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2012 | Book

Fast Spectrum Reactors

Editors: Alan E. Waltar, Donald R. Todd, Pavel V. Tsvetkov

Publisher: Springer US

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About this book

This book is a complete update of the classic 1981 FAST BREEDER REACTORS textbook authored by Alan E. Waltar and Albert B. Reynolds, which , along with the Russian translation, served as a major reference book for fast reactors systems. Major updates include transmutation physics (a key technology to substantially ameliorate issues associated with the storage of high-level nuclear waste ), advances in fuels and materials technology (including metal fuels and cladding materials capable of high-temperature and high burnup), and new approaches to reactor safety (including passive safety technology), New chapters on gas-cooled and lead-cooled fast spectrum reactors are also included.

Key international experts contributing to the text include Chaim Braun, (Stanford University) Ronald Omberg, (Pacific Northwest National Laboratory, Massimo Salvatores (CEA, France), Baldev Raj, (Indira Gandhi Center for Atomic Research, India) , John Sackett (Argonne National Laboratory), Kevan Weaver, (TerraPower Corporation) ,James Seinicki(Argonne National Laboratory). Russell Stachowski (General Electric), Toshikazu Takeda (University of Fukui, Japan), and Yoshitaka Chikazawa (Japan Atomic Energy Agency).

Table of Contents

Frontmatter

Overview

Frontmatter
Chapter 1. Sustainable Development of Nuclear Energy and the Role of Fast Spectrum Reactors
Abstract
Energy, abundantly produced and wisely used, has always been needed for the advancement of civilization. Until the last few centuries, productivity was severely limited because only human and animal power were available as prime movers. By the early nineteenth century, wood burning, along with wind and water power, had considerably advanced the human capability to do work. Coal and then oil and natural gas sequentially replaced wood, water, and wind as the world’s primary energy sources.
Pavel Tsvetkov, Alan Waltar, Donald Todd
Chapter 2. Introductory Design Considerations
Abstract
Before discussing the neutronics, systems, and safety considerations involved in designing fast spectrum reactors, it is appropriate to follow the lead of Wirtz [1] in sketching the bases for fast spectrum reactor designs. In this orientation, care will be taken to indicate the principal differences relative to thermal reactor systems with which the reader is more likely familiar. This introduction to design begins with a brief discussion of major design objectives, followed by an overview of the mechanical and thermal systems designs of fast spectrum reactors (with an emphasis in this chapter on fast breeder reactors, since most other applications of fast spectrum systems—such as waste transmutation—will be optimized if the reactor has a high internal conversion ratio and/or a high breeding ratio). Because of the position occupied by the sodium-cooled fast reactor (SFR) in the international fast spectrum reactor community, that system will be used for purposes of illustration.
Pavel Tsvetkov, Alan Waltar, Donald Todd
Chapter 3. Economic Analysis of Fast Spectrum Reactors
Abstract
Economics always plays a pivotal role in the decision process associated with the construction of any project. Accordingly, we shall endeavor in this chapter to outline the key factors that influence the cost of building a nuclear power plant—with special emphasis regarding fast spectrum reactors. It is very difficult at the present time, however, to provide firm cost estimates for fast spectrum systems because very few reactors of this type have been built in recent years and none of these could be considered fully commercial. Hence, we shall focus our discussion on comparative evaluations, i.e. citing the differences between fast spectrum systems and the current generation of light water reactors (LWRs). Specific mathematical techniques for determining actual costs, once key input numbers are known, are contained in Appendix D. Specific techniques for defining such items as the time value of money, levelized costs, etc. are detailed in this Appendix.
Chaim Braun

Neutronics

Frontmatter
Chapter 4. Nuclear Design
Abstract
The nuclear design of a reactor plant involves defining the nuclear environment that will exist inside the reactor core. This phase of design work has a great bearing on thermal-hydraulic and mechanical analyses; hence, close coordination with these activities must be maintained. Safety and control requirements are closely tied to the nuclear design effort and must be considered for all phases of the fuel cycle. Power distributions are needed in order to determine peak-to-average power factors for thermal-hydraulics analysis. Other neutronics calculations are needed to obtain the following kinds of information: required fissile fraction and inventories, fuel cycle data, shielding data, and transient response. The topics considered in this chapter include multigroup diffusion theory, geometrical considerations for obtaining input to the diffusion equation, and spatial power distributions and neutron flux spectra encountered in typical fast reactor designs.
Pavel Tsvetkov, Alan Waltar, Donald Todd
Chapter 5. Nuclear Data and Cross Section Processing
Abstract
The common approach of representing energy dependence of neutron–nucleus interactions consists of discretizing the energy dependence in a number of energy groups. During the fission reactions neutrons are emitted with an average energy of approximately 2 MeV. Neutron numbers are negligibly small above 10–15 MeV, making the maximum energy of interest in most nuclear fission reactors to be of about 15 MeV. Neutrons are then slowed down to much lower energies by collisions with the reactor components.
Pavel Tsvetkov, Alan Waltar
Chapter 6. Kinetics, Reactivity Effects, and Control Requirements
Abstract
Values for reactivity effects are required both for transient safety analysis and for control requirements during normal operation. Reactivity effects of importance in fast reactor design and safety include (1) effects of dimensional changes in core geometry, (2) the Doppler effect, (3) effects of sodium density changes or loss of sodium, and (4) long-term reactivity loss from fuel burnup. The reactor control system must compensate for these reactivities during normal operation and provide sufficient margin to handle off-normal situations. We begin this chapter with a review of the reactor kinetics equations (Section 6.2). We then proceed to discuss adjoint flux and perturbation theory (Section 6.3) since these are needed for an understanding of reactivity effects.
Pavel Tsvetkov, Alan Waltar, Donald Todd
Chapter 7. Fuel Management
Abstract
Fuel management deals with the irradiation and processing of fuel. An analysis of the fuel cycle is necessary to estimate fuel costs and to define operational requirements such as initial fuel compositions, how often to refuel, changes in power densities during operation, and reactivity control. The great flexibility of fast spectrum systems allows them to either “breed” desired fuel or “burn” undesired wastes—particularly the minor actinides (MA),1 which constitute the greatest long-term contribution to radiotoxicity and heat load in geologic waste repositories. Fuel costs represent one contribution to the total power costs, as discussed in Chapter 3. Unlike the light water reactor (LWR), fuel costs for a fast soectrum reactor are insensitive to U3O8, price. Hence, this contribution to total power cost is predicted to be lower for a fast breeder reactor than for a thermal reactor as the price of U3O8, rises. Since more fissile material is produced in a breeder reactor configuration than is consumed, the basic (feed) fuel for the fast breeder reactor is depleted uranium, which is available for centuries without further mining of uranium ore.
Pavel Tsvetkov, Alan Waltar, Massimo Salvatores

Systems

Frontmatter
Chapter 8. Fuel Pin and Assembly Design
Abstract
This chapter deals with the mechanical designs of fuel pins and assemblies. These core components must be designed to withstand the high temperature, high flux environment of a fast spectrum reactor for a long irradiation exposure time. In this chapter we will describe many of the factors that influence this design, and we will examine in some detail the stress analysis of the fuel pin. We begin in Section 8.2 with the basic geometric and heat transfer relationships for the fuel pin, and then discuss some topics related to fuel and fission gas that must be considered in analysis of steady-state fuel-pin performance. The discussion of fuel-pin design is continued in Section 8.3, in which failure criteria and stress analysis are presented. Discussion is then shifted in Section 8.4 to grouping the pins into a fuel assembly. This will include discussion of mechanical design problems such as fuel-pin spacing and duct swelling.
Alan Waltar, Donald Todd
Chapter 9. Fuel Pin Thermal Performance
Abstract
Fast reactor design requires the simultaneous application of mechanical and thermal-hydraulics analysis methods. We reviewed some aspects of mechanical analysis in Chapter 8; we will discuss mechanical design further in Chapter 12. Chapters 9 and 10 will deal with thermal-hydraulics analysis. In the present chapter we will investigate methods of determining temperature distributions within fuel pins. We will then extend these methods to assembly and core-wide temperature distributions in Chapter 10. While the actual analysis of fuel pin thermal performance depends strongly on the material, the mathematics and concepts associated with determining temperature distributions within fuel pins is essentially independent of the material in a fast reactor. Throughout this chapter, the discussions of correlations and closure relationships necessary to complete the mathematical analyses, and to introduce important concepts, are generally based on oxide fuel with notes where other fuel types show different behavior.
Alan Waltar, Donald Todd
Chapter 10. Core Thermal Hydraulics Design
Abstract
In the previous chapter we explored the methodology for determining the temperature field for a single fuel pin. Since a typical fast reactor core comprises several thousand fuel pins clustered in groups of several hundred pins per assembly, a complete thermal-hydraulic analysis requires knowledge of coolant distributions and pressure losses throughout the core. This chapter will address these determinations.
Alan Waltar, Donald Todd
Chapter 11. Core Materials
Abstract
The most hostile environment to be found in any nuclear reactor system is inside the core. Relative to a thermal reactor, the high flux, high burnup, and high temperature conditions encountered in a fast spectrum reactor place severe requirements on the materials selected for core design. Hence, considerable effort has been devoted to understanding and improving the performance of fuels and structural component candidates for fast spectrum reactor use.
This chapter is included to provide a more complete materials treatment of several of the general observations offered in Chapter 2 and of the design discussions included in Chapters 8, 9, and 10. However, because so much study has been given to the materials that comprise the primary building blocks of the fast spectrum reactor, it is not possible in an introductory text of this type to treat this subject with the degree of detail that a materials-oriented student would wish.
Baldev Raj
Chapter 12. Reactor Plant Systems
Abstract
The principal objective of the sodium-cooled fast reactor (SFR) power plant is to generate electricity. This is accomplished by transferring energy from nuclear fission to a steam system to run a turbine-generator. In this chapter we describe the SFR systems outside the core that are needed to meet this objective. The main emphasis, discussed in Section 12.2, is on the heat transport system, focusing on the design problems unique to SFRs. First, the overall heat transport system is described, including the primary and secondary sodium systems and the various steam cycles in use and proposed. Discussions then follow in Section 12.3 for the main components in the sodium system—the reactor vessel and reactor tank, sodium pumps, intermediate heat exchangers, and steam generators.
Pavel Tsvetkov, Alan Waltar, Donald Todd

Safety

Frontmatter
Chapter 13. General Safety Considerations
Abstract
Fast reactors exhibit some unique characteristics related to safety in comparison to thermal reactors. At first glance, it might appear that achieving exceptional safety in a fast reactor might be more challenging than in a thermal reactor, considering that sodium-cooled fast reactors (SFR) have a higher core power density, the neutron lifetime is shorter, the effective delayed neutron fraction is less, the core is not arranged in its most reactive configuration, the sodium void effect is usually positive, and sodium interacts rather violently with air or water. On the other hand, the boiling point of sodium is sufficiently high that the reactor can be operated near atmospheric conditions (eliminating the massive pressures required for water-cooled systems), sodium has a very high heat capacity and thermal conductivity, the neuron mean free path is sufficiently long that spatial power shifts are negligible, and xenon poisoning is a non-issue. Furthermore, it has been demonstrated that passive safety features can be more easily incorporated than in the thermal reactor systems.
John Sackett
Chapter 14. Protected Transients
Abstract
As one of the fundamental principles of defense-in-depth, there are multiple physical barriers to prevent radiation release and redundant defenses to protect them. In this way, the failure of any single physical barrier does not result in a risk to public health and safety. A typical example of the multiple barrier approach for previous sodium-cooled fast reactor designs such as EBR-II, FFTF, and CRBRP has been the use of cladding on the fuel as the first barrier, the closed primary coolant loop as the second barrier, and the containment building as the third barrier. There are other examples of fast reactors with both fewer and greater numbers of such barriers, and the adequacy of any specific approach is one of the evaluations performed by the appropriate national nuclear regulating body as part of reviewing a license application, such as the United States Nuclear Regulatory Commission (NRC).
John Sackett
Chapter 15. Unprotected Transients
Abstract
As indicated in the two previous chapters, there are several features that combine to make a SFR system safe and reliable. Only when a major off-normal condition is encountered, combined with a postulated failure of the Plant Protective System (PPS), can serious accident consequences be predicted. Even then, it has been demonstrated that a properly designed SFR can survive unprotected transients without damage to the fuel or other barriers to radiation release.
With this background, it is useful to address accidents in three categories as follows:
Protected transients. An event initiator occurs, such as a component failure, failure of a safety grade system (other than the reactor PPS), or an external event, followed by activation of the plant protection system to shut down the reactor.
John Sackett
Chapter 16. Severe Accidents and Containment Considerations
Abstract
The previous chapter considered transient sequences that were terminated without damage by self protecting features of the reactor system design. In this chapter, we provide a mostly qualitative approach to the sequential steps typically followed to evaluate hypothetical core-disruptive-accidents (HCDAs) with significant core damage. In addition, design consideration for containment and accommodation of large sodium fires are presented.
As noted in earlier chapters, because the fuel in fast reactors is not arranged in its most reactive configuration, early studies focused on the very conservative postulate that coherent fuel collapse during a major accident might lead to severe core disruption [1]. Recognition that this arbitrary assumption of coherent core collapse gave results that were much too conservative led to the development of a mechanistic approach to the analysis of core disruptive accidents [2].
John Sackett

Alternate Fast Reator Systems

Chapter 17. Gas-Cooled Fast Reactors
Abstract
The gas-cooled fast reactor (GFR) represents an alternative to the sodium-cooled fast reactor (SFR) described throughout this book or the lead-cooled fast reactor (LFR) described in Chapter 18. Although many parts of the book are relevant to all fast reactors (e.g., neutronic techniques), the use of a gaseous coolant in the GFR results in certain design and safety considerations that are fundamentally different from other fast reactor systems. This chapter addresses such differences, is focused on historical and modern GFR design features, and provides a review of relevant GFR design considerations, especially as they pertain to safety.
Designs for a gas-cooled fast reactor, originally referred to as the GCFR, were developed in the United States and Europe as an alternative to liquid metal reactors during the 1960s through 1980s. The concept was revisited in 2002 through the Generation IV International Forum (GIF) assessment, and the acronym was changed to GFR. However, some of the design goals and subsequent design choices within the GIF were much different than those pursued for the GCFR.
Kevan Weaver
Chapter 18. Lead-Cooled Fast Reactors
Abstract
This chapter describes fast neutron reactors utilizing either of two so-called Heavy Liquid Metal Coolants; namely, lead (Pb) and lead-bismuth eutectic (LBE), both having significantly higher densities and boiling temperatures than sodium. At the current time, the main driver for interest in such reactors is the potential for reductions in the nuclear power plant capital cost per unit electrical power, realized by taking advantage of the particular properties of the Heavy Liquid Metal Coolant. A lead-cooled fast reactor (LFR) is not a sodium-cooled fast reactor (SFR) with a different coolant. Effective LFR designs differ in significant ways from SFR designs and the coolant technologies for the Heavy Liquid Metal Coolants are significantly different from the coolant technology for sodium. The present chapter discusses the distinctive features of the Heavy Liquid Metal Coolants and their consideration in LFR design. Three examples of LFR concepts are described.
James Sienicki
Backmatter
Metadata
Title
Fast Spectrum Reactors
Editors
Alan E. Waltar
Donald R. Todd
Pavel V. Tsvetkov
Copyright Year
2012
Publisher
Springer US
Electronic ISBN
978-1-4419-9572-8
Print ISBN
978-1-4419-9571-1
DOI
https://doi.org/10.1007/978-1-4419-9572-8