Report to Congress on Abnormal Occurrences – Fiscal Year 2018 (NUREG-0090, Volume 41)

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Publication Information

Manuscript Completed: June 2019
Date Published: June 2019

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) modified the AO reporting frequency from quarterly to annually.

This report describes three events involving NRC licensees that the agency identified as AOs in fiscal year (FY) 2018 based on the criteria defined in Appendix A, "Abnormal Occurrence Criteria and Guidelines for Other Events of Interest," to this report. Two AOs were medical events as defined in Title 10 of the Code of Federal Regulations (10 CFR) Part 35, "Medical Use of Byproduct Material." The third AO event involved a category 2 source, as defined in Title 10 of the Code of Federal Regulations (10 CFR) Part 37, "Physical Protection of Category 1 and Category 2 Quantities of Radioactive Material." During this reporting period, the NRC did not identify any events at commercial nuclear power plants in the United States as AOs.

This report also describes eight AOs that occurred in Agreement States (AS) and that were identified as AOs during FY 2018 based on the criteria defined in Appendix A. Seven were medical events, as defined in 10 CFR Part 35, and one event involved radiography operations. AS are those States that have entered into formal agreements with the NRC, in accordance with Section 274 of the Atomic Energy Act of 1954, as amended (AEA) (Public Law 83-703), to regulate certain quantities of AEA material at facilities located within the States' borders. Currently, there are 38 AS.

Appendix A to this report presents the NRC's criteria for identifying AOs. No events were identified for inclusion in Appendix B, "Other Events of Interest," for this reporting period. Appendix C, "Updates of Previously Reported Abnormal Occurrences," provides updated information for one event that was identified in "Report to Congress on Abnormal Occurrences: Fiscal Year 2017" (NUREG-0090, Volume 40), issued May 2018. Appendix D, "Glossary," defines terms used throughout this report. Appendix E, "Conversion Table," presents conversions commonly used when calculating doses.

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