Overview of Nuclear Engineering
Nuclear engineering is concerned with the science of nuclear processes and their application to the development of various technologies. Nuclear processes are fundamental in the medical diagnosis and treatment fields, and in basic and applied research concerning accelerator, laser and superconducting magnetic systems. Utilization of nuclear fission energy for the production of electricity is the current major commercial application, and radioactive thermal generators power a number of spacecraft. For the longer term, electricity production based on nuclear fusion is expected to become an increasingly important segment of the field.
Nuclear engineers are therefore concerned with maintaining expertise in the design and development of advanced fission reactors, performing basic and applied research in the development and ultimate commercialization of fusion energy, developing both institutional and technical options for radioactive waste and nuclear materials management, and in fostering research in nuclear science and applications, with emphasis on bioengineering, detection and instrumentation and environmental science. The professional field, although highly interdisciplinary, is unified via a professional society, the American Nuclear Society.
Applications of Nuclear Engineering
Nuclear Engineering focuses on solving several of the world's most important grand-challenge problems. Our graduates help solve these problems in industry, the national laboratories, government and academia, applying the engineering science, the computational and analytical tools and the experimental methods we teach at U.C. Berkeley. Our graduates also apply their expertise more broadly, ranging from computational skills in dot-com startups to modeling the effects of cosmic rays spacecraft for aerospace companies.
Our work toward advanced energy systems, waste management, and nuclear medical applications is highly interdisciplinary, and thus many NE students pursue double major degrees: EECS for those interested in fusion energy systems and computational methods; ME for those interested in mechanical design and heat transfer; MSE for those interested in nuclear materials; and ChemE for those interested in nuclear chemistry. All NE students have opportunities to work in NE research laboratories, or at nearby National Laboratories if they desire, to obtain experience (and earn money) in nuclear engineering research during their undergraduate studies.
While energy is back in the headlines, many people are not aware of the level of activity in the nuclear field. The following sections give an update in the areas of, waste management, and medical applications, showing how NE graduates are now working to solve grand challenge problems.
The last thirty years have seen much happen for Nuclear Engineering.
Nuclear processes have an amazingly diverse range of applications, perhaps the most important being in medicine, where over 1/3 of all procedures in the United States use nuclear techniques. Nuclear processes are used to provide images inside the human body, to detect and measure biochemical processes, and to provide therapy. A major event in 2000 was the FDA approval of the first Monte-Carlo code for use by doctors to design radiation therapy for cancer. Based on nuclear reactor design methods, this new tool now allows doctors to take detailed magnetic resonance imaging data (another nuclear technique) and predict with great accuracy how to deposit precisely enough radiation to kill cancer tumors without damaging surrounding tissue. Previous crude calculation methods often forced doctors to cause damage to substantial amounts of healthy tissue, or to miss completely killing tumors. Students in the bionuclear program in NE learn how the principles of engineering physics can be applied to imaging and therapy.
The vision of fission energy is compelling. In the last two decades it has become the world's largest single source of emission-free energy, and it creates a waste stream sufficiently small and compact that we can conceive of isolating this waste permanently from the environment. For fission to provide more energy in the future, our grand challenge is to continue to improve the safety, economic performance, waste minimization, and proliferation resistance of fission power plants.
The U.S. has 103 nuclear power plants providing over 20 % of its electricity; worldwide the number is 433. These plants have helped stabilize electricity costs, particularly with the recent volatility of natural gas prices. Our nuclear plants reduce substantially the amount of carbon dioxide that world-wide electricity use releases to the atmosphere. Nuclear fission is the only non-fossil energy source that has been demonstrated at large scale, and that could be expanded substantially further. Nuclear's current contribution is sufficiently large that in 1999 just the increases in the operating capacity of existing U.S. nuclear power plants from improving equipment reliability accounted for over half of all carbon-dioxide reductions reported by the U.S. electrical industry.
We now expect most existing U.S. nuclear plants to apply for 20-year license extensions , which means that the existing U.S. nuclear fleet will operate out past 2030. Many of our U.S. plants has been sold by regulated utilities to large owner-operator companies like Excelon and Entergy. Besides encouraging further improvements in reliability and safety, the large technical expertise and financial resources available to these new nuclear-focused companies provides the best possible conditions for new plant orders. Designing the next generation of fission plants is where some of our most interesting work is now, ranging from planning for light water reactors with new passive safety features, to gas-cooled reactors with extremely durable fuel, to lead-cooled reactors that can burn more waste than they generate.
The development of economic fusion energy systems is one of Nuclear Engineering's greatest grand challenges, since such power sources would fundamentally alter the way that humankind interacts with its environment, to the benefit of both humans and nature. In a well-designed fusion power plant, burning one ounce of fusion fuel, plentifully available, makes as much energy as burning 300 tons of coal while making a negligible amount of waste. Worldwide progress toward fusion has been steady and impressive. In the last decade, we have seen magnetic fusion experiments create over 13 million watts of fusion power. In the coming decade, we expect to see the new National Ignition Facility use inertial confinement to ignite fusion fuel, and for the first time reach the fusion conditions needed in an actual inertial fusion power plant.
UC Berkeley's Nuclear Engineering Department plays a leading role in advancing fusion technology, both toward advanced approaches to magnetic fusion using compact toroidal plasma configurations, as well as collaborations with Lawrence Livermore and Lawrence Berkeley Laboratories to develop inertial fusion systems that can operate at high repetition rates for power production.
Radioactive Waste Management
Another grand challenge problem that our graduates work on is developing systems for the safe and permanent disposal of radioactive waste. The most significant milestone in this field occurred recently with the opening of WIPP, the world's first geologic repository. Located 1/2 mile underground in a 250-million-year-old salt formation in New Mexico, WIPP began emplacing waste contaminated with radioactive transuranic elements in 1999. The Yucca Mountain Project is now working toward submission of a license application in 2002 to develop a repository for commercial spent fuel and high level waste from early U.S. military activities. Against this backdrop, extensive international research continues to improve models for the transport of radionuclides from geologic repositories, with active participation by the U.C. Berkeley, Nuclear Research Laboratory. The primary concern for repositories is the long-term potential for the contamination of groundwater in areas near the repository, making it unsuitable for use by future generations. Besides improving models for transport in natural systems, efforts also focus on improving the quality of the engineered barriers that contain the waste, so that multiple barriers can reduce further the probability of radionuclide release.