Semantic search
Jump to navigation
Jump to search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 52996 | 30 September 2017 05:34:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Secondary Containment Declared Inoperable | At 0134 (EDT) on September 30, 2017, Nine Mile Point Unit 2 entered Tech Spec 3.6.4.1 when secondary containment was declared inoperable due to secondary containment differential pressure being above the Tech Spec Surveillance Requirement of -0.25 inches vacuum water gauge. The Division II Standby Gas Treatment System was started to restore differential pressure at 0135 (EDT) on September 30, 2017 the differential pressure was restored, the secondary containment was declared operable and the Tech Spec3.6.4.1 exited. Secondary containment being inoperable is a 8-hour report for 10 CFR 50.72(b)(3)(v)(C), Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. The cause of this condition is being investigated. The NRC Resident Inspector has been notified. The licensee will also inform the State of New York. | Secondary containment Standby Gas Treatment System | |
| ENS 51969 | 1 June 2016 14:46:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Nine Mile Point Unit 1 Momentary Loss of Secondary Containment | Nine Mile Point Unit 1 (NMP1) experienced a momentary loss of Secondary Containment due to both Reactor Building (RB) airlock doors being opened at the same time. At 1046 (EDT) on 06/01/16, both RB airlock doors were opened simultaneously for less than 5 seconds. This resulted in Secondary Containment being declared Inoperable (TS 3.4.3). The airlock doors were closed and Secondary Containment was restored to Operable. The event is reportable in accordance with 10 CFR 50.72(b)(3)(v)(c), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Resident Inspector has been notified. The licensee notified the State of New York. | Secondary containment | |
| ENS 51856 | 7 April 2016 21:30:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Doors of Secondary Containment Open Simultaneously | Nine Mile Point Unit 2 (NMP2) experienced a momentary loss of Secondary Containment due to both Reactor Building (RB) airlock doors being opened at the same time. At 1730 (EDT) on 04/07/16, both RB airlock doors were opened simultaneously for less than 5 seconds. This resulted in Secondary Containment being declared Inoperable (TS 3.6.4.1). Secondary Containment was restored to Operable when the doors were closed. The event is reportable in accordance with 10 CFR 50.72(b)(3)(v)(C), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Resident Inspector has been notified. There is no interlock on these doors, just lights to verify the opposite door is open or shut. An Operator was entering secondary containment as another Operator was leaving. | Secondary containment | |
| ENS 51289 | 5 August 2015 16:52:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Momentary Loss of Secondary Containment | Nine Mile Point Unit 1 (NMP1) experienced a momentary loss of Secondary Containment due to both Reactor Building (RB) airlock doors being opened at the same time. At 1252 (EDT) on 08/05/15, both RB airlock doors were opened simultaneously for less than 5 seconds. This resulted in Secondary Containment being declared inoperable (TS 3.4.3). Secondary Containment was restored to operable when the doors were closed. The event is reportable in accordance with 10 CFR 50.72(b)(3)(v)(c), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Resident Inspector has been notified. The licensee also notified the State of New York Public Service Commission. | Secondary containment | |
| ENS 50860 | 3 March 2015 13:37:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Momentary Loss of Secondary Containment Due to Both Airlocks Opening at Same Time | Nine Mile Point Unit 1 (NMP1) had a momentary loss of Secondary Containment due to both Reactor Building Airlock doors being opened at the same time. At 0837 (EST) on 03/03/2015, both Reactor Building Airlock doors at NMP1 were opened simultaneously for approximately 2 seconds. This results in a momentary loss of Secondary Containment operability (TS 3.4.3). The doors were closed and operability was restored. Secondary Containment being inoperable is an 8 hour notification per 10CFR50.72(b)(3)(v)(C), 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the Senior Resident NRC Inspector was notified. The licensee notified the State of New York. | Secondary containment | |
| ENS 50813 | 12 February 2015 00:41:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Nine Mile Point Momentary Loss of Secondary Containment | Nine Mile Point Unit 1 (NMP1) had a momentary loss of Secondary Containment due to both Reactor Building Airlock doors being opened at the same time. At 1941 EST on 02/11/2015, both Reactor Building Airlock doors at NMP1 were opened simultaneously for approximately 1 second. This results in a momentary loss of Secondary Containment operability (TS 3.4.3). The doors were closed and operability was restored. Secondary Containment being inoperable is an 8 hour notification per 10 CFR 50.72(b)(3)(v)(C), 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the Senior Resident NRC Inspector was notified. | Secondary containment | |
| ENS 50732 | 13 January 2015 00:39:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Degraded Secondary Containment Differential Pressure | At 1939 (EST) on January 12, 2015, Nine Mile Point Unit 2 entered Tech Spec 3.6.4.1 when secondary containment was declared inoperable due to secondary containment differential pressure being above the Tech Spec Surveillance Requirement of -0.25 inches vacuum water gauge. This condition is related to sustained high winds. At 1956 on January 12, 2015 the differential pressure was restored, the secondary containment was declared operable and the Tech Spec 3.6.4.1 exited. Secondary containment being inoperable is a 8-hour report for 10 CFR 50.72(b)(3)(v)(c), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident'. The NRC Resident Inspector has been notified. The licensee notified the New York Public Service Commission. | Secondary containment | |
| ENS 50553 | 20 October 2014 17:53:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Secondary Containment Airlock Doors Open Simultaneously | At 1353 EDT on 10/20/2014, both Reactor Building Airlock doors at NMP1 were opened simultaneously for a few seconds. This results in a momentary loss of Secondary Containment operability (TS 3.4.3). The doors were closed and operability was restored. Secondary Containment being inoperable is an 8 hour notification per 10CFR50.73(b)(3)(v)(C), 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Resident Inspector was notified. | Secondary containment | |
| ENS 50542 | 16 October 2014 14:42:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Momentary Loss of Secondary Containment | Nine Mile Point Unit 1 (NMP1) had a momentary loss of Secondary Containment due to both Reactor Building airlock doors being opened at the same time. At 1042 EDT on 10/16/2014, both Reactor Building airlock doors at NMP1 were opened simultaneously for less than 5 seconds. This results in a momentary loss of Secondary Containment operability (TS 3.4.3). The doors were closed and operability was restored. Secondary Containment being inoperable is an 8 hour notification per 10 CFR 50.72(b)(3)(v)(C), 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Senior Resident Inspector was notified. The licensee will be notifying the State of New York Public Service Commission. | Secondary containment | |
| ENS 50363 | 14 August 2014 03:18:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Momentary Loss of Secondary Containment | Nine Mile Point Unit 1 (NMP1) had a momentary loss of Secondary Containment due to both Reactor Building Airlock doors being opened at the same time. At 2318 (EDT) on 8/13/2014, both Reactor Building Airlock doors at NMP1 were open simultaneously for less than 5 seconds. This results in a momentary loss of Secondary Containment operability (TS 3.4.3). The doors were closed and operability was restored. Secondary Containment being inoperable is an 8 hour notification per 10 CFR 50.72(b)(3)(v)(C), 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The condition has been entered into the station's corrective action program and the NRC Senior Resident Inspector was notified. | Secondary containment | |
| ENS 50187 | 11 June 2014 00:32:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Secondary Containment Declared Inoperable | Nine Mile Point Unit 2 Secondary Containment was declared inoperable on 6/10/14 from 2032 EDT until 2036 EDT during the restoration of Reactor Building Ventilation System to a normal lineup. While performing actions to restore ventilation fans the Above Refuel Floor Exhaust Fan, 2HVR-FN5A, tripped when started resulting in building differential pressure becoming less negative than -0.25 inches. Tech Spec 3.6.4.1 Secondary Containment, Action A.1 to restore within 4 hours was entered at 2032 EDT on 6/10/14. The standby Above Refuel Floor Exhaust Fan, 2HVR-FN5B, was started per procedure and building differential pressure was restored. Secondary Containment was declared operable at 2036 EDT on 6/10/14 and Tech Spec 3.6.4.1 action was exited. Secondary containment being inoperable is a 8-hour report for 10 CFR 50.72(b)(3)(v)(c), Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. The licensee has notified the NRC Resident Inspector and will notify the State of New York. | Secondary containment Reactor Building Ventilation | |
| ENS 49985 | 2 April 2014 05:23:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Secondary Containment Inoperable Due to Two Air Lock Doors Open Simultaneously | At 0123 EDT on April 2, 2014, Nine Mile Point Unit 2 was in Mode 5, Refueling, and in the other specified condition of Operations with Potential for Draining the Reactor Vessel. During this condition both redundant personnel airlock doors were open at the same time in an airlock penetration of the reactor building. This condition represents a loss of Secondary Containment safety function. Technical Specification 3.6.4.1, Action A.1 was entered for the loss of Secondary Containment and was promptly exited when the doors were closed. Secondary containment being inoperable is an 8-hour report per 10 CFR 50.72(b)(3)(v)(C), Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. The NRC Resident Inspector has been notified. | Secondary containment | |
| ENS 49948 | 24 March 2014 04:31:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Secondary Containment Inoperable and Unplanned Isolation of the Reactor Building Vent Radiation Monitor | At 0031 (EDT) on March 24, 2014, Nine Mile Point Unit 2 was lowering power for the planned refueling outage. The loss of reactor building heating resulted in the isolation of the reactor building to maintain building temperature. Isolation of the reactor building resulted in the isolation of the reactor building vent radiation monitor (Vent WRGMS) which is a loss of emergency assessment capability. The isolation of the reactor building also resulted in declaring secondary containment inoperable due to secondary containment differential pressure being positive. Secondary containment was declared operable at 0034 (EDT) when differential pressure was restored to greater than negative 0.25 inches water gauge. Secondary containment being inoperable is a 8-hour report for 10 CFR 50.72(b)(3)(v)(c), any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. The unplanned isolation of Vent WRGMS is a 8-hour report for 10 CFR 50.72(b)(3)(xiii), any event that results in a major loss of emergency assessment capability. The NRC Resident Inspector has been notified. The licensee will notify the New York Public Service Commission. | Secondary containment | |
| ENS 49906 | 12 March 2014 18:22:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Secondary Containment Inoperable and Unplanned Isolation of Building Vent Radiation Monitor | At 1422 EDT on March 12, 2014, Nine Mile Point Unit 2 declared secondary containment inoperable due to secondary containment differential pressure being positive. The positive differential pressure was related to sustained high winds from the northeast associated with Winter Storm Vulcan. The reactor building was isolated at 1630 EDT and secondary containment declared operable at 1700 EDT when Secondary Containment Vacuum was restored to greater than 0.25 inch of vacuum water gauge. The isolation of the reactor building resulted in the isolation of the reactor building vent rad monitor (Vent WRGMS (Wide Range Gas Monitors)) which is a loss of emergency assessment capability. Secondary containment being inoperable is an 8-hour report for 10 CFR 50.72(b)(3)(v)(c), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control radioactive release.' The unplanned isolation of the Vent WRGMS is an 8-hour report for 10 CFR 50.72(b)(3)(xiii), 'Any event that results in a major loss of emergency assessment capability.' The NRC Resident Inspector has been informed. The licensee will notify the state. | Secondary containment | 05000410/LER-2014-005 |
| ENS 49043 | 15 May 2013 23:34:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Primary Containment Airlock Non-Functional Due to Degraded Seal on Inner Door Concurrent with Personnel Passing Through the Outer Door | At approximately 1934 EDT on May 15, 2013, maintenance personnel entered the primary containment personnel air lock to determine the cause of the inability to attain test pressure during a type B leak rate of the airlock. The inner door seal was found degraded and partially rolled from its required position allowing air from inside the airlock to enter the primary containment. During the limited time the outer airlock door was opened for access into the airlock concurrent with the degraded seal on the inner door, a condition existed that could have prevented the fulfillment of the safety function of the structure to control the release of radioactive material. The inner door seal was subsequently replaced and the leak rate of the personnel air lock completed with satisfactory results. During the seal replacement activity, the outer airlock door remained closed to provide the barrier against the release of radioactive material should it be required. This is a notification per 10 CFR 50.72(b)(3)(v) for a condition that could have prevented the control of the release of radioactive material. It is recognized that this notification (was) not within eight hours of the event. The condition has been entered into the station's corrective action program. The licensee will notify the New York State Public Service Commission and the NRC Resident Inspector.
This notification is being made to retract Event Notification #49043, which reported a condition that could have prevented the control of the release of radioactive material when the primary containment airlock inner door seal was found degraded concurrent with the outer door being open. Further analysis by engineering of the actual conditions which were recorded when the airlock Type B leak rate test was being performed and calibration checks of the leak rate monitor instrumentation used for the test, has determined that the leakage through the degraded inner airlock door seal, when combined with the Appendix J As-Left Minimum Pathway Type B and C leak rates, remains below the Technical Specification Primary Containment As-Left Minimum Pathway Leakage Limit of 0.6 La. Therefore, for the period in which the inner airlock door seal was degraded and the outer airlock door was open, the primary containment function to control the release of radioactive material was maintained and the initial notification per 10 CFR 50.72(b)(3)(v) is being retracted. The licensee has notified the NRC Resident Inspector and the New York State Public Service Commission. R1DO (Ferdas) notified. | Primary containment | |
| ENS 47368 | 24 October 2011 05:52:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Divisions of the Rwcu High Differential Flow Isolation Function Removed from Service | This event is being reported in accordance with 10CFR50.72(b)(3)(v)(C). On October 23, 2011 at 0915 EDT, the Division 1 Reactor Water Cleanup (RWCU) system differential flow - high channel was declared inoperable due to failing its channel check. A troubleshooting plan was developed to determine the cause for the failed channel check. In accordance with this troubleshooting plan, at three separate times (October 24, 2011 at 0152, 0258, and 0519), both the Division 1 and Division 2 RWCU differential flow timers were placed in bypass, and Technical Specification (TS) 3.3.6.1, Condition B was entered for one or more automatic functions with isolation capability not maintained. In each of the three instances, one channel of the RWCU differential flow - high function was restored to Operable status within 1 hour as required by TS 3.3.6.1 Required Action B.1. It was believed at the time of the troubleshooting evolutions that this condition was not reportable because it was a planned maintenance evolution performed in accordance with approved procedures and the plant TS; however, further review has concluded that disabling both divisions of the RWCU differential flow - high function constitutes a reportable condition in accordance with 10CFR50.72(b)(3)(v), as an event or condition that could have prevented fulfillment of a safety function. The licensee will notify the NRC Resident Inspector. | Reactor Water Cleanup | 05000410/LER-2011-004 |