The US Nuclear Regulatory Commission (NRC) recently issued its Report to Congress on Abnormal Occurrences for fiscal year 2020. The report documents key aspects of those events that the NRC considers “Abnormal Occurrences” (AOs) and allows the regulated community to review the operating experience of reactor, medical, and industrial users of radioactive materials. AOs are unscheduled events that the NRC determines to be significant from the standpoint of public health or safety.