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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 52423 | 10 December 2016 01:42:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Technical Specification Required Shutdown | On December 09, 2016 at 1734 EST, U2 Train-A NSCW (Nuclear Service Cooling Water) Transfer Pump #8 tripped during Return To Service Surveillance testing for Train-B NSCW Transfer pump #7. Technical Spec 3.7.9 Condition E entered at 1734 with Required Actions to be in M3 (mode 3, Hot Standby) in 6 hours AND M4 (mode 4, Hot Shutdown) in 12 hours. A unit shutdown was commenced at 2042 EST (as a conservative measure) to comply with TS 3.7.9 Condition E. At 1937, U2 B-train NSCW Transfer Pump #7 was declared operable and TS 3.7.9 Condition E was exited. The plant is currently raising power to 100%. The licensee notified the NRC Resident Inspector. | ||
| ENS 42434 | 20 March 2006 18:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Plant Shutdown Due to Rcs Pressure Boundary Leakage | At 03:56 on 03/20/2006 an intermediate radiation alarm was received on Containment Atmosphere Particulate Radiation Monitor, 2RE-2562A. A review of other containment parameters, such as containment pressure, moisture, temperature, sump levels and other containment radiation monitors were all stable. Chemistry was notified of the increasing particulate radiation levels in containment and immediately pulled the filter paper from radiation monitor 2RE-2562A. A gross count of the filter paper revealed the presence of Na-24 and Co-58. The presence of these two isotopes indicated the possibility of an active RCS leak. An RCS leakrate measurement was initiated. The results of the leakrate measurement showed no measurable change in leakrate. The total leakrate was calculated to be 0.13 gpm. At 06:03 on 03/20/2006 a high radiation alarm was received on Containment Atmosphere Particulate Radiation Monitor, 2RE-2562A. Preparations were begun to make a containment entry to walkdown outside the bio-shield and to take a robot, equipped with a camera, to inspect inside the bio-shield. At 13:00 personnel from the Unit 2 containment reported that a leak was visible from inside the bio-shield in the area of RCS Loop #1. Based on reports from personnel in containment, the leakage in containment was determined to be pressure boundary leakage and Tech Spec 3.4.13, "RCS Operational LEAKAGE," was entered. As required by TS 3.4.13, at 13:52 on 03/20/2006 a unit shutdown to Mode 3 was initiated to allow further investigations and repair of the leak inside containment. Abnormal Operating Procedure 18004-C, "RCS Leakage" was also entered at this time due to increasing radiation levels on, radiation monitor 2RE-2562A. Per Tech Spec 3.4.13, Mode 3 entry (is) required by no later than 19:00 on 3/20/2006 and Mode 5 entry no later than 01:00 on 3/22/2006. The Unit shutdown is currently in progress. This is the third shutdown at the Unit for a leak in this vicinity. See similar event reports #42309 dated February 3, 2006, and #42194 dated December 9, 2005. The licensee notified the NRC Resident Inspector. | ||
| ENS 42309 | 4 February 2006 02:24:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Identified Rcs Pressure Boundary Leakage | At 2124 hrs on 2/3/06, a containment leak inspection team reported pressure boundary leakage (RCS) at a welded connection on a 3/4" bypass line around the RHR loop suction valve 2HV8701B. Presently the unit is in Mode 3. Preparations are being made to commence cooldown to Mode 5 for repair of the leak. Unit 2 was taken from 100% RTP to approximately 30% RTP beginning at 1200 hrs on 2/01/06 for repairs of an EHC leak on the main turbine front standard. The EHC leak was repaired and power ascension to 100 % RTP commenced at 2213 hrs on 2/01/06. Approximately 100 % RTP was reached on 2/3/06 at 0600 hrs. Between 1900 hrs on 2/01/06 and 1600 hrs on 2/02/06, radiation monitor 2RE2562A went into Intermediate Alarm for short durations on three different occasions. Due to moving the plant, an accurate RCS leak rate could not be performed. A containment entry was performed on the night shift 2/2/06 and again on dayshift 2/3/06. Utilizing a robot and camera, leakage was observed inside the bioshield in the area of RCS Loop #1. The source of the leak on both containment entries was inconclusive. At 1412 hrs on 2/3/06, a shutdown of Unit 2 was initiated to allow further investigation/repair of the leak inside containment. Unit 2 was placed in Mode 3 at 1807 hrs on 2/3/06. See also EN# 42194 for a similar incident. The licensee notified the NRC Resident Inspector. | Main Turbine | |
| ENS 42194 | 9 December 2005 20:44:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Rcs Pressure Boundary Leakage Identified | At 1450 hours on 12/5/05, Unit 2 entered abnormal operating procedure 18004-C 'RCS Leakage' due to increasing containment atmospheric radiation levels as identified on 2RE2562A. Per procedure, an RCS leak rate determination was commenced and completed as of 1629 hours, 12/8/05 (identified = 0.032gpm, unidentified = 0.254gpm, total = 0.286gpm). While making preparations for a containment entry for leakage inspection, a second leak rate (determination) was completed at 2020 hours, 12/8/05 (identified = 0.070gpm, unidentified = 0.267gpm, total = 0.337gpm). At 2240 hours, 12/8/05, the team performing the containment leak inspection reported no leakage identified outside the bioshield. Another leak rate (determination) was completed at 0245 hours, 12/9/05, the team performing the containment leak inspection reported that by using a robotic camera, water was observed coming down the inside wall of the bioshield in the area of loop 2. At 0433 hours, 12/9/05, a shutdown of Unit 2 was initiated to allow further investigation / repair of the RCS leak inside containment. Unit 2 was placed in Mode 3 at 1313 hours, 12/9/05. At 1544 hours, 12/9/05, the containment leak inspection team reported pressure boundary leakage at a welded connection where a 3/4 inch bypass line is welded to the RCS loop upstream of the RHR loop suction valve 2HV8701B. (Plant Vogtle personnel are) presently preparing to commence shutdown to Mode 5 for repair of the leak. Technical specification 3.4.14 applies and requires no pressure boundary leakage. The plant is currently removing decay heat by steaming from the steam generators through the steam dump valves to the condenser. All safety related electrical buses are available. Emergency diesel generators are available and in standby. The licensee notified the NRC Resident Inspector.
Two corrections were communicated. The date of the initial event was "at 1450 hours on 12/8/05." The technical specification quoted is changed to 3.4.13. Notified the R2DO (Henson). | Steam Generator Emergency Diesel Generator |