The Value of State Oversight
In the Department of Energy
Nuclear Waste Disposal Operations
at Yucca Mountain

By Linda Lehman
Technical & Regulatory Evaluations Group, Inc.
13231 Henning Circle NE Prior Lake, MN 55372


The Nuclear Waste Policy Act of 1982 provides for review and oversight by States and Indian tribes which are affected by the federal high-level radioactive waste disposal program. This review and oversight was to be funded from the Nuclear Waste Fund, which was established under the l982 Act and supported by rate payers. The 1987 amendments to the Act, singled out Yucca Mountain as the only site under consideration for the nation's high-level waste repository and extended the right of review and oversight to affected local units of government in Nevada and California.

In October 1995, the DOE withheld the review and oversight funds from the State of Nevada and local governments. Fiscal Year l997 review and oversight funds to the State of Nevada and local governments were subsequently prohibited by the 1997 Appropriations Act. This action was justified within the Congress by implying that the State of Nevada was somehow to blame for the lack of progress toward disposal goals and that the technical reviews and research done by the State of Nevada were not scientifically valid, and were only offered to cause delays.

During the years that the State of Nevada did receive review and oversight funds, the amount of funding ranged from 1 - 2% of the annual DOE nuclear waste program budget. The State of Nevada utilized these funds for: activities which included technical reviews of program plans and reports related to Yucca Mountain site investigations; reviews of data and analyses being undertaken by the DOE, the NRC and their associated laboratories or contractors, and participation in the regulatory activities of the US EPA and the US NRC.

This technical oversight has allowed the States and local governments access to information which would otherwise be unavailable and to conduct independent analyses of data collected by the DOE regarding geologic and hydrologic characteristics of the Yucca Mountain area.

This so called "stake holder" involvement has been incorporated into most other DOE siting and cleanup projects, and has been quite successful in resolving critical issues and has sped the ability to develop or remediate these sites.

The Yucca Mountain Project is an unfortunate exception to this general DOE stakeholder rile. The Department of Energy throughout, has resisted the role of the State of Nevada as an independent reviewer in the geologic and geotechnical studies of Yucca Mountain. In fact, the DOE provided State funding for these activities only after being ordered to do so by a U.S. Circuit Court of Appeals1. Only recently, now that DOE considers most of the field investigations of Yucca Mountain to be complete, has it come to light that this resistance has only served to the detriment of the project.

There are numerous examples of State work which has been previously ignored or discounted, including analyses of surface processes, volcanism, tectonics and seismicity. One, significant to DOE projections of long-term waste isolation, arises from the independent State analyses of hydrology and performance assessment. The following elaboration of this example, is intended to illustrate that early acceptance of independent and alternative approaches to the scientific analyses at Yucca Mountain would have provided material benefits and a more credible, timely and cost effective investigation of the viability and suitability of the site as a high-level nuclear waste repository.

The State of Nevada initiated a hydrology and performance assessment review of the Yucca Mountain site in 1983, following the passage of the Nuclear Waste Policy Act of 1982. By the late 1980's and early 1990's the State hydrology reviews indicated a discrepancy between the available data and the models of the unsaturated zone used for calculating site performance, which were developed by the US Geological Survey and the DOE National Laboratories. Believing the DOE models to be in error, the State challenged these models through official comments on DOE documents 2.

The State of Nevada conceptual model of groundwater flow in the unsaturated zone was developed in December of 1991  (7,8)  and included fracture flow, focused recharge and discrete fracture flow. The State's position was that the DOE groundwater models by assuming a primarily matrix flow regime, greatly underestimated the groundwater flux through the site and therefore also greatly underestimated releases from the repository.

The State believed, contrary to the DOE assumptions, that flow at Yucca Mountain was primarily fracture-flow dominated and that water reached the repository level much sooner than the hundreds of thousands of years predicted by the DOE models. This State model was based in part, on available geochemical data indicating tritium to be present in locations below the repository horizon. The presence of tritium (created in bomb detonations) indicates that very rapid infiltration of water had occurred through the mountain, reaching the repository level or lower, in about 50 years. The State also challenged many of the boundary conditions used in the DOE models which also led to under estimates or forced unrealistic movements of flow. (4,5,6)

The analytical arm of the NRC, the Southwest Research Center for Regulatory Analyses located in San Antonio, Texas, did investigate the key model assumptions utilized by the State model in 1995 (3), and in fact announced the validity of these assumptions. However, the DOE did not change their models in light of this fact. Rather than investigating the basis of the State findings and claims, the DOE and their contractors concentrated solely on defending their models.

In late 1995 and early 1996, the excavation of the tunnel at Yucca Mountain, produced geochemical data which could no longer be ignored by the DOE. These data indicated that bomb pulse Chlorine 36 had also made its way into the tunnel and appeared to be coincident with many fault and fracture zones. This situation, which was predicted by the State models, forced the DOE to change their concepts of flow through the mountain, resulting in higher flux rates and time consuming and costly model revisions.

Not only are the DOE models in need of new assumptions, but the data base on which these models depend is not adequate to address this type of flow. Many critical parameters which control fracture flow have never been measured nor have assumptions in this regard been verified at Yucca Mountain.

In late 1996, the DOE finally recognized the validity of the State of Nevada models and assumptions, and is in fact now using the same, or higher flux rates and boundary conditions developed in the 1991 State model and in many other State publications and presentations.(See references 8 to 14)

This example of State review is important first, because it underscores the need for alternative and independent scientific approaches in a large and technical endeavor such as Yucca Mountain. Second, the DOE modeling, data collection and performance assessment programs have been seriously misguided, unnecessarily costly and wasteful.

While it has been understood from the outset that siting a high-level nuclear waste repository would be controversial and the relationship between potential hosts and the DOE, adversarial, their scientific studies should not have been ignored. Since Yucca Mountain was named the only site to be investigated, the DOE has increasingly gone to an "advocacy science" approach. This may be the reason for DOE's reluctance to accept any but the most favorable technical interpretations of site performance.

The example above and those mentioned, but not elaborated, reflect a trend in program development which is not only wasteful of time and other resources, but has also resulted in undermining the scientific credibility of the program.

DOE must now make a decision on the viability and safety of the Yucca Mountain site, based on a meager and inadequate data base.


References Cited

1. Nevada vs. Herrington, U.S. 9th Circuit Court of Appeals, CA Number 84-7846, December 2, 1985.

2. State of Nevada Comments on the U.S. Department of Energy Draft Environmental Assessment for the Proposed High Level Nuclear Waste Site at Yucca Mountain. Vol.I and Vol.ll., Compiled by Nevada Nuclear Waste Project Office, Carson City, NV., March 1985.

3. Ross Bagtzoglou, Presentation at the Evan's Conference on Unsaturated Fracture Flow, Univ. of Arizona and the US NRC, January 1995, Tucson, Arizona.

4. Lehman L.L., The Effects of Variability in Selected Model Inputs on Modeled Unsaturated Water Content Profiles at Yucca Mountain. Nevada, Third INTRAVAL Phase II workshop, San Antonio, November 1992.

5. Lehman L.L., Brown T.P., Testing Performance Assessment Parameter Sensitivity to Choice of Hydrologic Conceptual Model, ANS Topical Meeting "Spectrum 94: International Nuclear and Hazardous Waste Management", Atlanta, August 1994.

6. Lehman L L., Brown T.P., Testing Performance Assessment Parameter Sensitivity to Choice of Hydrologic Conceptual Model, 15th Annual U.S. DOE LLRW Management Conference, Tucson, December 1993.

7. L. Lehman, December l7, l99l, Alternative Conceptual Model of Groundwater Flow at Yucca Mountain Nevada, Report to the State of Nevada Nuclear Waste Project Office, Carson City, Nevada.

8. Lehman LL., Alternate Conceptual Model of Ground Water Flow at Yucca Mountain, International High-Level Radioactive Waste Management Conference, Las Vegas, Nv, April 1992.

9. Lehman L.L., Brown T.P., INTRAVAL Modeling Conclusions Addressing Non-unique Solutions, Presented to the Nuclear Waste Technical Review Board, Reno, NV, April 1993.

10. Brown T.P., Lehman L.L., Nieber J.L., Testing Conceptual Unsaturated Flow Models Using Numerical Stimulation of Real Data for the Proposed High Level Nuclear Was Repository at Yucca Mountain. Nye County. Nevada, 1993 American Geophysical Union Annual Meeting, Baltimore, May 1993.

11. Brown T.P., Lehman L.L., Nieber J.L., Testing Conceptual Unsaturated Zone Flow Models for Yucca Mountain. Nye County. Nevada, Third INTRAVAL Phase-2 Workshop, Stockholm, September 1993.

12. Brown T.P., Lehman L.L., Nieber J.L., Testing Conceptual Unsaturated Zone Flow Models for Yucca Mountain, International High-Level Nuclear Waste Management Conference, Las Vegas, May 1994.

13. Mifilin, M. Unsaturated Zone Hydrology. State of Nevada Technical Program, Presentation to the Advisory Committee on Nuclear Waste, February 23, l989.

14. Mifflin, M. Unsaturated Zone Hydrology. State of Nevada Technical Program, Presentation to the Nuclear Waste Technical Review Board, June 26, l989



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