Used Nuclear Fuel Management July 2000 Key Facts All the used nuclear fuel from nuclear power plants is in solid form. A typical nuclear power plant produces about 20 metric tons of used uranium fuel each year. All the used fuel produced by the U.S. nuclear energy industry in 40 years of operation—some 40,000 metric tons—would, if stacked end to end, cover an area the size of a football field to a depth of about five yards. Used fuel is stored at nuclear power plant sites, either in steel-lined, concrete pools filled with water or in dry containers—aboveground steel or steel-reinforced concrete containers with steel inner canisters. On-site storage is an interim measure, however. Although the Nuclear Regulatory Commission (NRC) determined that used fuel could be stored at plant sites for 100 years without adverse health or safety consequences, permanent disposal is necessary. The Nuclear Waste Policy Act of 1982 and its 1987 amendments require or authorize the Department of Energy (DOE) to locate, build and operate a deep, mined geologic repository for high-level waste and a facility for interim storage of used fuel, as well as a transportation system that safely links U.S. nuclear power plants, the interim storage facility and the permanent repository. The act's 1987 amendments designated Yucca Mountain in Nevada for study as a possible repository site, and DOE is conducting a comprehensive scientific investigation of its usefulness as a repository. The repository, which was to have been completed by 1998, is at least 12 years behind schedule, and no site has been selected for an interim storage facility. On Jan. 31, 1998, the federal government defaulted on its obligation—under the act and pursuant to contracts between utilities and DOE—to begin moving used fuel from the nation's nuclear power plants. Solid Used Fuel: Small Volumes, Safely Stored To generate electricity, nuclear power plants use uranium oxide. This fuel—in the form of small ceramic pellets—is placed inside metal fuel rods. These rods are grouped into bundles called assemblies. Fission—the splitting of uranium atoms in a chain reaction—produces a tremendous amount of heat energy for the amount of material consumed. This energy is used to boil water into steam, which drives a turbine generator to produce electricity. Every 18-24 months, the plant is shut down and the oldest fuel assemblies-which have released their energy but have become intensely radioactive as a result of fission-are removed and replaced. All of the country's nuclear power plants together produce about 2,000 metric tons of used fuel annually. Today, this used fuel is stored at the plant sites, either in used fuel pools or dry storage. The Nuclear Waste Policy Act of 1982 and 1987 The Nuclear Waste Policy Act of 1982 and its 1987 amendments require or authorize DOE to: locate, build and operate a deep, mined geologic repository for high-level waste locate, build and operate a facility for interim storage of used fuel develop a transportation system that safely links U.S. nuclear power plants, the interim storage facility and the permanent repository. The act provided for the Environmental Protection Agency to set radiation standards for the repository and for the Nuclear Regulatory Commission to license all facilities and transportation containers. The act also created the Nuclear Waste Technical Review Board, comprising 10 members appointed by the president from nominations made by the National Academy of Sciences, to serve as an independent source of expert advice on technical and scientific aspects of DOE's waste program. To pay for a permanent repository, an interim storage facility and the transportation of used fuel, the Nuclear Waste Policy Act established the Nuclear Waste Fund. Since 1982, electricity consumers have paid into the fund a fee of one-tenth of a cent for every nuclear-generated kilowatt-hour of electricity consumed. By the end of June 2000, these customer commitments plus interest totaled more than $17 billion. To comply with the requirement to locate and build a high-level waste repository, DOE selected nine locations in six states that met its criteria for consideration as potential repository sites. Technical studies and environmental assessments narrowed this field to five and then three sites: Yucca Mountain, Nev., Deaf Smith County, Texas, and Hanford, Wash. In its 1987 amendments to the Nuclear Waste Policy Act, Congress selected Yucca Mountain as the sole site to undergo an extensive scientific study process called "site characterization." The start of site characterization was delayed for several reasons, among them the refusal of Nevada to issue the environmental permits needed for surface-disturbing work such as maintaining roads, digging trenches and drilling boreholes. In 1989, DOE announced that the opening date for a repository would be delayed until 2010—12 years later than originally promised. Meanwhile, no site was selected for an interim storage facility, and the federal government defaulted on a longstanding obligation to begin moving used fuel from the nation's nuclear plants by January 1998. The Permanent Repository: Focus on Yucca Mountain Site characterization at Yucca Mountain has been one of the most thorough and comprehensive scientific investigations ever conducted, lasting two decades, costing $6.4 billion and involving thousands of scientists, engineers and technicians. Inside Yucca Mountain, DOE built an Exploratory Studies Facility—a system of tunnels that allows scientists to conduct seismological, geological and hydrological studies. The five-mile tunnel was completed in 1997. Since then, scientists have conducted numerous tests in the tunnel, examining the rocks that make up the potential repository, studying the movement of the small amount of water that flows through the mountain and simulating the reaction of rock and water to the heat released by used fuel. The data from these tests have helped scientists design the repository and assess its performance. DOE is using the results from its scientific investigation to evaluate Yucca Mountain's potential to perform as an effective repository for used nuclear fuel and high-level radioactive waste. The agency has released two reports that present this information to decision makers and the public. Yucca Mountain Viability Assessment. The viability assessment—a roadmap of completed and planned scientific and engineering work—was issued in December 1998. It included a design for the repository and explained how it will work, what it will take to license it and how much it will cost. The assessment concluded that the remote desert site was well suited for a geologic repository and that the ongoing work—to reach a decision in 2001 on whether or not to recommend the site—should proceed. Draft Environmental Impact Statement. In August 1999, DOE issued a draft environmental impact statement-as required by the National Environmental Policy Act. The statement found a repository's environmental impacts to be so small as to have no adverse impact on public health and safety. Following several months of public hearings around the country, as well as comments from stakeholders, DOE began work on the final environmental impact statement, which will be issued—together with the agency's final site recommendation—to the president in 2001. The Site Approval Process. Under the Nuclear Waste Policy Act, DOE is required to make a formal finding of suitability for the Yucca Mountain site. The public will have an opportunity to review the basis for that finding and provide comments to DOE when the agency releases its draft site recommendation consideration report in late 2000. If the finding is favorable, the secretary of energy will recommend to the president that the repository be built. That recommendation is scheduled for July 2001. If the president approves the recommendation, scheduled for January 2002, DOE will apply in March 2002 to the Nuclear Regulatory Commission for a license to build it. At this point, the state of Nevada can submit a "notice of disapproval," which can be overruled only by a majority vote in Congress. NRC licensing review of DOE's application provides for the participation of state and local governments, individuals and interested organizations. NRC approval is required before DOE can begin building the repository. In addition, the NRC must approve repository operation and it also must approve final repository closure (once all the waste is placed in the repository). Interim Storage: On Site The lack of a repository has placed nuclear power plants in the position of storing more used fuel than expected for longer than originally intended. The result is that many nuclear plants-which each produce an average of about 20 metric tons of used fuel annually-are running out of storage capacity. By the end of 2006, about 60 units will have no more storage space in their used fuel pools, and by the end of 2010, 78 will have exhausted their storage capacity. When a plant's used fuel pool nears its designed capacity, a utility has two options. The Re-Racking Option.Typically, the first choice is to re-rack the used fuel pool, moving the stored assemblies closer together. More than 130 re-rackings have been done at various nuclear plant sites, but re-racking has its limitations. Strict requirements exclude the possibility of unintended nuclear chain reactions, prevent overheating of the pool, and ensure that the pool's structural/earthquake resistance capability is not exceeded. These requirements restrict the extent to which the assemblies can be moved closer together, thus limiting the additional space that can be gained. Eventually, used fuel pools reach their capacity. Building a new used fuel pool is not an option. It is too costly and almost impossible to fit a new pool into the plant layout. Although a few companies have shipped used fuel from one plant to another with extra storage capacity, this option obviously is not available to everyone. Most nuclear plants have used the additional pool capacity gained by re-racking, and a growing number have built or are building dry storage facilities on site. The Dry Storage Option. A number of nuclear plants are storing used fuel in large, rugged containers made of steel or steel-reinforced concrete, 18 or more inches thick. The containers use materials like steel, concrete and lead—instead of water—as a radiation shield. Depending on the design, a dry container can hold from seven to 56 12-foot-long fuel assemblies. The NRC has approved several designs for use by utilities. The containers have a 20-year license. After 20 years they must be inspected, and with NRC approval the license could be extended. Various dry storage technologies are being successfully used by utilities today. Loaded containers are filled with an inert gas, sealed and stored either on reinforced concrete pads or inside steel-reinforced concrete bunkers. The containers are designed to withstand natural disasters such as tornadoes, hurricanes and floods, and to prevent the release of radioactivity. The designs require no mechanical devices for cooling and ventilation. Political Concerns. As nuclear plant operating companies contemplate the use of dry storage, some are finding political issues even more problematic than cost issues. State and local officials are concerned that, unless DOE fulfills its legal obligation to provide used fuel storage and/or disposal, used fuel may have to remain in on-site dry storage facilities beyond the envisioned 20-40 year period. This would prevent some nuclear plant sites from being used for other purposes after the plants are decommissioned. For these reasons, some state governments have opposed the licensing of additional dry storage, even though the facilities are proven safe. Cost Concerns. Designing, building and licensing a dry storage facility at a plant site requires an initial investment of $10-20 million. Once the facility is operational, it will cost $5-7 million a year to add containers as storage needs grow and to maintain the facility. These costs are above and beyond the contributions that electricity consumers already have made into the Nuclear Waste Fund, established to pay for used fuel disposal. As a result of DOE's default on its Jan. 31, 1998, obligation to begin moving used fuel from nuclear power plants, utility customers may have to pay an additional $5-7 billion for used fuel management (assuming the repository is available beginning in 2010). Interim Storage: Centralized off Site Until a repository is ready to accept used fuel from nuclear power plants, the United States needs a centralized storage facility. This facility would provide added safety and security by using a single dedicated site, rather than leaving used fuel at more than 70 locations across the country. Private Interim Storage Facility.In the absence of a federal centralized interim storage facility, a group of utilities, led by Northern States Power Co., signed an agreement in late 1996 with the Skull Valley Band of Goshutes for a possible privately financed used fuel storage facility on the tribe's land in Utah. The group applied for a 20-year operating license with the NRC in 1997. If approved, a storage facility could begin operating by mid-2002. Transportation of Used Nuclear Fuel Used nuclear fuel will be transported from nuclear power plants to storage and disposal facilities either by rail, by truck or, part of the way, by barge. The transportation containers used to ship used fuel typically have walls one-foot thick with shielding materials sandwiched between outer and inner metal shells. Those designed for truck transportation weigh between 25 and 40 tons, and carry one to seven used fuel assemblies. Railroad containers weigh up to 125 tons and carry more than 25 assemblies. To ensure that the transportation containers retain their integrity in the event of an accident, they are designed to withstand a consecutive series of highly destructive tests: a 30-foot fall onto a flat, unyielding surface; a 40-inch drop onto a vertical steel rod; exposure to a 1,475° F fire for 30 minutes; and submersion under three feet of water for eight hours. NRC studies showed that the engineering requirements create forces more destructive than would occur in actual accidents. Actual tests-conducted to examine the accuracy of computer models and scale-model tests to analyze the ability of containers to withstand the most severe accidents-drove containers into unyielding concrete walls at more than 65 miles per hour, simulated 80-mph train crashes and exposed containers to fully engulfing fires. The containers used in these brutal tests survived intact, and the computer codes and scale models were verified. During the past 30 years, more than 3,000 shipments of used fuel have been safely completed in the United States, and 10 times that number in other countries. While vehicle accidents have occurred, there has not been a release of radioactive materials or a single injury attributed to the radioactive nature of the cargo. When the federal government finally opens an interim storage facility or a permanent repository, the number of used fuel shipments is expected to range from 300 to 500 per year. Consensus on Safety of Long-Term Disposal Since the 1950s, scientific organizations around the world have examined the issue of radioactive waste management. Most organizations-from the National Academy of Sciences and the Office of Technology Assessment in the United States to the International Atomic Energy Agency (IAEA) and the Organization for Economic Cooperation and Development's Nuclear Energy Agency (OECD/NEA)-have reached the same conclusion. They believe that the best and safest long-term option for dealing with high-level radioactive waste is deep geologic disposal. Here is a sampling of the studies on geologic disposal: 1957: "We stress that the necessary geologic investigation of any proposed site must be completed and the decision as to a safe disposal means established before authorization for construction is given." National Academy of Sciences-National Research Council, Committee on Waste Disposal, Report on Disposal of Radioactive Waste on Land 1978: "Effective long-term isolation for used fuel, high-level or transuranic waste can be achieved by geologic emplacement. We recommend emplacement of high-level and transuranic wastes in a geologic repository." American Physical Society’s Study Group on Nuclear Fuel Cycles and Waste Management 1981: "While various concepts have been proposed and studied, it is generally agreed that underground disposal, with the wastes appropriately immobilized, should provide the necessary protection for man and the environment from the potential hazard they pose." International Atomic Energy Agency "Underground Disposal of Radioactive Wastes. Basic Guidance" 1985: "The disposal of radioactive waste in mined geologic repositories at depths from 1,000 to several thousand feet below the Earth’s surface is the final isolation technology most widely studied and favored by the worldwide scientific community. Three decades of study have revealed no insurmountable technical obstacles to the development of mined geologic repositories, provided suitable sites are found." Office of Technology Assessment, Managing the Nation’s Commercial High-Level Radioactive Waste 1985: "There is a high degree of confidence in the ability to design and operate disposal systems in deep geological structures which will assure long-term isolation for high-level waste or spent fuel and meet the relevant long-term safety objectives." Radioactive Waste Management Committee of OECD/NEA, Technical Appraisal of the Current Situation in the Field of Radioactive Waste Management 1986: "There is consensus in the community that isolation of wastes will be ensured by way of a multibarrier disposal system. And there is broad agreement that disposal in underground repositories is the preferred approach." IAEA Symposium on Siting, Design and Construction of Underground Repositories for Radioactive Wastes, concluding overview statement 1988: "The committee reaffirms its confidence in geological disposal for long-lived and high-level radioactive waste. Geological disposal is considered to be both feasible and safe in the short and long term." Radioactive Waste Management Committee of OECD/NEA, Geological Disposal of Radioactive Waste: In situ Research and Investigations in OECD Countries 1990: "There is no scientific or technical reason to think that a satisfactory geological repository cannot be built." National Research Council’s Board on Radioactive Waste Management, Rethinking High-Level Radioactive Waste Disposal 1999: "Substantial scientific and technical progress towards implementation of geologic disposal has been made in the last 10 years, thanks to the extensive work carried out in national programmes. … Opinions expressed by a wide cross-section of waste management experts thus confirm the consensus view that, at present and for the foreseeable future, geologic disposal represents the only truly available option for assuring safety and security over several tens of thousands of years and more." Radioactive Waste Management Committee of OECD/NEA, Progress Towards Geologic Disposal of Radioactive Waste: Where Do We Stand? The Archaeological Record Nature also provides compelling evidence that high-level waste can be contained geologically for hundreds of thousands, even millions, of years. One of the best examples of nature's ability to safely isolate radioactive elements over millions of years is provided by the natural nuclear reactors discovered in 1972 at the Oklo uranium mine in the West African republic of Gabon. This deposit of ore, which contained from 10 percent to 60 percent uranium, constituted a natural nuclear reactor. Millions of years ago, it began a self-sustaining chain reaction. Like all reactors, this one created its own high-level waste—12,000 pounds of used fuel. The Oklo chain reaction occurred intermittently for more than 500,000 years. Despite its location in a wet, tropical climate, Oklo's uranium deposit and high-level waste have remained securely locked in this natural repository for the past 200 million years. Many of the waste products stayed where they were created or moved only a few inches before decaying into harmless products.