Nuclear Waste Management

Frontmatter

Chapter 1. Introduction

Abstract

While nuclear energy provides the benefit of abundant energy supply as a low carbon energy source, it also produces nuclear waste. This chapter describes the nature of the problem of nuclear waste and introduces overall activities conducted to manage nuclear waste. An overview of nuclear waste generation from various sectors in the world is also provided as background for the discussions in the following chapters.

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Chapter 2. Policy and Regulations for Nuclear Waste Management

Abstract

Management of nuclear waste is largely a public policy problem requiring decisions by government. Policy for nuclear waste management defines goals, responsibilities, procedures, appropriation of resources in a national program while addressing various ethical issues involved. Policy also guides and supports technical activities including technology developments necessary to effectively support nuclear waste management. This chapter describes the process of policy making and how to conduct policy analysis. Development of laws, standards, and regulations as part of national policy for nuclear waste management is also discussed.

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Chapter 3. Basic Nuclear Science and Engineering

Abstract

Understanding the basics of nuclear and radiation science and engineering provides the basis of technical approaches to nuclear waste management. This chapter describes how various types of ionizing radiation are produced and interact with matter, and how nuclear reactor works. The process of nuclear fission as the fundamental step of nuclear energy generation is also described along with its implications in nuclear waste generation.

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Chapter 4. Basic Chemical Science for Nuclear Waste Management

Abstract

Chemistry controls stability and durability of materials in nuclear waste management as well as the fate and transport of radioactive materials in the environment upon their release from nuclear waste. This chapter describes the basics of chemical science such as role of electrons in chemical reactions, types of chemical bonds, various chemical reactions of importance, and the role of parameters such as free energy, pH, and oxidation potential in chemical reactions.

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Chapter 5. Science of Risk and Radiation Protection

Abstract

Providing appropriate level of safety in nuclear waste management requires understanding of biological effects of ionizing radiation. Starting with discussing radiation interactions in biological system, this chapter describes the process of energy transfer from ionizing radiation to biological targets and how such energy transfer leads to critical effects of concern such as cell death, mutation, and cancer. The chapter also discusses how the concept of “dose” is defined to characterize the risk of radiation among the exposed individuals.

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Chapter 6. Generation of Nuclear Waste from Nuclear Power

Abstract

Operation of nuclear power plants and the activities related to nuclear fuel preparation and handling of the associated waste represent the most significant source of nuclear waste generation. This chapter describes how nuclear fuels are prepared and utilized for nuclear reactor operation and how nuclear wastes are produced from the related processes. The chapter also describes how various nuclear wastes are classified for subsequent activities to appropriately manage the risk of nuclear waste.

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Chapter 7. Characteristics of Spent Fuel and Its Storage and Transportation

Abstract

As the most significant type of nuclear waste in terms of risk to humans, the irradiated nuclear fuels discharged from nuclear reactor demand utmost care in their handling. This chapter describes the composition, radionuclide inventory, decay heat, and radiation dose of spent fuel as a function of burnup and cooling time to provide the basis of its safe handling. Radiation shielding, cooling, and criticality control during storage and transportation of spent fuel are also described.

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Chapter 8. Spent Fuel Reprocessing and Nuclear Waste Transmutation

Abstract

Reprocessing is a key activity in the scheme of spent fuel recycling. Reprocessing allows better uranium resource utilization and the opportunity for nuclear waste transmutation at the expense of higher fuel cycle cost and increased nuclear security and nonproliferation concerns. This chapter provides an overview of the processes involved with two major reprocessing technologies, PUREX and pyroprocessing. Technology of nuclear waste transmutation as a way to render nuclear waste less hazardous is also discussed.

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Chapter 9. Engineered Barriers for Nuclear Waste Management

Abstract

Engineered barriers are used to achieve isolation and containment of nuclear waste thus to provide safety in nuclear waste management. This chapter discusses how various engineering materials are employed for the multiple barriers under the concept of defense in depth. Describes the use of man-made barriers in nuclear waste management with the focus on the final disposal phase. Starting with the basics of engineering materials, the types and behavior of materials used for waste forms and waste containers are described.

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Chapter 10. Geological Barriers for Disposal of Nuclear Waste

Abstract

Very long-term isolation of nuclear waste in deep geological formations is the final approach in nuclear waste management. Deep geological formations provide protection of engineered barriers and significantly delays in the development of potential impacts upon the failure of engineered barriers. This chapter describes key desired characteristics of a geologic disposal system in terms of physical and chemical properties of rocks as part of the discussion of disposal site selection process.

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Chapter 11. Movements of Radionuclides in Groundwater

Abstract

Movements of groundwater and the dissolved radionuclides therein connect geological repository with the human biosphere controlling long-term public health impacts of nuclear waste disposal. This chapter describes how groundwater transport and radionuclide migration in the porous rock medium occur subject to the natural site conditions of hydrology, geology, and geochemistry. Supporting mathematical equations are also derived and described for quantitative analysis along with the discussions of the importance of sorption and solubility of radionuclides in different geochemical environments.

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Chapter 12. Performance Assessment of Geological Repository

Abstract

Final disposal of nuclear waste requires the projection of the long-term behavior of the geological repository, through performance assessment, to demonstrate regulatory compliance with safety standards. Performance assessment considers natural as well as human initiated disruptions to describe the state of nuclear waste isolation and impacts of the failures of isolation on humans and the environment. This chapter describes how performance assessment is conceptualized and conducted and how the results are interpreted.

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Chapter 13. Management of Low and Intermediate Level Waste

Abstract

Low and intermediate level wastes (LILW) are generated from nuclear power plants, industrial processes, research laboratories, and hospitals. Although low in radioactivity contents in comparison to high level waste, LILW, with widespread presence of its generators in various sectors of society, demands foresight and careful planning and coordination for its safe management and disposal. This chapter describes an overview of LILW management approaches including their characterization, classification, treatment, packaging, and disposal. The issue of mixed hazardous and radioactive waste is also discussed.

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Chapter 14. Decommissioning a Nuclear Power Plant

Abstract

Decommissioning is the process of taking a nuclear power plant out of operation and shutting it down permanently. Therefore, it is a key component of environmental stewardship in the use of nuclear energy. Major options of decommissioning include DECON (decommissioning through immediate dismantlement), SAFSTOR (delayed dismantlement and decommissioning) as well as the choice between unrestricted and restricted site release. This chapter describes the overall steps and activities of decommissioning toward site release and the factors affecting decommissioning decisions.

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Chapter 15. Cross-Cutting Systems Issues: Economics, Nuclear Nonproliferation and Security

Abstract

Cost consideration is an important part of nuclear waste management. Also, due to the presence of special nuclear materials in spent nuclear fuel, the issues of nuclear nonproliferation and security must be addressed in nuclear waste management. These issues are particularly salient if the scheme of spent fuel recycling is adopted. This chapter describes how cost of spent fuel recycling is estimated in relation to various options of nuclear fuel cycle. International approaches to nuclear nonproliferation and security are also discussed along with the examination of the role of national policy in addressing these cross-cutting issues.

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Chapter 16. Social Aspects of Nuclear Waste Management

Abstract

The biggest challenges to successful nuclear waste management are societal. Although technologies for nuclear waste management have significantly advanced, there is a large gap between the scientific community’s achievements and the public’s perception toward nuclear waste. This chapter describes how public perception or attitude is formed through human cognitive processes under the influence of society and culture. Challenges to risk communication efforts are also discussed highlighting the differences among the stakeholders of nuclear waste management.

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Chapter 17. Addressing Key Challenges in Nuclear Waste Management

Abstract

Difficulties in nuclear waste management arise from the very long-term nature of the problem, inadequacies of human institutions to handle the problem, and difficulties in deriving social consensus. This chapter explores possible ways to overcome these difficulties and include discussions on building legitimacy, establishing stability in human institutional approaches, creating risk acceptability among the public, and considering alternative ways to addressing long-term safety in nuclear waste disposal.

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18. Correction to: Introduction

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Backmatter