05000416/LER-2016-003
| 06-06-2016 | On April 7, 2016 the Grand Gulf Nuclear Station, while at 100 percent reactor thermal power, experienced a loss of Secondary Containment safety function during the performance of routine Secondary Containment building roof inspection. During the inspection activity the roof hatch, which allows access/egress to the roof, was left open for approximately 20 minutes. Based on a review of the work activity it is believed this error has occurred a minimum of 30 times in the past 5 years.
The direct cause of the event was the failure to close the hatch. The apparent cause of the event was the failure to establish adequate work instructions to maintain control of the hatch and to ensure Secondary Containment was maintained OPERABLE. Corrective actions include closure of the hatch and the establishment of the appropriate control over the hatch in the work instructions. There were no actual nuclear safety consequences or radiological consequences during the event. This condition is reportable in accordance with 10 CFR 50.73(a)(2)(v)(C). A 10CFR 50.72 notification was not performed because the event was not identified until after compliance was restored. APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by Internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. 366A U.S. NUCLEAR REGULATORY COMMISSION ContentsCONTINUATION SHEET05000 416 PLANT CONDITIONS PRIOR TO THE EVENT100 percent reactor thermal power with no structures, components, or safety systems inoperable at the start of the event or contributing to the event. DESCRIPTIONOn April 7, 2016, while at 100 percent reactor thermal power, members of the Grand Gulf Nuclear Station (GGNS) staff were assigned to perform a routine inspection of the Secondary Containment [NG] roof surfaces and roof drain scuppers and screens. The purpose of this inspection was to verify the materials were in good working order and to identify any condition requiring maintenance/repair. The inspection is performed on a quarterly frequency and has been performed by the same lead individual for the past five years in the same manner. Therefore, it is estimated that the hatch has been inappropriately left open a minimum of 20 times in the past 5 years. After obtaining permission to start work the personnel proceeded to the roof access hatch, [DR] proceeded through the hatch, and performed the required inspection activities. The inspection requires approximately 30 minutes to complete all of the required tasks. Access to the roof is obtained via an access hatch that is normally closed and latched. The hatch can only be opened from inside the building. This required the personnel to leave the hatch open during the time period they were on the roof performing the inspection. Leaving the hatch open for purposes other than immediate access or egress results in a breach of the Secondary Containment boundary and a loss of safety function for the Secondary Containment boundary. This event occurred on April 7, 2016. The Nuclear Regulatory Commission Senior Resident Inspector questioned the acceptability of leaving the hatch in the open position. Members of the GGNS staff, based on the challenges from the Senior Resident Inspector, evaluated the concern and it was determined this event was reportable as a loss of safety function. REPORTABILITYA Licensee Event Report is required pursuant to Title 10 Code of Federal Regulations (10 CFR) 50.73(a)(2)(v)(C) for an event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to: (C) control the release of radioactive material. Specifically, the hatch was left open. APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may collection. NRC FORM366A U.S. NUCLEAR REGULATORY COMMISSION CONTINUATION SHEET2. DOCKET 3. LER NUMBER 05000 416 A 10CFR 50.72 notification was not performed because the event was not identified until after compliance was restored. CAUSEDirect Cause: The failure to immediately close the hatch upon completion of egress from Secondary Containment Building. Apparent Cause: The failure to establish adequate work instructions to maintain control of the hatch and to ensure Secondary Containment was maintained OPERABLE. CORRECTIVE ACTIONSImmediate: The hatch was closed and Secondary Containment integrity was restored. Pending Action: Work instructions for the work orders that require personnel to access/egress the Secondary Containment Roof Hatch will be revised to ensure the correct control of the hatch and maintenance of Secondary Containment OPERABILITY. The work instructions will be revised by June 30, 2016. SAFETY SIGNIFICANCEThere were no actual nuclear safety consequences or radiological consequences during the event. The time period for which there could have been an unmonitored release during an event was approximately 20 minutes. However, no abnormal event or release occurred during the time of the event, therefore, no radiological consequence occurred. NRC FORM366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2015 Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. CONTINUATION SHEET2. DOCKET 3. LER NUMBER 05000 416 PREVIOUS SIMILAR EVENTSDrawdown Test Valves Heat Removal Entergy has reviewed the above identified licensee event reports and has concluded that the causes and corrective actions associated with these licensee event reports could not have prevented the occurrence of the event documented in this licensee event report. |
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| Grand Gulf Nuclear Station, Unit 1 | |
| Event date: | 04-07-2016 |
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| Report date: | 06-06-2016 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material |
| 4162016003R00 - NRC Website | |
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