(Or how to test a nuclear thermal rocket without turning it on)
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
All 92 U.S. power reactors operating today need water—in the right place and at the right time. But extreme weather events, including floods, droughts, hurricanes, and heat waves, upend expectations and demand resilience: the ability to anticipate, accommodate, and recover from adverse impacts.
Resilience was built into today’s nuclear power plants decades ago. Weather data and climate forecasts not available then can be factored into risk analysis now to ensure the plants remain resilient in a changing climate.
Capacity factor is a measure of reliability, and reliability delivers results. The U.S. nuclear power fleet produced about 789.9 TWh of clean electricity in 2020 and ended the year with 94 operating reactors. According to Energy Information Administration data, that’s about 37 percent more electricity than the 576.9 TWh produced in 1990 by a much larger fleet of 112 reactors.
Nuclear News has tracked and analyzed the capacity factors of the U.S. fleet since the early 1980s, before concerted industry efforts yielded unforeseen performance improvements. High nuclear capacity factors are now less an achievement than an expectation. So much so, in fact, that advanced reactors in development today are assumed to be capable of achieving capacity factors above 90 or even 95 percent.
The U.S. fleet has maintained a median capacity factor near 90 percent for 20 years (see Fig. 1), and the median design electrical rating (DER) net capacity factor for 2018–2020, at 91.33, does not disappoint—unless by showing virtually no change relative to the median of 91.34 recorded in 2015–2017. However, this lack of meaningful difference only underscores the consistent reliability of the U.S. fleet.
Ratliff
Harris
When Floyd Harris began working at Duke Energy’s Brunswick nuclear plant about 24 years ago as a radiation protection technician, robotics and remote monitoring were considered tools for radiation protection and nothing more. Now, teams from across the site, including engineering, maintenance, and operations, rely on the system of robots and cameras Harris is responsible for. “If you want to put those technologies under one umbrella,” says Harris, who now holds the title of nuclear station scientist, “it would be monitoring plant conditions.”
That monitoring is critical to effective plant maintenance. As Plant Manager Jay Ratliff explains, the goal is to “find a problem before it finds us” and ensure safety and reliability. Nuclear News Staff Writer Susan Gallier talked with Ratliff and Harris about how robotics and remote systems are deployed to meet those goals.
At Brunswick, which hosts GE-designed boiling water reactors in Southport, N.C., ingenuity and hard work have produced a novel remote dosimetry turnstile to control access to high-radiation areas, an extensive network to handle data from monitoring cameras, rapid fleetwide access to camera feeds to support collaboration, and new applications for robots and drones.
The Operations Center at NRC headquarters in Rockville, Md., is put to the test during exercises designed to prove and improve U.S. nuclear emergency preparedness and incident response capabilities.
One essential lesson from the events at Three Mile Island-2 in March 1979 can be summed up in three words: Preparedness takes practice. The emergency response capacity of the Nuclear Regulatory Commission and nuclear plant operators is more than just a set of procedures. Active training and evaluation are required to coordinate effectively with local and state authorities and protect the public in the event of an off-site radiological release.
The NRC’s emergency preparedness and incident response teams work in the Office of Nuclear Security and Incident Response (NSIR) to support licensees’ mandated emergency preparedness programs. The Operations Center at NRC headquarters is staffed around-the-clock with NSIR officers who can respond to technical questions and evaluate licensee event reports, yet most of its infrastructure typically stands vacant, awaiting activation for an incident or a planned exercise. With full activation of the NRC’s incident response program, the Operations Center comes to life, and teams of staff populate workstations. That process is regularly tested during exercises that involve NRC licensees, state and local responders, and similar incident response centers at each of the NRC’s four regional offices.
No two exercises are the same. Not only is every exercise dependent on variable human performance and every plant located in a unique community, but emergency preparedness benchmarks continually evolve with advancements in technologies and procedures.
Regulatory relief, remote working, sanitation, and communication were key factors in the success of the spring refueling outage at Beaver Valley-2.
Penfield
Enos
Energy Harbor’s Beaver Valley plant, located about 34 miles northwest of Pittsburgh, Pa., was one of many nuclear sites preparing for a scheduled outage as the coronavirus pandemic intensified in March. The baseline objective of any planned outage—to complete refueling on time and get back to producing power—was complicated by the need to prevent the transmission of COVID-19.
While over 200 of the plant’s 850 staff members worked from home to support the outage, about 800 contractors were brought in for jobs that could only be done on-site. Nuclear News Staff Writer Susan Gallier talked with Beaver Valley Site Vice President Rod Penfield and General Plant Manager Matt Enos about the planning and communication required.
Beaver Valley can look forward to several more outages in the future, now that plans to shut down the two Westinghouse pressurized water reactors, each rated at about 960 MWe, were reversed in March. “The deactivation announcement happened in the middle of all our planning,” Enos said. “It’s a shame we haven’t had a chance to get together as a large group and celebrate that yet.”
While the focus remains on safe pandemic operations, the site now has two causes for celebration: an outage success and a long future ahead.
Once again, the U.S. fleet has achieved a new personal best, even as utilities and operators face formidable challenges.
In the early years of the Nuclear News capacity factors survey, any factor over 70 was deemed excellent; any factor under 50 was considered poor. By that standard, all but two operating U.S. power reactors chalked up excellent performance during 2017–2019. A record 809.4 TWh of electricity was generated in the United States from nuclear energy in 2019, according to the U.S. Energy Information Administration (EIA), besting the record of 807.1 TWh set in 2018.
Nuclear News staff developed the capacity factors survey in the early 1980s as a way to identify the most productive reactors in an expanding fleet. Fleet improvement was the industry’s self-identified goal, but no one could anticipate the startlingly rapid pace of improvement, spurred by the Institute of Nuclear Power Operations (INPO), which boosted fleetwide performance to highs that continue today.