Whither America's Nuclear Waste? (part II)
Five years ago (Spring 1992 issue, page 23) this Newsletter raised this question in response to an article in Science. The special June 1997 issue of Physics Today on radioactive waste prompts the raising of this question again.
Former Nuclear Regulatory Commission Chairman John Ahearne introduces the special section of five articles and authors the first one, "Radioactive Waste: The Size of the Problem." This article is followed by Kevin Crowley's assessment of "Nuclear Waste Disposal: The Technical Challenges" and William Kastenburg and Luca Gratton's description of "Hazards of Managing and Disposing of Nuclear Waste." Warner North writes about "Unresolved Problems of Radioactive Waste: Motivation for a New Paradigm," and Charles McCombie compares what the U.S. is doing with the programs of other countries in "Nuclear Waste Management Worldwide."
North points out that the 1982 Nuclear Waste Policy Act envisioned that the first repository to accept high level radioactive waste (spent fuel from nuclear reactors and fission fragments left over from the reprocessing of spent fuel, mostly in military reactors) would do so by 1998. The Yucca Mountain site, selected by Congress in 1987 as the only one to be explored, continues to be mired in local opposition of the host state, Nevada, and concerns about the future behavior of underground water in the area under various scenarios; and, with no alternatives on the horizon, America's spent nuclear fuel, now expected to exceed the 1992 estimate of 40,000 tons by the year 2000, will continue to accumulate in interim storage at the reactor sites. And this does not take into account the high level wastes generated by the production of nuclear weapons, most of them left over from reprocessing and occupying about 40 times the volume of the spent reactor fuel. Yet North also points out that the Nuclear Waste Technical Review Board sees no need to rush. A centralized storage facility for spent nuclear fuel is not needed until present nuclear power plants start shutting down in 2010.
According to McCombie, most other nations are in no rush, either: they envision a longer period of interim storage of their spent reactor fuel, and they understandably don't have as much of it as the United States. Nevertheless, these other countries have encountered the same technical, social, and political problems which have beset the United States:
The development and acceptance of disposal technology -- even within the technical and scientific community -- has proven less straightforward than was assumed.
The technical issues associated with site selection and, more particularly, site characterization are more complex than was anticipated.
The sociological and political problems raised by disposal projects have been massively underestimated. (Charles McCombie, "Nuclear Waste Management Worldwide," Physics Today, 50(6), 57 (Jun 97)
McCombie cites "the early lack of sensitivity of the nuclear industry to the interests of communal and regional groups" but notes that "the fact that apparently technological decisions are strongly influenced by perceived as well as actual risks is becoming increasingly recognized." In any case, "the natural time constants involved in achieving social consensus are longer than has been hoped for," but "belatedly, awareness has now grown that continuing dialog is important . . . an incremental process allowing trust to be built up is more promising."
The IAEA Safety Fundamentals cited by McCombie (see box) are principles everyone can agree with, but implementing them is quite another story. Kastenberg and Gratton note that geological waste repositories must keep deposited radioactive waste from the environment for 10,000 years, but that this is under review by the Environmental Protection Agency and could be lengthened. They also observe that the Yucca Mountain site could possibly meet the required standards for 10,000 years but not for 100,000 (for individuals drinking groundwater at the site after this time). On the other hand, North suggests that "By asking performance assessment if we can safely 'set it and forget it' for ten thousand to one million years, our regulatory system poses an extreme challenge that available science may not meet." He recommends that we "replace the previous goal in which the generation that created the waste would dispose of it once and for all."
Meanwhile, disposal of other types of radioactive waste does not appear so problematic. The Waste Isolation Pilot Plant near Carlsbad, NM, whose bedded salt environment is more stable against intrusion by groundwater than the tuff at Yucca Mountain, appears to be "on track" for accommodating the transuranic wastes left over from reprocessing spent nuclear fuel. (Because these isotopes have relatively long half lives, they are not immediately as radioactive as the high level waste destined for Yucca Mountain, but they must be kept isolated for a much longer time.) And, though the disposal of low-level waste has not proceeded in terms of the multistate compacts envisioned by Congress in 1980, the previous depositories in Richland, WA (now open only to a few states), and Barnwell, SC (open to all states except NC), have been joined by a depository operated by Envirocare in Clive, UT (open to all), and $90 million has been spent toward establishing a depository in NC.
Yet, without a long-term solution to high-level radioactive waste the future of nuclear energy seems all but doomed, if it is not doomed already. Almost thirty years ago, M. King Hubbert, famous for his analyses of the ascent and descent of fossil fuel discovery and use, wrote that
When Homo sapiens evolved from his immediate hominid ancestors a hundred thousand years ago, he existed in some sort of ecological adjustment with the rest of the ecological complex, and competed with other members of that complex for a share of the contemporary flux of solar energy essential for his existence. . . . Between this earliest stage and the dawn of recorded history, this species distinguished itself from all others in its inventiveness of means for the conquest of a larger and larger fraction of the available energy . . . thereby upsetting the ecologic balance in favor of an increased population of the human species, forcing adjustments of all other populations of the complex of which the human species was a member.
It now appears that the rapid population and industrial growth that has prevailed during the last few centuries, instead of being the normal order of things and capable of continuance into the indefinite future, is actually one of the most abnormal phases of human history. It represents only a brief transitional episode between two very much longer periods, each characterized by rates of change so slow as to be regarded essentially as a period of nongrowth. It is paradoxical that although the forthcoming period of nongrowth poses no insuperable physical or biological problems, it will entail a fundamental revision of those aspects of our current economic and social thinking which stem from the assumption that growth rates which have characterized this temporary period can be permanent. (M. King Hubbert, "Energy Resources," in Resources and Man (Freeman, San Francisco, 1969), pp. 159-160, 238-239.)
Hubbert perceived our present period dominated by fossil fuel use as a mere blip on the graph of eternity. Absent a solution to disposing of high-level radioactive waste, the expected age of nuclear energy may turn out to be a smaller blip on Hubbert's blip of the age of fossil fuels.
Meanwhile, the US Department of Energy continues to work on the problem. In August 1996 the Office of Science and Technology in its Office of Environmental Management published six Technology Summaries -- on "Radioactive Tank Waste Remediation," "Mixed Waste Characterization, Treatment & Disposal," "Efficient Separations & Processing Crosscutting," "Plutonium," "Robotics Crosscutting," and "Decontamination & Decommissioning." The Office of Science and Technology, whose name was changed from the Office of Technology Development in 1996, was formed to advance new technologies needed for the Office of Environmental Management to fulfill its mission to clean up "the legacy of radioactive and chemically hazardous waste."
Among the technologies they are advancing are laser ablation, mass and near infrared spectroscopy, a Raman probe/cone penetrometer, and electrical resistance tomography to do in situ characterization of waste in tanks at such locations as Hanford, WA (see Winter 1996 issue, page 13). Other technologies are designed to remove cesium and strontium, the dominant radioactive species in spent reactor fuel, by ion exchange and in-tank precipitation. In addition to ion exchange, solvent extraction and vacuum distillation are being explored to remove transuranic elements. Because of the long half lives of these elements, removing them reduces the volume of waste requiring long-term disposal and provides a way of concentrating them in the event that nuclear transmutation, presently impractical, becomes a viable alternative to geologic repositories.
The Technology Summaries are available from the U.S. Department of Commerce, Technology Administation, National Technical Information Service, Springfield, VA 22161, (703)-487-4650.
(Editor's Note: National Public Radio's All Things Considered on 20 September 1997 reported intentions of America's power companies to construct an interim repository for spent reactor fuel on the Skull Valley Indian Reservation, UT; it would begin operating in 2001.)
IAEA Safety Fundamentals: The Principles of Radioactive Waste Management
1. Protection of human health Radioactive waste shall be managed in such a way as to secure an acceptable level of protection for human health.
2. Protection of the environment Radioactive waste shall be managed in such a way as to provide an acceptable level of protection of the environment.
3. Protection beyond national borders Radioactive waste shall be managed in such a way as to assure that possible effects on human health and the environment beyond national borders will be taken into account.
4. Protection of future generations Radioactive waste shall be managed in such a way that predicted impacts on the health of future generations will not be greater than relevant levels of impact that are acceptable today.
5. Burdens on future generations Radioactive waste shall be managed in such a way that will not impose undue burdens on future generations.
6. National legal framework Radioactive waste shall be managed within an appropriate national legal framework including clear allocation of responsibilities and provision for independent regulatory functions.
7. Control of radioactive waste generation Radioactive waste shall be kept to the minimum practicable.
8. Radioactive waste generation and management inderdependencies Interdependencies among all steps in radioactive waste generation and management shall be appropriately taken into account.
9. Safety of facilities The safety of facilities for radioactive waste management shall be appropriately assured during their lifetime. (McCombie, op. cit.)
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