Normally, engineers can assess and improve upon the reliability of a new technology through operation. If a model car breaks down, the problem can be fixed before it hits the market. But not all developers have that luxury. In the case of geologic storage of high-level nuclear waste, currently planned for Nevada¿s Yucca Mountain, the potential consequences of a leak leave little room for experimental error. Such a plan, say researchers writing in the current issue of the journal Science, demands a much sharper analysis of geologic and atomic-scale processes than has been conducted thus far. For this reason, they argue, President George W. Bush's recent decision to recommend Yucca Mountain as a disposal site for high-level nuclear waste is premature, and the plans should not advance until the relevant scientific issues have been thoroughly explored.
The push to establish a repository at Yucca Mountain is based on political considerations and national security concerns, not hard science, Rodney Ewing of the University of Michigan and Allison Macfarlane of the Massachusetts Institute of Technology, assert. They point to recent shifts in the design strategy to support their view. For one, the role of engineered barriers for the waste has increased. Originally, Yucca Mountain was selected because of its natural characteristics: a repository could be placed 300 meters above the water table and, presumably, kept dry. But subsequent research results indicated that water may actually circulate upwards through the mountain, and near the proposed waste storage area. Accordingly, the plan now depends on engineered barriers, including durable drip shields that would prevent water from carrying away radioactive material. "By lessening the importance of geologic barriers, the properties of the site become less important," the authors write. "Indeed, the original concept of geologic disposal has been turned on its ear."
But this is hardly the only problem with the Yucca Mountain proposal, Ewing and Macfarlane observe. Other long-term factors, such as the influence of climate change, the durability of the metallic waste packages, and the impact of volcanic activity require detailed probing as well. Yucca Mountain may yet prove to be a good location, the researchers concede, but the proposal warrants more thoughtful and complete consideration before any such decision can be made. Quoting Thomas Jefferson, they conclude, "Delay is preferable to error."
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2 Comments
Add CommentThe revived interest in having more nuclear reactors to generate electrical energy recently came directly from unusually high oil prices. However, there are pros and cons.
Reply | Report Abuse | Link to thisNuclear energy is relatively cheap (as compared to some other renewable sources) and much cleaner, a plus for the environment. But the disposal of the highly radioactive waste has always been a bane, as scientists stress their concern on the safety of Yucca Mountain repository. With covert nuclear proliferation in the increase and thousands of reactors dotting the globe eventually, there will be no guarantee that the concentrated uranium would not be abused, especially by some irresponsible groups or nations. The limited supply of uranium ore could pose a problem too.
Whether oil continues to fetch a low price or not, the wells will certainly go dry in the not so distant future. Perhaps the solar based energy sources could still be a good bet for the energy hungry world, albeit the technology takes time to be fine-tuned.
The bottom line lies in the energy consumers. Use less energy wherever and whenever possible. Just dont waste.
(Tan Boon Tee)
The uncertainties involved in the geology and hydrology of Yucca Mt. and numerous others in the engineered casks (welds - how long will they hold? Vulcanism and seismic activity in the many faults right in there around the storage spece - historic; will it reoccur while the materials are still highly dangerous to all life? Climate change - models show many areas possibly getting wetter in the short term; what about the really long term involved?), in addition to Tan Boon Tee's concerns, definitively argue against further use of nuclear power.
Reply | Report Abuse | Link to thisShould proposed plants planned be built, another Yucca Mt. would have to be opened for storage of high level waste each year.
I have lived less than 100 miles from Yucca Mt. and heard the scientific arguments on the use of this mt for storage since the 980s.
Las Vegas is less than 90 miles to the south.
The mountain was chosen, not because it is remote. To the contrary, it is quite near Hwy 95 and Beatty, and Lathrop Wells. It was chosen because to site a repository farther in the contaminated former test site would preclude further atomic testing there. Such considerations ARE political, and not scientific at all.
Sites in the eastern US, which have no faults and no vulcanism in their history, were rejected by the very states which have the most nuclear power plants. Keep it in YOUR own back yard, please.
Sites which sequester it far below the water table, avoiding uncertainties of oxidation of containers (flowing water (around 17" of precip per year at Yucca) will quicken oxidation of almost all materials over the necessary sequestration period), are in Texas, farther east, and perhaps in Washington state. No real study of this preferred siting has been done.
No, nuclear power is NOT cheap.
Economics in our era involves externalizing costs - laying those costs onto the public (see LA Times archives for how uranium mining destroyed the health of the Navajo/Dine people poisoned their water, and the ecosystems in the southwest) or onto the unknowable future.
Such an unethical accounting "science" must be changed at its very root before humans destroy the biosphere and foul the entire earth.