Yucca Mountain Would Contaminate California’s Groundwater

Nevada’s opposition to DOE’s license application is driven by the unsuitability of the site for permanent geologic disposal and technical deficiencies in DOE’s repository engineering design. DOE proposes to locate the repository emplacement drifts in fractured rock above the water table. See Figure 1. The proposed repository would inevitably leak dangerous radionuclides into the groundwater, where they would be transported to an aquifer from which water is used for a variety of purposes. Contaminated groundwater from Yucca Mountain would inevitably result in radioactive contamination of the groundwater in California’s Death Valley.

Crosscut of water infiltration to ground water

Figure 1. Yucca Mountain Geology & Hydrology is Unsuitable for Permanent Geologic Disposal

Sandia National Laboratories (SNL) prepared groundwater analyses evaluating the potential for radioactive contamination of the groundwater in Nevada’s Amargosa Valley and California’s Death Valley. The flow paths calculated by SNL indicate that under some circumstances radioactive contamination could travel through Nevada’s Amargosa Valley and continue deep into Death Valley, reaching the Timbisha Shoshone Tribe trust lands at Furnace Creek.1 See Figure 2. The only uncertainties about radioactive contamination of groundwater are how much, how far, and how fast.2 The NRC staff in 2016 concluded that only minor contamination (up to 1.3 mrem/year) would occur in the Amargosa Valley farming area over the regulatory compliance period. Nevada’s analyses indicate that under some circumstances the off-site contamination could exceed the EPA 10,000 year-allowable standard (15 mrem/year) in less than 900 years and exceed the million-year-standard (100 mrem/year) in 2,000 years.3

Figure 2. Groundwater Contamination would Impact California and the Timbisha Shoshone Tribe

DOE submitted its License Application and supporting Environmental Impact Statements (EISs) to NRC in June 2008. After reviewing DOE’s documents, the NRC staff found in September 2008 that “the information provided in the EISs does not adequately characterize how potential contaminants may affect groundwater resources in the volcanic-alluvial aquifer, and the potential effects from surface discharge.” NRC staff could not accept DOE’s assessment of the repository’s cumulative impact on groundwater and the potential impacts of discharge of potentially contaminated groundwater to the surface, and informed DOE that their EISs would need to be supplemented.4

In December 2008, the State of Nevada submitted more than one hundred contentions (subsequently admitted) challenging various aspects of DOE’s license application regarding long-term repository performance and the resulting groundwater impacts.5 The State of California Department of Justice and the California Energy Commission submitted five contentions challenging DOE’s incomplete and inadequate analysis of the repository’s cumulative impact on groundwater, surface discharge of groundwater, and groundwater pumping.6 The County of Inyo, California submitted seven groundwater contentions,7 and the Timbisha Shoshone Tribe submitted four groundwater contentions.8

In 2013, the NRC requested that DOE prepare an EIS Supplement on groundwater impacts. DOE declined, and the Commission directed NRC staff to prepare the required NEPA document. NRC staff issued a Draft EIS Supplement on groundwater impacts in 2015, followed by a Final EIS Supplement in 2016, which concluded that “all of the impacts on the resources evaluated in this supplement would be SMALL.”9 If the adjudicatory portion of the NRC licensing proceeding resumes, the State of Nevada will contend that now both DOE and NRC have failed to fully evaluate groundwater contamination and surface discharges of contaminated groundwater.

Any contamination is a major concern for the Timbisha Shoshone Tribe. The Timbisha Shoshone Tribe commented extensively on the NRC’s 2015 draft evaluation of groundwater impacts, including the following statements:

“The [NRC Draft Groundwater EIS] Supplement admits that contaminated groundwater effluent from the repository will reach springs that the Timbisha Shoshone hold as sacred and require to be kept pure. SEIS, p. 3-38. Yet the Supplement contains no consideration or meaningful analysis of this injury to Timbisha Shoshone cultural interests or how these effects can be prevented. Id. (only public health and physiological impacts considered). This failure to adequately examine cultural and historical resources is in direct violation of NEPA’s mandates. 40 C.F.R. 1502.16(g); CEQ Guidance; see also 10 C.F.R. § 51.71(b).”10

“The United States has a trust obligation to ensure that the Timbisha’s Reservation remains livable and self-sustaining. Winters v. United States, 207 U.S. 564 (1908). This is the exact standard that is applied to the water supply available to reservations, and by its terms (livable and self-sustaining) it applies both to water quantity and to water quality. It is the responsibility of the United States to ensure that the Tribal springs and groundwater sources remain free of radioactive contamination in perpetuity.”11

1 State of Nevada, Comments to NRC on NUREG-2184 (Nov. 20, 2015), Docket ID NRC-2015-0051, (Nov. 20, 2015) Pp. 50-53. https://www.regulations.gov/comment/NRC-2015-0051-0108
2 The EPA and NRC regulations would limit radiation doses resulting from groundwater contamination to 15 mrem/year for 10,000 years and 100 mrem/year for the next 990,000 years. In their 2016 EIS supplement, NRC staff calculated that even if thousands of titanium drip shields were installed in the repository at Yucca Mountain, some off-site contamination resulting in individual radiological doses up to 1.3 mrem/year could occur over the regulatory compliance period. Nevada’s consultants calculated that without the drip shields, the 10,000-year standard (15 mrem/year) could be exceeded in less than 900 years and the one-million year-standard (100 mrem/year) could be exceeded in 2000 years. Nevada is also challenging the two-part EPA radiation protection standard in court.
3 Report and Recommendations of the Nevada Commission on Nuclear Projects, November 2019, p. 16. http://yuccamountain.wpengine.com/wp-content/uploads/2022/08/2019-Report-RecommendationADA-sm.pdf
4 NRC, Staff’s Adoption Determination Report, Pages 3-10 to 3-12 (September 5, 2008). https://www.nrc.gov/docs/ML0824/ML082420342.pdf
5 Report and Recommendations of the Nevada Commission on Nuclear Projects, November 2019, Pp. 38-41. http://yuccamountain.wpengine.com/wp-content/uploads/2022/08/2019-Report-RecommendationADA-sm.pdf All of Nevada’s contentions are available at: https://anp.nv.gov/uploadedFiles/anpnvgov/content/Legal/NRC_Licensing/Contentions_NV.pdf
6 California’s contentions are available at: http://www.state.nv.us/nucwaste/licensing/Contentions_CA.pdf.
7 Inyo County’s contentions are available at: http://www.state.nv.us/nucwaste/licensing/Contentions_Inyo.pdf
8 Timbisha Shoshone Tribe’s contentions are available at: http://www.state.nv.us/nucwaste/licensing/Contentions_Timbisha.pdf
9 NRC, Supplement to the USDOE’s EIS, Final Report, NUREG-2184, Page xii (May 2016). https://www.nrc.gov/docs/ML1612/ML16125A032.pdf
10 “Comments of the Timbisha Shoshone Tribe on the 2015 NRC Draft Supplement,” Attachment B, State of Nevada, Comments to NRC on NUREG-2184 (Nov. 20, 2015), Docket ID NRC-2015-0051, (Nov. 20, 2015) p. 72. https://www.regulations.gov/comment/NRC-2015-0051-0108
11 Ibid., p.75.
12 “Native Americans Belief in Water: An Environmental Justice Context,” Attachment C, State of Nevada, Comments to NRC on NUREG-2184 (Nov. 20, 2015), Docket ID NRC-2015-0051, Pp. 78-98. https://www.regulations.gov/comment/NRC-2015-0051-0108

Co-author Fred C. Dilger Ph.D., is executive director of the Nevada Agency for Nuclear Projects. Co-author Robert J. Halstead served as executive director of the Nevada Agency for Nuclear Projects from 2011 – 2020. Dr. Dilger and Mr. Halstead have more than 50 years combined experienced working on Yucca Mountain issues and have authored or co-authored more than 50 publications and reports on nuclear waste management, environmental impact assessment, and energy policy.