Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 52097 | 18 July 2016 20:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Offsite Communications Capability | At 1600 EDT, testing of the Everbridge ERO (Emergency Response Organization) notification system identified the system was not able to notify all ERO individuals. This constitutes a loss of offsite communications capability. The issue was reported resolved by the vendor and site testing has verified resolution as of 2130. This event is reportable under 10 CFR 50.72(b)(3)(xiii) as a loss of communications capability. The NRC Resident Inspector has been notified. Some of the ERO personnel did not receive a test page. The requirement is to have all ERO personnel receive the page within ten minutes. Compensatory measures were instituted while the system was not functional. | ||
| ENS 50932 | 27 March 2015 17:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Seismic Monitor Not Available for Emergency Plan Assessment | Three Mile Island Station has completed a review of seismic monitor performance. The seismic monitor is currently operable however, this review identified 1 time in the past 3 years that the seismic monitor was inoperable such that emergency classification at the ALERT level could not be obtained with site instrumentation. The seismic monitor was determined to be inoperable on the following date: 1) August 7, 2012 This unplanned inoperable condition of the seismic monitor was entered into the Three Mile Island Corrective Action Program when it occurred. While Exelon procedural direction allowed the use of offsite sources to obtain seismic data when the seismic monitor is incapable of assessing emergency plan Emergency Action Levels (EALs), this was not explicitly referenced in the approved EALs. The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). This report is required per 10 CFR 50.72(a)(1)(ii) as an event that occurred within 3 years of the date of discovery. The licensee has notified the NRC Resident Inspector. | ||
| ENS 48855 | 27 March 2013 12:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Ventilation Out of Service for Maintenance | This is a non-emergency eight hour notification for a loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the work activity affects the functionality of a emergency response facility. Planned maintenance activities are being performed today (March 27, 2013) to the Technical Support Center (TSC) HVAC. The work includes both corrective and preventive maintenance to the TSC HVAC system. This work activity is planned to be performed and completed expeditiously within about 14 hours. If an emergency condition occurs that requires activation of the TSC, plans are to utilize the TSC concurrent with this work activity as long as habitability conditions allow. Additionally, plans are in place to expedite the return of the system should an emergency condition occur. The emergency response organization duty team members will be relocated to an alternate location if required by habitability conditions in accordance with emergency implementing procedures. The licensee notified the NRC Resident Inspector.
The Technical Support Center has been returned to service. The licensee has notified the NRC Resident Inspector. Notified R1DO (Krohn). | HVAC | |
| ENS 48714 | 5 February 2013 13:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Ventilation System Out of Service | This is a non-emergency eight hour notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the work activity affects the functionality of an emergency response facility. Planned maintenance activities are being performed today (February 5, 2013) to the Technical Support Center (TSC) HVAC. The work entails performance of DOP (dioctyplthalate oil smoke test) and Halide testing. This work activity is planned to be performed and completed expeditiously within about 12 hours including establishing and removing the clearance and performing post maintenance testing. If an emergency condition occurs that requires activation of the TSC, plans are to utilize the TSC concurrent with this work activity as long as habitability conditions allow. Additionally, plans are in place to expedite the return of the system should an emergency condition occur. The Emergency Response Organization duty team members will be relocated to alternate location if required by habitability conditions in accordance with emergency implementing procedures. The licensee notified the NRC Resident Inspector.
TSC ventilation has been returned to service. Notified the R1DO (Powell) via e-mail. | HVAC | |
| ENS 48625 | 26 December 2012 09:10:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Ventilation System Out of Service | This is a non-emergency eight hour notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the work activity affects the functionality of an emergency response facility. Planned maintenance activities are being performed today (December 26, 2012) to the Technical Support Center (TSC) HVAC. The work entails removing power to the system fan and dampers to perform required preventative maintenance (PM) rendering the TSC HVAC non-functional during the performance of this work activity. This work activity is planned to be performed and completed expeditiously within about 16 hours including establishing and removing the clearance and performing post maintenance testing. If an emergency condition occurs that requires activation of the TSC, plans are to utilize the TSC concurrent with this work activity as long as habitability conditions allow. Additionally, plans are in place to expedite the return of the system should an emergency condition occur. The Emergency Response Organization duty team members will be relocated to alternate locations if required by habitability conditions in accordance with emergency implementing procedures. The licensee notified the NRC Resident Inspector. | HVAC | |
| ENS 47419 | 7 November 2011 01:03:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Spds and Plant Process Computer Due to Planned Maintenance | At 1203 EST on 11/06/2011, the Safety Parameter Display System (SPDS) was removed from service for planned maintenance of the Plant Process Computer. The Plant Process Computer and the SPDS function were restored at 2015 EST on 11/06/2011. This event is reportable per 10 CFR 50.72(b)(3)(xiii) since the SPDS was out of service for greater than 8 hours resulting in a major loss of emergency assessment capability. The licensee will inform the NRC Resident Inspector. | Safety Parameter Display System | |
| ENS 47390 | 29 October 2011 23:18:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Greater than 25% of Emergency Notification System Sirens Due to Weather Conditions | At approximately 1818 EDT on October 29, 2011, Three Mile Island Nuclear Generating Station received notification that 25 of 96 emergency notification system offsite sirens were not functional. The loss of >25% of the sirens is considered a Major Loss of Emergency Preparedness Capabilities (10CFR50.72(b)(3)(xiii)). The loss of offsite sirens was due to loss of electrical power caused by significant heavy snowfall in the area. Efforts are in place to restore offsite sirens to service. The licensee stated that compensatory measures are in place should their be a need to notify the areas affected by the lost sirens. The licensee has notified State and local authorities. The NRC Resident Inspector will be notified. | ||
| ENS 47031 | 6 July 2011 18:40:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center (Tsc) Hvac Out of Service Due to Loss of Power | At about 1440 EDT on July 6, 2011, the Technical Support Center (TSC) HVAC lost power during motor control switch testing. The transfer switch did not fully engage resulting in loss of power to the TSC HVAC fan motor. Troubleshooting was performed and power was restored to the TSC HVAC system at approximately 1625 EDT. This involved an emergent loss of the TSC capability that could not be readily remediated in less than the TSC staffing time of one hour. Unrelated to the first event, 13.2 KV power to the TMI station office buildings was lost at approximately 1740 EDT on July 6, 2011 due to a broken electric service pole. This resulted in another loss of the TSC HVAC that could not be readily remediated. At 2115 EDT power was restored and the ventilation was started. This event resulted in another reportable condition. These events affected the ability of the TSC ventilation to maintain adequate radiological habitability in the event of an emergency with an airborne radiological release. All other capabilities were unaffected by this emergent condition. Existing procedures provide direction to relocate TSC personnel in the event of a TSC habitability concern, however the backup facility does not have standby electrical power or a filtered ventilation system. The licensee has informed the NRC Resident Inspector. | HVAC | |
| ENS 45929 | 14 May 2010 19:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Nonfunctional | At 1530 on May 14th, 2010, Three Mile Islands Technical Support Center (TSC) ventilation, filtration and climate control system was identified as nonfunctional. Site emergency implementation procedures provide direction for performance of TSC functions in alternate locations. This failure affects the ability of the TSC ventilation to maintain adequate radiological habitability in the event of an emergency with an airborne radiological release. All other capabilities of the TSC are unaffected by this emergent condition. This condition is considered a major loss of emergency assessment capability and is reportable under 10CFR50.72(b)(3)(xiii). The NRC Resident Inspector has been notified.
The TSC ventilation system has been repaired and is fully functional as of 1100 on May 15, 2010. The NRC Resident Inspector has been notified. Notified R1DO(Miller). | ||
| ENS 45359 | 17 September 2009 17:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Emergency Response Data System Inoperable for Greater than Eight Hours | At 1300 hrs. on Thursday, September 17, 2009, TMI Unit 1 determined that there had been a degradation of the emergency preparedness response capabilities when a loss of the Emergency Response Data System (ERDS) was identified. While preparing for a future job in the same cabinet where the ERDS modem is located, technicians identified that the phone line for the ERDS modem was not connected. At 1400, the phone line was reconnected to the modem. After coordination with the NRC Operations Center testing personnel, a test of the ERDS system was initiated. At 1414, an active link was established. A successful ERDS link was confirmed with the NRC Operations Center. At 1426, the ERDS link was terminated. Work was performed on different equipment in the cabinet containing the ERDS modem on approximately September 1, 2009. It is probable that the phone line was inadvertently disconnected from the ERDS modem at that time. The last scheduled quarterly test was successfully completed on July 9, 2009. TMI 1 has determined that this event is reportable to the NRC as an 8-hour non-emergency report in accordance with 10 CFR 50.72 (b)(3)(xiii). The licensee has notified the NRC Resident Inspector. | Emergency Response Data System | |
| ENS 45231 | 27 July 2009 14:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center (Tsc) Hvac Found Degraded Due to Water Intrusion | At about 10:00, on July 27, 2009, the Technical Support Center (TSC) HVAC was found to be degraded. The fan motor was running but there was no air flow and the TSC rooms were not being maintained with a positive pressure. Upon investigation, the fan housing was found partially filled with water, submerging the motor and preventing air flow through the system. Repair of the motor will take more than one day and is being immediately pursued. This affects the ability of the TSC ventilation to maintain adequate radiological habitability in the event of an emergency with an airborne radiological release. All other capabilities of the TSC are unaffected by this emergent repair. Existing procedures provide direction to relocate TSC personnel in the event of a TSC habitability concern; however, the backup facility does not have standby electrical power or a filtered ventilation system. Therefore, this condition is considered a major loss of emergency assessment capability and is reportable under 10CFR50.72(b)(3)(xiii). The TSC HVAC was last functionally tested satisfactorily on 06/29/09. The licensee believes the water found in the HVAV fan housing may be a result of a clogged drain line. The licensee will inform the NRC Resident Inspector. | HVAC | |
| ENS 43772 | 5 November 2007 21:49:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Spds Out of Service for Planned Maintenance | At 16:49 hours, on 11/05 the Unit 1 SPDS and ERDS systems were removed from service to support restoration activities from a planned maintenance outage on the power supply. The duration of work is expected to be approximately 10 hours. (Scheduled for completion at 03:00 on 11/06/2007). During this time, Control Room indications and alternate methods will be available. Since the SPDS computer system will be unavailable for greater than 8 hours, this is considered a Loss of Emergency Assessment Capability and reportable under 10 CFR 50.72(b)(3)(xiii). A follow-up notification will be made to the NRC after the SPDS and ERDS system are returned to service. The licensee will notify the NRC Resident Inspector. * * * UPDATE AT 0315 ON 11/6/07 FROM J. PAULES TO P. SNYDER * * * At 0314 on 11/6/07 the SPDS and ERDS systems were returned to service. The licensee will notify the NRC Resident Inspector. Notified R1DO (M. Miller). | ||
| ENS 43760 | 31 October 2007 03:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Outage of Safety Parameter Display System (Spds) and Emergency Response Data | SYSTEM (ERDS) At 2330 hours, on 10/30/2007, the SPDS and ERDS system was removed from service to support activities from a planned maintenance outage on the 'C' vital bus power supply. The duration of work is expected to be approximately 12 hours. (Scheduled for completion at 11:30 hours on 10/31/2007). During this time, Control Room indications and alternate methods will be available. Since the SPDS computer system will be unavailable for greater than 8 hours, this is considered a Loss of Emergency Assessment Capability and reportable under 10CFR50.72(b)(3)(xiii). The licensee will notify the NRC Resident Inspector. Notified R1DO (Dental).
At 0230 hours, on 11/1/2007, the SPDS and ERDS system were returned to service. The licensee will notify the NRC Resident Inspector. Notified R1DO (Dental). | Safety Parameter Display System | |
| ENS 42413 | 13 March 2006 16:10:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Ventilation Fan Inoperable | The Technical Support Center ventilation system was discovered to be non-functional at 1110 on March 13, 2006. The cause of the ventilation problem was determined to be damaged drive belts on the supply fan. The belts were replaced and the ventilation system supply fan was returned to service at 1253 on March 13, 2006. This condition is considered a Loss of Offsite Response Capability and is therefore reportable under 10CFR50.72(b)(3)(xiii). A corrective action request has been generated to follow remedial action. The licensee notified the NRC Resident Inspector. | ||
| ENS 40178 | 19 September 2003 06:24:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Siren Capability Due to Adverse Weather Conditions | TMI is notifying the NRC Operations Center in accordance with 10 CFR 50.72 (b)(2)(xi), Notification of Other Government Agency and 10 CFR 50.72 (b)(3)(xiii) Major Loss of Emergency Preparedness Capabilities. At 0224 AM on Friday, September 19 it was determined that 25 of 79 of the public emergency sirens for Three Mile Island Unit 1 were inoperable due to loss of power due to Tropical Storm Isabel. Subsequently, it has been determined that 32 of 79 of the sirens are inoperable. The inoperable sirens are located throughout the five risk counties around TMI. The inoperability of the sirens around TMI impacts a large segment of the population. Contingency actions have been established for the deficient sirens. Automatic route alerting, that is the coordinated use of vehicles that will make loudspeaker announcements throughout affected areas will be utilized if the need should arise prior to restoration of power to the inoperable sirens. Local power company line crews have been notified of the loss of power to the sirens and are working to restore power on a priority basis to the sirens. The licensee informed the affected counties/PEMA and the NRC Resident Inspector. | ||
| ENS 40121 | 29 August 2003 19:05:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Degradation of Emergency Preparedness Response Capabilities | At 1505 hrs. on Friday August 29, 2003, TMI Unit 1 determined that there had been a degradation of the emergency preparedness response capabilities when there was a loss of the Emergency Notification System (ENS), the Health Physics Network (HPN) and the Emergency Response Data System (ERDS). In addition most site telephone lines were inoperable. The loss of these communications systems was most probably caused by a lightning strike. Limited telephonic communications remains with the TMI 1 control room, i.e., one commercial phone exchange, a satellite phone and the emergency management phone circuit remain operable. TMI 1 has verified operability of the ERO notification system (pagers), and the communication circuit used to notify the state and local counties. The siren system for local counties was unaffected by loss of site telephone systems. Plant page and radio systems remain operable. Adequate communications capabilities are operable at this time to implement the emergency plan. Repairs to restore the inoperable telephone systems are in progress at this time. A return to service time for all systems is to be determined. However, at the time of this report, the ENS line has been restored to an operable status. TMI 1 has determined that this event is reportable to the NRC as an 8-hour non-emergency report in accordance with 10 CFR 50.72 (b)(3)(xiii). The NRC Resident Inspector, the State of Pennsylvania, and local authorities have been notified by the licensee.
The licensee reported that the Emergency Notification System (ENS) was restored to service on 8/29/03 at approximately 2100 hours EDT and the Emergency Response Data System (ERDS) was returned to service on 8/29/03 at 2212 hours EDT. Notified R1DO (James Trapp). | Emergency Response Data System |