The goal of the evolved design is to keep things as simple and affordable as possible without compromising safety. Today’s U.S. nuclear plants include at least two redundant sets of safety equipment, including auxiliary pumps to supply cooling water to the reactors and auxiliary diesel generators to keep the equipment humming. One way of reducing the need for such systems is to make safety systems “passive.” For instance, huge tanks of water placed uphill can, in an emergency, flood reactors without the use of power or pumps.
“You can make [nuclear power plants] cheaper with less equipment, and that was the reason for the focus on passive safety,” says Keuter. Improvements in a range of supporting technologies, he argues, have enabled the construction of very safe plants. “Instrumentation and control systems have become much smaller and faster and solid state and more reliable, all of which allow you to monitor the operation more precisely.”
In its drive to execute a new power plant design, the NuStart coalition is benefiting from generous federal subsidies. NuStart and the U.S. government are splitting the $400 million to $500 million cost of coming up with the detailed designs for two versions of evolutionary water-cooled reactors, one from General Electric and the other from Westinghouse. The NRC has already approved a Westinghouse design for a 1,000-megawatt reactor; General Electric is readying the design of a 1,500-megawatt reactor for NRC approval later this year. Both of these reactors incorporate passive safety features.
After settling on a pair of possible designs, the consortium approached the delicate question of where to actually build a new plant. It was helped by a 1992 change in federal law that streamlined the permitting process. Previously, the NRC would authorize the construction of a reactor and then, when it was finished, issue a separate operating permit. The 1992 change created a combined construction and operating license.
In May, the NuStart coalition announced it had settled on six potential sites: Entergy’s Grand Gulf Nuclear Station in Port Gibson, MS, and River Bend Nuclear Station in St. Francisville, LA; Constellation Energy’s Calvert Cliffs Nuclear Power Plant in Lusby, MD, and Nine Mile Point Nuclear Station in Scriba, NY; and two federally owned sites, the Bellefonte Nuclear Plant in northeast Alabama, owned by the Tennessee Valley Authority, and the Savannah River Site, a U.S. Department of Energy facility near Aiken, SC. Of these, the coalition plans to pick two by October 1; it will then apply for construction and operation permits for both.
Now that NuStart has broken the ice, some utilities – members of the consortium and nonmembers alike – have gone ahead with their own permit applications or announcements. Three companies have applied for site permits: Entergy at Grand Gulf; Exelon Generation at a site in Clinton, IL; and Dominion Nuclear – which is not a member of NuStart – at its North Anna plant in Virginia. Finally, though it hasn’t applied for a site permit, Duke Energy of Charlotte, NC, says it is planning to seek an NRC combined construction-operation permit for an undisclosed site. Each of these plants would use one or the other of the two competing NuStart designs. The companies also say they need the U.S. Congress to continue subsidizing the process; subsidies are part of the president’s proposed energy bill.