Fukushima 10 years later: It still could happen here
Initially, the U.S. Nuclear Regulatory Commission had declined to take a closer look at the risks of a core meltdown at Duane Arnold atomic reactor in Iowa, severely damaged by a derecho in August 2020. (Duane Arnold never recovered, but instead announced permanent shutdown.) But an NRC staffer dissented, forcing the agency to take that harder look.
Lyman has tweeted the following:
The @NRCgov has released the final risk analysis of the derecho that struck the Duane Arnold #nuclear plant in #Iowa in August 2020 and caused a loss of offsite power. The mean risk of core damage was 1/1250, but without FLEX credit was nearly 1 percent. https://nrc.gov/docs/ML2105/ML
As Arnie Gundersen, chief engineer at Fairewinds Energy Education, has put it, "This was a close call."