Semantic search
| Entered date | Event description | |
|---|---|---|
| ENS 52364 | 14 November 2016 14:01:00 | At 1106 EST on 11/14/16, Fermi 2 discovered a sewage leak from a temporary restroom trailer that had reached a permeable gravel surface. The majority of the spill was confined to the impermeable surface below the restroom trailer. lt was estimated that the quantity of the spill which reached the permeable gravel surface was less than approximately 5 gallons. None of the sewage entered the storm drain system. The source of the sewage leak was eliminated by 1126 EST. A local sanitary contractor will be contacted to respond to the site to clean the affected areas. Reports to the Michigan Department of Environment.al Quality, the local health department (Monroe County), and the local news media are in progress. Since these reports are in the process of being made, this is considered a News Release or Notification to Other Government Agencies, therefore this event is reportable under 10 CFR 50.72(b)(2)(xi). The NRC Resident Inspector has been notified. |
| ENS 52146 | 2 August 2016 14:42:00 | On August 2, 2016 at 1015 EDT, while restoring the east train of Reactor Building HVAC (RBHVAC) after a surveillance test on Division 2 Standby Gas Treatment System (SGTS), the Technical Specification (TS) for the secondary containment pressure boundary was not met for a duration time of approximately 1 second. The maximum secondary containment pressure observed during that time was approximately 0.120 inches of vacuum water gauge. Secondary containment pressure was returned to within the TS operability limit by RBHVAC and SGTS already in operation. There were no radiological releases associated with this event. The cause of the event is under investigation. The TS requirement is to maintain secondary containment vacuum greater than or equal to 0.125 inches of vacuum water gauge (TS SR 3.6.4.1.1) for secondary containment operability. Declaring secondary containment inoperable is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented the fulfillment of a safety function needed to control the release of radioactive material. The licensee has notified the NRC Resident lnspector. |
| ENS 52076 | 8 July 2016 23:14:00 | On July 8 2016, at 19:09 (EDT) a severe thunderstorm warning was issued for Monroe County. This severe thunderstorm warning included the Fermi 2 site. Due to the high winds encountered during the thunderstorm, the Technical Specification (TS) for the secondary containment pressure boundary was not met two times during the storm for a duration time of 2 seconds total (one second for each event). At 20:05:21 Secondary Containment pressure went positive (0.22 inches of water gauge) and at 20:05:22 returned back below plant TS limits (-0.35 inches of water gauge). At 20:06:33 Secondary Containment pressure went greater than TS limits (-0.10 inches of water gauge) and at 20:06:34 returned below TS limits (-0.28 inches of water gauge). All plant equipment responded as required to the changing environmental conditions and Reactor Building HVAC returned the secondary containment pressure below the TS limits. There were no radiological releases associated with this event. The severe thunderstorm warning for the area was cancelled at 20:30. The TS requirement is to maintain secondary containment greater than or equal to 0.125 inches of vacuum water gauge (TS SR 3.6.4.1.1) for secondary containment operability. Declaring secondary containment inoperable is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented the fulfillment of a safety function needed to control the release of radioactive material. The licensee has notified the NRC Resident Inspector.
In this event notification, DTE Electric Company (DTE) reported conditions whereby the Fermi 2 secondary containment was believed to have exceeded Technical Specification Surveillance Requirements due to high winds. DTE hereby retracts this event notification as the Fermi 2 secondary containment has been determined to have been operable during this event as described below. The Fermi 2 secondary containment pressure is maintained at a pressure less than the external pressure to contain, dilute, hold up, and reduce the activity level of fission products prior to release to the environment, and to isolate and contain fission products that are released during a Design Basis Accident or certain operations. Secondary containment pressure is monitored by a number of differential pressure (dP) sensors. High wind gusts have resulted in momentary negative pressure on the leeward side of the building, causing a more positive pressure indication from one or more dP sensors. The secondary containment building pressure remains relatively constant during these 'wind events.' In December 2016, DTE implemented a software design change to display a 120-second rolling average for secondary containment dP indication. A 120-second rolling average recorded every second provides the operator a more accurate report of actual secondary containment conditions, while mitigating the signal noise and wind gust effects. The conditions associated with the subject event notification were re-reviewed in light of the improved secondary containment dP indication and it was determined that the Fermi 2 secondary containment was operable during this event. Specifically, the secondary containment pressure did not exceed Technical Specification Surveillance Requirements during this event. In summary, the above event notification is retracted because the Fermi 2 secondary containment was determined to have been fully operable during the conditions identified in the subject report. The licensee notified the NRC Resident Inspector. Notified R3DO (Stoedter). |
| ENS 51676 | 23 January 2016 00:20:00 | While performing a Technical Specification surveillance functional test of the Low Pressure Coolant Injection (LPCI) pump and valve surveillance, the Division 1 LPCI outboard Isolation Valve E1150F017A was closed for stroke time testing and would not reopen. Not being able to be open this valve renders the LPCI Loop Select function inoperable. Time of the event was 1935 (EST). This inoperability of LPCI loop Select results in entry into Technical Specification 3.0.3. Power reduction activities were briefed at time 2020, however, no power reduction commenced due to resolving the issue with the LPCI outboard Isolation Valve E1150F017A. During the investigation there was a loose screw found preventing the close contactor from fully releasing and allowing the open contactor to engage. No other abnormalities were found during this investigation. This screw was removed and the close contactor functioned normally and the valve was opened. The valve was retested satisfactory and the station exited Technical Specification 3.0.3 at 2145. This report is made pursuant to 10 CFR 50.72(b)(3)(v)(D), an event or condition that could have prevented the fulfillment of the safety function of systems needed to mitigate the consequences of an accident. The NRC Resident Inspector was notified. |
| ENS 51755 | 25 February 2016 16:35:00 | On January 6, 2016, at approximately 1514 EST, with Fermi 2 in Mode 1 operating at 100 percent reactor thermal power, the East and West Turbine Bypass Valves (TBVs) automatically opened for 3 minutes and 32 seconds in response to the number one High Pressure Turbine Stop Valve (TSV) drifting from full open to 25 percent open. Reactor power was subsequently lowered to 91.0 percent reactor thermal power and the bypass valves closed. Per Technical Specification Bases 3.3.1.1, TBVs must remain shut while reactor thermal power is at or above 29.5 percent to consider the TSV closure and Turbine Control Valve (TCV) fast closure Reactor Protection System (RPS) functions operable. The condition was recognized at the time of the event and the RPS functions were not declared inoperable since the functions were verified to remain enabled. Since the RPS functions were not declared inoperable, Fermi 2 did not report this event within 8 hours of occurrence. However, after further evaluation, it was determined that this event met the reporting criterion. Accordingly, this event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(A). The licensee informed the NRC Resident Inspector. The cause of the High Pressure Turbine Stop Valve drifting was due to an actuator malfunction that has since been corrected. This event was determined to be reportable at 1200 EST on 02/24/16. See EN #51756 for a similar event that occurred on 02/21/16.
Upon further review, it was determined that this event also meets the reporting criterion of 10CFR50.72(b)(3)(v)(D) for a condition that could have prevented the fulfillment of a safety function of structures or systems that are needed to mitigate the consequences of an accident. Although this event was determined to be reportable at 1200 EST on 02/24/16, it met the reporting requirement on the date of the event (01/06/2016). The licensee informed the NRC Resident Inspector. Notified R3DO (Valos). |
| ENS 51756 | 25 February 2016 16:35:00 | On February 21, 2015, at approximately 0030 EST, with Fermi 2 in Mode 1 operating at 100 percent reactor thermal power, the West Turbine Bypass Valve (TBV) automatically opened in response to the number two High Pressure Turbine Stop Valve (TSV) cycling from full open to closed and then to 22 percent open. Reactor power was subsequently lowered to 91.5 percent reactor thermal power and the bypass valve closed. Per Technical Specification Bases 3.3.1.1, TBVs must remain shut while reactor thermal power is at or above 29.5 percent to consider the TSV closure and Turbine Control Valve (TCV) fast closure Reactor Protection System (RPS) functions operable. The condition was recognized at the time of the event and the RPS functions were declared inoperable. The Limiting Condition for Operation was exited at 0031 EST following TBV closure. Since the RPS functions were verified to remain enabled, Fermi 2 did not report this event within 8 hours of occurrence. However, this event was subsequently determined to meet the reporting criterion and is being reported pursuant to 10 CFR 50.72(b)(3)(v)(A). The licensee informed the NRC Resident Inspector. The cause of the High Pressure Turbine Stop Valve cycling was due to a communication card failure that has since been corrected. This event was determined to be reportable at 1200 EST on 02/24/16. See EN #51755 for a similar event that occurred on 01/06/16.
Upon further review, it was determined that this event also meets the reporting criterion of 10CFR50.72(b)(3)(v)(D) for a condition that could have prevented the fulfillment of a safety function of structures or systems that are needed to mitigate the consequences of an accident. Although this event was determined to be reportable at 1200 EST on 02/24/16, it met the reporting requirement on the date of the event (02/21/2015). The licensee informed the NRC Resident Inspector. Notified R3DO (Valos). |
| ENS 48061 | 2 July 2012 08:25:00 | Beginning July 2, 2012, at approximately 0800, the Fermi 2 Integrated Plant Computer System (IPCS) will be removed from service to support installation of a Cyber Security Modification. The Safety Parameters Display System (SPDS) and Emergency Response Data System (ERDS) reside on the IPCS platform and will be out of service when the IPCS is removed from service. These systems will be unavailable to the Control Room and all other Emergency Response Facilities (ERFs) for approximately 20 hours. By 0300 on July 3, 2012, it is planned to restore IPCS, including SPDS and ERDS, to the Control Room, Operational Support Center, the Technical Support Center, and alternate facilities. During this time dose assessment capability will only be available in the manual data input mode. The majority of the Control Room indications remain available to the plant staff, and will be used for emergency response, if needed. Information will be communicated to the NRC using other available communication systems as needed. A follow-up notification will be submitted when the IPCS is completely restored. This notification is being made per the requirements of 8 Hour Non-Emergency Notification 10 CFR 50.72(b)(3)(xiii), any event that results in a major loss of emergency assessment capability. The licensee has notified the NRC Resident Inspector.
On July 3, 2012, at 01:00, the Fermi 2 Integrated Plant Computer System (IPCS) has been returned to service. Emergency assessment capabilities have been restored to all onsite emergency response facilities. Due to equipment problems, the Cyber Security Modification was not installed and the original IPCS configuration was restored. The licensee has notified the NRC Resident Inspector. R3DO (Daley) notified.
At approximately 02:04 on July 3, the Fermi 2 Integrated Plant Computer System (IPCS) failed. The Safety Parameters Display System (SPDS) and Emergency Response Data System (ERDS) reside on the IPCS platform. IPCS had previously been removed from service on 7/2/12 for a Cyber Security Modification and restored at 0100 on 7/3/12. At 0354, plant personnel were able to reboot IPCS and restore the system to normal with a Prime and Backup CPUs. Emergency assessment capabilities have been restored to all onsite emergency response facilities. This notification is being made per the requirements of 8 Hour Non-Emergency Notification 10 CFR 50.72(b)(3)(xiii), any event that results in a major loss of emergency assessment capability. The licensee has notified the NRC Resident Inspector. R3DO (Daley) notified. |