“It was one of the most important security events in the history of U.S. nuclear weapons, and yet it posed no significant threat to society,” Stein said. “It shows the resilience of these plants.”
NRC licensing requires reactor buildings to be built to withstand “tornado projectiles,” or enormous objects colliding at high speed, Stein added. “They are literally designed to withstand these types of events safely,” he said.
Still, NextEra plans to augment weather-related safety measures at the reopened Duane Arnold plant.
“We look at these events, try to draw conclusions and ask ourselves what can make the power plant even safer than it is now?” said NextEra consultant Michael Davis during a public information meeting held Nov. 13 in Cedar Rapids by the Iowa Utilities Commission.
The company is considering installing a third diesel generator to provide additional backup power and will also design replacement Duane Arnold water cooling towers with a higher wind resistance threshold, Davis said.
Google representatives did not respond to questions about whether damage at Duane Arnold during the 2020 derecho raised any nuclear safety concerns during severe weather events.
The NRC’s safety requirements require applicants to “take into account the most severe meteorological and seismic conditions known in the proposed area” when selecting reactor locations, an NRC representative wrote in a statement to Inside Climate News.
“It is important to understand that nuclear power plants are built to withstand extreme environmental hazards and that the NRC requires plants to maintain redundant systems, components and programs to be able to mitigate off-site power loss events,” the NRC added.
Lokenvitz, a former Duane Arnold engineer, sees the factory’s reopening as a resurrection of sorts. If the facility had not been slated for decommissioning when the derecho hit, Duane Arnold would have been rebuilt and still generating power, she added.
“This plant performed exactly as it was designed. It was just a perfect storm.”