“This was one of the most significant safety events in U.S. nuclear history, yet it posed little danger to the public,” said Stein. “That highlights the strength of these plants.” NRC licensing requires reactor buildings to be constructed to endure “tornado missiles,” which are large objects hitting at high speeds, Stein explained. “They are literally designed to safely withstand these kinds of events,” he said.
Nonetheless, NextEra plans to bolster weather-related safety measures at the reopened Duane Arnold plant. “We assess these events to learn lessons and ask what we can do to enhance the plant’s safety,” said NextEra consultant Michael Davis during a public information meeting held in Cedar Rapids by the Iowa Utilities Commission on November 13. The company is considering adding a third diesel generator for extra backup power and will also design Duane Arnold’s replacement cooling towers to handle higher wind resistance, Davis noted.
Google representatives did not respond to inquiries on whether the damage at Duane Arnold during the 2020 derecho raised any nuclear safety concerns in severe weather scenarios. According to an NRC representative who spoke to Inside Climate News, NRC safety requirements specify that applicants must “consider the most severe meteorologic and seismic conditions known in the proposed area” when choosing reactor sites.
“It’s crucial to realize that nuclear plants are built to endure extreme environmental hazards, and the NRC mandates that plants maintain redundant systems, components, and programs to mitigate loss of off-site power events,” the NRC added.
Lokenvitz, a former engineer at Duane Arnold, sees the plant’s reopening as a sort of revival. If the facility hadn’t already been set for decommissioning when the derecho occurred, Duane Arnold would have been rebuilt and continued generating power, she claimed. “That plant operated exactly as designed. It was just the perfect storm.”
