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This month--possibly even this week--the senate is expected to debate and vote on a resolution designating Yucca Mountain, Nevada, as the final resting place for 70,000 tons of high-level radioactive nuclear waste. The vote is a significant step in the nation's long and costly program to build a geological repository for nuclear waste. The outcome has implications beyond U.S. borders. Worldwide, nuclear proponents have long favored a geological repository as the ultimate home for high-level nuclear waste, but few nations have moved beyond discussing such emplacement. The U.S. government's effort at Yucca Mountain is far and away leading the pack. And for this reason alone, there are many eyes watching the Department of Energy's $60 billion construction project in Nevada's high desert, 100 miles northwest of Las Vegas. All but a small percentage of the waste destined for Nevada will come from commercial nuclear power plants that currently generate about 20% of U.S. electricity. Ten percent of capacity has been set aside for defense waste from DOE weapons plants and U.S. Navy nuclear warships. But commercial utility waste is the prime reason for the repository, and a consumer tax on nuclear energy has been earmarked to fund its construction. By the time the repository opens, however, industry-generated nuclear waste is likely to exceed the repository's designated capacity. DOE, the repository's designer and promoter, says Yucca Mountain will be operational by 2010, but few believe that that date is feasible, including many DOE officials. Initially, the repository was required by law to be opened in 1998, and DOE was sued by utilities when it failed to make that date.
Highly radioactive utility waste has been generated for decades by U.S. power companies that badly want to get the spent fuel rods away from their power plants--both for safety reasons and to help clear the decks for their plans to push ahead on a new generation of nuclear power plants. Yucca Mountain advocates and even opponents argue that the congressional vote is not over nuclear power, but it is hard to see continued growth for nuclear energy without a scientifically sound waste solution that is accepted by society. Currently, there is 43,000 metric tons of accumulated waste stored at commercial nuclear reactor sites, says Melanie Lyons, a spokeswoman for the Nuclear Energy Institute, a trade association. Some is stored in dry casks, but most of the spent fuel lies in pools of water. Lyons stresses that it is safe there but adds that the industry would like to get it to a central location, some place away from their plants. That waste, she says, is going to grow at about 2,000 metric tons per year for many more years. Many of today's 103 operating nuclear reactors are reaching the end of their 20-year legal lives, but most plan to get license extensions, allowing them to tack on another 20 years of operation. And if the current record-level high efficiencies and operation improvements of U.S. nuclear power plants continue, waste volumes will grow right along with the increase of nuclear-generated electricity. DOE and the Nuclear Regulatory Commission (NRC), which is charged with licensing reactors and overseeing their operation, have made several efforts recently to aid the relicensing of old plants and possibly speed approval of a new generation of reactors should any company come up with a proposal (C&EN, Sept. 3, 2001, page 29). Nuclear energy is on a roll. The President's energy plan of last year had several provisions to encourage nuclear power, including tax breaks and another look at fuel reprocessing and advanced technologies. DOE is even jumping in with a plan to help pay companies to find sites for new nuclear power plants. LAST FEBRUARY, Energy Secretary Spencer Abraham made a formal recommendation to move ahead with the Yucca site to President George W. Bush, and in less than 24 hours, the President authorized construction. Just hours later, Nevada Gov. Kenny Guinn, a Republican like Bush, announced he would veto the President's decision (C&EN, Feb. 25, page 8). Guinn's veto led to House and Senate votes under the terms in the Waste Policy Act. The act calls for a unique approval process. For instance, it does not allow Senate opponents to use a filibuster to stall action, and it allows any senator to bring a resolution to overturn Guinn's veto to the floor, which may prove particularly important because Senate Majority Leader Thomas A. Daschle (D-S.D.) opposes overturning the veto. It also sets a deadline for congressional action, which works out to July 27. The Nevada congressional delegation is united in opposition to the site. They lost in the House, however, by a large margin in May. In the Senate, they are likely to come closer, but Guinn's veto is expected to be overturned. Nevada has filed five lawsuits challenging the federal government. It has sued the Environmental Protection Agency, DOE, NRC, the President, and the energy secretary, says Robert R. Loux, executive director of the Nevada Agency for Nuclear Projects. "IF WE PREVAIL in the Senate, we think the Nuclear Energy Institute will challenge the constitutionality of the Waste Policy Act; if we lose, we may challenge it," Loux says. He expects more suits if the process moves to NRC licensing. Loux wants the waste to remain in pools or casks at the utilities that create it. He points to statements by NRC officials saying the waste would be safe there for decades. "What this is really about," he says, "is that utilities know no one will even let them even think about building more power plants unless they have removed waste temporarily or permanently--as if anyone would anyway. This has nothing to do with health and safety. It is about an industry's wish to expand." Abraham strongly disagrees. Speaking to a Senate committee in mid-May, the energy secretary left no doubt that a 24-year, $5 billion investment in studying the Nevada site has paid off. Radiation exposure to humans during the 10,000-year regulatory period set by law would be well within safe limits, he said. And problems that popped up during the long investigation--unexpected water movement through the mountain, volcanic activity, earthquakes--would not overcome DOE's reliance on engineered barriers coupled with the mountain's geology to keep the waste isolated, he said. Pressure for the site was driven by national security and energy security, he said, as well as the environmental need to dispose of weapons production waste at federal facilities. Abraham noted, however, that the repository design is a work-in-progress and is not complete, nor is there even a clear plan about how the waste will be transported to the mountain or in what form. An answer to these questions, he said several times during his presentation, would come during licensing procedures and would call for investigations yet to be conducted by "neutral experts" at NRC as they decide whether the site is safe enough to receive a license to build and operate and how the waste should be transported.
A General Accounting Office (GAO) report says essentially that the same information needed for the President's site recommendation is needed for a license application, and DOE was far from ready to move ahead with a license application. Gary L. Jones, director of GAO's Natural Resources & Environment Office, told the senators about some 293 technical areas in which NRC has said better data are needed from DOE. The areas include the engineered barriers that hold the waste, the physical properties of the mountain, and the models DOE is using to evaluate the site. Under a schedule in the Waste Policy Act, Jones said, DOE is expected to apply for an NRC license before the end of the year. But GAO's investigation found that DOE's contractor at the site had warned the department that it will take until January 2006 to prepare an application. DOE officials say they want the application in by December 2004, but delay is inherent in this vast project. Overall, GAO says the delays will mean the facility will not begin operating until possibly 2015 and could result in hasty and bad decisions. GAO urged DOE to formally readjust its schedule. The Nuclear Waste Technical Review Board, a congressionally created oversight body, gave DOE a "weak to moderate" assessment of the technical basis for the department's performance evaluation of the repository. The ranking was due primarily to unanswered questions over the repository design, particularly the effect of temperature on the radioactive waste and the characteristics of a new alloy DOE plans to use to slow waste canister degradation and block water from breaching the canisters. NEITHER OF the government reviewers said the site was inadequate, but both warned that DOE was not ready to move ahead. They have been joined by several nongovernment groups that worry about Yucca Mountain's geology and DOE's plan. Arjun Makhijani is a nuclear physicist with a history of making accurate assessments of faults in DOE projects. He is the executive director of the Institute for Energy & Environmental Research in Takoma Park, Md., a science-based think tank that focuses on energy issues. "The site is unique and complex, and that means that we have relatively low confidence about what can be said about the place over long time periods," he says. "Projecting out tens of thousands of years is a very iffy business." He notes that as DOE has learned more about the geology and hydrology of Yucca Mountain, its design plan has come to depend more upon engineered barriers to contain the waste rather than on geology. The same point is made by Victor Gilinsky, a former NRC commissioner who is now a consultant to Nevada. Gilinsky has said in an affidavit to support Nevada's litigation that DOE's current approach--relying on protected containers for the waste--could allow waste to be stored "in the basement of DOE's headquarters in the Forrestal Building" in Washington, D.C. Both Gilinsky and Makhijani urge that the waste be closely monitored and left at the power plant sites. Makhijani wants it in hardened containers where it would be safe from terrorists. Makhijani warns that politics and Nevada's lack of clout were the reasons for Yucca Mountain's selection, not the site's characteristics. THE U.S. IS FAR from alone in wrestling with the science, politics, and economics of nuclear waste. Nuclear power plants produce 17% of the world's electricity, and countries throughout the world have been studying nuclear repositories for more than 50 years, says John Paffenbarger, vice president for development and commercialization for Constellation Generation Group, a Baltimore energy company with two nuclear units. Paffenbarger conducted an analysis of nuclear power in Organization for Economic Cooperation & Development countries for the International Energy Agency. He found there is a growing demand in this group of 30 countries, including Western European, North American, and some Asian countries, to reach a waste solution after so many years of study. But he also found growing concern by the populations about practical aspects of actually implementing a plan. "What that has meant," he says, "is that timetables are always set beyond the reach of current politicians." Paffenbarger stressed that he was voicing his personal views. With the exception of the U.S., he says, no nation is close to a final decision about what to do with nuclear waste. "Some countries don't even have a target date for a waste facility, even though they continue to generate the waste," he says. "Some are hoping someone else will take their waste, or they are just waiting for a time it may be more propitious politically to move ahead." That view was echoed in a National Research Council report of a year ago. It found that, worldwide, repository decisions are far off, even in countries like France, which gets 75% of its electricity from nuclear generation. The French, the report said, had passed legislation requiring that the country avoid a decision until 2006 (C&EN, June 18, 2001, page 30). Paffenbarger says attempts to link solving waste solutions to future nuclear generation have been pretty much universally opposed by the countries' leaders as well as the nuclear industry since it would block development of the energy source. DOE is moving much faster than he expected a year or two ago, Paffenbarger notes. "There appears to be a limit to the patience of Washington congressional leaders," he says. "But the practical aspects remain, and they are the same ones other countries have found to be very daunting. What happens is when countries get specific, people react."
MOST OF THE WORK so far at Yucca Mountain has been scientific evaluations and sampling, says Paul Harrington, DOE's Yucca Mountain lead systems engineer. But DOE has bored a 5-mile, 25-foot-diameter U-shaped access "drift" through the rock. The tunnel was built for experimental purposes, but if Yucca Mountain moves ahead, the tunnel will provide access to the storage site. The tunnel will be used to take radioactive waste down to some 35 miles of "emplacement drifts" where the waste will be left. The department also has bored a 15-foot-diameter exploratory test tunnel, slightly above the area that will become the nuclear waste emplacement zone that is 1,000 feet below the mountain's surface and 1,000 feet above the water table. Once in operation, the waste will be placed in heavily shielded packages and hauled by locomotives down the access drifts, where they will be off-loaded and transferred to a huge gantry and crane operation. The gantry will be operated remotely and move on rails. It will pick up the canisters, which will rest on pallets, and move them to their final destination inside the 15-foot-diameter emplacement tunnels. All this will be done by remote controls since these waste packages will be hot, both in temperature and in radioactivity. The tubes of waste will be big--15 feet long, 5 feet in diameter and between 42 and 72 metric tons. They will be remotely monitored for at least 50 years or as long as 300 years, Harrington says. The facility will be busy. DOE plans to dig drifts while waste is being emplaced, Harrington says, to get a quicker start and to incorporate lessons learned as they go along. Also, much of the non-DOE waste will have to be repackaged upon receipt because standardized packages have not been developed. Along with remotely monitoring the canister, DOE will place probes inside the mountain, Harrington says, in order to monitor for water movement and the impact of temperature gradients between the drifts, which are about 240 feet apart. To eventually seal the tunnels, DOE must again return to NRC for approval. However, this may not be until 2300, and it is quite unlikely anything called DOE or NRC will still be around.
THE DEBATE over a nuclear waste repository goes well beyond expansion of nuclear energy or generation of electricity. Because of the extreme and long-lived hazard presented by this waste and the immense timescale of the project, the issue becomes a matter of human stewardship of Earth and the unforeseen impacts today's decisions will have on future generations. These points are not lost on Abe Van Luik, senior policy adviser for DOE's Yucca Mountain Project. He notes that federal regulations set a regulatory limit on the impact of these wastes to humans at 10,000 years after emplacement, and DOE found no significant impact in that time. But some of the radionuclides are very long-lived. Plutonium, for instance, has a half-life of 24,000 years, which leads to the assumption that it will take 240,000 years, 10 half-lives, to degrade to safe levels. Neptunium is worse yet, with a 2.14 million-year half-life. DOE site studies predict that thousands of years in the future, at a point 11 miles from the repository, people are likely to be exposed to radioactive-waste-contaminated groundwater. And its researchers have determined that 480,000 years out, this contamination will peak and people in the area could receive annual doses in the range of 150 millirem, 10 times above the EPA-set regulatory maximum. However, even at those doses, Van Luik says, humans are relatively safe. He cites recent international dose models that, if applied at Yucca Mountain, would cut safe maximums by one-quarter for these particular radionuclides. Van Luik is comforted that the projections show that an engineered barrier system and the mountain's geology have pushed high radiation exposure further into the future. He is joined by a host of Yucca Mountain advocates, but not by Makhijani, Loux, and others who will continue to hammer on the uncertainties in the government's program, its tests on containers, its geological findings, and its transportation scheme as they are developed. Meanwhile, nuclear waste continues to pile up around the nation.
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Chemical & Engineering News |
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