Report to Congress on Abnormal Occurrences – Fiscal Year 2021 (NUREG-0090, Volume 44)

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Publication Information

Manuscript Completed: August 2022
Date Published: August 2022

Office of Nuclear Regulatory Research
United States Nuclear Regulatory Commission
Washington, DC 20555-0001

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Section 208 of the Energy Reorganization Act of 1974, as amended (Public Law 93-438), defines an abnormal occurrence (AO) as an unscheduled incident or event that the U.S. Nuclear Regulatory Commission (NRC) determines to be significant from the standpoint of public health or safety. The Federal Reports Elimination and Sunset Act of 1995 (Public Law 104-66) changed the AO reporting frequency from quarterly to annual.

This report describes six events in Agreement States and two events involving NRC licensees that were identified as AOs during fiscal year 2021. These events were identified based on the criteria in the NRC policy statement “Abnormal Occurrence Reports,” published in Volume 82 of the Federal Register (FR), page 45907 (82 FR 45907; October 2, 2017). Six AOs were medical events as defined in Title 10 of the Code of Federal Regulations Part 35, “Medical Use of Byproduct Material.” There was one event at a medical facility and one event at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) that involved serious safety significant deficiencies in management or procedural controls. There were no events at a commercial nuclear power plant that met the criteria for AOs.

Appendix A, “Abnormal Occurrence Criteria,” to this report presents the NRC’s criteria for identifying AOs. In addition, the NRC identified no events during fiscal year 2021 that met the guidelines for inclusion in Appendix B, “Other Events of Interest.” No events met the guidelines for inclusion in Appendix C, “Updates on Previously Reported Abnormal Occurrences.” Appendix D, “Glossary,” defines terms used throughout this report. Appendix E, “Conversion Table,” presents conversions commonly used when calculating doses.

Page Last Reviewed/Updated Wednesday, August 10, 2022