Is It Possible to Solve the Nuclear Waste Problem?
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Allison Macfarlane Is It Possible To Solve The Nuclear Waste Problem? Innovations Case Discussion: Siting of Eurajoki Nuclear Waste Facility With the issuance of the latest Intergovernmental Panel on Climate Change report in February 2007 the world faces the stark reality that it must reduce greenhouse gas emissions immediately or face dire consequences. Nuclear energy provides a reliable source of carbon dioxide-free electricity, and a global expansion of nuclear power could replace fossil-fuel fired plants significantly within twenty to fifty years. One of the main impediments to the expansion of nuclear energy is the unresolved problem of what to do with the nuclear waste. Though nuclear power has been with us almost fifty years, to date, not one of the 30 countries with nuclear power plants has opened a nuclear waste repository. There is a general consensus among experts that geologic repositories are the solution to the problem of nuclear waste, and this consensus has been in place for 50 years.1 Given that, why has no repository yet opened? In 1998, the United States opened a facility to dispose of transuranic waste from the nuclear weapons com- plex (plutonium-contaminated materials) in southern New Mexico, the Waste Isolation Pilot Plant. The unresolved issue for the nuclear power industry is the disposition of used (“spent”) nuclear fuel and high-level nuclear waste from the reprocessing of spent nuclear fuel. Technically, it is feasible to dispose of nuclear waste. The main issues to resolve are where to site a repository and how long such a facility can prevent the radioac- Allison Macfarlane is an Associate Professor of Environmental Science and Policy at George Mason University in Fairfax, VA. She is also an affiliate of the Program in Science, Technology and Society at MIT and the Belfer Center for Science and International Affairs at Harvard University. She is currently and has served in the past on National Academy of Sciences panels on nuclear energy and nuclear weapons issues. She currently serves on the Board of the Bulletin of the Atomic Scientists .Her research focuses on international security and environmental policy issues associated with nuclear weapons and nuclear energy. She is a contributing co-editor of Uncertainty Underground: Yucca Mountain and the Nation’s High-Level Nuclear Waste, (MIT Press, 2006) which explores the unresolved technical issues for nuclear waste disposal at Yucca Mountain, Nevada. © 2007 Allison MacFarlane innovations / fall 2006 83 Downloaded from http://direct.mit.edu/itgg/article-pdf/1/4/83/704123/itgg.2006.1.4.83.pdf by guest on 30 September 2021 Allison MacFarlane tivity from nuclear waste to spread into the accessible environment. In the end, any site will never contain nuclear waste indefinitely. The goal is to select a site and engineered features, such as the waste canister, that maximize the amount of time the waste is isolated. Again, this can be done with some degree of certainty. One of the main roadblocks to opening a nuclear waste repository is public opposition.2 Distrust in the institutions that run the repository program, “Not In My Back Yard” local and regional resistance, lack of perceived fairness in siting decisions, and worries about nuclear waste transport all add up to powerful polit- ical resistance to siting and opening nuclear waste repositories. Juhani Vira offers an alternative perspective on public/institutional interactions and provides an example of successful siting via a responsive nuclear waste institution, which has overcome the majority of public opposition to developing a nuclear waste reposi- tory. The focus of this article is to consider the nuclear waste disposal issue, both from technical and political perspectives. Will it be possible to open a repository? If not, nuclear energy may play a limited role in climate change mitigation. Vira’s article shows that the Finnish repository siting experience offers guidelines for how to handle the political and societal issues associated with nuclear waste disposal. Given their experience, it may well be possible to open a nuclear waste repository. BACKGROUND Nuclear power in 2002 accounted for 17% of electricity generation globally (International Energy Agency, 2004). Thirty countries had nuclear power generat- ing capacity amounting to 369 GWe, which was produced by 440 reactors in 2005 (OECD Nuclear Energy Agency, 2005). Spent nuclear fuel is produced at a rate of about 25-30 tonnes per GWe per year for light water reactors (World Nuclear Association, 2003). As a result, about 12,000 tonnes of spent fuel are produced each year globally. The United States, which has the most nuclear power plants, pro- duces about 2,000 tonnes of spent fuel per year and had accumulated 56,000 tonnes of spent fuel by 2005. Globally, spent fuel is located either at nuclear power plants in cooling pools or dry cask storage, or in centralized interim storage facil- ities. A number of studies recently have projected a large global expansion of nuclear power in response to the need to reduce carbon dioxide emissions. Pacala and Socolow (2004) envisioned 700 GWe of new power plants over the next 50 years to fulfill one of seven “wedges” of carbon dioxide reduction to stabilize emis- sions at the current level of 25.6 Gt CO2/yr. A 2003 study by a group at MIT envi- sioned expansion of nuclear power to 1,000–1,500 GWe by 2050 to displace 15- 25% of predicted growth of carbon dioxide emissions (Ansolabehere, Deutch, Driscoll, Gray, Holdren, Joskow, Lester, Moniz and Todreas, 2003). Most of this expansion would occur in Asia, where there will be the greatest need for increased electricity resources. Expansion of nuclear power to 700 GWe would result in 17,500–21,000 tonnes 84 innovations / fall 2006 Downloaded from http://direct.mit.edu/itgg/article-pdf/1/4/83/704123/itgg.2006.1.4.83.pdf by guest on 30 September 2021 Is It Possible To Solve The Nuclear Waste Problem? of spent fuel per year. Expansion to 1,500 GWe would produce 37,500–45,000 tonnes spent fuel per year. The site for a nuclear waste repository in the United States, Yucca Mountain, Nevada, is designed to hold 70,000 tonnes of waste. A large expansion in nuclear power in the world could produce enough waste for a Yucca- Mountain-size repository every two years. Thus, there is an urgent need to devel- op a solution to the problem of nuclear waste before a large expansion of nuclear power begins. FUEL CYCLE IMPACT ON WASTE DISPOSAL There are two potential ways to operate the nuclear fuel cycle: closed and open. In an open fuel cycle, spent fuel is treated as a waste product and placed directly in a repository. In a closed fuel cycle, unused uranium and plutonium are extracted from spent fuel via reprocessing technology and reused as fuel. The remaining waste, fission products and transuranic elements produced in the reactor are solid- ified into glass form (now called high-level waste) and destined for a repository. Though reprocessing is appealing because usable materials are not “thrown away,” it is economically costly3 and poses a high risk of proliferation of nuclear weapons. Reprocessing technology creates separated plutonium, one of the two materials that can be used to power nuclear bombs. Reprocessing using PUREX (plutonium- uranium extraction) technology does not largely affect the size of a repository, either. The high-level waste, because it contains the fission products (especially cesium-137 and strontium-90), is still as thermally hot as spent fuel, and therefore needs the same volume as that needed for spent fuel. Other types of closed fuel cycles have been proposed recently, including the Global Nuclear Energy Partnership (GNEP) by the United States. GNEP proposes to close the fuel cycle using a different separations process called UREX (uranium extraction) that will separate plutonium in combination with other transuranics, in the hope that doing so will increase the barrier to using this material in a nuclear bomb. There is skepticism that such material will prove proliferation resistant.4 The GNEP program also plans to separate cesium-137 and strontium-90 from the remaining waste, and to store them in some form (still to be decided upon) for 300 years on the surface.5 GNEP proposes to further reduce the space required in a repository by using the plutonium and other transuranics as fuel for sodium- cooled fast reactors. All aspects of the proposal are not economically viable at this time, nor will they be unless there is scarce uranium (not expected for at least 100 years) in combination with very high carbon taxes. In the end, then, the most cost effective nuclear waste management plan is geo- logic disposal, which will be needed anyway, whether a closed or open cycle is employed. The only problem is that, to date, with almost 50 years of reactor oper- ating experience, no geologic repository for the disposal of high-level nuclear waste and spent fuel has opened and operated. There are two sources of issues with opening a repository: technical and political/societal. If both can be resolved to a reasonable degree, then a repository will open. innovations / fall 2006 85 Downloaded from http://direct.mit.edu/itgg/article-pdf/1/4/83/704123/itgg.2006.1.4.83.pdf by guest on 30 September 2021 Allison Macfarlane TECHNICAL ISUES A geologic repository should operate using the principle of multi-barriers. The geology itself should provide a barrier to movement of radionuclides and the engi- neered features, such as the waste form and the waste canisters should also provide a barrier. Working in concert, the two sets of barriers should provide adequate assurance that the waste is kept from humans and the environment for millennia.