Semantic search
Discovered date | Reporting criterion | Title | Event description | |
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ENS 56915 | 5 January 2024 15:40:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Emergency Ventilation Systems Inoperable | The following information was provided by the licensee via phone and email: At approximately 1111 EST on 01/05/2024, a mechanical penetration room door was discovered unlatched. Based on security badge history, the door was last opened at 1040 EST. The unlatched door resulted in both trains of the station emergency ventilation system being inoperable due to being unable to maintain the shield building negative pressure area. With both trains simultaneously inoperable, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The door was closed and verified latched upon discovery to restore the systems to an operable status. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
The station emergency ventilation system (EVS) was tested with the mechanical penetration room door unlatched. The test results showed that the station EVS attained the required negative pressure in the shield building within the time required by the Technical Specifications. Therefore, the station EVS remained operable with the door unlatched, and this issue did not prevent the system from fulfilling its safety function to control the release of radioactive material and mitigate the consequences of an accident. The NRC Resident Inspector has been notified. Notified R3DO (Orlikowski) |
ENS 54205 | 25 June 2019 22:13:00 | 10 CFR 50.73(a)(1), Submit an LER | Invalid Engineered Safety Feature Actuation Signal Due to Human Error | This 60-day telephone notification is being made in accordance with 10 CFR 50.73(a)(1) and 10 CFR 50.73(a)(2)(iv)(A) to provide information pertaining to an invalid Engineered Safety Feature actuation signal. On June 25, 2019, at Waterford 3, while performing an emergent replacement of relays on the Engineered Safety Features Actuation System Train A that affected Shield Building Ventilation Train A and HVAC Equipment Room Supply Fan AH-1 3A, unintentional contact was made between two contacts on the relay, resulting in an inadvertent initiation of other relays in the sequencer circuit. This caused the starting of Low Pressure Safety Injection Pump A, Switchgear Ventilation Fan A, and Boric Acid Makeup pumps. This was a partial actuation of Engineered Safety Features Actuation System Train A. Affected plant systems started and functioned successfully. This inadvertent actuation was caused by human error and was not a valid signal resulting from parameter inputs. The 1992 Statements of Consideration define an invalid signal to include human error. Therefore, this actuation is considered invalid. This event was entered into the Waterford 3 corrective action program for resolution. This event did not result in any adverse impact to the health and safety of the public. In accordance with 10 CFR 50.73(a)(1), a telephone notification is being made in lieu of submitting a written Licensee Event Report. The NRC Senior Resident Inspector has been notified. |
ENS 54127 | 20 June 2019 17:40:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Inoperability of Containment Shield Building | At 1340 EDT on June 20, 2019, a breach in excess of allowable margin in the Unit 2 Shield Building annulus was identified. T.S. LCO 3.6.15, Condition A was entered. The breach is expected to be repaired within the 24 hours allowed LCO time. No other equipment issues were identified. The Shield Building ensures that the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a Loss of Coolant Accident (LOCA). This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(C). NRC Resident Inspector has been notified. The breach consists of a tear in a flexible boot seal for a penetration associated with the suction path for gas treatment fans. There is no release of radioactive material associated with this event. |
ENS 53398 | 11 May 2018 14:11:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Shield Building Inoperable | At 1011 EDT on May 11, 2018, Containment Shield Building Annulus differential pressure exceeded the required limit. The Shield Building was declared inoperable requiring entry into Technical Specification (TS) 3.6.15 Conditions A and B. The event was initiated by failure of the operating annulus vacuum fan. Main Control Room Operators manually started the stand-by annulus vacuum fan to recover pressure. Shield Building Annulus differential pressure was restored to the required value at 1016 EDT and TS 3.6.15 Condition A and B were exited on May 11, 2018 at 1016 EDT. The failure mechanism for the annulus vacuum fan is being investigated. The Containment Shield Building ensures the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a Loss of Coolant Accident (LOCA). The Emergency Gas Treatment System (EGTS) would have automatically started and performed its design function to maintain the Shield Building Annulus differential pressure within required limits. The event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D). The NRC Resident has been notified. |
ENS 53173 | 18 January 2018 01:02:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Shield Building Inoperable | At 2002 EST on January 17, 2018, annulus differential pressure exceeded its pressure limit. At that time, the Shield Building was declared inoperable requiring entry into Technical Specification 3.6.15, Conditions A and B. Action was taken by field operators to swap annulus vacuum control dampers to restore annulus differential pressure. At 2024 EST, annulus differential pressure was restored to required limits, the Shield Building was declared operable, and LCO 3.6.15, Conditions A and B were exited. The temporary loss of the Shield Building resulted from a failure of the annulus vacuum control system to maintain the required differential pressure. Manual swap-over of pressure control to the backup damper restored differential pressure to required limits allowing exit from TS LCO 3.6.15 and restoration of the Shield Building safety function. The Shield Building ensures that the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a Loss of Coolant Accident (LOCA). The Emergency Gas Treatment System (EGTS) would have automatically started and performed its design function to maintain annulus vacuum within required limits. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified. |
ENS 52808 | 15 June 2017 16:19:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Temporary Loss of Shield Building | At 1219 (EDT) on June 15, 2017, annulus vacuum exceeded its pressure limit. At that time, the Shield Building was declared inoperable in accordance with Technical Specification 3.6.15 Condition A and B, due to the inoperability of the Shield Building (CRE). At 1222 (EDT), annulus pressure returned to normal, Shield Building was declared operable and LCO 3.6.15, Condition A and B were exited. The temporary loss of the Shield Building resulted from a loss of pressure control in the Auxiliary Building caused by a loss of Auxiliary Building General Ventilation. The Auxiliary Building Gas Treatment System was started to maintain Auxiliary Building pressure within limits and the non-safety related Annulus Vacuum system automatically restored annulus pressure. The Shield Building ensures that the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a LOCA. The EGTS system (Emergency Gas Treatment System) would have automatically started and performed it's design function to maintain Annulus Vacuum within required values. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). NRC Resident Inspector has been notified. |
ENS 51795 | 17 March 2016 05:15:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Loss of Emergency and Auxiliary Gas Treatment Systems | On March 17, 2016, at 0115 (EDT), Watts Bar Unit 1 (WBN1) entered Technical Specification Limiting Condition of Operation (TS LCO) 3.0.3 due to the inoperability of both trains of the Emergency Gas Treatment System (EGTS). TS LCO 3.7.12 Condition B was also entered at this time due to the inoperability of both trains of the Auxiliary Gas Treatment System (ABGTS). The train B EGTS and train B ABGTS had been removed from service for scheduled maintenance, when at 0115, the train A Auxiliary Air Compressor became inoperable. On March 17, 2016, at 0133, the train A Auxiliary Air Compressor was declared OPERABLE, and TS LCO 3.0.3 and 3.7.12 Condition B were exited. The auxiliary air system supports the EGTS by providing a safety grade air supply. When train A auxiliary air became inoperable, the supported train A EGTS and ABGTS became inoperable, creating a condition where both trains of EGTS and ABGTS were unavailable. In the event of an accident, the EGTS establishes a negative pressure in the annulus between the shield building and the steel containment vessel and the ABGTS establishes a negative pressure in the Auxiliary Building Secondary Containment Enclosure (ABSCE). Filters in these system mitigate the release of radioactive contaminants to the environment. WBN1 remained in Mode 1 at 100% power and no safety functions were required during the event. This event is reportable under 10 CFR 50.72(b)(3)(v)(C) and (D) as a condition that could have prevented the fulfillment of a safety function. The NRC Resident Inspector has been notified.
The purpose of this notification is to retract event report no. 51795 made on 3/17/16 at 0802 (EDT). Previously, Tennessee Valley Authority (TVA) reported a loss of the Emergency and Auxiliary Building Gas Treatment Systems (EGTS/ABGTS) at Watts Bar Nuclear Plant Unit 1 (WBN1). Both trains of EGTS and ABGTS were declared INOPERABLE when the train A auxiliary air system cooling water supply bypass valve was isolated, prior to completing the requisite post maintenance testing following repairs to the normal cooling water supply solenoid valve. Upon recognition, WBN1 operations personnel declared the train A auxiliary air system INOPERABLE, resulting in inoperability of Train A EGTS and ABGTS and forcing entry into TS LCO (Limiting Condition for Operation) 3.0.3 (from TS LCO 3.6.9 EGTS) and 3.7.12 Condition B for ABGTS. At the time the condition was recognized, train B EGTS and train B ABGTS were INOPERABLE for scheduled maintenance. Subsequently, TVA completed the post maintenance testing of the train A auxiliary air system ERCW (Emergency Raw Cooling Water) normal supply solenoid valve and determined that the valve, while not fully qualified at the time, was in fact operable and capable of performing its safety function. Therefore, entry into TS LCO 3.0.3 and 3.7.12 Condition B was not necessary and the event is no longer reportable under 10 CFR 50.72(b)(3)(v)(C) and (D) as a condition that could have prevented the fulfillment of a safety function. The NRC Resident Inspector has been notified. Notified the R2DO (McCoy). |
ENS 51528 | 11 November 2015 14:26:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Shield Building Vent Gas Radiation Monitor Out of Service for Planned Maintenance | At 0826 CST on 11/11/2015, 1R-22, Shield Building Vent Gas Radiation Monitor, was removed from service for planned maintenance. This monitor has no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs) - NUE (Notification of Unusual Event) and Alert classifications - when out of service. It is also used for offsite dose projection calculations. This results in a Loss of Emergency Assessment Capability while 1R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 Shield Building Ventilation Stack is also monitored by high range monitor, 1R-50, which is used for the same purpose in Site Area or General Emergency classifications. 1R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 1R-22 prior to its removal from service. The duration of this maintenance is scheduled for 24 hours and will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector.
The licensee indicated that the duration of maintenance was extended for approximately 24 hours to allow continued repair of the monitor. The NRC Resident Inspector was notified. Notified the R3DO (Kozak). |
ENS 51013 | 25 April 2015 02:25:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Assessment Capability Due to Out-Of-Service Radiation Monitors | At 2125 on 4/24/15, 1R-2, Containment Vessel Area Radiation Detector failed. Previously, 1R-7, Incore Seal Table Area Radiation Detector, had failed on 4/20/15. The compensatory measure for 1R-2 out-of-service is to verify 1R-7 operating properly and the compensatory measure for 1R-7 out-of-service is to verify 1R-2 operating properly. With both monitors out-of-service and Unit 1 operating in Mode 5, no compensatory measure is available that will allow timely classification of two Emergency Action Levels (EALs) - Notification of Unusual Event (NUE) classification (RU2.2) and Alert classification (RA3.2). This results in a Loss of Emergency Assessment Capability while 1R-2 and 1R-7 are concurrently out-of-service. This is a reportable condition per 10 CFR 50.72(b)(3)(xiii). Monitoring of radiological conditions in Unit 1 Containment showed no indication of RCS leakage or elevated radiation levels prior to the failure of 1R-2. Unit 1 Containment also remains monitored by 1R-48, Containment Hi Range Area Radiation Detector A and 1R-49, Containment Hi Range Area Radiation Detector B, which currently indicate normal radiation levels. Unit 1 Shield Building Stack is also monitored by 1R-50, Shield Building High Range Vent Gas Radiation Detector, which also currently indicates normal radiation levels. Additionally, a temporary portable radiation monitor has been placed near the location of 1R-2 and is being continuously monitored. The plant remains in a safe condition and there was no effect to the health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 50487 | 24 September 2014 12:28:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Shield Building Vent Gas Radiation Monitor Out of Service for Planned Maintenance | At 0728 CDT on 9/24/2014, 2R-22 Shield Building Vent Gas Radiation Monitor was removed from service for planned maintenance. This monitor has no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs) - NUE (Notification of Unusual Event) and Alert classifications - when out of service. It is also used for offsite dose projection calculations. This results in a Loss of Emergency Assessment Capability while 2R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 2 Shield Building Ventilation Stack is also monitored by high range monitor, 2R-50, which is used for the same purpose in Site Area or General Emergency classifications. 2R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 2R-22 prior to its removal from service. The duration of this maintenance is scheduled for 1 hour and will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 50446 | 11 September 2014 15:09:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Shield Building Vent Gas Radiation Monitor Out of Service for Planned Maintenance | At 1009 CDT on September 11, 2014, 1R-22 Shield Building Vent Gas Radiation Monitor was removed from service for planned maintenance. This monitor has no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs) - NUE (Notification of Unusual Event) and Alert classifications when out of service. It is also used for offsite dose projection calculations. This results in a Loss of Emergency Assessment Capability while 1R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 Shield Building Ventilation Stack is also monitored by high range monitor, 1R-50, which is used for the same purpose in Site Area or General Emergency classifications. 1R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 1R-22 prior to its removal from service. The duration of this maintenance is scheduled for 8 hours and will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of radioactivity to the environment and will not affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 50424 | 4 September 2014 13:43:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | 1R-50 Shield Building High Range Vent Gas Radiation Monitor Out of Service for Planned Maintenance | At 0843 CDT on September 4th, 2014, 1R-50 High Range Shield Building Vent Gas Monitor was removed from service for planned maintenance. This monitor provides indication of release of gaseous radioactivity to the environment. There is not a compensatory measure that will allow timely classification of two Emergency Action Levels when out of service: General Emergency Event RG1.1 and Site Area Emergency Event RS1.1. This results in a loss of emergency assessment Capability while 1R-50 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 Shield Building ventilation stack is also monitored by radiation monitor 1R-22 that is used for the same purpose in Alert or Unusual Event Emergency classifications. 1R-22 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 1R-50 prior to its removal from service. The maintenance is scheduled for ten hours or will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of radioactivity to the environment and will not affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 50381 | 18 August 2014 23:25:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Shield Building Boundary Door Failed to Latch | At 1925 EDT on 08/18/2014 an equipment failure prevented a boundary door to the Shield Building Negative Pressure Area to latch closed upon egress, thereby preventing fulfillment of the Station Emergency Ventilation System safety function. Necessary door repairs per normal station practices were completed at 1935 EDT to establish full safety system function. This event was previously considered not reportable. Subsequent review determined the event reportable. The NRC Resident has been notified of the event. The failure to meet the 8-hour reporting requirement has been entered into the Corrective Action Program. The licensee will notify the State, Ottawa, and Lucas counties
At approximately 0413 (EDT) on 8/20/14, the boundary door to the Shield Building Negative Pressure Area again failed to latch closed upon egress. The door was able to be closed and latched at 0419, restoring the Station Emergency Ventilation System safety function. Door use will be limited to essential activities until final repairs to the door closure and latching mechanism are complete. The NRC Resident has been notified of the event. The licensee will notify the State of Ohio and local authorities. Notified R3DO (Passehl). |
ENS 50266 | 10 July 2014 13:38:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | High Range Shield Building Vent Stack Gas Monitor Removed from Service for Maintenance | At 0830 CDT on July 10, 2014, 2R-50 High Range Shield Building Vent Stack Gas Monitor was removed from service for planned maintenance. 2R-50 was planned for an out of service time of approximately 8 hours. The clearance order associated with the work isolated the flow path to the sample pump. Subsequent to the execution of the clearance order, it was discovered that the flow path to the alternate sample pump was also unavailable inhibiting the ability to implement compensatory measures. With 2R-50 rad monitor sample pump out of service and no alternate sampling available, timely classification of two Emergency Action Levels (EALs), SAE (Notification of Site Area Emergency) and General Emergency classifications would not be achievable. This results in a Loss of Emergency Assessment Capability while 2R-50 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 2 Shield Building Ventilation Stack is also monitored by the Shield Building Vent Gas Monitor, 2R-22, which is used for the same purpose in NUE (Notification of Unusual Event) and Alert classifications. 2R-22 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 2R-22 prior to removing 2R-50 from service. This planned maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 50051 | 23 April 2014 15:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | 2R-22 Shield Building Vent Gas Radiation Monitor Removed from Service for Planned Maintenance | At 1000 CDT on April 23, 2014, 2R-22, Shield Building Vent Gas Radiation Monitor was removed from service for planned maintenance. This monitor has no compensatory measures that will allow timely classification of two Emergency Action Levels (EALs); NUE (Notification of Unusual Event) and Alert classifications when out of service. It is also used for offsite dose projection calculations. This results in a loss of emergency assessment capability while 2R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). The Unit 2 Shield Building Ventilation Stack is also monitored by the high range monitor, 2R-50, which is used for the same purpose in Site Area Emergency classifications. 2R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidence by normal reading on 2R-22 prior to its removal from service. Maintenance is expected to last approximately 4 hours and will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of the radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 49943 | 21 March 2014 18:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Shield Building Vent Gas Rad Monitors Out of Service for Planned Maintenance | At 1330 CDT on March 21, 2014, 1R-22 and 2R-22, Shield Building Vent Gas Radiation Monitors will be removed from service for planned preventative maintenance and therefore (will be) nonfunctional. These monitors have no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs); NUE (Notification of Unusual Event) and Alert classifications when out of service. They are also used for offsite dose projection calculations. This will result in a Loss of Emergency Assessment Capability while 1R-22 and 2R-22 are out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 and Unit 2 Shield Building Ventilation Stacks are also monitored by high range monitors, 1R-50 and 2R-50, which are used for the same purpose in Site Area or General Emergency classifications. 1R-50 and 2R-50 are being monitored and are indicating normal values. There are no radioactive leaks that will impact the Shield Buildings as evidenced by normal readings on 1(2)R-22 prior to their removal from service. Preventative maintenance (belt inspections) is expected to last approximately 1 hour. Maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 49828 | 14 February 2014 08:25:00 | 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | Shield Building Construction Opening | On 02/14/2014, an unfilled area was discovered in the concrete along the top of the shield building construction opening on the annulus side. The condition was discovered during the current steam generator replacement outage, and is likely due to not completely repouring the shield building wall opening in 2011. Analysis shows this condition is bounded by previous calculations that demonstrate the containment function is maintained such that the protection of the health and safety of the public was not in question. Further analysis is planned to reconfirm previous calculations. The NRC Resident Inspector has been notified.
The FirstEnergy Nuclear Operating Company is retracting the 8-hour non-emergency notification made on 02/14/2014 (EN# 49828). Engineering evaluation of the unfilled concrete area along the top of the shield building construction opening determined the condition did not prevent the shield building from performing all design functions as described in the Updated Safety Analysis Report. Therefore, this issue did not represent a condition that significantly degraded plant safety, and the notification made per 10CFR 50.72(b)(3)(ii)(B) is being retracted. The NRC Resident Inspector has been briefed on the evaluation results and informed of this retraction. Notified the R3DO (Kunowski). |
ENS 49806 | 7 February 2014 12:20:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Shield Building Vent Gas Radiation Monitor Failure | At 0620 CST on February 7, 2014, 1R-22 Shield Building Vent Gas Radiation Monitor failed and was declared nonfunctional. This monitor has no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs); NUE (Notification of Unusual Event) and Alert classifications when out of service. It is also used for offsite dose projection calculations. This results in a Loss of Emergency Assessment Capability while 1R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 Shield Building Ventilation Stack is also monitored by high range monitor, 1R-50, which is used for the same purpose in Site Area or General Emergency classifications. 1R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 1R-22 prior to its failure. Corrective maintenance is in progress and will continue until the monitor is returned to service. Maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 49799 | 6 February 2014 13:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Radiation Monitor Out of Service for Maintenance | At approximately 0730 CST on February 6, 2014, 1R-22 Shield Building Vent Gas Radiation Monitor will be removed from service for planned maintenance. This monitor has no compensatory measure that will allow timely classification of two Emergency Action Levels (EALs), NUE (Notification of Unusual Event) and Alert classifications when out of service. It is also used for offsite dose projection calculations. This results in a Loss of Emergency Assessment Capability while 1R-22 is out of service. This is a reportable condition in accordance with 10 CFR 50.72(b)(3)(xiii). Unit 1 Shield Building Ventilation Stack is also monitored by high range monitor, 1R-50, which is used for the same purpose in Site Area or General Emergency classifications. 1R-50 is being monitored and is indicating normal values. There are no radioactive leaks that will impact the Shield Building as evidenced by normal readings on 1R-22 prior to removing it from service. This planned maintenance will not result in the unplanned release of radioactivity to the environment and will not adversely affect the safe operation of the plant or health and safety of the public. The licensee has notified the NRC Resident Inspector. |
ENS 49745 | 20 January 2014 08:16:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Shield Building Gaseous Radiation Monitor | 2R-22, Unit 2 Shield Building Ventilation Gaseous Radiation Monitor was removed from service at 0216 CST on 01/20/2014 due to a broken belt. 2R-22 is important to the site's emergency plan for Notification of Unusual Event and Alert classifications in the event of an unplanned gaseous release from the Unit 2 Shield Building stack. It is also used for offsite dose projection calculations. There is no backup instrumentation or compensatory measure to perform these functions while 2R-22 is out of service. This results in a loss of emergency assessment capability, thus is reportable per 10CFR 50.72(b)(3)(xiii). 2R-22 readings were normal prior to the equipment failure. Unit 2 Shield Building Ventilation Stack is also monitored by high range monitor, 2R-50, which is used for the same purpose in Site Area or General Emergency classifications. 2R-50 is being monitored and is indicating normal values. This event did not result in the unplanned release of radioactivity to the environment and did not adversely affect the safe operation of the plant or health and safety of the public. Immediate efforts are underway to repair 2R-22. The licensee has notified the NRC Resident Inspector. |
ENS 49369 | 20 September 2013 18:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Press Release Notification | A press release is being made today by the FirstEnergy Nuclear Operating Company regarding routine inspections of the Davis-Besse Nuclear Power Station's concrete shield building. These routine inspections of the Davis-Besse Nuclear Power Station's concrete shield building conducted to date have confirmed that the building continues to maintain its structural integrity and ability to safely perform its functions. The NRC Resident Inspector has been informed.
The press release originally provided to the NRC was revised prior to release to the public to update the inspections completed to date. The NRC Resident Inspector has been informed. Notified R3DO (Riemer). |
ENS 48995 | 3 May 2013 05:11:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Temporary Loss of Both Trains of Emergency Gas Treatment System | On May 3, 2013, at 0111 (EDT), Technical Specification Limiting Condition of Operation (TS LCO) 3.0.3 was entered due to the loss of both trains of Emergency Gas Treatment System (EGTS). The Train B EGTS had been removed from service for scheduled maintenance and at 0111 the Train A auxiliary air dryer stopped functioning. On May 3, 2013, at 0155, Train B EGTS was restored to service and declared Operable, and TS LCO 3.0.3 was exited. The auxiliary air system is required to support multiple safety related systems. The auxiliary air system is the safety grade air supply for EGTS. As Train A auxiliary air was no longer Operable, and the B train EGTS system was inoperable, the safety function supported by EGTS was not available. The EGTS establishes a negative pressure in the annulus between the shield building and the steel containment vessel. Filters in the system then control the release of radioactive contaminants to the environment. Watts Bar Unit 1 remained in Mode 1 at 100% power. No reactivity was added to the plant. This event is reportable under 10 CFR 50.72(b)(3)(v)(C) and (D) as a condition that could have prevented the fulfillment of a safety function. The NRC Resident Inspector has been notified. |
ENS 45511 | 27 September 2009 22:48:00 | 10 CFR 50.73(a)(1), Submit an LER | Optional 60-Day Telephonic Notification for Invalid Specified System Actuation | (This is a) telephone notification made under 10 CFR 50.73(a)(2)(iv)(A) in lieu of submitting written Licensee Event Report. On September 27, 2009, following reactor shutdown and cooldown for a planned refueling outage, 4160 VAC Safeguard Bus 5 was being restored to normal electrical lineup. Emergency Diesel Generator (EDG) A was powering Bus 5 following successful completion of planned testing to satisfy Technical Specification requirements for testing of EDG automatic start, load shedding, and restoration, initiated by a simulated loss of all normal AC power. At 1648, while restoring Bus 5 to normal electrical lineup, breaker 1-503, Tertiary Auxiliary Transformer (TAT) supply to Bus 5, reopened after being closed. EDG A continued to supply Bus 5 without interruption. The following equipment tripped when breaker 1-503 opened: Residual Heat Removal (RHR) Pump A, Containment Fan Coil Units (CFCUs) A & B, Shield Building Ventilation (SBV) Fan A, and Service Water (SW) Pump A1. Auxiliary Feedwater (AFW) Pump A, Component Cooling (CC) Pump A, and SW Pump A2 were tripped and restarted by the blackout sequencer. All actuations were completed as designed and the components started and functioned successfully. AFW Train A had been properly removed from service for the EDG test and operated on minimum recirculation following AFW Pump A start. The equipment actuations resulted from an invalid signal caused by an electrical jumper for the blackout signal remaining installed during Bus 5 restoration. The jumper continued to inject a simulated loss of voltage (blackout) signal, causing the TAT supply breaker opening and load shedding and sequencer operation as designed. Inspection of breaker 1-503 was completed with no abnormalities noted. The jumper was removed and Bus 5 was restored to normal lineup. Corrective actions were initiated to revise the test procedure to more appropriately control bus restoration. Although the actuating signal that caused this event was invalid and the electrical bus had been appropriately aligned for the EDG test, this event is being reported because of the multiple and diverse components that were inadvertently actuated. The licensee has notified the NRC Resident Inspector. |
ENS 43651 | 18 September 2007 17:00:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Shield Building Ventilation System Inoperable | At 1200 a condition associated with the Shield Building Ventilation Train A damper controller was identified that rendered the system inoperable. This condition was identified while Shield Building Ventilation Train B was inoperable for routine maintenance. Consequently, both trains of Shield Building Ventilation were simultaneously inoperable. Technical Specification TS 3.6.c requires a reactor shutdown within 12 hours of this condition. The routine maintenance on Shield Building Ventilation Train B was completed and retest performed at 1331. Shield Building Ventilation Train B was returned to operable and Technical Specification requirements to shutdown were exited. The plant remains in a 7 day Action Statement per TS 3.6.c with Shield Building Ventilation Train A inoperable . This event is reportable under 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.' I&C technician was walking down a different job in the area and noticed a light illuminated on the A control board which should not have been illuminated. Additional investigation revealed an electrical condition would have prevented the modulation of the dampers thereby rendering the A train system inoperable. The licensee notified the NRC Resident Inspector. |
ENS 43633 | 11 September 2007 19:39:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Auxiliary Building Special Ventilation and Shield Building Ventilation Systems Inoperable | At 1439 the Control Room received a Condition Report that identified an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems which resulted in declaring this equipment inoperable. The issue was recirculation flow from Auxiliary Building Special Ventilation back to the Auxiliary Building added additional area heat gain resulting in exceeding the design capacity for the area fan coil units. Technical Specification LCO was entered per TS 3.6.c requiring a reactor shutdown within 12 hours. At 1654 Engineering provided information that if the control switch for Auxiliary Building Special Ventilation Train A was maintained in the off position, the area heat load was within the capacity of area fan coil units. This was completed and both trains of Shield Building Ventilation and Auxiliary Building Special Ventilation Train B was returned to operable. Technical Specification requirements to shutdown were exited. The plant remains in a 7 day Action Statement per TS 3.6.c with Auxiliary Building Special Ventilation Train A inoperable. This event is reportable under 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 licensee notified the NRC Resident Inspector.
On September 11, 2007 Kewaunee Power Station reported an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems, which resulted in declaring the equipment inoperable. The issue involved recirculation flow from the Auxiliary Building Special Ventilation System back into the Auxiliary Building causing additional area heat gain resulting in exceeding the design capacity for the area fan coil units. A subsequent engineering review concluded that required equipment in the Auxiliary Building Fan Floor area would have remained functional during a design basis accident provided service water temperature does not exceed 78.14 degrees Fahrenheit. A review of service water temperatures over the past three years did not identify any occurrences exceeding this value. Therefore, the safety function of the systems would have been met. Based on the analysis performed, Event Notification EN# 43633 is hereby retracted. The Auxiliary Building Special Ventilation and Shield Building Ventilation Systems remain in a non-conforming condition because the maximum service water design temperature is 80 degrees Fahrenheit. Service water temperature is being administratively limited to 71 degrees Fahrenheit pending final corrective action. The licensee has notified the Point Beach NRC Senior Resident Inspector. Notified R3DO (Madera). |
ENS 43410 | 6 June 2007 17:10:00 | 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | Containment Isolation Valves Found Misaligned | On 6/06/07 at 13:10 EDT while performing a surveillance to verify the position of administratively locked valves for Containment and Shield Building Integrity, two manual Containment Isolation valves were found Locked Open, versus the required Locked Closed position. The valves were restored to the Locked Closed position at 13:30 EDT of the same day. The subject valves, V18794 and V18796, provide Service Air (a non-safety class system) to the Containment during Mode 5 and 6 conditions through Containment Penetration #8. The subject valves are required to be returned to Locked Closed prior to entering Mode 4 in accordance with the Plant Technical Specifications 3.6.1.1 for Containment Integrity and plant procedures. The valves are to be verified in the Locked Closed position once every 31 days per Administrative Procedure 1-0010123 Appendix E, which was last performed on 5/09/07. Unit 1 exited Mode 5 and entered Mode 4 on 5/20/07 following a refueling outage and is currently in Mode 1 at 100% power. It is assumed the valves have been incorrectly positioned since entering Mode 4. The Service Air System is intact and pressurized at approximately 110 psig. There is no open path from Containment to the outside atmosphere. This event is being reported pursuant to 10CFR50.72(b)(3)(ii)(A), based on principal safety barriers being seriously degraded. The licensee notified the NRC Resident Inspector. |
ENS 42534 | 28 April 2006 00:29:00 | 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | Two Trains of Shield Building Ventilation Inoperable | At 19:29 on 04/27/2006 the Kewaunee Power Station declared two trains of Shield Building Ventilation (SBV) inoperable. Train B SBV was declared inoperable on 4/25/2006 at 17:25 when SW Train B was declared out of service for a leak that developed on the branch header to Diesel Generator B and TS 3.3.e.2 was entered. On 4/27/2006 at 19:29 QA typing discrepancies in RR-119 were discovered. QA-2 components were used in a QA-1 system, which could potentially cause a failure of some safety related equipment powered from this relay rack. As a result, all safety related equipment powered from RR-119 were declared inoperable and the appropriate technical specifications entered. SBV Train A Damper Control is powered from RR-119 and was declared inoperable at 19:29 on 4/27/2006 resulting in two trains of SBV being inoperable and TS 3.6.c.1 entered. The QA-2 components that may have an adverse affect on QA-1 safety related components in RR-119 have been removed and both trains of SBV were declared operable at 00:29 on 4/28/2006. The licensee notified the NRC Resident Inspector.
This event was reported on April 27, 2006 (Event Number 42534) for two trains of shield building ventilation (SBV) being declared inoperable. Train B SBV was declared inoperable due to loss of the service water spray system for the SBV charcoal filters and Train A SBV was declared inoperable due to relay rack RR-119 Quality Assurance typing discrepancies (relay rack provides power for SBV Damper Control). Subsequent review of analysis determined that the SBV spray system is not required for post-LOCA operation to control the release of radioactive material. Therefore, Train B of SBV was not required to be declared inoperable when Train B service water was declared out of service. With only one Train of SBV being inoperable, this event is not reportable and is being retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (P. Louden). |
ENS 42509 | 18 April 2006 17:00:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Shield Building Ventillation System Declared Inoperable | On 4/18/2006, at 1200 hours, while the plant was operating at full power, the plant entered a 12 hour Technical Specification (TS) action statement for both trains of the Shield Building Ventilation (SBV) System being declared inoperable. The SBV System action statement was entered when the plant declared Relay Flacks RR-119 and RR-120 inoperable due to non-qualified fuses and cables being installed in six (6) of the boxes contained in these racks. The instruments associated with the six (6) boxes were not found in Technical Specification required instruments or alarms. The issue was that a downstream failure on the non-qualified Instruments may not have qualified fault protection, therefore a fault could impact safety related equipment. Other Technical Specification equipment affected by the inoperability of RR-119 and RR-120 include both trains of Inadequate Core Cooling Monitoring System (ICCMS), Reactor Vessel Level Indication (RVLIS), Pressurizer Safety Valve Outlet Temperature, and Pressurizer Power Operated Relief Valve Outlet Temperature. At 1611 actions taken by plant staff returned RR-120 to operable and the 12 hour action statement for SBV was exited. The plant remains in a 7 Day Limiting Condition of Operation (LCO) pending the return of RR-119. Due to the fact that Train B of SBV has been made operable, a plant shutdown was not commenced. This event is being reported under 10CFR50.72(b)(3)(v)(C) 'Any event that at the time of discovery could have prevented the fulfillment of the safety function of systems that are needed to control the release of radioactive material'. The licensee notified the NRC Resident Inspector. |
ENS 42152 | 17 November 2005 22:51:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Trains of Shield Building Ventilation Declared Inoperable Due to Missing Clamps | At 1651 on 11/17/2005 both trains of Shield Building Ventilation were declared out-of-service because it was identified that Shield Building penetrations 31 and 36NW flexible boot seals were not clamped per the design drawing. Since there is no documentation to show that Shield Building Ventilation would be able to perform its function during a design basis event with no clamps installed, Shield Building Vent was declared inoperable. Clamps have been installed and the penetrations were returned to the design configuration. At 1810 CST Shield Building Ventilation was declared Operable. The licensee notified the NRC Resident Inspector.
The licensee has performed an engineering review and determined that the boot seals would have been capable of performing their design basis function without the clamps installed. Consequently, this event is no longer considered reportable and is being retracted. The NRC Resident Inspector has been notified by the licensee. R3DO (O'Brien) has also been notified. |
ENS 40403 | 20 December 2003 14:49:00 | 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | Rps Actuation Due to Loss of Turbine Generator Excitation | On December 20, 2003, at 0949 hours, an automatic reactor trip occurred due to a loss of excitation of the turbine generator. All plant safety functions were maintained throughout the event. The plant was stabilized in Mode 3. All plant safety systems responded normally with the exception of the 2C Auxiliary Feedwater Pump (steam driven) which tripped on mechanical overspeed. The 2A and 2B Auxiliary Feedwater Pumps (electric driven) functioned normally to restore the 2A and 2B Steam Generator levels. Post trip system anomalies include RCS Letdown isolated, Steam Generator Blowdown isolation valves closed, Control Room ventilation system swapped to recirculation mode, and the Fuel Handling Building ventilation system swapped to the Shield Building. An Emergency Response Team has been formed to review these conditions prior to plant restart. This non-emergency notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) due to the automatic RPS Reactor Trip. All controls inserted properly. Decay heat is being removed using the turbine bypass valves. The Licensee notified the NRC Resident Inspector.
This update is provided to include the 10CFR50.72(b)(3)(iv)(A) notification criterion for the auxiliary feedwater actuation. The NRC Resident Inspector was notified., Reg 2 RDO(Fredrickson) was informed. |
ENS 40375 | 4 December 2003 21:32:00 | 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation | St. Lucie Unit 2 Manual Reactor Trip Due to Loss of Condensate Pump | On December 4, 2003, at 1605 hours, a down power was initiated due to a failing bearing on the 2A Condensate Pump. The pump bearing was hot and smoking. The plant fire team was deployed as a precautionary action. Due to continued degradation of the Pump bearing, a Manual Reactor Trip was initiated at approximately 60% power. Feed to the 2A and 2B Steam Generators was maintained via the 2B Main Feedwater Pump. All plant safety systems responded normally and plant safety functions were maintained throughout the event. The Plant was stabilized In Mode 3. Plant post trip anomalies include Steam Generator Blowdown isolation valves closed, Control Room ventilation system swapped to recirculation mode, the Fuel Handling Building ventilation system swapped to the Shield Building, and it was necessary to take Steam Bypass Control System to manual. An Emergency Response Team was formed to review these conditions prior to plant restart. This non-emergency notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) due to the manual initiation of the RPS Reactor Trip. All control rods fully inserted into the reactor on the trip. The emergency diesel generators are available and the offsite electrical grid is in a normal configuration. No safety relief valves or power operated relief valves were known to have actuated during this event. St. Lucie Unit 1 was not affected and continues to operate in mode 1 at 100% rated thermal power. The licensee has notified the NRC Resident Inspector. |