Abstract:
The Future of Nuclear Energy
Mujid Kazimi, Director, Center for advanced nuclear energy systems, Boston
Nuclear plants in 32 countries around the world have provided about 15% of the electricity used by humanity in 2008. In several of these countries the plants operated at 90% capacity factors, 10% above the fossil plants capacity factors, and nearly three times the capacity factors of the intermittent wind and solar energies. This improved reliability of the nuclear power plants has recaptured the interest of energy planners. Today several countries, notably China and India, are looking to substantially increase the share of nuclear generated electricity in order to cut back on their dependence on coal as the primary source of their electricity. Other countries, such as the UK and Italy, that had forgone the nuclear energy option in the last two decades have announced their plans to examine it for future supply of electricity. Almost all the countries, but particularly in the US, the nuclear plants have been operating at increasing power levels, and for longer lifetimes than originally conceived.
Long term use of nuclear power requires attention both to uranium resources and management of spent fuel. Uranium extracted from mines or from phosphates can supply LWRs (the current type of reactors which use only about 1% of the ultimate energy potential of uranium) for the rest of the century if worldwide nuclear electricity generation grows at a robust rate of 3%, well ahead of electricity growth. Introduction of fuel recycling in breeder reactors by 2050 will assure that the rise in the cost of uranium will be limited. Breeder reactors will multiply the energy derivable from uranium by 60-70 fold, thus enabling nuclear power to be an important contributor to CO2-free energy for thousands of years. Subsequently, either uranium from seawater or thorium can be used. Each of these sources can supply 15,000 years of today’s world energy needs.
Thus, expanding the use of nuclear power, for both electricity and for transportation, is not impeded by the resource availability. On the other hand, there are issues that have to be faced. One is the cost of new plants, which need to be driven downward to facilitate financing such large projects. Another issue is the isolation of the nuclear waste from the environment, which is required for a very long time. Some argue for an earlier start of recycling to help reduce the level of long-lived radioactivity in the eventual geologic repository of nuclear waste. While such a goal can be achieved, it has costs as well as benefits. It might be that interim central storage is the least cost policy until the need for breeding fuel arises, at which time the spent LWR fuel can be processed to extend the fuel resources as well as reducing the waste burden.
Considering the world-wide benefits of nuclear energy, there is a need to develop an internationally agreed upon system of trade in nuclear fuel that enables some countries to rely on others for fuel supplies, spent fuel storage and treatment and eventual waste disposal. Regional centers for enrichment of fresh fuel and storage of spent fuel might be a good way to assure the world of peaceful expansion of the use of nuclear energy.