In some ways, it seems as though nuclear power plants are the Energizer Bunny of electric-generating technology—they just keep going. Constructed between 1969 and 1996, the nation’s 104 nuclear reactors were licensed initially for 40 years of operation. Almost 60 of these plants already have been granted operating licenses for an additional 20 years, and more than 25 are being studied for such extensions. Plant owners and regulators aren’t stopping there. As they investigate the case for a 60-year lifespan, they’re also considering what might be needed to keep these facilities running safely for an 80-year lifespan.
These plants provide more than just revenue to their owners’ balance sheets. Nuclear generating stations also generate approximately 20 percent of the electricity used in the United States. Some regions, such as the Southeast, are even more dependent on their output. Replacing that capacity with other fuel sources would be difficult and expensive.
“The key is two things—first, really low cost compared to gas and about the same as coal,” said Ken Anderson, president of CKA Associates, a Brewster, Mass.-based consulting firm with an international client base of nuclear-industry suppliers and producers. “The other thing is they are base-load plants—I think people consider nuclear plants to be a pretty important part of our fuel mix.”
With most current plants just hitting their early 40s, it may seem early to be thinking about adding another 20 years to a now-licensed 60-year lifespan. However, nothing happens quickly when it comes to nuclear-generating stations, and owners want to know if an 80-year life is practical as they begin outlining the maintenance efforts that will keep the plants online in the current maintenance cycle.
“With the [20-year] extensions, most plants will run to 2035–2050,” Anderson said, noting, though, that plant owners can require 15 to 20 years of lead time to plan their investigations and upgrades within scheduled plant shutdowns that might only occur every year or two. “So, now is a good time to figure out what you need to figure out.”
The relicensing process may raise operational issues unrelated to safety. For example, Exelon, owner of New Jersey’s Oyster Creek, the nation’s oldest operating reactor, had announced it will tear the plant down in 2019, 10 years before its current 20-year license expires. State environmental officials were forcing Exelon to add cooling towers to the plant, ending the practice of dumping hot water into the adjacent Barnegat Bay. A December agreement will allow operation until 2019 without this expensive modification.
However, safety issues remain a primary concern for both owners and regulators. To that end, the Electric Power Research Institute (EPRI) is leading a collaborative effort that also includes nuclear plant owners and the U.S. Department of Energy to determine potential vulnerabilities and improvements.
“We know we’ll need to verify the safety case,” said John Gaertner, a technical executive, EPRI.
The collaborative working group has established a common set of potential issues and related assessments required to ensure safe operations over the next 40 years.
In addition to concerns regarding aging and the safety risks radiation exposure could pose, these examinations also will consider possible modernization efforts, which may involve systems and technologies that are still fully functional but don’t reflect today’s capabilities. Such decisions aren’t as easy to make as they may seem.
“Instrumentation and control systems in nuclear plants are of old technology,” Gaertner said, citing one such example. “But, because they are so critical to the safety of the plant, people are hesitant to change them.”
The EPRI-led team will begin a demonstration effort at two New York State plants—Constellation Energy’s Ginna and Nine Mile Point Unit 1—initially looking closely at the containment structures’ concrete integrity and at internal reactor components. The intent is to inspect these areas for aging issues that could affect safety if plants were to remain operating more than 60 years. Knowledge gained will help inform procedures all operators would likely follow.
In general, experts sound hopeful that plants built in the 1960s and 1970s could still be generating electricity 40 or more years from now, particularly because their owners have done such a good job with maintenance up until now. Unlike gas- or coal-fired facilities, many nuclear operations have been virtually rebuilt from the inside out, as companies have improved and replaced everything from piping to building-sized steam generators.
“A fossil [fuel] plant isn’t maintained in the same way,” Anderson said, “because a failure of those plants isn’t a major safety concern.”
With such ongoing attention, even 80-year lifespans may be eventually exceeded. While attention currently is focused on the 60- to 80-year period, imaginations are reaching toward the century mark.
“Clearly, there are people talking longer,” Gaertner said. “Once we get into asset management and refurbishment, then we have to see if there’s anything that absolutely can’t be replaced, and so far, we haven’t found that.”
ROSS is a freelance writer located in Brewster, Mass. He can be reached at firstname.lastname@example.org.