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This chapter reveals that nuclear energy can be utilized to supply power in specialized cases. First, nuclear-powered ships and submarines were the inspiration of today’s commercial pressurized water reactors. Second, reactors can be employed for the propulsion and powering of space vehicles. Besides reactors, radioisotopes have been placed into service for heating and electric power generation in both terrestrial and space borne platforms. Future extraterrestrial applications include power for interplanetary exploration and terraforming.

This chapter explores the use of radioisotopes in extracting information. Radioisotopic tracers permit measurement of fluid velocities. Medical diagnosis and therapy routinely employ radiopharmaceuticals. To generate three-dimensional images, various tomography methods rely upon the signatures generated from the passage of radiation through matter. Although carbon-14 dating is well known, other radionuclides are better suited to dating items of greater age. The activation of samples exposed to neutrons allows quantification of the impurities present. Radiography uses photons and neutrons to study the internal composition of living organisms and inanimate objects. Portable nuclear gauges measure density and moisture content of the ground.

This chapter reviews the history related to nuclear energy beginning with scientific investigations in the late 1800s that led to the discovery of subatomic particles and both atomic and nuclear structure. Those research efforts spawned the discovery of fission. The Manhattan Project to develop an atomic bomb then accelerated the knowledge base of nuclear phenomena. After World War II, the Atomic Energy Commission was established and later the International Atomic Energy Agency. Research and development efforts led to the deployment of the first nuclear power plants. This chapter ends by addressing the controversies surrounding nuclear energy in the late twentieth century.

This chapter establishes a solid foundation for understanding nuclear reactions such as transmutation. Writing a nuclear reaction formula requires balancing nucleons, charge, momentum and total energy. Application of conservation of energy permits determination of the Q value from which a reaction is categorized as endothermic or exothermic. Additionally, conservation of momentum, a vector quantity, allows calculation of the product kinetic energies. Microscopic cross sections, which vary with the energy of the incident particle, quantify the likelihood of one of a multitude of different reactions occurring with a nucleus including scattering, capture, and fission. Reaction rates are the product of the particle flux and the macroscopic cross section. Neutron scattering is the key process to reduce neutron energy while they diffuse in a medium. Neutrons experience attenuation in a medium by an exponential law.

This chapter delves into the important heating processes within a nuclear power plant. Applying Fourier’s law of heat conduction permits determining temperature distributions within the nuclear fuel rods. In contrast, convective cooling occurs on the rod surface. The coolant, cladding and fuel temperature distributions through a reactor are determined. Besides heat transfer in the reactor core, some power plants employ heat exchangers to generate steam that is fed to a turbine-generator to produce electricity. As a consequence of the second law of thermodynamics, thermal power plants reject condenser heat to the environment through mechanisms such as cooling towers.

This chapter examines the interaction of various radiations with matter beginning at the atomic level and finally at the macroscopic level. Incident electrons, beta particles and heavy ions are stopped primarily by the orbital electrons through Coulombic interactions. Additionally, electrons and betas can produce bremsstrahlung. Heavy charged particles (ions) also may undergo nuclear reactions. Photons such as X-rays and gamma rays experience three major interactions, namely photoelectric effect, Compton scattering, and pair production, where the latter leads to annihilation radiation. The neutral radiations (photons and neutrons) are considered indirectly ionizing, while the charged particles (electrons and ions) are directly ionizing. Radiation causes changes in material macroscopic properties.

This chapter presents the physics behind a variety of particle accelerators, which are used in nuclear physics research and other applications. A brief review of the effects of electric and magnetic fields on charged particles is provided. Early approaches were the high-voltage machines such as the Van de Graaff electrostatic generator and the Cockroft-Walton voltage multiplier. The linear accelerator (LINAC) utilizes successive particle accelerations through a series of tubular electrodes. By employing a magnetic field, the cyclotron accelerates particles in a circular direction. Within the betatron, a changing magnetic field produces an electric field that accelerates electrons to relativistic speeds; whereas in the synchrotron, both radiofrequency and time-varying magnetic fields are used.

This chapter faces the realization that the same atoms that can produce life-saving electricity can also be used to construct weapons of mass destruction. Some facilities, such as enrichment and reprocessing, in the nuclear fuel cycle can also serve dual uses when considering proliferation. The original atomic bombs were constructed of highly enriched uranium and high-grade plutonium, but their development led to thermonuclear devices with much larger yields. Thus far, nuclear war has been avoided by policies such as mutual assured destruction and international agreements such as the Non-Proliferation Treaty. The International Atomic Energy Agency (IAEA) is charged with performing worldwide nuclear material safeguards inspections. The legacy of the nuclear weapons arms race has left considerable weapons-grade materials that must be dealt with.

This chapter presents various beneficial uses of radiation, such as crop mutations and insect control. Most people are cognizant of the use of radiation for treating cancer, but less well-known applications include food preservation through elimination of pathogens, bacteria, and other contaminants. Sterilization via radiation exposure is performed on medical instruments and products. Local energy deposition can stimulate chemical reactions and transform the structure of plastics and semiconductors. Neutrons and X-rays are used to investigate basic physical and biological processes.

This chapter explores the breeding of fissile material within a reactor in order to extract greater amounts of energy in uranium and thorium resources. From neutronic considerations, fast reactors are found to be more appropriate to serve as a breeder reactor. Differential equations describing the buildup of plutonium in a U-238 fueled reactor are solved. Several liquid metal fast breeder reactors have been built worldwide with two basic configurations: pool and loop systems. The economics of breeders is linked with the cost, and therefore available resources, of uranium. The interrelationship between breeder reactors and reprocessing is explained.

This chapter describes the biological effect of radiation on cells, tissues, organs, and individuals. Quantifiers for radiation dose and units such as rad, rem, gray, and sievert are identified. Some radiations, namely ions and neutrons, are found to have a more detrimental impact on biological entities for the same dose. Radioactive decay and biological elimination of radionuclides lead to an effective decay constant. Related concepts addressed include radiation sickness, lethal dose, chronic and acute exposures, and hormesis. The philosophy and practice of setting limits on exposure are reviewed with special attention given to regulations related to the nuclear power industry.

Research by Gast and Bournia on nuclear reactor cores in the form of elliptical cylinders is revisited. Derivations are presented, and data are extended in scope and accuracy. Findings on asymptotic series for constants needed in the evaluation of Mathieu functions are reported, along with accurate alternative techniques. Geometric bucklings are expressed in terms of circular cylinders with equivalent surface-to-volume ratios in a form that allows easy interpolation from tables. The estimation of extrapolation distances at boundaries of elliptical systems is addressed. Applications considered include a possible research reactor, the damage of fuel storage/shipping casks, and decommissioning of the damaged Windscale reactor.

Explicit relations are derived for the angular distribution in the laboratory of elastically scattered particles, assuming isotropic scattering in the center-of-mass system. Cases considered are mass ratios target/projectile greater than, equal to, and less than unity.

This chapter focuses on the protection of biologic entities from radiation, with an overarching principle being ALARA—as low as reasonably achievable. Radiation exposure is reduced by minimizing time, maximizing distance, and incorporating proper shielding. Dose calculations are performed for an external photon source and internal sources emitting short-range particles. In a vacuum, particle flux, and therefore dose, is found to be inversely proportional to the distance squared between a point source and the radiation absorbing object. Reductions in the uncollided neutron and photon fluxes are accommodated by using removal cross sections and attenuation coefficients, respectively. A variety of radionuclides is found in the environment, having originated from primordial, cosmic, and anthropogenic sources. To assess internal exposure, metrics such as the committed effective dose equivalent, annual limit of intake (ALI), and derived air concentration (DAC) are introduced.

This chapter delves into the engineering approaches to releasing the power of fusion. From a comparison of fusion reactions, the deuterium-tritium reaction is seen as that employed in the first generation of fusion reactors. The Lawson criterion provides density and confinement time requirements for practical fusion reactors. Two fundamental confinement approaches, magnetic and inertial, are being pursued. The international ITER tokamak project appears to have the lead in achieving the demonstration of a fusion reactor system.

This chapter details the nuclear fission process. Fission, either neutron induced or via spontaneous decay, yields radioactive fission fragments, neutrons, gamma rays, and beta particles. The emitted neutrons serve to continue a chain reaction. The kinetic energies of these products lead to heat deposition of nearly 200 MeV/fission in a nuclear reactor. The reproduction factor η is a metric for comparing the efficacy of nuclear fuels, which are transuranic nuclides such as uranium and plutonium. At the macroscopic level, the fuel burned and consumed per megawatt-day of heat production are computed.

This chapter tackles the crucial topic of nuclear safety beginning with the realization that it extends far beyond nuclear power plants. Reactor safety is assured through active, passive, and inherent safety mechanisms. As the basic strategy of reactor safety is the retention of the radioactive material present, the plant systems, including containment isolation and cooling and emergency core cooling, serving such a purpose are explained. The discipline of probabilistic risk assessment is explained by example. A major focus of this chapter is to explain the events that took place at three major nuclear reactor accidents, specifically, Three Mile Island, Chernobyl, and Fukushima. After discussing the concept of risk, the nuclear security is briefly considered.

This chapter focuses on radioactivity at both the nuclear level and for a collection of radioactive atoms, termed radionuclides or radioisotopes. Radioactivity is explained in terms of a neutron excess or deficiency. The various decay modes, such as electron capture, and the particles emitted are delineated, including alpha, beta, positron, neutrino and gamma ray. The half-life and principal radiations for important radionuclides are tabulated. The decay law is derived and its exponential solution provided from which the activity is obtained. Besides simple parent to daughter decay, more complex situations including radionuclide buildup, compound decay and decay chains are introduced.

This chapter attempts to concisely describe the role that nuclear power may take in the meeting the world’s future energy needs. Historically, economic considerations have triumphed all other considerations when selecting an energy source. Nuclear power growth stagnated in the late twentieth century for a variety of reasons. A revival in nuclear reactor construction is beginning in the United States and elsewhere at the start of the twenty-first century. World energy—and especially electricity—use is increasing and sustainable approaches to meeting this need are sought. With rising concern about climate change, nuclear power is found to be the lowest contributor to carbon dioxide emissions, even compared to solar and wind power. Besides electricity generation, power reactors can be utilized for large-scale desalination and hydrogen generation.

This chapter concentrates on the final disposition of radioactive materials. After explaining the difference between open and closed nuclear fuel cycles, the categories of nuclear waste, such as high and low level, are defined. Spent reactor fuel is stored in pools, generally near the reactor, until sufficient thermal and radioactive cooling occurs. Transportation is regulated by the federal government, and stringent testing is performed on canisters that carry nuclear materials. Although not commercially permitted in the United States, nuclear fuel reprocessing separates radioactive waste from the remaining fissionable materials that can be re-used in a reactor. In the U.S. political issues have delayed the completion of a geologic repository for high-level waste disposal. Low-level wastes are generated by a variety of facilities including universities and hospitals. The nuclear weapons race had a significant negative impact on the environment at those defense sites involved. Several methods have been approved for nuclear power plant decommissioning.

This chapter opens with an explanation of neutron population increase according to the multiplication factor, which permits tracking the approach to criticality of an assembly of fissionable material. Increases and decreases in neutron density and flux follow an exponential trend in relation to the reactor period. Delayed neutrons, as contrasted with prompt neutrons, are found to be key in the control of the fission process. Inherent reactivity feedback mechanisms from fuel and moderator temperature changes can partially regulate the reactor power. The presence of xenon and samarium fission product poisons require operational adjustments. Finally, core loading patterns and fuel cycle design compensate for long-term burnup of fuel.

This chapter focuses on principles of physics that are needed for the study of the release of nuclear energy and its conversion into thermal and electrical form. A limited number of basic forces exist—gravitational, electrostatic, electromagnetic, and nuclear. Associated with each of these is the ability to do work. Thus energy in different forms may be stored, released, transformed, transferred, and “used” in both natural processes and man-made devices. It is often convenient to view nature in terms of only two basic entities—particles and energy. Even this distinction can be removed, because the matter can be converted into energy and vice versa. The addition of thermal energy to a substance causes an increase in temperature. Electromagnetic radiation arising from electrical devices, atoms, or nuclei may be considered to be composed of waves or of photons. Matter can be converted into energy and vice versa according to Einstein's formula. The energy of nuclear fission is millions of times as large as that from chemical reactions. Energy is fundamental to all human endeavors and survival.

This chapter elucidates the means by which ionizing radiation is detected and measured. Instrument performance is quantified by specifications such as efficiency, dead time, and energy resolution. The gas counters consist of ionization chambers, proportional counters, and the Geiger-Mueller detector. Neutrons are detected by selecting reactions appropriate to the neutron energy within sensors such as fission chambers and He-3 probes. Specialized scintillator materials emit a flash of light when particular ionizing radiations strike the material. Thermoluminescent materials are commonly used in personnel dosimetry. Spectroscopy applications for radionuclide identification and quantification typically employ solid-state detectors. The probabilistic nature of radioactive decay requires applying statistics in radiation counting. Radiation detectors are deployed to assist in intercepting illicit nuclear material shipments and diversions.

This chapter examines processes and machines that can alter the natural isotopic abundances of a material. An early approach was the mass spectrograph that deflects ions using a magnetic field. Gaseous diffusion employs multiple stages having a permeable membrane that passes lighter molecules more readily. Presently, gas centrifuges are the dominate technology thanks to the greater separation factor, leading to lower expenses. Uranium enrichment is an energy intensive process with the cost being expressed in terms of separative work units. The state-of-the-art technique uses laser excitation to selectively ionize U-235 nuclei. Deuterium may be separated from ordinary hydrogen via several different methods.

This chapter analyzes criticality in a neutron multiplying medium. Infinite and effective multiplication factors (k∞ and keff) quantify the degree of criticality in infinite and finite media, respectively, with neutron leakage distinguishing the interrelationship between k∞ and keff. Four central nuclear engineering parameters describe the neutron lifecycle: the reproduction factor η, the thermal utilization f, the resonance escape probability ℘, and the fast fission factor e. The product of these four factors is utilized to compute k∞ of a thermal reactor, whereas the fast reactor k∞ can be expressed with a subset of these four parameters. Reactor thermal power may be calculated from the fission rate via the neutron flux. A natural reactor existed at Oklo, Africa about 2 billion years ago.

The solution of the point-kinetics equations with a neutron source can be expressed in terms of the solution without a source by a simple scaling involving reactivities, with an added constant term. Proof is provided by both the Laplace transform and matrix methods

This chapter describes the dependence of numbers of neutrons and reactor power on the multiplication factor, which is in turn affected by temperature and control rod absorbers. It examines the precautions taken to prevent release of radioactive materials to the surroundings and discusses the philosophy of safety. Prevention of release of radioactive fission products and fuel isotopes is the ultimate purpose of safety features. Delayed neutrons and temperature effects provide inherent reactor safety. Control rods permit rapid shutdown, and reactor components are designed and constructed to minimize the chance of failure. Emergency core cooling equipment is installed to reduce the hazard in the event of an accident. Licensing is administered by the Nuclear Regulatory Commission, which expects plants to use probabilistic safety risk analysis (PRA).

Publisher Summary This chapter describes the biological effects of radiation on cells, tissues, organs, and individuals. It provides an overview of the units of measurement of radiation and its effect and reviews the philosophy and practice of setting limits on exposure. All living species are exposed to a certain amount of natural radiation in the form of particles and rays. In addition to the sunlight, without which life would be impossible to sustain, all beings experience cosmic radiation from space outside the earth and natural background radiation from materials on the earth. There are rather large variations in the radiation from one place to another, depending on mineral content of the ground and on the elevation above sea level. Man and other species have survived and evolved within such an environment despite the fact that radiation has a damaging effect on biological tissue. The situation has changed somewhat by the discovery of the means to generate high-energy radiation, using various devices such as X-ray machines, particle accelerators, and nuclear reactors. When radiation interacts with biological tissue, energy is deposited and ionization takes place that causes damage to cells. The effect on organisms is somatic, related to body health, and genetic—related to inherited characteristics. Exposure limits are set by use of data on radiation effects at high dosages with a conservative linear hypothesis applied to predict effects at low dose rates.

Publisher Summary This chapter reviews some important facts and ideas about nuclear explosions and their uses. It presents the connection between nuclear power and nuclear weapons, identifies the technical aspects and strategic issues involved in the military use of nuclear processes, and provides an overview of the threat of nuclear annihilation of life on earth. The chapter describes nuclear explosions, nuclear weapons proliferation and safeguards, disarmament, and peaceful applications. Although spent fuel from power reactors contains plutonium, it is not the same as a nuclear weapon. The original atom bombs used U-235 and Pu, but the much more powerful modern weapons are based on the fusion of hydrogen isotopes. Intercontinental ballistic missiles from land and missiles from submarines make up the bulk of the arsenals of the U.S. and the U.S.S.R. Continual efforts are made to prevent further proliferation of nuclear weapons. The central concern of people throughout the world is that civilization may be destroyed by nuclear weapons. There are several peaceful civil engineering applications of nuclear explosions, but limitations on surface or above-ground weapons testing prevent their use.

Publisher Summary This chapter describes the interactions in the microscopic sense and discusses the phenomena that affect the ability to achieve a practical large-scale source of energy from fusion. When two light nuclear particles combine or “fuse” together, energy is released because the product nuclei have less mass than the original particles. Such fusion reactions can be caused by bombarding targets with charged particles, by use of an accelerator, or by raising the temperature of a gas to a high enough level for nuclear reactions to take place. Nuclear energy is released when nuclei of two light elements combine. The most favorable fusion reactions involve deuterium, which is a natural component of water and thus is a very abundant fuel. The reaction takes place only when the nuclei have a high enough speed to overcome the electrostatic repulsion of their charges. In a highly ionized electrical medium, the plasma, at temperatures of the order of 400,000,000 K, the fusion energy can exceed the energy loss because of radiation.

Publisher Summary The most important feature of the fission process is, of course, the enormous energy release from each reaction. Another significant fact, however, is that for each neutron absorbed in a fuel such as U-235, more than two neutrons are released. Only one is needed to maintain the chain reaction. Any extra neutrons available can, thus, be used to produce other fissile materials. This chapter presents the relationship between the production factor and breeding. It also describes the physical features of the liquid metal fast breeder reactor and discusses the compatibility of uranium fuel resources and requirements. The performance of a breeder reactor involves many isotopes of fertile and fissionable materials. In addition to the U-235 and U-238, there is short-lived neptunium-239, Pu-239, Pu-240, Pu-24, and Pu-242, as well as americium and curium isotopes resulting from multiple neutron capture. A fast breeder reactor using liquid sodium as coolant is being developed for commercial power, with leadership provided by Japan. There is a great disparity between uranium resources and uranium use among the countries of the world. Application of the breeder could stretch the fission power option from a few decades to many centuries.

Publisher Summary This chapter focuses on radioactivity, which is the spontaneous disintegration (decay) of the nucleus with the emission of a particle. The rate at which a radioactive substance disintegrates (and thus the rate of release of particles) depends on the isotopic species, but there is a definite “decay law” that governs the process. Many elements that are found in nature or are man-made are radioactive, emitting α particles, β particles, and γ-rays. The process is governed by an exponential relation, such that half of a sample decays in a time called the half-life tH. Values of tH range from fractions of a second to billions of years among the hundreds of radioisotopes known. Measurement of the activity, as the disintegration rate of a sample, yields half-life values, of importance in radiation use and protection.

Publisher Summary Compliance with licensing rules plays an important role in the operation of any nuclear facility. A number of other organizations have evolved to provide technical information, develop standards, protect against diversion of nuclear materials, improve nuclear power operations, and perform private research and development. This chapter discusses the Atomic Energy Acts. The first law in the U.S. dealing with control of nuclear energy was the Atomic Energy Act of 1946. Issues of the times were involvement of the military, security of information, and freedom of scientists to do research. The federal government through the Nuclear Regulatory Commission (NRC) has the authority to license and regulate nuclear facilities of all types, from a multireactor power station down to isotope research in an individual laboratory. The Office of Nuclear Reactor Regulation of the NRC requires applicants for a reactor license to submit a detailed safety analysis report and an environmental report. These documents provide the basis for issuance of a construction permit, and later when the plant is completed, an operating license. The process involves several steps. Once a plant is licensed, the Office of Inspection and Enforcement has oversight. The nuclear operations are subject to continual scrutiny by the resident inspector and periodic inspection by teams from the regional NRC office. Training of operating personnel goes on continuously, with one shift in training while the other shifts running the plant. The chapter also discusses The Energy Policy Act of 1992, which provides comprehensive national goals and requirements on energy efficiency and generation.

The sources, treatment, storage and transport, and disposal of nuclear wastes are presented. Regulations are provided by the Nuclear Regulatory Commission and the U.S. Environmental Protection Agency. The principal sources of waste from nuclear reactors are fission products and neutron activation products. Many treatment methods are available to reduce waste volume whether it involves management of spent fuel or low-level waste. Most spent fuel is stored in water pools at reactor sites, awaiting completion of a repository. Dry storage is an alternative. Disposal by deep burial is planned for spent fuel, and by enhanced confinement near the surface for low-level waste. Site characterization is being carried out. Isolation of waste from the public is essential. The future of nuclear power depends in part on successful waste disposal. Keywords: radioactivity; nuclear reactors; sources; storage; disposal; transport; low-level waste treatment; spent fuel treatment; high-level waste; transuranic waste; waste management