Since the time this column was written, President Bush
announced his approval Feb. 15 of Yucca Mountain as the site for the geologic
disposal of nuclear waste. From Feb. 15, Nevada has 60 days to file a Notice
of Disapproval to Congress. Congress must overturn this notice within 90 days
while in session, and can do so with a majority vote. Should Congress overturn
the disapproval, DOE then has 90 days to submit an application to the Nuclear
Regulatory Commission for a license to dispose of nuclear waste at Yucca Mountain.
In early January of this year, Secretary of Energy Spencer Abraham notified Nevada’s governor and legislature of his intention to recommend Yucca Mountain to President Bush as the nation’s geological repository for nuclear waste. Secretary Abraham based his recommendation on his “belief that the science behind this project is sound and that the site is technically suitable for this purpose.” Recent independent reports call into question the Secretary’s claim that the Department of Energy’s (DOE) work is “scientifically sound,” and suggest that the search for a permanent burial ground for this country’s nuclear waste has been driven more by politics and bureaucratic bias than by science.
The first of these reports comes from the Nuclear Waste Technical Review Board (NWTRB), which Congress established as an independent federal agency charged with evaluating DOE’s work on the Yucca Mountain Project. The board sent a letter to Congress in January 2002 outlining a long list of deficiencies in DOE’s work: “the Board’s view is that the technical basis for DOE’s repository design is weak to moderate at this time.” One of the greatest weaknesses involves the soundness of flow and solute-transport models in the saturated and unsaturated zones. The NWTRB letter describes inconsistencies among different models and between models and field data, as well as problems with model linkages. DOE also lacks sufficient data on the physical and chemical environment of Yucca Mountain, radionuclide uptake in the biosphere, and the possibilities and consequences of volcanic activity.
NWTRB has sharply and frequently criticized DOE for relying solely on a complicated mathematical model — the Total System Performance Assessment — as the principal method for predicting exposure risks over the next 10,000 years. The uncertainties and assumptions associated with this model have led NWTRB to conclude that the “Total System Performance Assessment by itself may never be able to show repository safety with confidence.” For years, NWTRB has recommended that DOE pursue “multiple lines of evidence,” such as natural and engineered analogues that would supplement data collected in field and laboratory experiments. The board’s letter to Congress stresses that DOE has only recently begun to look at these analogues and that its work in this area is incomplete.
It also points out that DOE wants to finalize the Yucca Mountain performance assessment before deciding whether to operate the repository at high or low temperatures. Accurate modeling of the operating temperature of the repository is especially critical because DOE no longer expects that climatic and geological conditions alone will contain radioactive waste. Instead, DOE’s repository design relies heavily on engineered barriers constructed of newly developed alloys. The long-term corrosion resistance of these alloys is poorly understood, but basic laws of chemical reactivity predict that corrosion will be greater in a high-temperature repository. NWTRB has concluded that gaps in data on the performance of waste packaging materials constitute “a critical technical weakness.”
In a report released in December 2001, the General Accounting Office (GAO) questioned the “prudence and practicality” of making a site recommendation to the President in light of the “significant amount of work remaining to be done” in collecting and analyzing data on Yucca Mountain geology and the engineered barriers designed to prevent nuclear waste from migrating off-site. GAO cites 293 unresolved technical issues concerning the estimated lifetime of waste containers, solute transport in the saturated and unsaturated zones, and the stability of the repository under a range of temperature conditions. The GAO report echoes the NWTRB concerns about the compounding of uncertainties and conflicting assumptions in the Total System Performance Assessment.
By law, DOE must use the same data in both the site recommendation and in its application for a license from the U.S.
Nuclear Regulatory Commission to store nuclear waste at the site. By recommending Yucca Mountain to the President, Secretary Abraham set in motion a statutory time frame that requires DOE to submit a license application five to eight months after the President accepts his recommendation. GAO estimates that it will take DOE at least four years to prepare a site license application. Given the questions GAO and NWTRB have raised, Secretary Abraham’s latest decision is at best premature and at worst illustrates disregard of sound science.
DOE’s science is incomplete and fails to provide a basis for fairly evaluating whether Yucca Mountain is a safe site for isolating nuclear waste for more than 10,000 years. Despite Secretary Abraham’s recommendation, DOE has yet to prove that disposal of high-level nuclear waste less than 100 miles from the fastest growing urban area in the country can be done safely. And DOE has yet to prove that the waste can be transported safely across America’s highways and railways in the more than 56,000 shipments to Yucca Mountain that would be required. As citizens and scientists, members of the geoscience community should play an important role in this debate. I urge you to evaluate the technical issues associated with high-level nuclear waste disposal in a scientific manner based on peer-reviewed science, not just the substantial and polished propaganda produced by DOE.