes in a probabilistic model that can be used to assess how a repository might perform over long periods of time. The TSPA-SR was a next-generation analysis after the viability assessment. The TSPA-SR was the result of some significant changes in the preliminary design of the repository and also some further advancement in knowledge from ongoing research activities. Despite the extensive scientific studies described in the S&ER Rev. 1, the DOE has always recognized that uncertainties would remain in any assessment of the performance of a repository over thousands of years, as discussed in the S&ER Rev. 1, Sections 1.5, 4.1, and 4.4. These uncertainties are attributable to a variety of causes, ranging from uncertainty regarding the fundamental processes that may affect radionuclide migration to uncertainty related to the preliminary design and operation of the repository. For this reason, one part of the DOE approach to dealing with uncertainty relies on multiple lines of evidence that may contribute to the understanding of the performance of the repository. Another part of the DOE approach is a performance confirmation program. This program would extend to permanent closure of the repository. An important aspect of the TSPA-SR model is the presence of unquantified uncertainties. These are uncertainties for which a realistic distribution of parameters is not identified, but rather a conservative bounding value or bounding range is used. Additional studies have been conducted to investigate effects of unquantified uncertainties and sensitivities in the model. Part of the additional studies was to add several features to the performance assessment to better quantify uncertainties and the affected processes. A supplemental performance assessment, the SSPA Volumes 1 and 2, was prepared discussing this additional research and describing the modifications to the TSPA-SR model (SSPA Vol. 2, Sections 3 and 4). These sections summarize areas in which the supplemental model benefited from these additional uncertainty studies. Increased confidence is provided through a strategy of defense in depth that is related to the natural and engineered barriers. Confidence in the outcome of performance assessment modeling is provided for through reliance upon multiple barriers that ensure overall performance, despite the failure of one or more components to perform as expected. For example, the potential of the physical properties of geologic materials to provide natural barriers that retard radionuclide transport is included in the assessment of overall performance. The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. The bases of the approach are summarized as follows:
Sufficient information is not before DOE at this time to warrant even the most preliminary conclusions regarding the site's ability to function as intended by the Nuclear Waste Policy Act or meet EPA release standards for the 10,000-year licensing period. A scientifically sound determination of site suitability cannot be made at this juncture, nor any time in the near future.Response The DOE believes that all of the requirements of the NWPA regarding the information that must be available to the Secretary before he can make any recommendation regarding the suitability of the Yucca Mountain site have been met. Based on more than 20 years of scientific investigations and analyses described in such documents as the FEIS, the S&ER Rev. 1 and the SSE, the DOE concludes that it has sufficient information to determine whether the site is suitable and to estimate potential impacts from the construction, operation, and monitoring, and eventual closure of a repository at Yucca Mountain. The SSE shows that a repository at Yucca Mountain is likely to meet the applicable NRC radiation protection standards for licensing. 3.2.2 (12375) Remus, Andrew Comment
DOE's attempts to evaluate site suitability are based on proposed site suitability guidelines, not the site evaluation guidelines currently in place and legally in effect. It seems obvious to most observers that site suitability explorations must revolve around those officially adopted, legally binding guidelines already in place, not the proposed, hypothetical, hopeful and legally meaningless guidelines which have served for the framework of the Preliminary Site Suitability Evaluation.Response The final site suitability guidelines for a repository at Yucca Mountain are contained in 10 CFR Part 963 (66 FR 57298). 10 CFR Part 960 is no longer applicable to a Yucca Mountain repository, having been superseded by 10 CFR Part 963, which was issued as final guidelines on November 14, 2001. Public comments received as part of the Part 963 rule-making process were considered by DOE before the final guidelines were issued. The NRC reviewed proposed 10 CFR Part 963 and, based on that review, concurred in the final draft guidelines (66 FR 54303). The PSSE was prepared based on the proposed 10 CFR Part 963. The SSE was prepared based on the final 10 CFR Part 963, which was issued November 14, 2001 (66 FR 57298). The SSE would be part of the suite of documents that will be available to support any recommendation of the Yucca Mountain site. 3.2.2 (12376) Remus, Andrew Comment
The current set of scheduled Site Recommendation Consideration Hearings are premature, inadequate and a clear violation of the letter and intent of the Nuclear Waste Policy Act. They are premature for the same reason that the Site Suitability Evaluation is premature. DOE's attempt to hold field hearings in Inyo County falls woefully short of meeting the needs and expectations of Inyo County as stated clearly in the Board of Supervisors letter to Secretary Abraham, dated September 4, 2001. In that letter, we requested a full public hearing on Site Suitability, attended by Secretary Abraham, at Furnace Creek in Death Valley National Park, the area potentially most negatively impacted from the operation of a repository at Yucca Mountain. Our request gained immediate and unambiguous support in the form of a joint letter from Congressman Jerry Lewis and Senator Dianne Feinstein to Secretary Abraham. Instead of granting our request, the Department has seen fit to ignore it and stage, with minimal notice and lead time, "field hearings" which have none of the scope, scale or exposure warranted of a hearing on a project the magnitude of the proposed repository. We would like to point out that Section 114(a)(1) of the Nuclear Waste Policy Act, as amended, specifies that, The Secretary shall hold public hearings in the vicinity of the Yucca Mountain site, for the purposes of informing the residents of such consideration (i.e., consideration of site suitability) and receiving their comments regarding the possible recommendation of such site. Inyo County, whose border lies just 17 miles from the Yucca Mountain site, certainly qualifies as being in the vicinity of the site. There is no doubt that the Nuclear Waste Policy Act obligates DOE to provide real hearings in Inyo County. Further, Section 114 points to a hearing process limited to receiving comments from residents of the area and their elected representatives. Testimony at these hearings should be limited to parties within, or representative of, the vicinity of the site, in other words, from the Inyo, San Bernardino, Nye and Clark Counties. DOE failed to seriously attempt or achieve compliance with NWPA Section 114(a)(1) at the September 5, 2001 public hearing in Las Vegas, Nevada, and would be well advised to comply fully with this requirement with respect to California and Inyo County.Response Hearings were initially held in Las Vegas, Pahrump, and Amargosa Valley as these sites were considered to be the locations of the major population groups that would be most affected by the project. The latter two sites are also within relatively close proximity to Inyo County. Subsequently, the DOE announced "...additional opportunities, in various localities in Nevada and California, for the public to provide comments on the possible recommendation of the Yucca Mountain site in Nevada for development..." These opportunities consisted of 29 hearings to be held in each county in Nevada and Inyo County, California. In addition, the public comment period was extended and citizens of these areas were provided with additional notification of the various ways that comments could be submitted to the Secretary including use of the U.S. Mail, e-mail, fax, and the use of public stenographers provided by the DOE for this purpose. 3.2.2 (12377) Remus, Andrew Comment
Inyo County is unique in its status as the ultimate destination for those radionuclides that will, under all repository design variants under consideration by DOE, escape from the repository block and travel via groundwater into the Southern Amargosa Valley and Death Valley National Park. Inyo and San Bernardino Counties contain major sections of the aquifers through which radionuclides are predicted to travel, as well as the Amargosa River system that may serve to transport these same materials via surface water.Response As described in Section 4.2.9 of the S&ER Rev. 1, the DOE has conducted an extensive program to characterize the direction and nature of groundwater flow and likely transport pathways from the Yucca Mountain site. Based on the overall configuration of the potentiometric surface that has been constructed from water-level measurements in wells in the site area (YMSD, Section 9.3.4), the general path of water moving through the saturated zone beneath Yucca Mountain is southward toward Amargosa Valley, where the groundwater from beneath Yucca Mountain merges with underflow from Fortymile Wash, and flows into the very large groundwater reservoir in the Amargosa Desert. A major intermediate discharge area is believed to occur farther south at Alkali Flat (Franklin Lake Playa), a playa at the southern terminus of the Alkali Flat-Furnace Creek groundwater basin consisting of an area of extensive surface evapotranspiration. Both groundwater and intermittent surface flow breach the southern boundary of the basin along the Amargosa River, providing inflow into the Southern Death Valley subregion (YMSD, Section 9.2.4.3). Figure 9.2-8 of the YMSD depicts the conceptualized groundwater flow path along the Amargosa River into the southern Death Valley subregion. The analysis also indicates that dispersive processes that occur during saturated zone flow and transport would substantially contribute to the dilution of all radioactive species (SSE, Section 3.3.8.3). The TSPA-SR model and the supplemental TSPA model, using the saturated zone flow and transport model (SSE, Section 3.3.8.1.4), forecast exposures at a point 18 kilometers (11 miles) southward from within the repository footprint. Doses would fall below the NRC licensing radiation protection standards for the regulatory period. The increased dispersion and dilution occurring over greater distances would provide even more protection for Inyo and San Bernardino counties. Section 801 of the Energy Policy Act of 1992 requires the EPA (not the DOE) to set standards for the protection of public health and safety from releases of radioactive materials stored or disposed of at Yucca Mountain. For licensing, the NRC's groundwater and individual protection licensing standards, in 10 CFR Part 63, implement the corresponding EPA standards in 40 CFR Part 197 (66 FR 32074). The groundwater protection standards are compatible with relevant EPA drinking water standards for the entire United States, and the individual protection standard is 15 millirem per year. The dose standards are low compared to the average radiation exposure from natural sources of radiation of 300 millirem per year. To address the NRC groundwater protection standards for licensing, the revised supplemental TSPA model evaluated groundwater concentrations of radionuclides released from the disposal system into the accessible environment consistent with 10 CFR 63.331 and 10 CFR 63.332 (66 FR 55814). Section 3.1.2.5 of the SSE discusses the results of these analyses. A description of the revised supplemental model can be found in "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation REV 00 ICN 02." Letter from N.H. Williams (BSC) to J.R. Summerson (DOE/YMSCO), December 11, 2001, RWA:cs-1204010670, with enclosure. ACC: MOL.20011213.0056.]. The calculated peak mean activity concentration for alpha-emitting radionuclides for the 10,000-year postclosure period is 1.8 x 10E-8 picocuries per liter, from a repository at Yucca Mountain that operates at higher temperatures and 3.3 x 10E-8 picocuries per liter for lower-temperature operation. These gross alpha concentrations do not include 1.1 picocuries per liter from natural background. The NRC groundwater protection standard for licensing, in 10 CFR Part 63, limits gross alpha concentration to 15 picocuries per liter, which includes natural background. The calculated peak mean activity concentration for combined radium-226 and radium-228 activity for the 10,000-year postclosure period is less than 1 x 10E-10 picocuries per liter for both the higher- and the lower-temperature operating mode. These radium concentrations do not include 1.04 picocuries per liter from natural background. The NRC groundwater protection standards for licensing, in 10 CFR Part 63, limit total radium concentration to 5 picocuries per liter, which includes natural background. The revised supplemental model also calculated the mean annual dose from the combined beta- and photon-emitting radionuclides based on consuming 2 liters of groundwater per day. For beta- and photon-emitting radionuclides, the model forecasts 2.3 x 10E-5 millirem per year from a repository at Yucca Mountain operating at higher temperatures and 1.3 x 10E-5 millirem per year for operating at lower temperatures. Both calculations consider the whole body and any organ. The NRC groundwater protection standard for licensing, in 10 CFR Part 63, limits exposures from consuming two liters of water per day from the representative volume of groundwater to 4 millirem per year to the whole body or any organ. 3.2.2 (12379) Remus, Andrew Comment
The Preliminary Site Suitability Evaluation claims that the site appears to be capable of meeting the EPA radiation protection standards. This gives us no comfort whatsoever. The EPA's radiation protection standards allow for the destruction of those aquifers that provide sustenance for humans and Federally-protected [sic] natural habitat in both the Amargosa Valley and Death Valley National Park. These standards are entirely unacceptable to Inyo County. No proposal or design that allows the release of radioactive materials should be recommended to the President. DOE should concede that the hydrogeologic prerequisites necessary to isolate nuclear waste from the human environment are not present at the Yucca Mountain site and seek further direction from Congress regarding the issue of long-term handling of spent fuel and high-level nuclear waste.Response Congress, in the Energy Policy Act of 1992 (Public Law No. 102-486), directed the EPA to develop public health and safety standards for the protection of the public from releases of radioactive materials stored or disposed of in a repository at the Yucca Mountain site. Congress also directed the NRC to publish criteria for licensing the repository that would be consistent with the radiation protection standards established by the EPA. Section 801 of the Energy Policy Act of 1992 requires the EPA (not DOE) to set standards for the protection of public health and safety from releases of radioactive materials stored or disposed of at Yucca Mountain. For licensing, the NRC groundwater protection standards follow the EPA's groundwater protection standards in 40 CFR Part 197 (66 FR 32074), which are compatible with relevant EPA drinking water standards for the entire United States. For licensing, the NRC individual protection standard is 15 millirem per year. This is low compared to the average radiation exposure from natural sources of radiation of 300 millirem per year. 3.2.2 (12438) Remus, Andrew Comment
We urge Secretary Abraham to recognize Yucca Mountain as the dead-end effort that it is, and proactively seek Congressional consideration of reasonable alternatives - alternatives that will save our society billions of dollars, will save the Federal Government decades worth of litigation, and it will spare California and Nevada centuries of threat to our water and our citizens.Response Recognizing the national need to safely dispose of spent nuclear fuel and high-level radioactive wastes, the NWPA requires the Secretary to conduct activities to characterize the Yucca Mountain site and to make a determination whether to recommend that site to the President as the first geologic repository for spent nuclear fuel and high-level radioactive waste. If upon completion of such activities, a determination is made that the site is acceptable, the Secretary would decide whether to recommend approval of such site to the President. If the Secretary at any time determines the Yucca Mountain site to be unsuitable, the Secretary is required to, among other things, report to Congress not later than 6 months after such determination the Secretary's recommendations for further action to assure the safe, permanent disposal of spent nuclear fuel and high-level radioactive waste, including the need for new legislative authority (42 U.S.C. 10133). 3.2.2 (13522) Remus, Andrew Comment
If we assume, for the sake of argument, that the entire process of manufacturing and transporting dry casks, retrofitting nuclear generator, [sic] DOE and DOD sites to meet NRC on-site storage license requirements, and development and implementation of monitoring and security measures for all sites totals out at $15 billion, we can see a clear, relatively inexpensive and expedient path to meet the nation's long-term storage needs without building a centralized repository, without incurring the health, accident and terrorism risks associated with a 24-year spent fuel transportation campaign, and without extracting an entire $56 billion from nuclear power consumers. In addition, the spent fuel would remain packaged in accessible, readily monitored, repaired and replaced containers for future reprocessing, transmutation, or burial as necessary to our future needs and priorities.Response As described in the Executive Summary and Section 1 of the S&ER Rev. 1, commercial nuclear power plants, nuclear weapons production, operation of naval reactors, and research and development activities produce spent nuclear fuel and high-level radioactive waste. As of December 1999, the United States had generated about 40,000 MTHM of spent nuclear fuel from commercial nuclear power plants. By 2035, the United States will also have about 2,500 MTHM of spent nuclear fuel from research reactors, naval reactors, reactor prototypes, and reactors that produced nuclear weapons materials. This spent nuclear fuel is currently stored at DOE and commercial reactor sites in various parts of the country. In addition, about 380 million liters (100 million gallons) of liquid waste from nuclear weapons production are stored in underground tanks at many of these same DOE sites. This waste would have to be solidified prior to shipment to a repository. The total inventory of spent nuclear fuel and high-level radioactive waste could eventually exceed 100,000 MTHM, depending on the number of reactors that receive operating life extensions. However, the NWPA limits the capacity of the first repository to 70,000 MTHM until such time that a second repository is in operation. Any change to this limitation would necessitate further Congressional action. The purpose of a repository is permanent disposal rather than indeterminate storage. The concept of permanently disposing of radioactive waste in a deep geologic repository stems from studies initiated in the 1950s by the National Academy of Sciences. Continued studies in the United States and abroad have concluded that deep geologic disposal can keep radioactive waste isolated from the environment in geologic formations known to have been stable for millions of years, thus providing a safe location for the waste to decay into a stable form. In 1990, a panel of the National Academy of Sciences confirmed again the overall concept of geologic disposal, noting that there is "a worldwide scientific consensus that geological disposal, the approach followed by the United States, is the best option for disposing of high-level radioactive waste" [National Research Council 1990. "Rethinking High-Level Radioactive Waste Disposal, A Position Statement of the Board on Radioactive Waste Management." Washington, D.C.: National Academy Press. TIC: 205153. Page vii.]. The Academy in 2001 again confirmed the geologic disposal concept in a report titled "Disposition of High-Level Waste and Spent Nuclear Fuel, The Continuing Societal and Technical Challenges." [National Research Council 2001. "Disposition of High-Level Waste and Spent Nuclear Fuel, The Continuing Societal and Technical Challenges." Washington, D.C.: National Academy Press. TIC: 250101.]. Recognizing that the accumulation of spent nuclear fuel from commercial and naval nuclear reactors and high-level radioactive waste from reprocessing of spent nuclear fuel and defense activities has created the need for a national solution, Congress enacted the NWPA (42 U.S.C. 10101 et seq.). The NWPA provides for the permanent disposal of spent nuclear fuel and high-level radioactive waste to protect the public health and safety and the environment. With the passage of the NWPA, the national policy for the disposition of spent nuclear fuel and high-level radioactive waste was defined to be geologic disposal. 3.2.2 (12827) Remus, Andrew
| Commenter | Comment Document No. |
| Inyo County, California, Board of Supervisors | SR330116 |
| Remus, Andrew |
This attempt at a hearing falls woefully short of meeting the needs and expectations of Inyo County as stated clearly in the Board of Supervisor's letter to DOE Secretary Abraham dated September 4, 2001. In that letter we requested a full public hearing on Site Suitability, attended by Secretary Abraham, at Furnace Creek in Death Valley National Park, the area potentially most negatively impacted from the operation of a repository at Yucca Mountain. Our request gained immediate and unambiguous support in the form of a joint letter from Congressman Jerry Lewis and Senator Dianne Feinstein to Secretary Abraham. Instead of granting our request, the Department has seen fit to ignore it and stage, with minimal notice and lead time, "field hearings" which have none of the scope, scale or exposure warranted of a hearing on a project the magnitude of the proposed repository.Response The DOE held all of the site recommendation consideration hearings, including those in Inyo County, California, consistent with the NWPA. The NWPA requires the Secretary of Energy to hold public hearings in the vicinity of the Yucca Mountain site, for the purposes of informing the residents and to receive comments regarding the possible recommendation of the site. Two hearings were held in Inyo County, California in addition to all counties in Nevada. During the course of the hearings and meetings associated with the Yucca Mountain site recommendation process, Secretary Abraham has been consistently represented by members of his senior staff. All of the hearings have been transcribed and the transcripts have been made available to support any recommendation of Yucca Mountain site. All comment documents received during the course of these activities will be available to support any recommendation of the Yucca Mountain site. 3.2.2 (12830) Remus, Andrew Comment
Section 114(a)(1) of the Nuclear Waste Policy Act, as amended, specifies that: The Secretary (DOE) shall hold public hearings in the vicinity of the Yucca Mountain site, for the purposes of informing the residents of the area of such consideration (consideration of site suitability) and receiving their comments regarding the possible recommendation of such site. Neither of Inyo County's "field hearings" is in the vicinity of the Yucca Mountain Site, nor have these hearings been afforded the attention that the critical juncture of site recommendation deserves. Since the County received notice of this hearing just six days ago, and the Federal Register notice came out today, October 3rd, the residents of the impacted area have received little if any notice of the conduct of this hearing, and have in that respect been denied the opportunity clearly afforded them by the Nuclear Waste Policy Act. It is obvious that, besides being premature and inadequate, these hearings are a clear violation of the letter and intent of the Nuclear Waste Policy Act. The field hearings are a poorly disguised attempt to placate concerned parties in our County, to avoid further high-profile debacles like the September 5th site characterization hearing in Las Vegas, to enable DOE management to claim they have held public hearings in California, and to expedite the review process to enable DOE to forward a positive recommendation on Yucca Mountain years ahead of the completion of comprehensive scientific studies of the site and before the glaring absence of a transportation risk assessment for Yucca Mountain comes to the attention of Secretary Ridge and the Office of Homeland Security. Absent better placed, noticed and organized hearings, held after completion of the Final Environmental Impact Statement and respectful of Inyo County's status as an Affected Unit of Local Government and the jurisdiction most likely to be negatively impacted by the proposed repository, the County will consider DOE's attempt to inform our residents and receive their comments completely inadequate and will pursue correction of DOE's public hearing process by whatever means available.Response The DOE held all of the site recommendation consideration hearings, including those in Inyo County, California, consistent with the NWPA. All reasonable efforts were made to ensure that hearings were adequately advertised and members of the public were aware of the intent of the hearings and the role that they could play in those hearings. In addition to the Federal Register notices, before each hearing the DOE placed advertisements in local newspapers, including Spanish-language newspapers, and distributed text for public service announcements and press releases to local and national stakeholders and media outlets to publicize information that was accessible to the general public and to minority and low-income communities. Additional mailings were sent to stakeholders announcing any changes, and additions to the list of public hearings were also made available on the Yucca Mountain Site Characterization Project website (www.ymp.gov) throughout the comment period. Hearings were initially held in Las Vegas, Pahrump, and Amargosa Valley as these sites were considered to be the locations of the major population groups that would be most affected by the project. The latter two sites are also within relatively close proximity to Inyo County. Subsequently, the DOE announced "...additional opportunities, in various localities in Nevada and California, for the public to provide comments on the possible recommendation of the Yucca Mountain site in Nevada for development...." These opportunities consisted of 29 hearings to be held in each county in Nevada and Inyo County, California. Information was provided and comments were recorded in each of the 29 hearings, just as they were in the initial three scheduled hearings. Responses to comments received at all the hearings are presented in this CSD, which will be available to support any recommendation of the Yucca Mountain site. 3.2.2 (12762) Selinder, Bjorn
| Commenter | Comment Document No. |
| Churchill County, Nevada, County Manager | SR330069 |
| Selinder, Bjorn |
Storage of the nation's spent nuclear fuel and high-level nuclear waste must ensure long-term isolation without necessarily relying upon future institutional or governmental control.Response As noted in 10 CFR 63.102(l) (66 FR 55805), the licensing requirements for a repository at Yucca Mountain do not assume that isolation would be maintained based upon institutional or governmental control. As discussed in Section 4.6.2 of the S&ER, neither the extent nor the length of the institutional control programs are prescribed by statute. The NRC's implementing licensing regulation, at 10 CFR Part 63.51 (66 FR 55801), identifies institutional control and postclosure monitoring considerations that the DOE must address satisfactorily before the NRC would amend the license to authorize permanent closure of the repository. Therefore, the details of this program would be defined during the processing of the license amendment for closure of the repository. Section 4.1.5 of the S&ER Rev. 1 discusses repository closure activities, including postclosure monitoring and the use of institutional controls such as land records and warning systems to inform future generations of the location and hazards of the closed repository. Institutional controls (markers, records, etc.) would be put in place during closure for the information of future generations as required by the NRC at 10 CFR 63.51 (66 FR 55801). 3.2.2 (12763) Selinder, Bjorn Comment
Yucca Mountain today remains extremely unpopular among a majority of Nevadans. It's probably one of the largest, most unpopular federal projects ever conceived in that no state wants to host such a facility. It is in effect a solution for many areas of the country and yet another contribution to Nevada's long and disproportional burden as host for many of the nation's nuclear-related programs. That sense of obligation and purpose was reduced to political convenience with the passage of the 1987 Nuclear Waste Policy Amendments Act that targeted Yucca Mountain as the only site to be studied for a geologic repository.Response The disposal of spent nuclear fuel and high-level radioactive waste is a concern for the country as a whole, as well as the State of Nevada. The NWPA began a process for selecting sites for technical study as potential geologic repository locations. In accordance with this process, the DOE identified nine candidate sites, the Secretary of Energy nominated five of the nine sites for further consideration and DOE issued environmental assessments for the five sites. DOE recommended three of the five sites, of which Yucca Mountain was one, for study as repository site candidates. In 1987, Congress amended the NWPA, directing the Secretary of Energy to perform site characterization activities at the Yucca Mountain site, and, if the site is found suitable, make a recommendation to the President on whether to approve the site for development of a repository. If the Secretary of Energy makes a recommendation, the President must then decide whether to recommend the site to Congress. If the President recommended the site, the State of Nevada would have 60 days in which to submit a notice of disapproval regarding the site designation. This notice of disapproval would become final unless both houses of Congress, within 90 calendar days of continuous session of Congress following receipt of the notice of disapproval from the State, pass a resolution of siting approval, and such resolution becomes law. 3.2.2 (12764) Selinder, Bjorn Comment
Although DOE has spent some 15 years studying Yucca Mountain, we remain concerned about recent activities that appear to have more focus on meeting politically-imposed [sic] schedules than determining without question Yucca Mountain's ability to isolate dangerous materials.Response The Secretary has stated that any recommendation regarding the suitability of Yucca Mountain will be based on science not politics. In response to this direction, the DOE has conducted a series of investigations and evaluations (the site characterization program) to assess the suitability of the Yucca Mountain site as a geologic repository. The results of these investigations and evaluations have been documented in a series of documents that have been made available to the public, including the S&ER, issued May 7, 2001, and the PSSE, issued August 21, 2001. These activities have been subjected to ongoing review by the NRC, NWTRB, other agencies, the State of Nevada, Native American tribes, and affected units of local government. The results of the investigations and evaluations performed by the DOE would serve as part of the basis for any recommendation to the President regarding the potential development of a repository at Yucca Mountain. 3.2.2 (12765) Selinder, Bjorn Comment
Still today the project does not have a final design. Instead, DOE wants to continue to rely upon what has been conveniently termed flexible design concepts and boundary analysis in attempts to quantify unknowns and uncertainties about repository performance. There remain uncertainties associated with high thermal load designs and the ability of engineered barrier systems to contain waste over the regulatory period of compliance.Response The DOE has noted that the analyzed designs were preliminary and were likely to evolve in various ways. The DOE has continued to evaluate design features and operating modes that would reduce uncertainties in or improve long-term repository performance and that would improve operational safety and efficiency. The result of the design evolution process was the development of the flexible design described in the S&ER. The DOE has developed a design for a monitored geologic repository at Yucca Mountain that could give future generations the choice of either closing and sealing the repository as early as allowable under NRC regulations for licensing, or keeping it open and monitoring it for a longer time period. Aspects of the design are likely to continue to evolve, particularly in relation to the means of controlling heat generated by spent nuclear fuel. The DOE must provide a description of the proposed repository, including preliminary engineering specifications, as part of the site recommendation. A more detailed design would be developed for use in any license application to the NRC. In November 2001, the DOE posted several documents to their Internet site (www.ymp.gov), including "Uncertainty Analyses and Strategy" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Uncertainty Analyses and Strategy Letter Report, REV 00, Activity #SA011481M4." Letter from N.H. Williams (BSC) to S.J. Brocoum (DOE/YMSCO), November 19, 2001, JM:cs-111601010483, with enclosure. ACC: MOL.20020109.0064.]. These documents were available during the supplemental comment period from November 14 through December 14, 2001. The purpose of this report was (1) to briefly summarize and consolidate the discussion of much of the work that had been done over the past few years to evaluate, clarify, and improve the representation of uncertainties in the TSPA and performance projections for a repository at Yucca Mountain, (2) to develop a strategy for how uncertainties may be handled in the TSPA and supporting analyses and models to support a license application, should the site be recommended, and (3) to discuss issues related to communication about uncertainties, and propose some approaches the DOE may use in the future to improve how it communicates uncertainty in its models and performance assessments to decision-makers and to technical audiences. The DOE concludes that the information in the S&ER Rev. 1, the SSE, the FEIS and other documents developed by the project over the years is sufficient to support any recommendation of the Yucca Mountain site. This belief is based on the level of information and analysis, the analytical methods and approaches used to represent conservatively the reasonably foreseeable impacts, and the use of bounding assumptions where information is incomplete or unavailable, or where uncertainties exist. 3.2.2 (12766) Selinder, Bjorn Comment
As originally envisioned, the Yucca Mountain host rock was supposed to isolate waste from the human environment. Instead, we now have a repository that relies almost entirely on manmade barrier systems to contain wastes.Response The use of both engineered and natural barriers does not conflict with the NWPA and is consistent with both EPA standards and NRC regulations for licensing. Section 121(b)(1)(B) of the NWPA encourages the use of multiple barriers and directs the NRC to develop criteria that would provide for the use of multiple barriers in the design of the repository. The NRC has incorporated the multiple barrier concept at 10 CFR 63.102(h) and 10 CFR 63.113 (66 FR 55805 and 55807) to enhance the resiliency of the repository and increase confidence that performance objectives would be met. Thus, the use of complementary natural and engineered barriers in the assessment of disposal system performance does not contravene the intent of the NWPA, and is consistent with Yucca Mountain-specific radiation protection regulations for licensing. Both the natural barriers and engineered barriers would work together to contribute to the overall performance of a repository. Natural barriers limit the amount of water that could contact the waste and provide a geochemical environment that prevents mobilization and transport of most species of radionuclides. Equally important, there would be little percolation of water down through the rock layers to the repository block even during cooler, wetter periods. Engineered barriers also limit the amount of water that could contact the waste; moreover, the waste package would contain many species of radionuclides until they decay away. For example, strontium-90 and cesium-137 would have decayed away after the first 1,000 years. Additionally, of those few species that are mobile, natural conditions of the unsaturated rock, as well as zeolites in the rock layers underlying the repository, would retard the migration of many species of radionuclides. Many species would sorb onto the zeolites and thus provide additional delay to allow additional time for these species of radionuclides to decay away. Thus, the natural and engineered barriers working together prevent the vast majority of radionuclide species from ever reaching the accessible environment. 3.2.2 (12767) Selinder, Bjorn Comment
DOE insists on or is being forced into moving forward when there is no conclusive evidence with regard to waste package performance, particularly with respect to waste package corrosion rates. At best, DOE can only claim that expert solicitation or what is otherwise known as an informed opinion finds no reason to believe the waste packages would fail or, more importantly, fail prematurely, resulting in a release of radioactive materials.Response Testing of waste package materials by the DOE, which has been underway for over two years, has shown the corrosion rates are very low (much less than one micrometer per year) and are near the level of detection by the standard methods, such as weight loss measurements. These low values are consistent with data in the literature from both short-term and long-term tests on Alloy 22 and related alloys. Thus, a sufficient database exists to move forward. The degradation of the waste package is detailed in Section 4.2.4 of the S&ER Rev. 1. Corrosion of waste package materials has been conducted under conditions expected at Yucca Mountain and at conditions outside of those expected conditions to better understand the material's corrosion susceptibility. These tests have included service condition testing, as well as accelerated testing. Accelerated testing has included a variety of electrochemical potential tests conducted under aggressive chemistry conditions. The DOE plans to continue laboratory testing throughout the preclosure period to confirm the expected waste package performance. The DOE continues to take advantage of data on other alloy materials of similar chemistry, engineering analogues, that have a much longer (approximately 50-year) experience base. The DOE is also testing thinner specimens to reduce measurement error, is evaluating the use of sensitivity probes that would permit online measurements of and changes to corrosion rates, and plans to collect data during the performance confirmation period. 3.2.2 (12768) Selinder, Bjorn Comment
With the acknowledgement that the repository rock cannot by itself contain waste, the public and, more importantly, the public in Nevada is asked to place their confidence in a host of models that are supposed to identify repository performance for a period of at least 10,000 years into the future. The use of models add yet another layer of uncertainty. It has now become a question of when and how much radiation will reach the accessible environment.Response The DOE approach to handling uncertainty in data and models and compensating for these uncertainties is through a comprehensive evaluation of these uncertainties combined with the assessment of performance. Increased confidence in the approach is gained by defense in depth that relies on the natural barriers of the site and the engineered barriers of the preliminary repository design. The approach to handling uncertainties would also be used in any license application to demonstrate with reasonable expectation that the licensing regulations in 10 CFR Part 63 (66 FR 55732) would be met. The DOE acknowledges that it is not possible to forecast with complete certainty what would occur hundreds or thousands of years in the future. The National Academy of Sciences, the EPA, and the NRC also recognize the difficulty of understanding the behavior of complex systems over long time periods. In 10 CFR Part 63 (66 FR 55732), the NRC acknowledges that "[P]roof that the geologic repository will conform with the objectives for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the understanding of the evolution of the geologic setting, biosphere, and engineered barrier system. For such long-term performance, what is required for licensing is reasonable expectation...." In 40 CFR Part 197, the EPA establishes "reasonable expectation" as a test of compliance, with diminished "weight of evidence" with time. The EPA also recognizes the potential need for expert judgment in assigning scenario probabilities, selecting simulation models, and assigning parameter distributions. Consistent with National Academy of Science observations [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588.], the DOE has designed performance assessments based on a combination of mathematical modeling, site data and information, laboratory and literature data, and natural analogues. The DOE has conducted a comprehensive quantitative analysis of the possible future behavior of a Yucca Mountain repository (TSPA-SR). This analysis combined the results of detailed conceptual and numerical models of each of the individual and coupled processes in a single probabilistic model that can be used to assess how a repository might perform over long periods of time. The TSPA-SR was a next-generation analysis after the viability assessment. The TSPA-SR was the result of some significant changes in the preliminary design of the repository and also some further advancement in knowledge from ongoing research activities. Despite the extensive scientific studies described in the S&ER Rev. 1, the DOE has always recognized that significant uncertainties would remain in any assessment of the performance of a repository over thousands of years, as discussed in the S&ER Rev. 1, Sections 1.5, 4.1, and 4.4. These uncertainties are attributable to a variety of causes, ranging from uncertainty regarding the fundamental processes that may affect radionuclide migration to uncertainty related to the preliminary design and operation of the repository. For this reason, one part of the DOE approach to dealing with uncertainty relies on multiple lines of evidence that may contribute to the understanding of the performance of the repository. Another part of the DOE approach is a commitment to a performance confirmation program, as provided in 10 CFR Part 63. This program would extend beyond the possible recommendation of the site and to permanent closure. An important aspect of the TSPA-SR model is the presence of unquantified uncertainties. These are uncertainties for which a realistic distribution of parameters is not identified, but rather a very conservative bounding value or bounding range is chosen. Additional studies have been conducted to investigate effects of unquantified uncertainties and sensitivities in the model. Part of the additional studies was to add several features to the performance assessment to better quantify uncertainties and the affected processes. An additional performance assessment, the SSPA Volume 1 and 2, was prepared discussing this additional research and describing the modifications to the TSPA-SR model (SSPA Vol. 2, Sections 3 and 4). These sections summarize areas in which the supplemental model benefited from these additional uncertainty studies. Increased confidence is provided through a strategy of defense in depth that is related to the natural and engineered barriers. Confidence in the outcome of performance assessment modeling is provided for through reliance upon multiple barriers that ensure overall performance, despite the failure of one or more components to perform as expected. For example, the potential of the physical properties of geologic materials to provide natural barriers that retard radionuclide transport is included in the assessment of overall performance. The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. The bases of the approach are summarized as follows:
These few examples clearly support the notion that DOE is not ready for a site recommendation. We do not believe that DOE has met the threshold needed to ensure the long-term isolation of spent nuclear fuel and high-level nuclear waste.Response The DOE believes that the requirements of the NWPA regarding the information that must be available for any site recommendation have been met. Any decision would be based on a review and understanding of relevant regulations, documents produced by the project, and comments received from the public. The DOE has conducted a series of investigations and evaluations (the site characterization program) to assess the suitability of the Yucca Mountain site as a geologic repository. The results of these investigations and evaluations have been documented in a series of documents that have been made available to the public, including the S&ER, issued May 7, 2001, and the PSSE, issued August 21, 2001. In addition, supplemental information was made available on November 14, 2001. The results of the investigations and evaluations performed by the DOE would serve as part of the basis for any recommendation to the President regarding the potential development of a repository at Yucca Mountain. 3.2.2 (12770) Selinder, Bjorn Comment
The site recommendation should be postponed until such time that DOE has developed a firm proposal for the repository design and can provide supportable evidence without the somewhat long list of uncertainties and unknowns currently associated with the characterization program and the ability to model future performance.Response Section 114(a) of the NWPA requires preliminary engineering specifications at the time any recommendation by the Secretary is made. A more complete design would be submitted to the NRC as part of the facility licensing process if the site is approved. As with virtually all substantial scientific and technical projects, information regarding the underlying scientific and technical concepts would continue to be gathered across the entire life of the project. DOE expects that additional investigations would continue throughout the entire project period and this information will be evaluated to support a closure decision 3.2.2 (16075) Selinder, Bjorn Comment
In fact, the Yucca Mountain draft EIS may well suggest that the transportation component poses the greatest exposure risk, yet the DOE fails to provide a comprehensive national transportation proposal for waste shipments to a repository. For example, I believe that the DOE draft EIS showed that rail transportation of waste would be overall safer than truck, but there is no policy recommendation. It may, in my opinion, be a mistake to allow individual generator sites and even states to select what will become the most politically acceptable modes and routes for repository shipments. We may ultimately develop a spider-web network of routes passing through all areas of the country that results in even greater risks, higher costs, and a less efficient and reliable transportation program.Response The DOE has identified in the FEIS, mostly rail as the preferred mode for transportation of spent nuclear fuel and high-level waste both nationally and in the State of Nevada. At this time, however, the DOE has not identified a preference among the five candidate rail corridors in Nevada. The FEIS analyzes the potential environmental impacts that could result from the transportation of spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. This is based on the level of information and analysis, the analytical methods and approaches used to represent conservatively the reasonably foreseeable impacts, and the use of bounding assumptions where information is incomplete or unavailable, or where uncertainties exist. The use of widely accepted analytical tools, latest reasonably available information, and cautious but reasonable assumptions offer the most appropriate means to arrive at conservative estimates of transportation-related impacts. For the reasons discussed above, the DOE believes that the FEIS provides the environmental impact information necessary to make certain broad transportation-related decisions, namely the choice of a national mode of transportation outside of Nevada (mostly rail or mostly legal-weight truck), the choice among alternative transportation modes in Nevada (mostly rail, mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternative rail corridors or heavy-haul truck routes with use of an associated intermodal station in Nevada. The DOE has identified mostly rail as its preferred mode of transportation, both nationally and in the State of Nevada. At this time, however, the DOE has not identified a preference among the five candidate rail corridors in Nevada. If the Yucca Mountain site was recommended and approved, at some future date the DOE would issue a Record of Decision to select a mode of transportation. If, for example, mostly rail was selected (both nationally and in Nevada), the DOE would identify a preference for one of the rail corridors in consultation with affected stakeholders, particularly the State of Nevada. In this example, the DOE would announce a preferred corridor in the Federal Register and other media. No sooner than 30 days after the announcement of a preference, the DOE would publish its selection of a rail corridor in a Record of Decision. Other transportation decisions, such as the selection of a specific rail alignment within a corridor, would require additional field surveys, state and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews. For legal-weight or heavy-haul truck transportation of spent nuclear fuel and high-level radioactive waste in Nevada, a motor carrier would use only routes that comply with the requirements contained in U.S. Department of Transportation regulations (49 CFR 397.101). These U.S. Department of Transportation regulations require use of routes designated as preferred routes that reduce the time in transit; these preferred routes are interstate system highways, interstate system beltways and bypasses, and state-designated preferred routes. There are exceptions for pick-up and delivery routes used to travel to and from a nearest preferred route. The State of Nevada and Native American tribal governments can designate alternate preferred routes. 3.2.2 (12833) Selinder, Bjorn
| Commenter | Comment Document No. |
| Churchill County, Nevada, County Manager | SR330117 |
| Selinder, Bjorn |
Yucca Mountain today remains extremely unpopular among a majority of Nevadans. It's probably one of the largest, most unpopular federal projects ever conceived in that no state would want to host such a facility. It is in effect a solution for many areas of the country and yet another contribution to Nevada's long and disproportional burden as host for many of the Nation's nuclear related programs.Response Nevadans benefit from the generation of nuclear power as such power is a vital part of the electric utility grid that serves the entire western United States. In addition, a portion of the wastes that would be disposed of in a repository at Yucca Mountain are generated in defense related activities that are in the best interest of and serve the entire population of the United States. Although multiple sites for a repository were initially considered by DOE, Congress amended the NWPA in 1987 to direct the DOE to focus its efforts towards determining whether a single site at Yucca Mountain in the State of Nevada was suitable for a geologic repository. In response to this direction, the DOE has conducted a series of investigations and evaluations (the site characterization program) to assess the suitability of the Yucca Mountain site as a geologic repository. The results of these investigations and evaluations have been documented in a series of documents that have been made available to the public, including the S&ER, issued May 7, 2001, and the PSSE, issued August 21, 2001. In addition, these activities have been subjected to ongoing review by the NRC, NWTRB, and other agencies, the State of Nevada, Native American tribes, and affected units of local government. 3.2.2 (12836) Selinder, Bjorn Comment
Although DOE has spent some 15 years studying Yucca Mountain, we remain concerned about recent activities that appear to have more focus on meeting politically imposed schedules than determining without question Yucca Mountain's ability to isolate dangerous materials.Response Any recommendation regarding the suitability of Yucca Mountain will be based on science not politics. The DOE has conducted a series of investigations and evaluations (the site characterization program) to assess the suitability of the Yucca Mountain site as a geologic repository. The results of these investigations and evaluations have been documented in a series of documents that have been made available to the public, including the S&ER, issued May 7, 2001, and the PSSE, issued August 21, 2001. These activities have been subjected to ongoing review by the NRC, NWTRB, other agencies, the State of Nevada, Native American tribes, and affected units of local government. The results of the investigations and evaluations performed by the DOE would serve as a basis for any recommendation to the President regarding the potential development of a repository at Yucca Mountain. 3.2.2 (12841) Selinder, Bjorn Comment
Still today the project does not have a final design. Instead, DOE wants to continue to rely upon what has been conveniently termed "flexible" design concepts and boundary analysis in attempts to quantify unknowns and uncertainties about repository performance. There remain uncertainties associated with high thermal load designs and the ability of engineered barriers systems to contain waste over the regulatory period of compliance.Response The DOE has noted that the analyzed designs were preliminary and were likely to evolve in various ways. The DOE has continued to evaluate design features and operating modes that would reduce uncertainties in or improve long-term repository performance and that would improve operational safety and efficiency. The result of the design evolution process was the development of the flexible design described in the S&ER Rev. 1. The DOE has developed a design for a monitored geologic repository at Yucca Mountain that could give future generations the choice of either closing and sealing the repository as early as allowable under NRC licensing-related regulations, or keeping it open and monitoring it for a longer time period. Aspects of the design are likely to continue to evolve, particularly in relation to the means of controlling heat generated by spent nuclear fuel. The DOE must provide a description of the proposed repository, including preliminary engineering specifications, as part of the site recommendation. A more detailed design would be developed for use in any license application to the NRC. The DOE approach to addressing data and model uncertainty includes comprehensive evaluation of uncertainties combined with assessment of performance. Increased confidence in the approach is gained by defense in depth that relies on the natural barriers of the site and the engineered barriers of the preliminary repository design. The approach to handling uncertainties would also be used in any license application to demonstrate with reasonable expectation that the regulations in 10 CFR Part 63 (66 FR 55732) would be met. The NRC, in a letter dated November 13, 2001, from Mr. Richard Meserve, Chairman, to Robert G. Card, Under Secretary, Energy, Science, and Environment, DOE, stated their position that based on existing knowledge and agreements between the DOE and NRC, sufficient information either is available or will be available to the DOE to support an acceptable license application if a decision is made to proceed with the Yucca Mountain Project. The DOE acknowledges that it is not possible to forecast with complete certainty what would occur hundreds or thousands of years in the future. The National Academy of Sciences, the EPA, and the NRC also recognize the difficulty of understanding the behavior of complex systems over long time periods. In 10 CFR Part 63 (66 FR 55732), the NRC acknowledges that "[P]roof that the geologic repository will conform with the objectives for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the understanding of the evolution of the geologic setting, biosphere, and engineered barrier system. For such long-term performance, what is required for licensing is reasonable expectation..." In 40 CFR Part 197, the EPA establishes "reasonable expectation" as a test of compliance, with diminished "weight of evidence" with time. The EPA also recognizes the potential need for expert judgment in assigning scenario probabilities, selecting simulation models, and assigning parameter distributions Consistent with National Academy of Science observations [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588.], the DOE has designed performance assessments based on a combination of mathematical modeling, site data and information, laboratory and literature data, and natural analogues. The DOE has conducted a comprehensive quantitative analysis of the possible future behavior of a Yucca Mountain repository (TSPA-SR). This analysis combined the results of detailed conceptual and numerical models of each of the individual and coupled processes in a single probabilistic model that can be used to assess how a repository might perform over long periods of time. The TSPA-SR was a next-generation analysis after the viability assessment. The TSPA-SR was the result of some significant changes in the preliminary design of the repository and also some further advancement in knowledge from ongoing research activities. Despite the extensive scientific studies described in the S&ER Rev. 1, the DOE has always recognized that significant uncertainties would remain in any assessment of the performance of a repository over thousands of years, as discussed in the S&ER Rev. 1, Sections 1.5, 4.1, and 4.4. These uncertainties are attributable to a variety of causes, ranging from uncertainty regarding the fundamental processes that may affect radionuclide migration to uncertainty related to the preliminary design and operation of the repository. For this reason, one part of the DOE approach to dealing with uncertainty relies on multiple lines of evidence that may contribute to the understanding of the performance of the repository. Another part of the DOE approach is a commitment to a performance confirmation program, as provided in 10 CFR Part 63. This program would extend beyond the possible recommendation of the site and through permanent closure. An important aspect of the TSPA-SR model is the presence of unquantified uncertainties. These are uncertainties for which a realistic distribution of parameters is not identified, but rather a very conservative bounding value or bounding range is chosen. Additional studies have been conducted to investigate effects of unquantified uncertainties and sensitivities in the model. Part of the additional studies was to add several features to the performance assessment to better quantify uncertainties and the affected processes. An additional performance assessment, the SSPA Volume 1 and 2, was prepared discussing this additional research and describing the modifications to the TSPA-SR model (SSPA Vol. 2, Sections 3 and 4). These sections summarize areas in which the supplemental model benefited from these additional uncertainty studies. Increased confidence is provided through a strategy of defense in depth that is related to the natural and engineered barriers. Confidence in the outcome of performance assessment modeling is provided for through reliance upon multiple barriers that ensure overall performance, despite the failure of one or more components to perform as expected. For example, the potential of the physical properties of geologic materials to provide natural barriers that retard radionuclide transport is included in the assessment of overall performance. The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. The bases of the approach are summarized as follows:
As originally envisioned the Yucca Mountain host rock was supposed to isolated [sic] waste from the human environment. Instead we now have a repository that relies almost entirely on manmade barrier systems to contain wastes.Response The use of engineered barriers does not conflict with the NWPA and is consistent with both EPA standards and NRC licensing-related regulations. Section 121(b)(1)(B) of the NWPA encourages the use of multiple barriers and directs the NRC to develop criteria that would provide for the use of multiple barriers in the design of the repository. The NRC has incorporated the multiple barrier concept at 10 CFR 63.102(h) and 10 CFR 63.113 (66 FR 55805 and 55807) to enhance the resiliency of the repository and increase confidence that performance objectives will be met. Thus, the use of complementary natural and engineered barriers in the assessment of disposal system performance does not contravene the intent of the NWPA, and is consistent with Yucca Mountain-specific licensing-related regulations. Both the natural barriers and engineered barriers would work together to contribute to the overall performance of a repository. Natural barriers limit the amount of water that could contact the waste and provide a geochemical environment that prevents mobilization and transport of most species of radionuclides. Equally important, there would be little percolation of water down through the rock layers to the repository block even during cooler, wetter periods. Engineered barriers also limit the amount of water that could contact the waste; moreover, the waste package would contain many species of radionuclides until they decay away. For example, strontium-90 and cesium-137 would have decayed away after the first 1,000 years. Far in the future, should the waste package breach and water dissolve the cladding and waste form, the movement of the long-lived radionuclides would be retarded by the physical and chemical properties of the geologic setting. Additionally, of those few species that are mobile, natural conditions of the unsaturated rock, as well as zeolites in the rock layers underlying the repository, would retard the migration of many species of radionuclides. Many species would sorb onto the zeolites and thus provide additional delay to allow additional time for these species of radionuclides to decay away. Thus, the natural and engineered barriers working together prevent the vast majority of radionuclide species from ever reaching the accessible environment. 3.2.2 (12843) Selinder, Bjorn Comment
DOE insists on, or is being forced, into moving forward when there is no conclusive evidence with regard to waste package performance, particularly with respect to waste package corrosion rates. At best, DOE can only claim that expert solicitation or what is otherwise known as an "informed opinion," finds no reason to believe the waste packages would fail, or more importantly, fail prematurely resulting in a release of radioactive materials.Response Corrosion testing by the DOE, which has been underway for over two years, has shown the corrosion rates are very low (much less than one micrometer per year) and are near the level of detection by the standard methods, such as weight loss measurements. These low values are consistent with data in the literature from both short-term and long-term tests on Alloy 22 and related alloys. Thus, a sufficient database exists to move forward. The degradation of the waste package is detailed in Section 4.2.4 of the S&ER Rev. 1. Corrosion of waste package materials has been conducted under conditions expected at Yucca Mountain and at conditions outside of those expected conditions to better understand the material's corrosion susceptibility. These tests have included service-condition testing, as well as accelerated testing. Accelerated testing has included a variety of electrochemical potential tests conducted under aggressive chemistry conditions. The DOE plans to continue laboratory testing throughout the preclosure period to confirm the expected waste package performance. The DOE continues to take advantage of data on other alloy materials of similar chemistry, engineering analogues, that have a much longer (approximately 50-year) experience base. The DOE is also installing thinner specimens to reduce measurement error and is evaluating the use of sensitivity probes that would permit on-line measurements of and changes to corrosion rates. 3.2.2 (12844) Selinder, Bjorn Comment
With the acknowledgement that the repository rock cannot by itself contain wastes, the public and more importantly the public in Nevada, is asked to place their confidence in a host of models that are supposed to predict repository performance for a period of at least 10,000 years into the future. The use of models add [sic] yet another layer of uncertainty. It has now become a question of when and how much radiation will reach the accessible environment.Response The DOE approach to addressing data and model uncertainty includes comprehensive evaluation of uncertainties combined with assessment of performance. Increased confidence in the approach is gained by defense in depth that relies on the natural barriers of the site and the engineered barriers of the preliminary repository design. The approach to handling uncertainties would also be used in any license application to demonstrate with reasonable expectation that the licensing regulations in 10 CFR Part 63 (66 FR 55732) would be met. The NRC, in a letter dated November 13, 2001, from Mr. Richard Meserve, Chairman, to Robert G. Card, Under Secretary, Energy, Science, and Environment, DOE, stated their position that based on existing knowledge and agreements between the DOE and NRC, sufficient information either is available or will be available to the DOE to support an acceptable license application if a decision is made to proceed with the Yucca Mountain Project. The DOE acknowledges that it is not possible to forecast with complete certainty what would occur hundreds or thousands of years in the future. The National Academy of Sciences, the EPA, and the NRC also recognize the difficulty of understanding the behavior of complex systems over long time periods. In its licensing regulation at 10 CFR Part 63 (66 FR 55732), the NRC acknowledges that "[P]roof that the geologic repository will conform with the objectives for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the understanding of the evolution of the geologic setting, biosphere, and engineered barrier system. For such long-term performance, what is required for licensing is reasonable expectation..." In 40 CFR Part 197, the EPA establishes "reasonable expectation" as a test of compliance, with diminished "weight of evidence" with time. The EPA also recognizes the potential need for expert judgment in assigning scenario probabilities, selecting simulation models, and assigning parameter distributions Consistent with National Academy of Science observations [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588.], the DOE has designed performance assessments based on a combination of mathematical modeling, site data and information, laboratory and literature data, and natural analogues. The DOE has conducted a comprehensive quantitative analysis of the possible future behavior of a Yucca Mountain repository (TSPA-SR and subsequent supplements). This analysis combined the results of detailed conceptual and numerical models of each of the individual and coupled processes in a single probabilistic model that can be used to assess how a repository might perform over long periods of time. The TSPA-SR was a next-generation analysis after the viability assessment. The TSPA-SR was the result of some significant changes in the preliminary design of the repository and also some further advancement in knowledge from ongoing research activities. Despite the extensive scientific studies described in the S&ER Rev. 1, the DOE has always recognized that significant uncertainties would remain in any assessment of the performance of a repository over thousands of years, as discussed in the S&ER Rev. 1, Sections 1.5, 4.1, and 4.4. These uncertainties are attributable to a variety of causes, ranging from uncertainty regarding the fundamental processes that may affect radionuclide migration to uncertainty related to the preliminary design and operation of the repository. For this reason, one part of the DOE approach to dealing with uncertainty relies on multiple lines of evidence that may contribute to the understanding of the performance of the repository. Another part of the DOE approach is a commitment to a performance confirmation program, as provided in 10 CFR Part 63. This program would extend beyond the possible recommendation of the site and through permanent closure. An important aspect of the TSPA-SR model is the presence of unquantified uncertainties. These are uncertainties for which a realistic distribution of parameters is not identified, but rather a very conservative bounding value or bounding range is chosen. Additional studies have been conducted to investigate effects of unquantified uncertainties and sensitivities in the model. Part of the additional studies was to add several features to the performance assessment to better quantify uncertainties and the affected processes. An additional performance assessment, the SSPA Volumes 1 and 2, was prepared discussing this additional research and describing the modifications to the TSPA-SR model (SSPA Vol. 2, Sections 3 and 4). These sections summarize areas in which the supplemental model benefited from these additional uncertainty studies. Increased confidence is provided through a strategy of defense in depth that is related to the natural and engineered barriers. Confidence in the outcome of performance assessment modeling is provided for through reliance upon multiple barriers that ensure overall performance, despite the failure of one or more components to perform as expected. For example, the potential of the physical properties of geologic materials to provide natural barriers that retard radionuclide transport is included in the assessment of overall performance. The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. The bases of the approach are summarized as follows:
We do not believe that DOE has met the threshold needed to ensure the long-term isolation of spent nuclear fuel and high-level nuclear waste. The site recommendation should be postponed until such time that DOE has developed a firm proposal for the repository design and can provide supportable evidence without the somewhat long list of uncertainties and unknowns currently associated with the characterization program and the ability to model future performance.Response Section 114(a) of the NWPA requires preliminary engineering specifications at the time any recommendation by the Secretary is made. A more complete design would be submitted to the NRC as part of the facility licensing process if the site is approved. As with virtually all substantial scientific and technical projects, information regarding the underlying scientific and technical concepts would continue to be gathered across the entire life of the project. DOE expects that additional investigations would continue throughout the entire project period and this information would be evaluated to support a closure decision. 3.2.2 (12846) Selinder, Bjorn Comment
I would also note that according to DOE, the repository is capable of being built and operated without substantial risk to the public. In fact, the Yucca Mountain Draft EIS may well suggest that the transportation component poses the greatest exposure risk. Yet, DOE fails to provide a comprehensive national transportation proposal for waste shipments to a repository. For example, I believe, that the DOE Draft EIS showed that rail transportation of waste would be overall safer than truck, but there is no policy recommendation. It may, in my opinion, be a mistake to allow individual generator sites and even states to select what would become the most politically acceptable modes and routes for repository shipments. We may ultimately develop a spider-web network of routes passing through all areas of the country that results in even greater risks, higher costs, and a less efficient and reliable transportation program.Response The DOE has identified in the FEIS mostly rail as the preferred mode for transportation of spent nuclear fuel and high-level waste both nationally and in the State of Nevada. At this time, however, the DOE has not identified a preference among the five candidate rail corridors in Nevada. The FEIS analyzes the potential environmental impacts that could result from the transportation of spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. This is based on the level of information and analysis, the analytical methods and approaches used to represent conservatively the reasonably foreseeable impacts, and the use of bounding assumptions where information is incomplete or unavailable, or where uncertainties exist. The use of widely accepted analytical tools, latest reasonably available information, and cautious but reasonable assumptions offer the most appropriate means to arrive at conservative estimates of transportation-related impacts. If the Yucca Mountain site were recommended and approved, at some future date the DOE would issue a Record of Decision to select a mode of transportation. If, for example, mostly rail was selected (both nationally and in Nevada), the DOE would identify a preference for one of the rail corridors in consultation with affected stakeholders, including the State of Nevada and affected counties. In this example, the DOE would announce a preferred corridor in the Federal Register and other media. No sooner than 30 days after the announcement of a preference, the DOE would publish its selection of a rail corridor in a Record of Decision. Other transportation decisions, such as the selection of a specific rail alignment within a corridor, would require additional field surveys, state and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews. For legal-weight or heavy-haul truck transportation of spent nuclear fuel and high-level radioactive waste, a motor carrier would use only routes that comply with the requirements contained in U.S. Department of Transportation regulations (per 49 CFR 397.101). These U.S. Department of Transportation regulations require use of routes designated as preferred routes that reduce the time in transit; these preferred routes are interstate system highways, interstate system beltways and bypasses, and state-designated preferred routes. There are exceptions for pick-up and delivery routes used to travel to and from a nearest preferred route. The State of Nevada and Native American tribal governments can designate alternate preferred routes. 3.2.2 (3965) Shankle, Judith
| Commenter | Comment Document No. |
| Mineral County, Nevada, Nuclear Projects Office | SR330031 |
| Shankle, Judith |
The DOE does not give the public enough time to respond, and information about the suitability of the Yucca Mountain (YM) site as a repository for Spent Nuclear Fuel (SNF) and High-Level Radioactive Waste (HLRW) is still coming out. How can the public make informed comments when all the evidence has not been presented yet? At the very least, the closing date for public comments should be extended an additional 90 days (December 20th, 2001) in order to provide the public a reasonable amount of time to review the PSSE and comment.Response The comment period of 165 days began on May 7, 2001, was extended 30 days by the Secretary as a result of public comments, and closed on October 19, 2001. The large amount of information developed by the DOE on the Yucca Mountain site was made available in stages to provide the public with ample time to review all the available materials and formulate their comments regarding a possible site recommendation by the Secretary. By the conclusion of the initial comment period, the DOE had held 57 public hearings on the consideration of Yucca Mountain across Nevada's 17 counties, and in Inyo County, California, which provided 165 days of public comment and 345 hours of public hearing time. In addition, on November 14, 2001, after the NRC finalized 10 CFR Part 63 for licensing (66 FR 55732) and the DOE finalized 10 CFR Part 963, (66 FR 57298) the Secretary of Energy announced a 30-day supplemental comment period, extending from November 14, 2001, to December 14, 2001, including nine hearings in Nevada to provide citizens an opportunity to comment on information that was not available at the conclusion of the initial comment period. 3.2.2 (3968) Shankle, Judith Comment
Mineral County believes the DOE violates not only Administrative Procedures Act ....Response The DOE has and will continue to follow the NWPA, as well as any other relevant statutory and regulatory requirements, in carrying out its responsibilities related to Yucca Mountain. 3.2.2 (4907) Shankle, Judith Comment
[Mineral County believes the DOE violates...] public trust that this program is supposed to promote.Response The DOE places great emphasis on openness and public involvement. It is the DOE's policy that the business of the DOE must be open to the full view of those whom it serves; consistent with applicable laws, regulations, contracts, and national security interests. The DOE has incorporated public input into its decisions when appropriate and feasible, and continues to provide feedback to the public on its reasoning. For example, the process for examining the suitability of a repository at Yucca Mountain was structured to provide input and scrutiny of the preliminary evaluation. Public hearings and public review of the S&ER, PSSE, DEIS, and SDEIS by public stakeholders, agencies, Native Americans, and others during the comment periods comprised an important part of the process. The review periods provided interested parties with the opportunity to examine the assumptions, analyses, and conclusions; and the opportunity to provide input on how the DOE should address these issues and other concerns. To facilitate public review and comment on the large amount of information the DOE has compiled over the years regarding the Yucca Mountain site, in May 2001 the DOE issued the S&ER. The information and data compiled in this report addresses the subjects described in Section 114(a)(1)(A)-(C) of the NWPA, as amended. In addition, on August 21, 2001, the DOE issued a Federal Register notice that announced the release of the PSSE for public review and comment. The DEIS and the SDEIS had also been previously made available to the public. By providing this information to the public in advance of public hearings, the DOE sought to enhance the ability of the public to review and comment on the data the DOE has compiled to date. Subsequent to the release of these documents, the DOE held numerous public hearings in the vicinity of Yucca Mountain. By the end of the site recommendation comment period, October 19, 2001, the DOE had held 57 public hearings on the consideration of Yucca Mountain across Nevada's 17 counties, including Mineral County, providing 165 days of public comment and 345 hours of public hearing time. In addition, on November 14, 2001, after the NRC finalized 10 CFR Part 63 for licensing and the DOE finalized 10 CFR Part 963, the Secretary announced a supplemental 30-day comment period, including nine supplemental hearings in Nevada to provide citizens an opportunity to comment on information that was not available at the conclusion of the initial comment period. The DOE believes that the documents and information provided to the public and the time allotted for their review were sufficient to enable the public to formulate their comments regarding a possible site recommendation by the Secretary. 3.2.2 (16190) Shankle, Judith Comment
Therefore, Mineral County suggests that the DOE immediately suspend the current notice that is in the Federal Register, conduct an evaluation of the Yucca Mountain site under the 10 CFR Part 960 guidelines, and publish the results of that evaluation in the Federal Register for public review and comment.Response The final site suitability guidelines for a repository at Yucca Mountain are contained in 10 CFR Part 963 (66 FR 57298). 10 CFR Part 960 is no longer applicable to a Yucca Mountain repository, having been superseded by 10 CFR Part 963, which was issued as final guidelines on November 14, 2001. Public comments received as part of the Part 963 rule-making process were considered by DOE before the final guidelines were issued. The NRC reviewed proposed 10 CFR Part 963 and, based on that review, concurred in the final draft guidelines (66 FR 54303). The PSSE was prepared based on the proposed 10 CFR Part 963. The SSE was prepared based on the final 10 CFR Part 963 (66 FR 55732), which was issued November 14, 2001. The SSE would be part of the suite of documents available to support any site recommendation. The DOE provided a supplemental 30 day public comment period to afford the public an additional opportunity to comment on information that was not available during the comment period that ended on October 19, 2001, including the final NRC licensing regulations and DOE guidelines, and the documents noted below. The DOE also posted several documents to its Yucca Mountain Internet Site (www.ymp.gov). These documents include: (1) "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain-Input to the Final Environmental Impact Statement and Site Suitability Evaluation" [Williams, N.H. 2001. "Contract No. DE-AC08-012RW12101—Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation REV 00 ICN 02." Letter from N.H. Williams (BSC) to J.R. Summerson (DOE/YMSCO), December 11, 2001, RWA:cs-1204010670, with enclosure. ACC: MOL.20011213.0056.]; (2) "Total System Performance Assessment Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment—Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations, Rev 00 ICN 01." Letter from N.H. Williams (BSC) to S.J. Brocoum (DOE/YMSCO), December 11, 2001, RWA:cs-1204010669, with enclosure. ACC: MOL.20011213.0057.]; and (3) "Technical Update Impact Letter Report" [BSC (Bechtel SAIC Company) 2001. "Technical Update Impact Letter Report." MIS-MGR-RL-000001 REV 00. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011211.0309.]. 3.2.2 (4910) Shankle, Judith Comment
...under any objective and scientific criteria, the YM Project would have been abandoned long ago.Response The DOE has conducted a series of investigations and evaluations (the site characterization program) to assess the suitability of the Yucca Mountain site as a geologic repository. These activities have been subjected to ongoing review by the NRC, NWTRB, other agencies, the State of Nevada, Native American tribes, and affected units of local government. The results of these investigations and evaluations have been documented in a series of documents that have been made available to the public, including the S&ER, issued May 7, 2001, and the PSSE, issued August 21, 2001. In addition, supplemental information was made available on November 14, 2001, as described in 66 FR 57049. The results of the investigations and evaluations performed by the DOE would serve as a basis for any recommendation to the President regarding the potential development of a repository at Yucca Mountain. 3.2.2 (15715) Shankle, Judith
| Commenter | Comment Document No. |
| Mineral County, Nevada, Nuclear Projects Office | SR330045 |
| Shankle, Judith |
As tragic as terrorist attacks are, the magnitude of damage would not come close to what would happen if these terrorist fanatics were to get a hold of the nuclear waste. The Japanese incident, terrorist's attacks and human error--the WIPP incident where a truck transporting low-level nuclear waste got mis-routed--are only wake-up calls and should be heeded to, when considering a campaign of this magnitude. If DOE and the nation are not ready to take on a campaign of this magnitude.Response The physical security measures already in place by the NRC and the exceptional strength and durability of the transportation casks would protect shipments of radioactive waste from acts of terrorism or sabotage. The same design features that make transportation casks capable of surviving severe accidents also limit their vulnerability to sabotage. Also, programs and processes to guard against potential sabotage would be developed by the DOE and submitted to the NRC for review and approval before any spent nuclear fuel or high-level radioactive waste is transported to Yucca Mountain. Shipments of spent nuclear fuel and high-level radioactive waste would be subject to physical protection regulations of the NRC (10 CFR 73.37). The NRC establishes regulations to minimize the possibility of sabotage events. Security measures include armed escorts, tracking, safeguarding schedule and itinerary information, security arrangements for the shipments, and arrangements with law enforcement agencies. In addition, transportation casks are massive metal containers designed to contain their radioactive contents following a severe accident sequence (e.g., drop, puncture, fire, and immersion in water). If the regulations for safeguards and security measures that apply to spent nuclear fuel transport were revised, the DOE would comply with the revised regulations in place at the time of shipments. For the purpose of analysis in the FEIS, the DOE assumes that a sabotage event occurs, and considers the consequences. As discussed in the FEIS, a successful sabotage attempt would not likely release significant quantities of radioactive materials. Casks are designed and built to prevent release of their contents under severe accident conditions. Most types of sabotage events would not likely result in more damage to the casks than the severe transportation accident for which the casks were intended to survive. 3.2.2 (15716) Shankle, Judith Comment
Both the State of Nevada and the DOE agree that once radioactive materials leave the breached waste containers, they can begin showing up in wells 11 miles from Yucca Mountain within 500 years.Response Section 4.2.1.4 of the S&ER Rev. 1 discusses the time required for a nonsorbing tracer to reach the water table from the repository. These breakthrough times can vary from 400 years to 600,000 years depending on the upper and lower infiltration rates. Section 4.2.8.3.3 of the S&ER Rev. 1 provides related discussion about both field measurements and numerical predictions of the movement of radionuclides from the potential repository horizon to the water table. For the 10,000-year postclosure period, radionuclides available for transport from a repository would be small to nonexistent. 3.2.2 (15720) Shankle, Judith Comment
Both the DOE and the state agree that water is the vehicle by which the radiation can and eventually will escape the proposed repository traveling downward through fractures in the rock. The DOE and the scientific community accept that the water travels from the surface to the proposed repository horizon in 50 years or less. After 50 years, the water enters the tunnels where the waste is to be deposited through a series of engineered barriers that the DOE is proposing to keep water away from the waste.Response The DOE has used a variety of naturally occurring isotopic indicators, including chlorine-36 and tritium, to investigate the nature of infiltration and deep percolation of water in the unsaturated zone at the site (S&ER Rev. 1, Section 4.2.1.2.11). The study results were used for estimating and bounding infiltration rates and percolation fluxes in the unsaturated zone, and are the primary data used for model calibration and for testing the accuracy of the unsaturated zone flow and transport model that is being used to evaluate the possible transport of radioactive materials through the unsaturated zone beneath the repository (S&ER Rev. 1, Section 4.2.1.3.1.5). The results of the chlorine-36 tracer studies indicate that there may be fast pathways from ground surface to the repository level. These pathways are associated with faults and are consistent with the conceptual model of water flow through the mountain. The results of the chlorine-36 studies are not conclusive and are the subject of ongoing verification studies. To compensate for this uncertainty, it was assumed for the purposes of performance assessment that fast pathways exist, which is a conservative assumption (tending to over-state the risk estimate). Even with this conservative assumption, the results of the performance assessment evaluations indicate that the repository would perform in conformance with the regulatory licensing requirements promulgated by the NRC in 10 CFR Part 63 (66 FR 55732). "Bomb-pulse" chlorine-36 originated from thermonuclear testing during the 1950s and 1960s, primarily in the Pacific Proving Grounds (YMSD, Section 5.3.7.3.1). Detection of elevated levels of chlorine-36 at the repository horizon level could be evidence of a connected pathway through which surface precipitation has percolated to the repository depth within the last 50 years. Results from the chlorine-36 analyses indicate elevated amounts (that is, values significantly above normal [natural] background measurements) of bomb-pulse chlorine-36 at some locations within the Exploratory Studies Facility and the Enhanced Characterization of the Repository Block Cross-Drift. Detection of this bomb-pulse chlorine-36 in the subsurface at Yucca Mountain is almost exclusively associated with faults and well-developed fracture systems close to these faults (S&ER Rev. 1, Section 4.2.1.3.1.5). These are locations where faster flow of downward percolating groundwater was anticipated. Overall, most of the water that infiltrates Yucca Mountain moves slowly through the matrix and fracture network of the rock. Only a very small fraction of downward percolating groundwater moves through the fracture network with the relatively fast travel times suggested by the bomb-pulse chlorine-36 occurrences, and these pathways have been observed almost exclusively to be well-defined fracture networks associated with faults (YMSD, Section 8.9.1.7). The generally slow movement of water through the rock matrix is supported, for example, by carbon isotope data from water extracted from within the rock matrix (water within the rock body, away from fractures) that correspond to residence times of thousands of years (YMSD, Section 5.3.7.4.2). At present, there remains some uncertainty regarding the results of the chlorine-36 results and these uncertainties are being studied. Acknowledging the potential uncertainty of the analytical results, the site characterization models assume that the elevated chlorine-36 results are valid. Therefore, the locations of these presumed fast pathways have been included in both unsaturated zone characterization and future-case transport models to evaluate the expected future performance of the repository at Yucca Mountain. In other words, the model predictions assume that there are fast pathways even though there is evidence to suggest that there are not, thus resulting in very conservative assumptions for evaluating repository performance (S&ER, Section 4.2.1.3.1.5). Evidence for the overall lack of observable fluid flow in the subsurface includes the fact that throughout the excavation of more than 11 kilometers (6.8 miles) of tunnels (Exploratory Studies Facility and Enhanced Characterization of the Repository Block Cross-Drift) and testing alcoves, only one fracture was observed to be moist (S&ER Rev. 1, Section 4.2.1.2.12, Figure 4-18). No active subsurface flow of water was observed. Analysis of the water from the single moist fracture detected no bomb-pulse chlorine-36. Only background levels of chlorine-36 were found, indicating that the age of the water was greater than 50 years. Further observations from testing alcoves that have been isolated from the effects of tunnel ventilation for several years confirm the lack of observable natural seepage at the repository level. Finally, while it is true that the barrier system would include engineered barriers (for example, waste packages and drip shields), the intent of these engineered systems is to contribute to the long-term isolation of radioactive waste materials by complementing the natural attributes of the site's geologic and hydrologic setting (S&ER Rev. 1, Section 4.5.1). 3.2.2 (15721) Shankle, Judith Comment
Problems with the Barrier System includes but are not limited to the following: The DOE proposes to place a series of titanium drip shields over the disposal containers. While the DOE believes that these shields will remain intact for thousands of years, research by the state of Nevada and the Nuclear Regulatory Commission shows that because of fluoride dissolved in Yucca Mountain water, the shields will probably last for less than 100 years.Response The DOE has concluded, on the basis of testing conducted at Lawrence Livermore National Laboratory, as well as data from the literature, that the corrosion rates of the titanium alloys selected for the drip shield are very low (much less than one micrometer per year) and that the drip shields would perform their function for the 10,000-year postclosure period. While fluoride is known to cause corrosion at very high (more than 1000 parts per million) concentrations and acid conditions, the concentrations expected at Yucca Mountain would be low (a few parts per million) under acid conditions, partly due to the fact that most of the fluorine deposits as fluorides on the rock fracture surfaces and would be essentially unavailable for transport to the waste packages. The DOE tests have been conducted with concentrated J-13 well waters that contain inhibitor (beneficial) anions. Studies are underway to evaluate the amounts of the individual inhibitor ions needed to decrease the susceptibility to localized corrosion. A wide spectrum of potential corrosion mechanisms was evaluated for each of the candidate drip shield materials given the expected Yucca Mountain environment (S&ER Rev. 1, Section 4.2.4.3). These mechanisms include dry oxidation; humid air corrosion; general aqueous corrosion; localized corrosion, including crevice and pitting corrosion; stress corrosion cracking; hydrogen induced cracking; heavy metal embrittlement; thermal embrittlement; microbially influenced corrosion; radiolysis enhanced corrosion; and galvanic corrosion. The response of each material to the listed corrosion mechanisms is detailed in the S&ER Rev. 1, Section 4.2.4.3. The DOE has concluded that humid air corrosion, general aqueous corrosion, and hydrogen induced cracking could potentially occur for titanium under Yucca Mountain conditions, but the corrosion rates are expected to be very low. Stress corrosion cracking can also occur as a result of rockfall; however, the cracks generated are expected to be tight and readily filled with corrosion products. The rocks could also potentially dent the drip shield; however, the stiffeners added to the design preclude these dents leading to the focusing of dripping water. 3.2.2 (15723) Shankle, Judith Comment
The DOE uses the engineered barriers to provide most of the protection whereas the Nuclear Waste Policy Act of 1982 originally envisioned that most of the protection would be from a natural or geological barrier. Mineral County believes that when both natural and engineered barriers are used, the natural barriers should be the basis for isolating the waste.Response The use of engineered barriers does not conflict with the NWPA and is consistent with both EPA standards and NRC licensing regulations. Section 121(b)(1)(B) of the NWPA (42 U.S.C. 10141(b)(1)(B)) encourages, rather than limits or otherwise prohibits, the use of engineered barriers for a geologic repository at Yucca Mountain. The NRC has incorporated the multiple barrier concept in 10 CFR 63.102(h) and 10 CFR 63.113 (66 FR 55805 and 55807). Thus, the use of complimentary natural and engineered barriers in the assessment of disposal system performance does not contravene the intent of the NWPA (42 U.S.C. 10101 et seq.), and is consistent with Yucca Mountain-specific licensing regulations. Both the natural barriers and engineered barriers would work together to contribute to the overall performance of a repository. Natural barriers limit the amount of water that could contact the waste and provide a geochemical environment that prevents mobilization and transport of most species of radionuclides. Equally important, there would be little percolation of water down through the rock layers to the repository block even during cooler,