America's Energy Future Technology and Transformation (2009) / Chapter Skim
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8 Nuclear Energy
8 Nuclear Energy
Pages 445-562
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From page 445... ...
had received 17 applications for combined construction and operating licenses1 for 26 units, and it expects to receive a total of 22 applications for 33 units by the end of 2010.2 The 104 currently operating nuclear plants (largely constructed in the 1970s and 1980s) contribute substantially to the U.S.
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From page 446... ...
. Following the Chernobyl accident in 1986, Italy banned construction of new nuclear reactors; the govern ments of Sweden and Germany pledged to phase out their own nuclear plants; resistance to new construction in the United Kingdom was strong; and Spain put in place a moratorium on new construction.
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From page 447... ...
These estimates also take into account the global concern over climate change caused by the increasing concentration of greenhouse gases in the atmosphere, and the signing of the Kyoto Protocol." 6Both nuclear plants and coal plants with carbon capture and storage (CCS) present intergen erational issues: nuclear plants because of the very long-lived radioactive waste, and coal with CCS because of the need for stored CO2 to remain underground for long periods.
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TECHNOLOGIES The existing nuclear plants in the United States were built with technology devel oped in the 1960s and 1970s. In the intervening decades, ways to make better use of the existing plants have been developed, as well as new technologies that are intended to improve safety and security, reduce cost, and decrease the amount of high-level nuclear waste generated, among other objectives.
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In 2008 alone, the USNRC approved 10 upgrades to existing plants, adding a total generating capacity equivalent to about half of one new nuclear plant. Eleven applications are pending, and the USNRC expects 40 more applications through 2013.12 If 9Overnight cost is the cost of a construction project if no interest was incurred during construction, as if the project was completed "overnight." All costs are expressed in 2007 dollars.
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In the United States, the initial license term for a nuclear power plant -- 40 years -- is subject to extensions in increments of up to 20 years.13 In the 1990s, the USNRC established a regulatory system to assess applications for such extended licenses. In the majority of cases, the owners of the currently operating U.S.
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From page 451... ...
Existing plants have been operated with increasing efficiency over time, and average plant capacity factors (averaged across all operating nuclear plants) have increased markedly, from 66 percent in 1990 to 91.8 percent in 2007 (NEI, 2008)
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In the sections that follow, the committee discusses these new designs, which are grouped into two categories: Evolutionary reactor designs, which are modifications that have evolved from LWR designs currently operating in the United States Alternative reactor designs, which range from more significant modifi cations of currently deployed designs to entirely different concepts 16Baseload power is the minimum power that must be supplied by electric generation or utility companies to satisfy the expected continuous requirements of their customers. Baseload power plants generally run at steady rates, although they might cycle somewhat to meet some variation in customer demand.
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In most cases, alternative reactor designs will require significant development efforts before they can be ready for deployment. Evolutionary Reactor Designs Any new nuclear plants constructed before 2020 will be evolutionary designs that are modifications (often significant)
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From page 454... ...
. These designs are all modifications of current-generation LWR designs.20 Because construction of new nuclear plants is likely to require a long lead time, the first deployment of evolutionary nuclear reactors in the United States is unlikely to be until after 2015.
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Alternative Reactor Designs In addition to the evolutionary reactor designs just discussed, alternative nuclear reactor designs are being developed (and, in some countries, have been used) .24 21When nuclear fuel is removed from the reactor after use, it not only is highly radioactive, but also emits heat.
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Many new alternative reactor designs are intended to increase safety and efficiency and improve economic com petitiveness, as well as to perform missions beyond electricity production. The alternative reactor technologies that could be deployed in the United States include fast and thermal reactor designs.
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A great deal of engineering development work will be required to move these reactor designs from the drawing board through prototypes and pilot plants to full-scale facilities. In addition, further study will be needed to improve reliability and reduce costs (some experts have estimated fast reactors may cost between 10 and 30 percent more than LWRs, as discussed in the section titled "Cost of Alternative Plant Designs and Fuel Cycles" later in the chapter)
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From page 458... ...
. focused on the technical challenges of the back end of the nuclear fuel cycle" but not to pursue near-term commercial demonstration projects for closed fuel cycle technologies at present.35 Closed fuel cycle technologies (for either burning or breeding)
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However, higher cost projections for closed fuel cycles (compared to once-through fuel cycles) as well as political resistance are likely to push potential commercial deployment well past 2020.
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For example, if proven technically suc cessful and economic, burning fuel cycles (intended to reduce the volume of long lived high-level radioactive waste) could, over the long term, substantially change the discussion on storage and disposal of radioactive waste.
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Two major categories of burning fuel cycles -- full recycle and limited recycle -- as well as associated technology challenges are briefly discussed in the paragraphs that follow.43 A full recycle program (such as that envisioned by the second Bush administration) would involve processing used fuel, making new fuel using some of the recovered material, and using that fuel in fast burner reactors (discussed in the section titled "Nuclear Reactor Technologies")
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As is the case with many of the alternative concepts, the economic viability of the approach is very uncertain. Based on the preceding discussion, it is clear that pursuing alternative fuel cycle options (including burning fuel cycles)
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And the costs of alternative plants and fuel cycles are even less clear at this point. These cost issues are discussed in the following sections.
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. The estimates discussed in this section are limited to evolutionary reactor designs and assume a once-through fuel cycle.
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In recent years, the use of nuclear power plants has generally been very profitable for merchant producers because the prices they have obtained have generally been the much higher prices for electricity produced by natural gas plants. 1Utilities can also generate electricity using their own plants, particularly in traditional markets.
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. The committee estimated the LCOE of new nuclear plants using an 80:20 debt-to-equity ratio, and assuming that federal loan guarantees for 80 percent of the eligible project costs are acquired.
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The LCOE for new nuclear plants does not change in current-year dollars between 2020 and 2035. Overall, the LCOE ranges for new coal plants with CCS and new evolutionary nuclear power plants appear to be comparable, as shown in Chapter 2 of this report.
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The loan guarantees are likely to have a larger effect. EPAct05 allows the Secretary of Energy, after consultation with the Secretary of the Treasury, to provide loan guarantees for up to 80 percent of eligible project costs for nuclear plant construction.
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For nuclear power plants in particular, these policies include, for example, the Price-Anderson Act and federal responsibility for the disposal of used nuclear fuel. 2EPAct05 provides loan guarantees for other technologies in addition to nuclear -- for exam ple, renewable-energy technologies.
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If the decision is made to pursue fast reactors, further R&D to reduce costs will be valuable. The LCOE for plants using alternative fuel cycles is likely to be higher than for those using once-through fuel cycles, though how much higher remains uncertain.
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From page 471... ...
On the other hand, as discussed in the section on "Alternative Fuel Cycles," such a closed cycle would produce a smaller volume of long-lived high-level waste than the once-through fuel cycle produces, and the long-term heat load could be reduced owing to the destruction of a large frac tion of transuranics in the used fuel. If fission products were also removed from the fuel and handled separately, the short-term heat load could also be reduced, potentially allowing closer packing of waste in a repository.
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From page 472... ...
.65 Thus, if the prospective owner/operator of a nuclear plant applied for a combined construction and operating license (COL) in 2009, the plant would be unlikely to produce electricity before 2017.66 65The estimate of 4–7 years is a committee judgment based on discussions with various stake holders.
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GWe = gigawatts-electric; IOU = investor-owned utility; IPP = independent power producer; LCOE = levelized cost of electricity; TWh = terawatt-hours. aExtending the operating licenses for a fraction of currently operating plants to 80 years would decrease the number of plants retired between 2035 and 2050.
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For the purposes of this report, this value is used as an estimate of the representative capacity for future reactors, although the value may change, particularly for the post–2020 period. 70Because none of the currently operating plants is likely to be retired by 2020, any new plants will add to the present nuclear capacity.
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By 2035, about 30 GW will be retired; by 2050, nearly all currently operating nuclear plants will be retired. Because of the long lead times 71Improvements or efficiency gains not yet identified have not been included in the calcula tion, and further improvements to existing plants may be possible.
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Blue squares represent the generation capacity of currently operating nuclear power plants assuming license extensions to allow for 60-year operating lives. Green diamonds represent the capacity of the current fleet of plants assuming that all 104 plants receive license extensions to allow for 80-year operating lives.
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Ultimately, however, the number of plants built will be influenced by future electricity demand, public attitudes about nuclear power, and the economic competitiveness of nuclear power compared to alternative sources of electricity. POTENTIAL BARRIERS Although there are several potential barriers to deployment of new nuclear power plants, the committee judges that these barriers can be reduced or eliminated if the first handful of plants are constructed on schedule and on budget, and they dem onstrate initial safe and secure operation.
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Nuclear plants have not been built in the United States for decades, but there are unpleasant memories, because construction of some of the currently operating plants was associated with substantial cost overruns and delays. There is also a significant gap between when construction is initiated and when return on invest ment is realized.
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html; accessed July 2009. 76A 2008 Zogby poll found that 67 percent of Americans surveyed support the building of new nuclear plants (23 percent were opposed, while 10 percent were unsure)
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. Public opinion about the safety of nuclear plants has become more posi tive over time: a 2006 poll showed that 60-plus percent of respondents believed nuclear power plants to be highly safe, in contrast to 35 percent with the same pollster in 1984 (Bisconti Research, Inc., 2006)
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Storing and disposing of used fuel is discussed in the "Impacts" section of this chapter. 82Eleven states require that the USNRC make some finding regarding the potential for dis posal of used nuclear fuel before an existing moratorium on new nuclear power plants within their borders is lifted.
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In 2007, U.S. nuclear power plants were responsible for approximately 70 percent of the greenhouse-gas-free electricity production in the United States.86 However, before 2020, new nuclear plants will contribute relatively little to reduc ing the total greenhouse gas emissions from the U.S.
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emissions from uranium enrichment are likely to decrease in the future because several energy-efficient gas centrifuge enrichment 87The source for the low and high supply estimates as well as capacity factors and other as sumptions can be found in the section of this chapter on deployment of new nuclear plants. 88This calculation assumes that nuclear power plants emit 40 tonnes of CO equivalent per 2 GWh (including emissions from construction, mining, fuel fabrication, and other processes)
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In addition, if future sources of electric power used for fuel enrichment emit less CO2, this will be reflected in the life-cycle emissions of operating nuclear plants. Mining and Milling of Nuclear Fuel Environmental impacts occur from the multiple processes involved in fabricating nuclear fuel.
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Nuclear power plants on average require more cooling water per kilowatt-hour of electricity produced than do fossil-fuel plants of comparable age, due to nuclear power plants' lower average thermal efficiency.
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Hybrid cooling may be used in several evolutionary nuclear plants proposed for construction in the United States in the near term, including the new reactor planned by UniStar for the Calvert Cliffs site in Maryland (Pelton, 2007)
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From page 487... ...
First, the burn-up of nuclear fuel will likely increase as new fuel designs are developed. This will reduce the mass of used fuel generated per unit of electricity generation, although it will increase the volume of transuranics and fission products (resulting in more radioactivity)
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The statutory limit for the amount of used fuel that was planned for disposal at Yucca Mountain is less than the amount of used fuel that will ultimately be produced by existing commercial reactors. Thus, even if Yucca Mountain were approved, a second geologic repository would be needed, or modification of the statutory limit for Yucca Mountain would be required, or the fuel cycle would have had to be altered.
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Safety and Security The safety and security of nuclear power involve not only the resistance to accidents and attacks on the plants themselves but also the safety and security of the associated fuel cycles -- including the potential for proliferation of weapons-usable nuclear materials and technologies. Resistance to Accidents and Attack102 It is possible that an accident at a nuclear power plant or an attack on it could result in off-site releases of radioactive material.
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nuclear plant has the capability to withstand an attack at the level of the Design Basis Threat (DBT) ,105 which is approved by the USNRC and is subject to periodic force-on-force testing.
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The proliferation debate focuses primarily on this impact of nuclear power in other countries. Nuclear power plants themselves are not a proliferation risk,106 but nuclear fuel cycle technologies such as enrichment and reprocessing introduce the risk that weapons-usable material could be produced.
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Uranium Resources World uranium supplies will not be a barrier to the continuing operation of the current fleet of plants or to the expansion of nuclear power in the time periods considered in this report. The estimated supply of uranium is sufficient to sup ply the current and projected fleet of plants using a once-through fuel cycle for more than a century (OECD/NEA, 2007)
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nuclear plants in 2007. Secondary sources of uranium (from government and commercial inventories, including dismantled nuclear warheads and re-enriched uranium tailings)
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Reasons cited include favorable recent experience with existing nuclear plants, particularly with regard to improved reliability and safety; concerns about natural gas prices; barriers to the construction of new coal-fired power plants; and concerns about the potential for future regulatory restrictions on CO2 emissions. Like renewable sources, nuclear power plants produce no greenhouse gases during operations.
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If all of the spent fuel currently in storage at U.S. commercial nuclear plants were to be stored together in dry casks 1.5 cask diameters apart, they would cover an area equivalent to about one-sixth of a square mile (see Annex 8.D)
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From page 496... ...
If ultimately pursued, the license application for Yucca Mountain would have to survive regulatory review by the USNRC and likely judicial challenges. As currently restricted by leg islation, a repository at Yucca Mountain would not have sufficient capacity to handle all of the used fuel generated by currently operat ing nuclear plants; however, the site is estimated to be able to accom modate up to four times the legislated limit.
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From page 497... ...
Nearly all cur rently operating nuclear plants are likely to receive 20-year exten sions to their current 40-year operating licenses, allowing for 60 year operating lifetimes. Work has begun to assess the technical fea sibility and economic viability of extending licenses for an additional 20 years.
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The absence of a permanent disposal facility for used nuclear fuel does not present a technical barrier to new construction. However, there are political and societal barriers to selecting the location(s)
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From page 499... ...
Alternative fuel cycles. Considerable R&D is needed before alter native fuel cycles will be ready for deployment.
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2001. Interim Storage of Spent Nuclear Fuel: A Safe, Flexible, and Cost-Effective Approach to Spent Fuel Management.
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2008. Reactor design and fuel cycle choices.
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1994. The Economics of the Nuclear Fuel Cycle.
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; and Alternative reactor designs, which range from more significant modifi cations of currently deployed designs to entirely different concepts. In the next few decades, the majority of the new nuclear plants constructed will be based on evolutionary reactor designs.
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From page 504... ...
owner-operators have plans to use the AP-1000 design; others have identified the USEPR, the ABWR, the economic simplified boiling water reactor, or the APWR as their reactor of choice. Alternative Nuclear Reactor Designs In addition to the evolutionary reactor designs just discussed, alternative nuclear reactor designs are being developed (and in some cases, are already in use)
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From page 505... ...
DOE Energy Information Administration (www.eia.doe.gov/cneaf/nuclear/page/analysis/nucenviss2.html; accessed May 12, 2009) ; and Areva, SWR 1000: The Boiling Water Reactor with a New Safety Concept (available at www.areva-np.com/ common/liblocal/docs/Brochure/SWR1000_new_safety_concept.pdf; accessed July 2009)
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, a 10-nation (plus the European Union) organization, to lay out a path for development of the next generation of nuclear plants.7 Both ther mal and fast reactor designs were considered.
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Around the world, several alternative reactor designs are in use or planned: for example, two new types of gas-cooled reactors are planned or operating, and two sodium-cooled fast reactors are planned to be operating in the near future (in addition to the one that is currently operating)
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From page 508... ...
Note: GIF = Generation IV International Forum; GFR = gas-cooled fast reactor; LFR = lead-cooled fast reactor; MSR = molten salt reactor; MWe = megawatts-electric; MWt = megawatts-thermal; SCWR = supercritical water reactor; SFR = sodium-cooled fast reactor; VHTR = very-high-temperature reactor. a"The VHTR can also generate electricity with high efficiency, over 50 percent at 1000°C" (GIF/NERAC, 2005)
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. Small Modular Reactors In the United States, some companies have expressed interest in submitting applications for design certification of alternative reactor designs within the next few years.
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. In particular, fast reactor designs intended to reduce the quantity of long lived high-level waste by transmitting long-lived radioisotopes into shorter lived isotopes as part of a closed fuel cycle ("burner reactors")
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, under the Obama administration, the DOE plans to "no longer pursu[e] near-term commercial demonstration projects." Very-High-Temperature Reactors Under the Next Generation Nuclear Plant (NGNP)
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Source: Data from Alberta Department of Energy, 2007; Chenier, 2002; DOE, 2000; Gary et al., 2007; Moorhouse, 2007; NREL, 2001. Research and Development Opportunities Although R&D is not needed to deploy evolutionary nuclear plants in the near term, there are many R&D opportunities remaining for evolutionary LWR tech nologies (some of which could potentially be used in existing plants)
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Test reactors and the first prototypes of new reactors using gas and liquid metal coolants are likely to be operable in some countries by 2020 or shortly thereafter. Efficiency improvements in currently operating and evolutionary LWRs may be able to be gained by using coolant additives.
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The development of significantly higher burn-up fuel for LWRs could allow operating cycles to be prolonged; it could also allow the long-term heat load of the used nuclear fuel and the total amount to be stored or disposed of to be reduced.13 R&D to increase fuel burn-up would focus on the materials issues asso ciated with fuel integrity under long-term exposure to ionizing radiation as well as mechanical design issues which limit fuel lifetimes. For example, one issue requir ing R&D is swelling of the higher burn-up fuel rods due to build-up of fission products, and the resulting risk of cladding breach.
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. Technical questions raised by lifetime extension are driven by material aging issues requiring techniques for nondestructively assessing the status of operating plants.
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This suggests that significantly more effective use of advanced simulation codes is unlikely to occur before 2020.
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Types of Closed Fuel Cycles Closed fuel cycles fall into two major categories: (1) fuel cycles designed to pro duce at least as much new fissionable material as is destroyed in producing energy ("breeding fuel cycles")
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. This fact, com bined with concerns about radioactive waste management has led to an emphasis on burning fuel cycles (as opposed to breeding fuel cycles)
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Burning fuel cycles can be further separated into limited recycle and full recycle, as illustrated in Figure 8.B.1. Under limited recycle, the used fuel from LWRs is chemically or electrochemically processed to separate fissionable material from transuranics and fission products.
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(Top) In the once-through fuel cycle, used light-water reactor (LWR)
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Alternative Separations Technologies To implement either a burning fuel cycle or a breeding fuel cycle, separations technologies are needed to recycle (or reprocess) used nuclear fuel.
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. The primary reprocessing technology that has been under investigation as part of the DOE's Advanced Fuel Cycle Initiative is UREX+ (DOE, 2007)
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Available at www-fp.mcs.anl.gov/nprcsafc/Presentations/NucPhysConf.pdf; accessed May 12, 2009. separation is also considered to be in the proof-of-principle stage of development, and commercial-scale deployment of this technology is unlikely before 2035.19 Thorium Fuel Cycles In addition to the fuel cycles described above, closed fuel cycles using thorium (an element approximately three times more abundant in nature than uranium)
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However, the thorium fuel cycle is technically more complicated than uranium or uranium/plutonium fuel cycles. By absorbing ther mal neutrons, thorium-232 produces fissile uranium-233, which can be used as a nuclear fuel.
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Simulation and Modeling Although significant systems analysis and comparison of once-through and closed fuel cycles has been done, further research in this regard will be essential. In addition, work on modeling and simulations will be needed, from high-level alternative system evaluations, through assessing combined nuclear and chemical processes, and detailed fuel design, to evaluation and qualification.
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From page 526... ...
Based on a range of overnight costs drawn from the open literature, the AEF Committee has produced an estimate22 of the range for the LCOE for nuclear power plants deployed in the United States before 2020.23 These estimates were produced using the financial model developed for the Keystone Nuclear Power 20The "levelized cost of electricity" at the busbar encompasses the cost to the utility of pro ducing the power on a per-kilowatt-hour basis over the lifetime of the facility, including interest on outstanding capital investments, fuel, ongoing operating and maintenance (O&M) costs, and other expenses.
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From page 527... ...
Due to the large up-front capital investment required, the LCOE for new nuclear plants is sensitive to the assumptions made for the financing of construction costs. All currently operating plants were built either by publicly owned26 or by investor-owned regulated utilities (IOU)
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From page 528... ...
cThe average capacity factor assumes that the lessons learned over the last few decades that have resulted in increasing capacity factors at existing nuclear plants will carry over to evolutionary designs. If plant life is extended, it may no longer be appropriate to continue to assume a 90 percent capacity factor.
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Although CWIP may not affect the levelized cost of electricity (LCOE) from a new power plant, it can have a significant effect on a utility's decision process.
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These calculations do not take into account federal incentives for nuclear power, such as loan guarantees or produc tion tax credits. Nearly all of the recent estimates of the range of LCOE from new nuclear power plants of which the committee is aware overlap with these ranges, as shown in Table 8.C.3.
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From page 531... ...
All costs have been rounded to the nearest cent. EPRI = Electric Power Research Institute; IOU = investor-owned utility; IPP = independent power producer; LCOE = levelized cost of electricity; MIT = Massachusetts Institute of Technology; NEI = Nuclear Energy Institute; PUC = public utility commission.
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From page 532... ...
DOE is authorized to provide $18.5 billion in loan guarantees for nuclear power facilities, but it is not yet clear whether this allocation will be sufficient for the four to five plants the committee judges will be needed to demonstrate whether new nuclear plants can be built on schedule and on budget. The DOE has found it difficult to implement the program, in part because of the challenge associated with estimating the appropriate fee.
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From page 533... ...
However, the envi ronmental impacts from the nuclear fuel cycle are not negligible. This annex dis cusses the environmental impacts of nuclear power plants and associated fuel cycle technologies as well as the potential for additional impacts from an expanded nuclear deployment.
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nuclear fuel cycle is maintained, could range from 16 to 55 g CO2 equiva lent per kilowatt-hour.35 For comparison, coal plants without carbon capture and sequestration produce an average of 1000 g CO2 equivalent per kilowatt hour. This range includes many of the published life-cycle analyses the com mittee is aware of, with the notable exception of several European studies that estimate lower emissions (including the life-cycle estimate of 8 g CO2 equivalent per kilowatt-hour used by the Organisation for Economic Co-operation and Development/Nuclear Energy Agency [OECD/NEA, 2008]
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From page 535... ...
The red bars represent the estimates of Fthnakis and Kim for nuclear power plants built and operated in the United States. The estimates below this range include European and Japanese estimates that assume that nearly all fuel enrichment is done via gas centrifuge; this would not be the case in the United States in the near future.
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From page 536... ...
However, by 2050, as much as 730–2300 million tonnes of CO2 equivalent per year could be displaced. Impacts on Waste from Production of Nuclear Fuel There are environmental impacts from the multiple processes involved in produc ing nuclear fuel.
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. Radon emissions from mill tailings due to radioactive decay of uranium were previously an issue of public concern in the United States.
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However, as noted previously, very little uranium is mined in the United States, and few nuclear plants are likely to be constructed in the United States before 2020. Thus, domestic environmen tal impacts related to the front end of the nuclear fuel cycle due to an increased 38"Down-blending" refers to a process in which low enriched uranium (reactor grade)
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From page 539... ...
The amount of water required can create problems if the location does not have an adequate water supply, or if power output at some sites must be constrained to comply with permit limitations on the temperature increase that can be accepted in the receiving waters. The amount of cooling required is determined by the thermal efficiency of the plant; nuclear power plants on average require more cooling water per kilowatt-hour of electricity produced than do fossil-fuel plants of comparable age (due to nuclear power plants' lower average thermal efficiency.)
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From page 540... ...
A hybrid cooling system was built in 1988 at the Neckarwestheim Nuclear Plant in Germany. Hybrid cool ing is also proposed for use in several evolutionary nuclear plants intended to be built in the United States in the near term, including the new reactor proposed by UniStar for the Calvert Cliffs site in Maryland (Pelton, 2007)
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From page 541... ...
The reports take into account any interim used fuel storage on the site as well as the operation of the plant itself, and the releases are limited by the license of the plant.44 These emissions are typically several orders of magnitude below statutory limits and would not be expected to produce meaningful health risks to people living near the plants. Nonetheless, these emissions can be of great concern to local citizens who may not have confidence in statutory limits, as seen in the controversy over tritium leaks at the Braidwood plant in Will County, Illinois.45 Disposal of Used Nuclear Fuel and Other Waste The operation of a nuclear power plant generates several types of radioactive waste, which must be stored and eventually disposed of.
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The following sections and Table 8.D.1 provide further detail on the management and disposal of these wastes in the United States. Used Nuclear Fuel The 104 currently operating nuclear plants in the United States generate about 2200 metric tons of uranium (MTU)
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Radioactivity Long-lived, highly Mostly short-lived, Mostly short-lived, low-to radioactive low-to-intermediate intermediate radioactivity; radioactivity; small small volumes of long-lived volumes of long-lived highly radioactive waste highly radioactive waste Dry storage (drums and No storage of Class A, B, C Storage Pools: about 58,000 casks) at plant sites; waste; storage of Greater MTU at 65 operating storage of Greater-Than- Than-Class-C waste in pools sites, 9 sites with no Class-C waste in pools and casks operating reactors, and and casks one centralized storage site Dry casks: about 10,500 MTU in about 900 dry casks at 40 sites Disposal Deep underground Land disposal facilities Land disposal facilities for repositories for Class A, B, C waste; Class A, B, C waste; no no disposal pathway for disposal pathway for Greater Than-Class-C wastea Greater-Than-Class-C waste Current availability Adequate wet and dry Adequate storage Waste can be stored on-site of storage storage available on-site available on-site during decommissioning Current availability None Adequate for Class A Adequate for Class A waste; of disposal waste; limited for Class limited for Class B, C waste; B, C waste; none for none for Greater-Than-Class Greater-Than-Class-C C waste waste Note: MTU = metric tons of uranium.
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From page 544... ...
FIGURE 8.D.2 Toxicity of nuclides in used fuel from a light-water reactor. Toxicity is defined here as the volume of water required to dilute the radionuclide to its maximum permissible concentration per unit mass of the radionuclide.
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From page 545... ...
However, a decision as to how to permanently dispose of this material was not made until 1982. The Nuclear Waste Policy Act of 1982 provided that the disposal of used fuel from commercial nuclear power plants was a federal responsibility, as well as that the federal government would construct and operate a deep geological repository for this purpose.48 In 1987, the Nuclear Waste Policy Act Amendments Act directed the federal government to investigate Yucca Mountain, Nevada, as the nation's first disposal site.
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From page 546... ...
In 2001, the Environmental Protection Agency (EPA) published standards for the disposal of used nuclear fuel and high-level radioactive waste at the geologic repository planned at Yucca Mountain, Nevada.
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From page 547... ...
In addition, the facilities can be actively monitored and maintained for an indefinite period of time. At present, used fuel is being stored at currently operating plant sites; this practice could be continued.52 As of 2009, approximately 58,000 MTU of used fuel was in storage in pools at 75 sites, and about 10,500 MTU was in dry cask storage at 40 sites.
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From page 548... ...
For example, the licensing process for the centralized storage site proposed by Private Fuel Storage, LLC at Skull Valley, Utah, required almost 9 years from the filing of the license application with the USNRC until a draft license was issued.55 Thus, it is unlikely that sufficient facilities could be identified and licensed before 2020. Other Operating Wastes In addition to used nuclear fuel, other radioactive wastes are generated during nuclear power plant operations.
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From page 549... ...
This waste will remain at these sites until a disposal facility is available to accept it. In recent years, the nuclear industry has made an effort to reduce the amount 56That is, low-level wastes are the wastes that do not fall into other regulatory categories, such as used nuclear fuel, HLW, or transuranic waste.
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From page 550... ...
estimated that to complete the Maine Yankee nuclear plant decommissioning, in total, 246 million pounds of radioactive waste would need to be shipped off-site, the majority being radioactively contami nated concrete versus 151 million pounds of nonradioactive waste. In contrast, the majority of the waste that was disposed of in the decommissioning of the Big Rock Point reactor was made up of "clean" concrete (Carraway and Wills, 2001; EPRI, 2005)
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From page 551... ...
New waste forms requiring disposal may emerge from alternative fuel cycle technologies. New nuclear power plants will produce waste that is similar to the waste produced by current plants, with two possible exceptions.
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From page 552... ...
This suggests that such stor age could be incorporated into the design of new plants. In contrast, technologies such as advanced fuel cycles may produce waste forms that are different from those produced by current U.S.
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From page 553... ...
The following discus sion is drawn from a recent National Research Council report on the safety and security of commercial spent nuclear fuel storage (NRC, 2006)
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From page 554... ...
Nuclear plants have backup systems and procedures designed to prevent or mitigate the consequences from the accidental disruption of coolant flow to the reactor core or used-fuel pool. For example, the reactor containment is designed to limit the release of any radioactive material from the reactor core in the event of an accident.
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From page 555... ...
Security In addition to reactor accidents, after the attacks of September 11, 2001, terrorist threats to nuclear power plants have become a concern. As noted above, the primary concern is that a terrorist attack on a nuclear reactor might result in a radioactive release to the surrounding area.
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From page 556... ...
Impacts from Expanded or New Deployments New evolutionary nuclear plant designs are intended to improve both safety and security over currently operating plant designs. Some modern designs for reac tors of the types that are proposed for near-term construction in the United States (discussed in Annex 8.A)
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From page 557... ...
. In addition, the USNRC recently promulgated a rule requiring applicants for new nuclear reactors to identify features and functional capabilities of their designs that would provide additional inherent protection from or mitigate the effects of aircraft attacks.
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From page 558... ...
2008b. USDOE Final Supplemental Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada.
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From page 559... ...
2005. Thorium Fuel Cycle -- Potential Benefits and Challenges.
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From page 560... ...
2008. US DOE, Reactor design and fuel cycle choices.
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From page 561... ...
1999. Using thorium in a commercial nuclear fuel cycle: How to do it.
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From page 562... ...
2008. New nuclear development: Part of the strategy for a lower carbon energy future.
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Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.