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Should Nuclear Waste be Buried at Yucca Mountain?. Jun Yong Bang Prof. Seth Stein Geological Science 107. About the Project.
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Should Nuclear Waste be Buried at Yucca Mountain? Jun Yong Bang Prof. Seth Stein Geological Science 107
About the Project • The Yucca Mountain Project has conducted an extensive scientific effort to determine whether Yucca Mountain, Nevada is a suitable site for a deep underground facility called a repository. • The purpose is to safely isolate highly radioactive nuclear waste for at least 10,000 years.
Yucca Mountain • located on federal land in southern Nevada • occupies about 230 square miles (150,000 acres) of federal land • No residents live in the area. • Yucca Mountain is a ridge comprised of layers of volcanic rock, called “tuff.” • There are no known natural resources of commercial value at Yucca Mountain
Geological Traits of Yucca Mountain • Dry Climate - less than 7.5 inches of precipitation per year. • Remoteness - surrounded by thousands of additional acres of land withdrawn from the public domain (5,470 square miles.) • Stable Geology -it is highly unlikely that volcanoes, erosion, or other geologic processes and events would disrupt • Deep Water Table -The repository will be located about 1,000 feet above the water table. • Closed Water Basin - is located in a closed basin, which is an area completely surrounded by higher land
Brief History of the Project • 1982- Congress established a national policy to solve the problem of nuclear waste disposal. (the Nuclear Waste Policy Act). • 1983- Nine locations were selected for consideration as potential repository sites. • 1987- Congress directed U.S. Department of Energy to study only Yucca Mountain. • July 9, 2002- the U.S. Senate cast the final legislative vote approving the development of a repository at Yucca Mountain. • July 23, 2002- President Bush signed House Joint Resolution 87, allowing to build a safe repository. • The Yucca Mountain Project is currently preparing an application to obtain a license from the U.S. Nuclear Regulatory Commission.
Radiation and Nuclear waste • The atoms of certain heavy elements like uranium and plutonium emit a type of high-powered energy called “ionizing radiation.” Ionizing radiation has enough energy to change the structure of the atoms it collides with. • An atom that emits ionizing radiation is described as “radioactive.” • Spent nuclear fuel and high-level radioactive waste will be placed at Yucca Mountain in solid form such as metals, ceramics, and glass with small amounts of radioactive gases.
Nuclear Waste • Spent Nuclear FuelSpent nuclear fuel is used fuel from nuclear reactors at commercial power plants, research reactors, government facilities, and from Navy vessels. To make electricity, nuclear reactors use fuel made of solid ceramic pellets of enriched uranium that are sealed in strong metal tubes. After three or four years in a reactor, however, the uranium pellets are no longer efficient for producing electricity and the assembly is removed from the reactor. After removal, the entire assembly (now called spent nuclear fuel) is highly radioactive. • High-Level Radioactive WasteWith the end of the Cold War, the United States has been working to close and clean up obsolete weapons plants and dispose of nuclear weapons materials. This has created a need to dispose of highly radioactive material associated with weapons production. This material is called high-level radioactive waste.Until the late 1970s, the United States acquired materials for nuclear weapons by reprocessing spent nuclear fuel from government-owned nuclear reactors. Reprocessing is a method of chemically treating spent fuel to separate out uranium and plutonium. The byproduct of reprocessing is a highly radioactive sludge-like residue.
The Repository Concept • A geologic repository is required to keep nuclear waste away for 10,000 years. • If the waste stays in solid form and remains deep underground, it is not harmful because layers of rock will shield its radiation. • However, if enough water contacted the waste, over time it could break it down into tiny radioactive particles and then carry the particles into the environment. • The concept for a repository at Yucca Mountain is to seal the waste in extremely durable containers called waste packages, then place the containers in deep underground tunnels.
How the Site is Designed • The waste will be sealed in containers called waste packages, then place the containers in deep underground tunnels. • Drip shields made of another corrosion resistant metal will be placed over the waste packages. • About one thousand feet of solid rock will be above the repository to restrict the amount of water that could reach the tunnels. • The drip shields and corrosion-resistant waste packages would protect and contain the waste.
Tunnel Layout and Design • The repository design includes more than 50 horizontal tunnels for storing the waste. • These tunnels would be excavated in solid rock about 1,000 feet beneath the surface of the mountain and, on average, about 1,000 feet above the water table. • The tunnels would be 16.5 feet in diameter and about 2000 feet long and would be reinforced with steel sets, rock bolts, and wire mesh to prevent rock from falling on the engineered features.
Stop the Project:Scientifically Unsound • “Yucca Mountain is a scientifically sound site in which to dispose of spent nuclear fuel” Counterarguments • Volcanic “Tuff” is not expected to provide an adequate barrier • Even the DOE’s own assessments indicate that Yucca Mountain is not capable of isolating radioactive waste for long time (Institute for Energy and Environmental Research ) • Under the threat of earthquakes • U.S Department of Energy assessments assume that the metal canisters will provide adequate containment • Evidence that water has welled up into the region according to a study by an independent technical group
Stop the Project:Just Another Waste Dump • “The spent nuclear fuel stored in pools at reactor sites is too vulnerable to proliferation and terrorism to lean in place, so it just be moved to Yucca Mountain.” Counterarguments • Moving waste to Yucca Mountain will not eliminate risks associated with nuclear power plants, it would only create another waste dump. • Shipping waste to Yucca Mountain will increase the terrorist threat associated with spent fuel • Storage of spent fuel on-site for several decades is feasible and can generally be done relatively safely
Stop the Project:Better Alternatives • “If not Yucca Mountain, then what?” Counterarguments • The Institute for Energy and Environmental Research (IEER), a scientific institution with expertise in nuclear waste management published an alternative plan. • In the short term, irradiated reactor fuel should be stored as safely as possible on site or as close to the point of generation as possible for an interim period (several decades). • In light of the attacks of September 11, IEER has recommended on-site or close-to-site subsurface dry storage of spent fuel • For the long-term, more research on various geologic settings is needed (ex- geologic disposal on land, sub-seabed disposal, and upper mantle disposal)
Furthermore: Top Ten Reasons to Oppose the Yucca Mountain Plan (By Nuclear Age Peace Foundation) • Accomplishes No Reasonable Objective • Provides Minimal Protection • Creates More Nuclear Waste • Adverse Effects on Future Generations • Earthquake Danger
Top Ten Reasons to Oppose the Yucca Mountain Plan • Fifty Million People Endangered • Terrorist Attacks • Costly Accidents and Limited Liability • Adverse Impact on Water Sources • Violates Treaties
Conclusion • It is premature at this time to select actual repository sites or even to engage in a site selection process. Finding an appropriate repository site is a very difficult and complex process that must balance a wide range of considerations, including sound science, which has not yet been completed.