CHAPEL HILL -- Efforts to promote energy efficiency, encourage sustainable lifestyle changes and exploit renewable energy sources are laudable, but they will not be sufficient to meet the projected growth in demand for electricity. The United States and the world need to increase the use of nuclear power, particularly for energy security and to limit climate-changing emissions. Nothing that has happened in Japan has made nuclear power any less essential.
The Fukushima nuclear power plant accident was caused by a major earthquake and tsunami of the sort that are not likely to occur here, but we can learn from the cascade of events that led to reactor meltdowns and hydrogen explosions there. The U.S. Nuclear Regulatory Commission is studying the accident, and its findings could lead to a number of changes, especially better protection against a loss of power from extreme events like hurricanes, earthquakes and floods. Lessons learned from Japan's crisis would improve nuclear safety, as other changes did following the Three Mile Island accident in 1979.
Change could also come from a different direction:
development of a new generation of small modular reactors similar in size to those that have successfully powered U.S. submarines and aircraft carriers for decades.
No bigger than a double-wide trailer and built in a factory for a fraction of the cost of a large nuclear plant, the small modular reactor (SMR) is an environmentally friendly and cost-effective way to help meet growing demand for electricity.
SMRs have the potential to replace older coal plants and to provide a hedge against volatility in natural gas prices. And while solar and wind are attractive energy sources, both produce power only intermittently and require back-up power in the event the weather is not cooperating.
Established nuclear-energy companies engaged in the development of SMRs include Westinghouse, General Electric, General Atomics and Charlotte-based Babcock & Wilcox. But the field also includes some smaller start-ups such as NuScale Power in Oregon, Hyperion Power Generation in New Mexico and TerraPower, based on the outskirts of Seattle and established with support from Bill Gates.
Ground has been broken for construction of large nuclear plants in Georgia and South Carolina, but many other projects have been delayed due to the downturn in the economy, a surge in natural gas production and the high cost of building large new power plants. So the SMR may be emblematic of nuclear power's future.
President Barack Obama has allocated $500 million to be spent on research and development of SMRs over the next five years. Energy Secretary Steven Chu says he expects an SMR to be operating in this country by the end of this decade. In Congress, Republicans and Democrats alike support SMR development.
In contrast to a conventional nuclear plant, SMRs could be added one at a time in a cluster of modules, as the need for electricity rises. The cluster's costs would be paid for over time, softening the financial impact. The modules could be factory assembled and be delivered by rail to an existing nuclear plant site. In such a configuration, one SMR could be taken out of service for maintenance or repair without affecting operation of the other units.
Most SMRs would be situated beneath the ground to provide better security. Typically they would operate for many years - possibly decades - without refueling and produce far less waste than conventional reactors.
Significantly, almost all of the SMR development is being done with private financing. Companies are using their own resources to develop the small reactors, without government support from mandates or subsidies of the sort that renewable energy sources now require. An SMR designed by Babcock & Wilcox would generate 125 megawatts, using conventional light-water reactor technology. The Tennessee Valley Authority is considering deploying six of the Babcock & Wilcox modules at its Clinch River site near the Oak Ridge National Laboratory.
Another SMR on the drawing board would be an advanced, sodium-cooled "fast" reactor producing just 25 megawatts - enough electricity to power a rural community or a military installation. Hyperion Power Generation has formed a partnership with the Savannah River National Laboratory to build a sodium-cooled reactor as part of a clean energy park near Aiken, S.C.
Looking ahead, SMRs could be an important element in a balanced mix of clean energy sources in North Carolina and nationally. It's likely that a large number of older fossil-fuel power plants will have to be shut down within the next few years. These plants are relatively inefficient, and it would not be cost-effective to equip them with the sort of state-of-the-art environmental controls that will be needed to meet air quality standards.
That capacity must be replaced, and additional electricity generation will be needed to meet forecasts for rising demand. SMRs are a safe and affordable source of energy that should be considered for use in the United States.
David N. McNelis is director of the Center for Sustainable Energy, Environment and Economic Development in the Institute for the Environment at UNC-Chapel Hill.
