ENS 44668
ENS Event | |
|---|---|
22:00 Nov 19, 2008 | |
| Title | Radioactive Contamination Greater than Expected |
| Event Description | {{#Wiki_filter:10CFR70, Appendix A: A condition that results in the facility being in a state that was not analyzed, was improperly analyzed, or is different from that analyzed.
The residual radioactivity contained within these buildings is primarily in the form of surface contamination. The results of previous characterization data indicate that the residual mass was approximately 250 grams of U-235. However, the preliminary results of more recent characterization surveys and sampling have provided information that suggests the inventory of residual mass may be higher than previously estimated. Based on the results of recent radiological surveys performed within the process buildings, small quantities of uranium contamination have been identified in partially dismantled piping and ventilation filter housings. The potential for exposure to workers and to members of the public is minimal since the uranium is present in the form of contamination fixed to interior surfaces of the building, piping and interiors of equipment that remains within the building. Recent radiological surveys performed within the process buildings have revealed the potential for small quantities of uranium contamination in partially dismantled piping and ventilation filter housings. These radiological surveys were performed to gather additional information to support work planning associated with building demolition. This condition does not represent degradation or failure of structures, systems, equipment, components, or activities of personnel relied on to prevent potential accidents or mitigate their consequences. No structures, systems, equipment, components are relied upon to prevent potential accidents. The activities of personnel have been curtailed to include only the performance of radiological characterization necessary to refine and complete the estimate of the U-235 mass. Additional actions taken by the licensee in response to the event: 1. Restricted access to the buildings during non-work hours. 2. Limited access to the building during working hours to those personnel performing radiological characterization activities necessary to refine and complete the estimate of the U�235 mass, and those engaged in minor maintenance activities not associated with the interior surfaces of piping and equipment. 3. Provided instructions to personnel allowed access that piping, remaining equipment and any other component that may contain residual U-235 are not to be disturbed in any manner except for actions necessary to support completion of radiological contamination estimates; re-configuration of these shall not occur. The licensee suspects that the contamination is in the order of 700g U-235. Contact readings were less than 1.5 mR/hr.
As a result of further discussions and preliminary evaluations, Westinghouse wishes to provide a revised report pursuant to 10 CFR Section 70.50(b)(i). Section 70.24 requires that each licensee authorized to possess special nuclear material in specified quantities maintain in each area in which such special nuclear material is handled, used, or stored, a criticality monitoring system. Further specific guidance is contained in Regulatory Guide 3.71 approved by the NRC Staff. As previously reported, the process building or specific areas within may potentially contain more than the threshold amount of special nuclear material to trigger this requirement. If so, a report is required pursuant to the cited section in that previously installed criticality monitoring equipment has been disabled, i.e., removed, and such equipment would be required by regulation. This report is being made provisionally as there is insufficient time to definitively determine whether the entry conditions for the building as a whole have been met, i.e., whether 700 grams of uranium-235 are stored therein, and whether the building can be considered to be comprised of separate areas which could each be evaluated for the need to have criticality monitoring provisions. This report under 10 CFR 70.50(b)(2)(i) is subject to being withdrawn with an appropriate explanation and evaluation, if it is determined that the reporting threshold had not been met. Additional actions taken by the licensee in response to the event: 1. Issued a Stop Work Order and assured all necessary personnel have been briefed to restrict access and all work activities associated with the Process Building. 2. Procuring necessary instrumentation to utilize as the regulatory required equipment and upon concurrence from NRC, proceed with the radiological characterization of the Process Building. Discussions [are] ongoing with representatives of the USNRC Headquarters and Region III. Notified R3DO (Hills) and NMSS EO (Smith). }}[[Event description::Description::{{#Regex_clear:10CFR70, Appendix A: A condition that results in the facility being in a state that was not analyzed, was improperly analyzed, or is different from that analyzed. The residual radioactivity contained within these buildings is primarily in the form of surface contamination. The results of previous characterization data indicate that the residual mass was approximately 250 grams of U-235. However, the preliminary results of more recent characterization surveys and sampling have provided information that suggests the inventory of residual mass may be higher than previously estimated. Based on the results of recent radiological surveys performed within the process buildings, small quantities of uranium contamination have been identified in partially dismantled piping and ventilation filter housings. The potential for exposure to workers and to members of the public is minimal since the uranium is present in the form of contamination fixed to interior surfaces of the building, piping and interiors of equipment that remains within the building. Recent radiological surveys performed within the process buildings have revealed the potential for small quantities of uranium contamination in partially dismantled piping and ventilation filter housings. These radiological surveys were performed to gather additional information to support work planning associated with building demolition. This condition does not represent degradation or failure of structures, systems, equipment, components, or activities of personnel relied on to prevent potential accidents or mitigate their consequences. No structures, systems, equipment, components are relied upon to prevent potential accidents. The activities of personnel have been curtailed to include only the performance of radiological characterization necessary to refine and complete the estimate of the U-235 mass. Additional actions taken by the licensee in response to the event: 1. Restricted access to the buildings during non-work hours. 2. Limited access to the building during working hours to those personnel performing radiological characterization activities necessary to refine and complete the estimate of the U�235 mass, and those engaged in minor maintenance activities not associated with the interior surfaces of piping and equipment. 3. Provided instructions to personnel allowed access that piping, remaining equipment and any other component that may contain residual U-235 are not to be disturbed in any manner except for actions necessary to support completion of radiological contamination estimates; re-configuration of these shall not occur. The licensee suspects that the contamination is in the order of 700g U-235. Contact readings were less than 1.5 mR/hr.
As a result of further discussions and preliminary evaluations, Westinghouse wishes to provide a revised report pursuant to 10 CFR Section 70.50(b)(i). Section 70.24 requires that each licensee authorized to possess special nuclear material in specified quantities maintain in each area in which such special nuclear material is handled, used, or stored, a criticality monitoring system. Further specific guidance is contained in Regulatory Guide 3.71 approved by the NRC Staff. As previously reported, the process building or specific areas within may potentially contain more than the threshold amount of special nuclear material to trigger this requirement. If so, a report is required pursuant to the cited section in that previously installed criticality monitoring equipment has been disabled, i.e., removed, and such equipment would be required by regulation. This report is being made provisionally as there is insufficient time to definitively determine whether the entry conditions for the building as a whole have been met, i.e., whether 700 grams of uranium-235 are stored therein, and whether the building can be considered to be comprised of separate areas which could each be evaluated for the need to have criticality monitoring provisions. This report under 10 CFR 70.50(b)(2)(i) is subject to being withdrawn with an appropriate explanation and evaluation, if it is determined that the reporting threshold had not been met. Additional actions taken by the licensee in response to the event: 1. Issued a Stop Work Order and assured all necessary personnel have been briefed to restrict access and all work activities associated with the Process Building. 2. Procuring necessary instrumentation to utilize as the regulatory required equipment and upon concurrence from NRC, proceed with the radiological characterization of the Process Building. Discussions [are] ongoing with representatives of the USNRC Headquarters and Region III. Notified R3DO (Hills) and NMSS EO (Smith). }}| ]] |
| Where | |
|---|---|
| Westinghouse Hematite Hematite, Missouri (NRC Region 3) | |
| License number: | SNM-33 |
| Reporting | |
| Part 70 App A (B)(1) | |
| Time - Person (Reporting Time:+-0.93 h-0.0388 days <br />-0.00554 weeks <br />-0.00127 months <br />) | |
| Opened: | Gerry Couture 21:04 Nov 19, 2008 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Nov 21, 2008 |
| 44668 - NRC Website | |
Westinghouse Hematite with Part 70 App A (B)(1) | |
WEEKMONTHYEARENS 446682008-11-19T22:00:00019 November 2008 22:00:00
[Table view]Part 70 App A (B)(1) Radioactive Contamination Greater than Expected 2008-11-19T22:00:00 | |