Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 53285 | 23 March 2018 17:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Assessement Capability | This report is made for a loss of Emergency Assessment Capability associated with Emergency Action Levels for Toxic and Flammable Gas and is reportable under 10 CFR 50.72(b)(3)(xiii). During an emergency equipment inventory, it was identified that methods were not available to detect levels of toxic or flammable gas at the IDLH (Immediately Dangerous to Life and Health) level for a number of substances due to the detector having an unsuitable range. The IDLH is used to assess the Emergency Action Level Alert Range. The ability of the Control Room Staff to detect and respond to the presence of toxic or flammable gas is unaffected. Because there have been no chemical spills or releases that would require sampling to be performed, the health and safety of the public was not affected. The resident NRC Inspector has been notified. The licensee will be notifying the state of Minnesota. | ||
| ENS 52781 | 1 June 2017 21:45:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Lost Ability to Receive Meteorogic Data | Planned maintenance to restore normal power to Plant Computer Systems resulted in an unexpected loss of all Meteorological (MET) Tower Data (at 1645 CDT). As a result, this represents a Loss of Emergency Assessment Capability and is reportable under 10CFR 50.72 (b)(3)(xiii). The isolation was restored and MET Tower Data was restored at 1845. The health and safety of the public was not affected as the plant is operating in a normal condition with no severe weather or storms in the area. Additionally meteorological data was available from the National Weather Service should this data had been necessary. The NRC Resident Inspector has been notified." The licensee will be notifying the State of Minnesota. | ||
| ENS 52153 | 4 August 2016 19:15:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Battery Room Fire Detection System Inoperable | At 1415 CDT on August 4, 2016, while performing a scheduled fire protection surveillance, it was discovered that a component within fire panel FZCP-7, BATTERY ROOM FIRE DETECTION had failed resulting in the inability of the installed fire detectors to detect a fire within the Division 1 and Division 2, 125 VDC battery rooms as well as the Division 2, 250 VDC battery room. This is being reported under 10 CFR 50.72(b)(3)(xiii) for a Loss Of Emergency Assessment Capability as the Control Room would not receive automatic notification of a fire in these areas for evaluation of HU2.1 and HA2.1 for fire within impacted battery rooms which are located within the Protected Area. There is no impact to the health and safety of the public. A 15 minute fire watch has been established for the affected fire zones. The NRC Resident Inspector has been notified.
Event Notification 52153 completed at 2204 EDT on 8/4/2016 shown above contains an error. The failure of FZCP-7, BATTERY ROOM FIRE DETECTION, resulted in the inability to detect a fire within the Division 1 and Division 2 125 VDC battery rooms as well as the Division 1 250 VDC battery room. The Division 2 250 VDC battery room was not affected by this issue. Additionally, the State of Minnesota was notified of this issue. The NRC Resident Inspector has been notified of this update. Notified R3DO (Skokowski) | ||
| ENS 50496 | 26 September 2014 03:00:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Isolation Declared Inoperable Due to Relay Age | At 2200 CDT on September 25, 2014, the Duty Shift Manager was notified that Agastat relays associated with Primary Containment Isolation valves on the Hydrogen-Oxygen Analyzing System are beyond the analyzed shelf life for relays that are in the normally energized state and are considered INOPERABLE. This affected both primary containment isolation valves for a containment penetration on multiple flow paths. This issue was determined to be reportable under (10 CFR) 50.72 (b)(3)(v)(C) & (D) for an 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 and mitigate the consequences of an accident. Additionally, the required actions involved isolating six flow paths via manual isolation valves. This action rendered the Hydrogen-Oxygen Analyzers non-functional for both trains and constitutes a loss of Emergency Preparedness and Accident Assessment Capability. This is reportable under (10 CFR) 50. 72(b)(3)(xiii). The Primary Containment Isolation Valves have been, and remain, in their closed position to satisfy their Primary Containment Function and protect the health and safety of the public. The NRC Senior Resident Inspector has been notified. The licensee will notify the State of Minnesota. The relays of concern were manufactured 19 years ago and have been in operation for 11 years, versus a manufacturer assumption of a 10 year operational lifespan.
Partial retraction for EN 50496. This is an update of Emergency Notification System (ENS) report 50496 that was submitted at 0253 EDT on Friday, September 26, 2014. ENS notification was made due to four relays associated with the sampling valves on the Hydrogen-Oxygen Analyzing (HOA) system that perform Primary Containment Isolation Valve (PCIV) functions. These relays were discovered installed beyond their manufacturer qualified service life, which called operability into question. The portions 10 CFR 50.72 (b)(3)(v)(C) & (D) are being retracted after subsequent bench testing and investigation of system operability. Based on the past operability evaluation, all four relays associated with PCIV functions on the HOA system would have performed their specific safety function of primary containment isolation, as required by the facility's technical specifications. Therefore, this event does not meet the threshold of an event or condition that would prevent fulfilment of a safety function. The loss of emergency preparedness and accident assessment capability previously reported under 10 CFR 50.72 (b)(3)(xiii) remains unchanged. The NRC Resident Inspector has been notified. Notified R3DO (Peterson). | Primary containment | |
| ENS 50411 | 28 August 2014 14:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Both Discharge Canal Radiation Monitors Removed from Service for Planned Maintenance | 'Planned preventive maintenance will render both divisions of discharge canal radiation monitors non-functional. As a result, this represents a loss of emergency assessment capability and is reportable under 10 CFR 50.72(b)(3)(xiii). The planned maintenance is expected to last two hours. During this time, alternate plant parameters will be monitored and sampling performed if needed. The health and safety of the public remains protected as the plant is operating in a normal condition. The NRC Resident Inspector was notified prior to removing the discharge canal radiation monitors from service. | ||
| ENS 50364 | 14 August 2014 12:55:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Service Water Radiation Monitor Nonfunctional for Planned Maintenance | The service water radiation monitor system will be rendered nonfunctional during planned preventive maintenance. As a result, this represents a loss of emergency assessment capability and is reportable per 10CFR50.72(b)(3)(xiii). The planned maintenance is expected to last 4 hours. During this time, plant parameters will be monitored and sampling will be performed which will support sustaining the health and safety of the public during this planned maintenance activity. The NRC Resident Inspector will be notified prior to removing the service water radiation monitor from service. | Service water | |
| ENS 50327 | 31 July 2014 12:20:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Service Water Radiation Monitor Out of Service for Maintenance | Planned preventative maintenance on the Service Water Radiation Monitor (SWRM) strainer will remove the SWRM from service. As a result, this represents a loss of emergency assessment capability since the SWRM is used to assess NUE and ALERT thresholds. The activity is expected to last 6 hours. During this time, the site will be monitoring alternate indications to detect leakage and the Chemistry Department will perform grab samples as required to ensure the ability to detect NUE levels of radioactivity in a timely manner and protect the health and safety of the public. The NRC Resident Inspector has been notified prior to removing the SWRM from service. | Service water | |
| ENS 50225 | 25 June 2014 05:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Various Telecommunication Lines and Erds Outage for Planned Maintenance | Planned preventive maintenance will render parts of telephone system and Emergency Response Data System (ERDS) nonfunctional. As a result, this represents a loss of emergency communications capability and is reportable under 10 CFR 50.72(b)(3)(xiii). The maintenance is scheduled to begin on 6/25/2014 at 00:00 (CDT), and is expected to last approximately 5 hours. During this maintenance window, various communication connections will be intermittently interrupted for short periods of time. Affected communication connections include some local telephone company lines, Federal Telephone System, ERDS, the Monticello's NRC office, and automatic ring down lines to the state of Minnesota's Emergency Operations Center. During the planned maintenance window, communications to offsite will be available via radios, cell phones, and satellite communications. This ensures that the plant can adequately communicate with the NRC, state, and local agencies to ensure protection of the health and safety of the general public. The NRC Resident Inspector has been notified of the planned telecommunications maintenance. Licensee also notified the Minnesota State Duty Officer and the Wright and Sherburne County Sheriff dispatchers.
At 0500 (CDT) on 6/25/2014, planned maintenance on the Monticello telecommunications system was completed. At 1630 (CDT) on 6/25/2014, testing of all telecommunications was completed. All systems are functioning properly. The NRC Resident Inspector has been notified that the telecommunications system is functional. The Minnesota State Duty Officer and the Wright and Sherburne County Sheriff dispatchers have been notified that the telecommunications system is functional. Notified R3DO (Lara). | Emergency Response Data System | |
| ENS 50175 | 5 June 2014 21:01:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Discharge Canal Radiation Monitors Removed from Service for Planned Maintenance | Planned preventive maintenance will render the discharge canal radiation monitors inoperable for both A and B trains. As a result, this represents a loss of emergency assessment capability and is reportable under 10 CFR 50.72 (b)(3)(xiii). The planned maintenance is expected to last two hours. During this time, the site Chemistry Department will be perform sampling as a compensatory measure. The health and safety of the public remains protected as the plant is operating in a normal condition. The NRC Resident Inspector was notified prior to removing the discharge canal radiation monitors from service. | ||
| ENS 50136 | 23 May 2014 16:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Assessment Capability Due to Failed Area Radiation Monitor | At 1130 CDT, an Area Radiation Monitor (ARM) was determined to be non-functional as a result of a failed calibration test. This represents a loss of assessment capability reportable under 10CFR50.72(b)(3)(xiii). A portable radiation monitor has been placed in the affected area as a compensatory measure. The health and safety of the public was protected as the plant was in a normal condition with no initiating event in progress or signs of elevated radiation levels on any other radiation monitors. The NRC Resident Inspector has been notified. The failed ARM is located in the 'A' RHR core spray room. | Core Spray | |
| ENS 50077 | 1 May 2014 13:40:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Service Water Radiation Monitor Taken Out of Service for Planned Maintenance | The Service Water Radiation Monitor will be removed from service to facilitate planned preventative maintenance. As a result, this represents a loss of emergency assessment capability under NUREG 1022 revision 3 specific to RU 1.2 and RA 1.2. The planned maintenance is expected to last 7 hours. During this time, the site Chemistry Department will perform sampling every thirty minutes per procedure. As a result of the sampling, reasonable assurance exists to monitor and detect rising radiation levels in order to protect the health and safety of the public. The NRC Resident Inspector has been informed. | Service water | |
| ENS 50005 | 7 April 2014 20:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Removal of Radiation Monitors from Service for Planned Maintenance | Both Discharge Canal Radiation Monitor Sample Pumps will be removed from service to facilitate planned maintenance activities. This represents a loss of emergency assessment capability under NUREG-1022 Revision 3 since the Discharge Canal Radiation Monitors are used to assess NUE (Notification of Unusual Event) and Alert thresholds. The Sample Pumps are expected to be unavailable for approximately two hours. During this time, Chemistry will be obtaining samples every 2 hours. As a result of the sampling, reasonable assurance exists that rising radiation levels will be able to be detected and monitored in order to protect the health and safety of the public. The NRC Resident (Inspector) has been notified prior to removing the Radiation Monitors from service. | ||
| ENS 49846 | 21 February 2014 07:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Failed Power Supply Affecting Radiation Monitors | At 0130 CST, a degraded power supply resulted in multiple Area Radiation Monitors (ARMs) reading erroneously low. As a result, this condition is reportable under 10 CFR 50.72(b)(3)(xiii) as these ARMs are used to assess NUE and Alert thresholds. Portable Radiation Monitors have been placed in identified affected areas as a compensatory measure. The health and safety of the public was maintained as the plant was in a normal condition with no initiating event in progress or signs of elevated radiation on any other unaffected radiation monitors. The NRC Resident Inspector has been notified. | ||
| ENS 49820 | 12 February 2014 14:15:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Service Water Radiation Monitor Removed from Service for Planned Maintenance | Planned preventive maintenance on service water piping will remove the service water radiation monitor from service. As a result, this represents a loss of emergency assessment capability under NUREG 1022, Revision 3, since the radiation monitor is used to assess NUE (Notification of Unusual Event) and Alert thresholds. The planned maintenance is expected to last 8 hours. During this time, the site Chemistry Department will perform sampling at this location every 30 minutes. The sampling is documented in a station procedure and allows the ability to detect NUE levels in a timely manner. As a result of sampling, reasonable assurance exists to monitor and detect rising radiation levels in order to protect the health and safety of the public. The NRC Resident Inspector will be notified prior to removing the service water radiation monitor from service. | Service water | |
| ENS 49586 | 27 November 2013 13:40:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Service Water Radiation Monitor Removed from Service | Planned preventative maintenance on service water piping will remove the service water radiation monitor from service. This represents a loss of emergency assessment capability under NUREG-1022, revision 3, specific to RU1.1, RU1.2, RA1.1, and RA1.2. The planned maintenance is expected to last eight hours. The NRC Resident Inspector was notified prior to removing the service water radiation monitor from service. | Service water | |
| ENS 49580 | 26 November 2013 10:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Discharge Canal Radiation Monitor Removed from Service | Planned preventative maintenance on the discharge canal piping will remove the discharge canal radiation monitor from service. This represents a loss of emergency assessment capability under NUREG-1022, revision 3, specific to RU1.1, RU1.2, RA1.1, and RA1.2. The planned maintenance is expected to last 13 hours. The NRC Senior Resident Inspector was notified (by the licensee) prior to removing the discharge canal radiation monitor from service. | ||
| ENS 49390 | 27 September 2013 18:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Assessment Capability Due to Radiation Monitors Out of Service | On 9/27/13, Monticello Nuclear Generating Plant personnel identified that when the Service Water Radiation Monitor or the Discharge Canal Radiation Monitors are removed from service for planned maintenance activities, a loss of emergency assessment capability may occur. The adequacy of compensatory measures for when these radiation monitors are removed from service is under evaluation. The Service Water Radiation Monitor is taken out of service weekly for flushing. This last occurred at 0221 (CDT) on 9/26/13. The Discharge Canal Radiation Monitors are taken out of service approximately once a year for cleaning. The last time these monitors were removed from service was at 1250 (CDT) on 9/18/13. In accordance with 10CFR50.72(b)(3)(3)(xiii) these past occurrences are being reported as a loss of emergency assessment capability. The NRC Resident Inspector has been notified. | Service water | |
| ENS 49388 | 27 September 2013 13:20:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Planned Maintenance | On 9/27/13, Monticello Nuclear Generating Plant's Technical Support Center power supply will be isolated to perform a planned maintenance activity. The maintenance activity may require implementation of compensatory measures to maintain TSC functionality during the activity. The compensatory measures include having the Emergency Director report to the Control Room and co-locating the remaining TSC staff at the EOF should an event be declared requiring ERO activation. The ERO has previously successfully demonstrated the ability to implement these compensatory measures. The maintenance activity is scheduled to be completed with the TSC returned to full functionality by the end of the dayshift on 9/27/13. The Site Emergency Response Organization has been notified of the maintenance activity. The licensee has notified the NRC Resident Inspector.
On 9/27/13, Monticello Nuclear Generating Plant's Technical Support Center power supply was isolated to perform a planned maintenance activity. The maintenance activity required implementation of compensatory measures to maintain TSC functional during the activity. Maintenance activity is completed and TSC is fully functional and returned to service. Site Emergency Response Organization has been notified. The licensee has notified the NRC Resident Inspector. Notified R3DO (Dickson). | ||
| ENS 49048 | 17 May 2013 20:27:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Plant Process Computer Removed from Service for Maintenance and Upgrades | This is a non-emergency 8-hour notification for a planned loss of emergency assessment capability. This event is reportable in accordance with 10CFR50.72(b)(3)(xiii) because the work activities affects the functionality of the Plant Process Computer System. Monticello Nuclear Generating Plant will remove the Plant Process Computer System (PPCS) from service on 5/17/13 at 1527 (CDT) to perform system upgrades and planned maintenance. The PPCS system is planned to be non-functional for less than 4 hours. While the system is out of service, the Emergency Plan can still be implemented as assessment capabilities are available under alternate means and communication of the assessment results using communication equipment. ERDS will be out of service during this period. Compensatory measures for the loss will be implemented. The NRC Resident Inspector has been notified. | ||
| ENS 48618 | 21 December 2012 13:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Response Data System (Erds) | At approximately 0730 CST, Xcel Energy Monticello Nuclear Generating Plant was informed of a loss of internet and data services due to equipment problems with the Wide Area Network (WAN). The loss of data services resulted in the loss of ERDS communication capabilities with the NRC. Compensatory actions were established to communicate plant parameters verbally via the Emergency Notification System, which was verified functional at 0836 CST. The WAN and ERDS were restored at 0921 CST and ERDS was verified functional at 0948 CST. This issue is being reported as a loss of communications capability non-emergency event notification under 10CFR50.72(b)(3)(xiii) as defined in NUREG 1022, Rev. 2. The licensee has notified the NRC Resident Inspector. | Emergency Response Data System | |
| ENS 48378 | 4 October 2012 21:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Primary and Backup Meteorological Towers Out of Service | At 1600 CDT on 10/4/2012, it was determined that the plant backup meteorological tower was not reliable as a source of data and was declared non-functional. At the time of this determination, the primary meteorological tower was out of service for maintenance and was also non-functional. Based on both the primary and backup meteorological towers being non-functional, this is considered a loss of emergency assessment capability. The ability to assess certain Emergency Action Levels (EALs) or perform dose assessment calculations could potentially be hampered by the unavailability of the meteorological monitoring instrumentation. The alternate method per procedure is to contact the National Weather Service for information. The station implemented the alternative method for information gathering. The primary met tower was returned to service at 2011 CDT on 10/4/2012. The licensee has notified the NRC Resident Inspector. | ||
| ENS 48345 | 26 September 2012 13:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center (Tsc) Planned Maintenance Activity | On 9/26/12, the Monticello Nuclear Generating Plant's TSC power supply will be isolated to perform a planned maintenance activity. The maintenance activity requires implementation of compensatory measures to maintain TSC functions during the planned activity. Compensatory measures include having the Emergency Director report to Control Room and relocating the remaining TSC staff at the EOF should an event be declared requiring Emergency Response Organization (ERO) activation. Maintenance activity is scheduled to be complete with the TSC fully functional by end of dayshift on 9/26/12. Site ERO has been notified of maintenance activity and instructed on planned compensatory measures to be implemented during activity if required. This event is considered reportable per 10CFR50.72(b)(3)(xiii). The licensee notified the NRC Resident Inspector. The licensee will notify the Minnesota State Duty Officer, and the Sherriff Departments for both Wright and Sherburne Counties.
At approximately 1520 Central time, a disturbance occurred in the 12.5kV system during restoration activities for the TSC power supply. This would have caused a Major Loss of Emergency Assessment Capability and thus is reportable under 10CFR50.72(b)(3)(xiii). The licensee is investigating the disturbance. The EOF and all other emergency assessment capabilities were verified functional. The licensee notified NRC Resident Inspector. The disturbance to the 12.5kV system did not affect plant operations. Notified R3DO (Lipa). | ||
| ENS 48109 | 16 July 2012 19:03:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Ac Power to Emergency Operations Facility | At approximately 1403 (CDT) on 7/16/12, a loss of AC power (Linn Street substation) occurred affecting emergency response capability of the primary Emergency Operations Facility (EOF). The Technical Support Center (TSC) remained functional throughout the event. The Backup EOF located in Minneapolis, MN was inspected and verified to be functional. In the event of an emergency declaration requiring an EOF, the Emergency Response Organization (ERO) would have been directed to report to the Backup EOF. At approximately 1540 (CDT), the Linn Street substation power was restored. The primary EOF was inspected and declared functional at 1725 (CDT). The NRC Resident Inspectors were notified of this event. | ||
| ENS 47950 | 22 May 2012 22:32:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Fifty-Eight Sirens Were Not Functional in Wright County Minnesota | On May 22, 2012 at 1732 (CDT) Monticello Nuclear Generating Plant (MNGP) was notified by the Wright County siren vendor of an equipment malfunction with the siren activation system. Due to this issue, they are unable to activate any sirens in Wright County. The vendor discovered the issue during the completion of siren work in the county today. The vendor requested the dispatcher to issue a cancel test. The cancel test did not work. The issue is affecting both the primary and back up activation systems. The vendor will be following up until the issue is resolved. 58 sirens are impacted. The vendor anticipates investigation and repairs to be completed this evening. A compensatory measure, route alerting, is in place. The NRC Resident Inspector has been notified. MNGP was notified by the vendor at 2120 (CDT) on 5/22/2012 that the issue had been resolved and the sirens are now functional. The NRC Resident Inspector has been notified. | ||
| ENS 47543 | 21 December 2011 18:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Plant Computer Calculation Incorrect for Back-Up Meteorological Data | During specification review of the computer points for the Monticello Nuclear Generating Plant backup meteorological tower (MET), it was identified by the station that the computer program software for the backup MET had not calculated the correct 15 minute average wind direction in all instances, A review and analysis of the historical data revealed that there were times that this condition existed when the site's primary MET had been out-of-service for maintenance or equipment issues. During those times the backup MET was relied on for determination of wind direction. Analysis determined that during those times the potential existed to incorrectly report affected sectors for Protective Action Recommendations. Currently the station's primary MET has been verified to be in service and functioning properly. The licensee has notified the NRC Resident Inspector. | ||
| ENS 47212 | 29 August 2011 11:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Planned Maintenance Activity | On 8/29/11, Monticello Nuclear Generating Plant's Technical Support Center (TSC) power supply will be isolated to perform a planned maintenance activity. The maintenance activity requires implementation of compensatory measures to maintain TSC functions during the activity. The compensatory measures include having the Emergency Director report to the Control Room and co-locating the remaining TSC staff at the EOF should an event be declared requiring ERO activation. The ERO has successfully previously demonstrated the ability to implement these compensatory measures. The maintenance activity is scheduled to be completed with the TSC returned to full functionality by the end of the dayshift on 8/29/11. The site Emergency Response Organization has been notified of the maintenance activity and instructed on the planned compensatory measures to be implemented during the activity. The licensee has notified the NRC Resident Inspector.
The licensee reports that TSC maintenance activities were completed at 1308 CDT and that the TSC was declared fully operational at 1545 CDT on 8/29/11. The licensee has notified the NRC Resident Inspector. R3DO (Kunowski) notified. | ||
| ENS 46833 | 10 May 2011 14:15:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Assessment Capability | Dose assessment cannot be performed onsite. Pursuant to 10CFR50.72 (b)(3)(xiii), Monticello Nuclear Generating Plant is reporting a planned loss of emergency assessment capability scheduled for 0915 hours on May 10, 2011 for system maintenance. Dose assessment in the control room, TSC, and EOF are non-functional. Main meteorological tower data is unavailable. Projected outage duration is approximately 7 hours. Control room and local instrumentation/annunciation remain available for accident assessment. Telephone lines remain available between site emergency response facilities and offsite agencies for communication of plant status information. Dose assessment capabilities will exist at the backup EOF. Backup meteorological data will be available in the control room, TSC, and EOF. The licensee will not be in any Technical Specification action statements as a result of this evolution. The NRC Resident Inspector has been notified. * * * UPDATE FROM JEFF OLSON TO PETE SNYDER ON 5/10/11 AT 1650 EDT * * * The licensee has restored their dose assessment capability. Notified R3DO (Passehl). | ||
| ENS 46727 | 5 April 2011 19:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Planned Loss of Emergency Assessment Capability for Scheduled Maintenace | Monticello Nuclear Generating Station reported a planned loss of emergency assessment capability for maintenance, at 1430 (CDT) on 04/05/11. Unavailable systems and functions include the Safety Parameter Display System (SPDS), communications between the Process Computer System (PCS) and the Man-Machine Integration Design and Analysis System (MIDAS) computer, and data transfer capability via Emergency Response Data System (ERDS) link to the Nuclear Regulatory Commission (NRC). Projected outage duration is approximately 4 hours. Control Room and local instrumentation, and annunciators remain available for accident assessment. Telephone lines remain available between site emergency response facilities and offsite agencies for communication of plant status information. During this period, MIDAS remains available to perform dose assessment in the manual input mode. The licensee will notify the NRC Resident Inspector and the State Emergency Response Center. | Emergency Response Data System Safety Parameter Display System | |
| ENS 46280 | 25 September 2010 07:57:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Erds, Spds and Tsc Phone Lines Due to Uninteruptable Power Supply Failure | On 9/25/10 at approximately 0237 CDT, the site experienced a loss of the Uninterruptable Power Supply UPS Y91. This resulted in a loss of power to the Safety Parameter Display System (SPDS) and site computer servers which disabled the Emergency Response Data System (ERDS). In addition, in-house Technical Support Center (TSC) telephones were lost (the NRC phone lines in the TSC are still available) rendering the TSC non-functional. The alternate TSC is functional and will be used, if needed, to implement the Emergency Plan (EOF Phones were unaffected). Alternate assessment capability is fully functional and will meet necessary requirements to implement the Emergency Plan. Troubleshooting efforts are underway. This event is reportable under 10 CFR 50.72(b)(3)(xiii). The licensee stated that the Y91 UPS supplies a non-vital 125 volt dc bus and has no safety impact on plant operation and is not subject to any technical specification LCO. The NRC Resident Inspector has been notified. * * * UPDATE FROM MARTIN RAJKOWSKI TO PETE SNYDER AT 1656 ON 9/25/10 * * * All equipment noted as out of service above has been returned to service as of 1541 CDT on 9/25/10. Notified R3DO (Skokowski). | Emergency Response Data System Safety Parameter Display System | |
| ENS 46152 | 6 August 2010 12:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center (Tsc) Planned Maintenance Activity | On 8/6/10 at 0700 CDT the Monticello Nuclear Generating Plant's (MNGP) Technical Support Center uninterruptible power supply will be isolated to perform a planned maintenance activity. The maintenance activity requires implementation of compensatory measures to maintain TSC functions during the activity. The compensatory measures include having the Emergency Director report to the Control Room and co-locating the remaining TSC staff at the EOF should an event be declared requiring ERO activation. The ERO has previously successfully demonstrated the ability to implement these compensatory measures. The maintenance activity is scheduled to be completed with the TSC returned to full functionality by the end of the dayshift on 8/6/10. The Site Emergency Response Organization has been notified of the maintenance activity and instructed on the planned compensatory measures to be implemented during the activity. MNGP will notify the NRC upon completion of the activity restoring full TSC operability. This event is considered reportable per 10CFR50.72(b)(3)(xiii). The licensee has notified the NRC Resident Inspector. The licensee will inform both State and local agencies.
On 8/6/10 at 1705 CDT the Monticello Nuclear Generating Plant's Technical Support Center was returned to full operability. The Monticello Emergency Response Organization has been notified and the compensatory measures that were in effect have been terminated. The licensee has notified the NRC Resident Inspector. The licensee will inform both State and local agencies. Notified R3DO (Stone). | ||
| ENS 46016 | 16 June 2010 15:15:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Sirens | On June 16, 2010, at approximately 1015 hours (CDT), the Monticello Nuclear Generating plant determined that there was a loss of 48 out of 106 Emergency Preparedness sirens. No counties other than Sherburne County were affected. Availability of less than 70% of the total number of sirens is considered to be a loss of emergency off-site response capability and is reportable under 10 CFR 50.72(b)(3)(xiii), 'Loss of Emergency Preparedness Capabilities.' Notification to the public in the event of an emergency has not been compromised since a back-up notification method is provided in the station's Emergency Plan. At this time there is no estimated return to service time for the sirens. The station is working on restoration of the sirens. A follow-up notification of the return to service of the sirens will be provided once the issue is corrected. Sherburne County, the State of Minnesota, and the NRC Resident (Inspectors) have been informed of this event. Updated Information: At 1320 hours on June 16, 2010, sirens have been returned to service. Siren activation capability has been restored via the secondary method of activation. Investigation and repair of the primary method of siren activation continues. | ||
| ENS 45830 | 10 April 2010 13:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Plant Phone System Out of Service for Planned Maintenance | On April 10, 2010, the Monticello Nuclear Generating Plant (MNGP) will be performing planned maintenance to upgrade the site phone system. The maintenance activity will result in the majority of commercial phone lines to the site and the onsite phone system being taken out-of-service for approximately two hours starting at approximately 0800 CDT. The site NRC Emergency Telephone System (ETS), phone lines (which includes ENS, HPN, and ERDS), auto ring lines between the site and the State of MN Emergency Operations Center, onsite radio communication systems, offsite radio communications systems, and the plant Gaitronics system will be unaffected by the maintenance activity. In addition, a commercial phone line in the Control Room and dedicated cellular phone for the Shift Manager will be available for off-site communications. The licensee notified the NRC Resident Inspector and will notify state and local agencies.
On April 10, 2010 at 1030 hours use of the commercial phone lines and the on-site phone system was restored to the Monticello Nuclear Generating Plant (MNGP). Testing activities are in progress/completed to verify the functionality of affected phones. The licensee has notified the NRC Resident Inspector. Notified R3DO (Peterson). | ||
| ENS 45247 | 6 August 2009 11:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Planned Maintenance to Affect Technical Support Center | On 8/6/09 at 0600 hours CDT the Monticello Nuclear Generating Plant's Technical Support Center uninterruptable power supply will be isolated to perform a planned maintenance activity. The maintenance activity requires implementation of compensatory measures to maintain TSC functions during the activity. The compensatory measures include having the Emergency Director report to the Control Room and co-locating the remaining TSC staff at the EOF should an event be declared requiring ERO activation. The ERO has previously successfully demonstrated the ability to implement these compensatory measures. The maintenance activity is scheduled to be completed with the TSC returned to full functionality by the end of the dayshift on 8/6/09. The Site Emergency Response Organization has been notified of the maintenance activity and instructed on the planned compensatory measures to be implemented during the activity. MNGP will notify the NRC upon completion of the activity restoring full TSC operability. This event is considered reportable per 10CFR50.72(b)(3)(iii). The licensee has notified the NRC Resident Inspector. * * * UPDATE FROM D. BARNETT TO P. SNYDER AT 1943 ON 8/6/09 * * * On 8/6/09 at 1700 CDT the Monticello Nuclear Generating Plant's Technical Support Center was returned to service and declared functional. The Monticello Emergency Response Organization has been notified and the compensatory measures that were in effect have been terminated. The licensee has notified the NRC Resident Inspector. Notified R3DO (Skokowski). | ||
| ENS 44797 | 22 January 2009 15:30:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Phone Communications | At approximately 0930 CST on 01/22/2009, the Monticello Nuclear Generating Plant became aware of a loss of ENS, HPN, and ERDS lines as well as a partial loss of in-coming commercial lines. Cell phone communications were not affected. The NRC Operations Center was contacted, and a back-up means of communication was established. The back-up communication methods to off-site State and Local agencies remained available. The ENS communications were conducted via commercial phone lines or a cell phone line to the NRC Operations Center. The NRC Resident Inspector, NRC Region III, NRC Operations Center, State and local government agencies were notified. At 1300, all communications were re-established. At 1455 communication capabilities in the Control Room, Shift Managers Office, TSC, and EOF were verified to be operating properly. Communications were lost due to a problem at the local telephone company office, and not due to any on-site equipment issues. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii). | ||
| ENS 43847 | 17 December 2007 08:03:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Assessment Capability (Spds) | At 0203 CST, the plant experienced a loss of the Safety Parameter Display System (SPDS) and other computer systems used for emergency assessment in the Control Room, Technical Support Center (TSC) and Emergency Operating Facility. This capability was fully restored at 0600 CST. The cause of the loss was an electrical fault in an intercom box in the TSC. The licensee will notify the NRC Resident Inspector. | Safety Parameter Display System | |
| ENS 43788 | 16 November 2007 17:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Degredation of Emergency Preparedness Response Capabilities | At approximately 1100 CST on Friday November 16, 2007, Monticello Nuclear Generating Plant determined that there had been a degradation of the Emergency Preparedness response capabilities when the Emergency Response Data System, Offsite Dose Projection (MIDAS), Safety Data Parameter System, selected telephones, and site computer terminals became inoperable in the Technical Support Center (TSC). The loss of these systems is associated with a partial loss of power to the TSC. As a result of these conditions, the TSC was declared non-functional. Emergency Communications remain available with the Emergency Telecommunication System, and Health Physics Network being operable. Monticello 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 systems. Plant page and radio systems remain operable. Adequate communications capabilities are operable at this time to implement the emergency plan. The site's Emergency Operations Facility (EOF), which is the back-up facility for the TSC, is fully operational and measures are being implemented to direct TSC personnel to the near site EOF in the event of an actual emergency condition. The station has informed Wright and Sherburne counties and the Minnesota State Duty Officer of this condition. Troubleshooting efforts are in progress. A return to service time for all systems is to be determined. Monticello 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 notified the NRC Resident Inspector. * * * UPDATE FROM K. HAUGEN TO P. SNYDER AT 1253 ON 11/17/07 * * * The TSC has been restored to an operable configuration. The licensee notified the NRC Resident Inspector. Notified R3DO (Passehl). | Emergency Response Data System | |
| ENS 43492 | 17 July 2007 12:00:00 | 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Technical Support Center Inoperable Due to Planned Relocation | On 07/17/07 at 0700 hours CDT the Monticello Nuclear Generating Plant's (MNGP) Technical Support Center (TSC) will begin relocation to a new facility. The relocation activities include implementation of compensatory measures to maintain the TSC functions during the transition. The compensatory measures include having the Emergency Director report to the Control Room and co-locating the remaining TSC staff at the EOF should an event declared requiring Emergency Response Organization (ERO) activation. The ERO has previously successfully demonstrated the ability to implement these compensatory measures. The relocation and testing of equipment in the new TSC are scheduled to be complete(d) on or before 07/23/07. The site Emergency Response Organization has been notified of the relocation and instructed on the planned compensatory measures to be implemented during the move. MNGP will notify the NRC upon completion of the relocation and declaration of TSC operability in the new location. This event is considered reportable per 10 CFR 50.72 (b)(3)(xiii). The licensee has notified the NRC Resident Inspector.
On 07/19/07 at 1400 hours CDT the Monticello Nuclear Generating Plant's Technical Support Center (TSC) was declared operable after its relocation to a new facility. Relocation and testing activities have been completed and the Emergency Response Organization has been notified of the cessation of compensatory measures. NRC R3DO (Eric Duncan) notified. The licensee has notified the NRC Resident Inspector. |