Report to Congress on Abnormal Occurrences - Fiscal Year 2006 (NUREG-0090, Volume 29)

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Publication Information

Date Published: April 2007

U.S. Nuclear Regulatory Commission
Office of Nuclear Regulatory Research
Washington, DC 20555-0001

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Section 208 of the Energy Reorganization Act of 1974 (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) requires that the NRC must report AOs to Congress annually. This report describes those events that the NRC or an Agreement State identified as AOs during fiscal year (FY) 2006.

Appendix A "Abnormal Occurrence Criteria and Guidelines for Other Events of Interest," to this report presents the NRC's criteria for selecting AOs, as well as the guidelines for selecting "Other Events of Interest." Appendix B, "Updates of Previously Reported Abnormal Occurrences," notes that the NRC does not have any updated information on events reported in the FY 2005 Report to Congress on Abnormal Occurrences. Appendix C, "Other Events of Interest," presents nine events of interest identified during FY 2006 on ground-water contamination due to undetected leakage of radioactive water at nuclear power plants.

This report describes three events at NRC-licensed facilities that meet the criteria to be classified as AOs, as defined in Appendix A. The first AO involved a spill of high-enriched uranium at a fuel fabrication facility, the second AO involved a medical event, and the third AO involved an unintended dose to an embryo/fetus.

Reports from Agreement States are also included. Agreement States are those States who have entered into formal agreements with the NRC pursuant to Section 274 of the Atomic Energy Act (AEA) to regulate certain quantities of AEA material at facilities located within their borders. Currently, there are 34 Agreement States (Minnesota became the 34th Agreement State on March 31, 2006). During FY 2006, Agreement States reported six events that occurred at Agreement State-licensed facilities that met the AO criteria, including four medical events, one unintended dose to an embryo/fetus, and one industrial event.

The NRC revised the Appendix A criteria to make them more risk-informed and they became effective on October 12, 2006. These criteria are consistent with the NRC's Strategic Plan for FY 2004-2009, Title 10 of the Code of Federal Regulations (CFR) Part 35, "Medical Use of Byproduct Material," and Title 10 CFR Appendix P, "Category 1 and 2 Radioactive Material." The revised criteria can be found in Appendix D of this report, "Revised Abnormal Occurrence Criteria and Guidelines for Other Events of Interest." The NRC will use the revised criteria to select AOs for the annual report to Congress in FY 2007.

Also, the Energy Policy Act of 2005 (EPAct) expanded the NRC's regulatory jurisdiction by amending the definition of byproduct material to include discrete sources of radium-226, accelerator-produced radioactive material, and other discrete sources of naturally occurring radioactive material. The NRC is developing a rule to implement the EPAct. Once the rule is promulgated, the NRC and Agreement States will monitor events involving these materials that may meet the revised AO criteria.

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