The Atomic Energy Act authorizes the Nuclear Regulatory Commission (NRC) to issue licenses for commercial power reactors to operate for up to 40 years. These licenses can be renewed for an additional 20 years at a time. The period after the initial licensing term is known as the period of extended operation.
The decision to seek license renewal rests entirely with nuclear power plant owners. The NRC says economic and antitrust considerations determined the original 40-year term for reactor licenses, not limitations of nuclear technology. Each power reactor is licensed based on a specific set of requirements, depending primarily on its design. This set of requirements is called the plant’s “licensing basis.” The license renewal review process provides continued assurance that the current licensing basis will maintain an acceptable level of safety for the period of extended operation.
As of June 15, 2023, 87 of the 92 commercially operating nuclear reactors in the U.S. have had their licenses extended to 60 years. Furthermore, 16 reactors have applied for subsequent license renewal (SLR), which would authorize units to operate for another 20 years beyond the 60 years of the initial license and the first renewal. SLRs were issued for six reactors—Turkey Point Units 3 and 4, Peach Bottom Units 2 and 3, and Surry Units 1 and 2—however, in February 2022, the Turkey Point and Peach Bottom approvals were reversed based on a technicality. The reversal followed a successful challenge by four environmental groups that claimed the NRC’s reliance on the “Generic Environmental Impact Statement for License Renewal of Nuclear Plants” used in the approval process did not apply to SLRs. Therefore, the Surry units are currently the only reactors in the U.S. licensed to operate for up to 80 years.
Owners of at least nine other reactors have informed the NRC that they intend to submit SLR applications. Among them is the Tennessee Valley Authority (TVA), which has said it plans to submit SLR applications for its Browns Ferry reactors by December 2023.
The Browns Ferry site (Figure 1) comprises three boiling water reactors (BWRs) located near Athens, Alabama. TVA also owns and operates two pressurized water reactors (PWRs) at the Sequoyah Nuclear Plant near Soddy-Daisy, Tennessee, and two additional PWRs at the Watts Bar Nuclear Plant near Spring City, in eastern Tennessee. It is expected that Sequoyah and Watts Bar will also submit SLRs at some point in time.
Manu Sivaraman, site vice president for the Browns Ferry Nuclear Plant, talked about the SLR process as a guest on The POWER Podcast. “There’s a lot of analysis that you do when you’re going to submit for a license renewal, especially a second license renewal,” he said. “So, number one is we benchmarked other sites that have done a 60 to 80 license application, because it’s not like this has been done hundreds of times. There’ve been a few sites that have done it, some similar to ours—a boiling water—so we took all those lessons learned and then built the project plan around: ‘How did everybody else do it?’ ”
According to the NRC, the license renewal process proceeds along two tracks—one for review of safety issues (10 Code of Federal Regulations [CFR] Part 54) and another for environmental issues (10 CFR Part 51). “An applicant must address the technical aspects of plant aging and describe how those effects will be managed. It must also evaluate potential environmental impacts of the plant operating another 20 years,” the NRC says. The NRC reviews the application and verifies its evaluation through inspections. “The NRC will renew a license only if it determines that a currently operating plant will continue to maintain the required level of safety,” it says.
While a great deal of analysis is required to complete the SLR process, Sivaraman said even more work must be done to ensure the plant can operate reliably for another 20 years. “It’s a living process,” Sivaraman explained. “We’ve got close to 100 major capital projects laid out for the next 20 years. And when we say major, we’re not talking go replace a small pump, we’re talking change the turbine rotor out—all the blades, the rotor, generator change outs, cooling tower replacements for long-term operation.” He suggested having TVA’s backing and commitment to extending the lives of the units, allows planning for prolonged operation and not simply trying to manage stop-gap projects from year to year.
“There’s also a whole host of modernization things we’re going to do—main control room modernization, digitalization of different systems, rad monitor change outs,” Sivaraman said, noting that many companies and industry groups, including the Electric Power Research Institute (EPRI), are regularly developing improvements to nuclear plant systems that enhance operations and safety.
Meanwhile, having a long-term plan is also good for employee morale and helps in attracting new workers, because people can have confidence in the plant being a steady source of employment for many years to come. “It’s a great opportunity to retain people because they know they’ve got a place to work and what they do matters,” said Sivaraman.
The NRC says license renewal schedules depend on a number of factors, including available staff resources and the number of current and projected applications. In addition, the quality of the application, the complexity of the review, applicant timeliness in responding to requests for additional information, and the coordination of the timing for on-site audits and inspections may all affect the review timeline. If the licensee submits a renewal application at least five years before expiration of its current license and the agency is still reviewing the application at the expiration date, the plant can continue to operate until the NRC completes its review. However, if a sufficient application is not submitted at least five years before the current license expires, the plant may have to stop operating if the license expires before a renewal decision is made.
Notably, 80 years may not be the end of the line for nuclear plants. “It’s very preliminary, but there are conversations occurring in different pockets like EPRI—even the NRC—that I think have to do with ‘Okay, what does a 100-year extension look like?’ ” said Sivaraman. “It’s at its infancy, probably, right? But the fact that that discussion is happening, we can’t focus on just trying to get to 80, we need to think as though it can go past that.”
Sivaraman suggested the long-term planning process is the key to success. “It is not a once and done thing. It’s a living process that needs to have intelligence built into it as you go,” he said.
To hear the full interview with Sivaraman, which contains more about TVA’s plans for the future including a discussion on small modular reactors and other advanced technology, listen to The POWER Podcast. Click on the SoundCloud player below to listen in your browser now or use the following links to reach the show page on your favorite podcast platform:
For more power podcasts, visit The POWER Podcast archives.
—Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).