Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 57002 | 1 March 2024 19:45:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Inadvertent Siren Activation | The following information was provided by the licensee via email: At 1330 CST, on March 1, 2024, an equipment vendor was coordinating with Wright County performing maintenance on an emergency siren when the county operator mistakenly sent an alarm signal instead of cancel signal, activating all Wright County emergency sirens for approximately 17 seconds. At 1345 CST, the Monticello Nuclear Generating Plant (MNGP) emergency planning coordinator received a notification from the vendor and notified the duty shift manager (of the inadvertent activation). Wright County officials are planning to make a public notification via social media to local residents. No press release by the licensee is planned at this time. This event is reportable per 10 CFR 50.72(b)(2)(xi), 'News Release or Notification of Other Government Agencies.' This is a 4-hour Reporting requirement. The NRC Resident has been notified. | ||
| ENS 56535 | 22 May 2023 23:38:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Notification to Another Government Agency | The following information was provided by the licensee via phone and fax: On 5/22/23, Xcel Energy performed a notification to the state of Minnesota Duty Officer, in accordance with Minnesota Statute 115.061, regarding 300-600 gallons of pumped ground water that overflowed from a holding tank and returned to the ground area from which it was pumped. The groundwater being pumped is related to recovery activities associated with the event reported on November 22, 2022 (EN 56236). This notification is being made solely as a four-hour, non-emergency report for notification to other government agency. An update is being provided to the Monticello community and published on Xcel Energy's website. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact on the health and safety of public or plant personnel. The NRC Resident Inspector has been notified. | ||
| ENS 56236 | 22 November 2022 21:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Notification of Environmental Report to Another Government Agency | The following information was provided by the licensee via email: On 11/22/2022, Monticello Nuclear Generating Plant initiated a voluntary communication to the State of Minnesota after receiving analysis results for an on-site monitoring well that indicated tritium activity above the (Offsite Dose Calculation Manual) ODCM and Nuclear Energy Institute (NEI) Groundwater Protection Initiative (GPI) reporting levels. The source of the tritium is under investigation and the station will continue to monitor and sample accordingly. This notification is being made solely as a four-hour, non-emergency report for a Notification of Other Government Agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. | ||
| ENS 54938 | 8 October 2020 16:25:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notification of an Unusual Event | At 1125 CDT on 10/8/20 Monticello Nuclear Generating Plant declared a Notification of an Unusual Event (NOUE) due to a Security Condition that did not involve a hostile action, due to a helicopter that hovered over the site for approximately 10 minutes. The unit remained at 100 percent power during the event. The licensee notified the NRC Resident Inspector, the Minnesota State Duty Officer and the Wright County and Sherburne County Sherriff departments of the event. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At 1715 CDT Monticello Nuclear Generating Plant terminated the Notice of Unusual Event (HU1.1), upon confirmation through federal law enforcement and conversation with the aircraft owner that the aircraft in question was performing power line inspections for a different utility and was not a threat to the plant. Monticello determined that this condition did not meet the 1-hour reporting requirements of 10 CFR 73.71. Notified R3DO (Orlikowski), NRR EO (Miller), and IRD MOC (Gott). Additionally, notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
Monticello Nuclear Generating Plant (MNGP) is retracting this event notification based on subsequent information received that was not available at the time of the original notification. Following review of the additional information collected by the site through an investigation performed with input from local and federal law enforcement, Xcel Energy determined the helicopter did not constitute a credible threat or compromise site safety or security. There was no impact to public health or safety. The NRC Resident Inspector has been notified. The licensee will notify the State and county. Notified R3DO (Peterson). | ||
| ENS 52715 | 28 April 2017 21:43:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification for Release of Wastewater | This report is being made pursuant to 10 CFR 50.72(b)(2)(xi), as an event where notification to other government agencies has been made. On April 28, 2017, notification to the Minnesota State Duty Office was made due to a non-compliance with release of wastewater requirements in the Monticello Nuclear Generating Plant's National Pollutant Discharge Elimination System permit. There were no consequences to the health and safety of the public. The licensee notified the NRC Resident Inspector. | ||
| ENS 52156 | 5 August 2016 15:14:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Drinking Water Exceeding Limits | On 8/5/2016 at 1014 (CDT), the Monticello Nuclear Generating Plant (MNGP) was notified by the Minnesota Department of Health (MDH) of a notice of violation for exceeding the drinking water limit for carbon tetrachloride in the drinking water well that supplies the Security Access Facility. Additionally the MDH will be notifying the Minnesota Pollution Control Agency regarding the violation. As a result, this issue is being reported under 10CFR50.72(b)(2)(xi) for notifications to other offsite government agencies. There was no impact to the health and safety of the general public as a result of this issue. The drinking fountains in the Security Access Facility have been isolated. The NRC Resident Inspector has been notified. | ||
| ENS 52020 | 18 June 2016 07:59:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Spurious Emergency Siren Activation | On 6/18/16 at approximately 0259 CDT, the Monticello Nuclear Generating Plant was notified by the Wright County Sheriffs Office of a spurious actuation of one emergency siren in the city of Monticello. As a result, this issue is being reported under 10CFR50.72(b)(2)(xi) for notifications to other off site government agencies as the licensee was notified by the Wright County Sheriff's Office. The source of the siren activation has not been determined. Wright County Sheriff's Office successfully deactivated the siren at 0322 CDT. There was no impact to the health and safety of the public as a result of this event as the offsite response capabilities remain functional with a single siren failure. The site is operating normally with no emergency conditions present. The NRC Resident Inspector has been notified. The licensee will notify the State of Minnesota concerning this event. | ||
| ENS 51566 | 24 November 2015 18:53:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification for a Discharge Canal Temperature Change Causing a Fish Kill | At 1253 CST on 11/24/2015, XCEL Energy Environmental Services made a report to the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Natural Resources (DNR) due to the recorded total fish loss (59) as a result of the Monticello Plant's discharge canal temperature change following the reactor scram on 11/23/2015. This notification is being made under 10 CFR 50.72(b)(2)(xi) based on a notification to another government agency. This issue has no safety significance and no impact on the health and safety of the general public. NRC Resident Inspector has been notified. | ||
| ENS 51306 | 10 August 2015 20:35:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Inadvertent Activation of a Single Emergency Siren | On August 10, 2015, at approximately 1555 CDT, the licensee was notified that emergency siren S-07 in Sherburne County, MN had inadvertently activated from approximately 1525-1538 CDT. The cause of the activation is under investigation. The siren vendor (NELCOM) was also contacted and made the notification to the licensee. As a result, this issue is being reported under 10CFR50.72(b)(2)(xi) for notifications to other offsite government agencies as the licensee was notified by the Sherburne County Sherriff's Office. The source of the activation signal has not been determined. The vendor is investigating. The siren is no longer actuating. There was no impact to the health and safety of the public as a result of this event as the offsite response capabilities remain functional with a failure of only 1 out of 106 total sirens. The site is operating normally with no emergency present. (The) NRC Resident Inspector has been notified. The licensee will notify the State. | ||
| ENS 51241 | 20 July 2015 13:55:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Spurious Actuation of Emergency Siren | On 7/20/2015 at approximately 0931 CDT, the Monticello nuclear generating plant was notified by Wright County Sheriffs Office of a spurious actuation of one emergency response siren in the city of Monticello that occurred at approximately 0855 CDT (lasted for approximately three minutes). This actuation was confirmed by vendor system monitoring. As a result, this issue is being reported under 10 CFR 50.72(b)(2)(xi) for notifications to other offsite government agencies as the licensee was notified by the Wright County Sheriffs Office. The source of the activation signal has not been determined. The vendor is investigating. The siren is no longer actuating. There was no impact to the health and safety of the public as a result of this event as the offsite response capabilities remain functional with a single siren failure. The site is operating normally with no emergency conditions present. The NRC Resident Inspector has been notified. The State of Minnesota will be notified. | ||
| ENS 50052 | 23 April 2014 15:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Deceased Migratory Bird Found on Plant Property | Monticello Nuclear Generating Plant personnel discovered the remains of a deceased migratory bird on plant property. The cause of death was not immediately apparent and no work was ongoing in the vicinity at the time the bird was found. Notifications to the United States Fish and Wildlife Service will be made for this discovery. This event is being reported per 10CFR50.72(b)(2)(xi). The licensee has informed the NRC Resident Inspector. | ||
| ENS 50049 | 22 April 2014 19:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Deceased Migratory Bird Found on Plant Property | Monticello Nuclear Generating Plant personnel discovered the remains of a deceased migratory bird on plant property. The cause of death was not immediately apparent, no work was ongoing in the vicinity at the time the bird was found. Notifications to the Minnesota Department of Natural Resources and the Division of Fish and Wildlife will be made for this discovery. This event is being reported per 10CFR50.72(b)(2)(xi). The NRC Resident Inspector will be informed. | ||
| ENS 50026 | 11 April 2014 02:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to a Dead Duck Found on Site | Monticello Nuclear Generating Plant personnel discovered the remains of what appeared to be a deceased duck on plant property. The cause of death was not immediately apparent, no work was ongoing within the vicinity at the time. Notifications to the Minnesota Department of Natural Resources and the Division of Fish and Wildlife will be made for this discovery. This event is reported per 10CFR50.72(b)(2)(xi). The licensee has notified the NRC Senior Resident Inspector. Plant personnel could not determine if the duck was an endangered species. | ||
| ENS 49876 | 5 March 2014 21:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 72.75(b)(2), Offsite Notification | Offsite Notification Due to Dry Shielded Canister Test Results | This report is being made to provide information to the NRC regarding Monticello Dry Shielded Canister (DSC)-16. On February 17, 2014, dye penetrant examinations were performed on the outer top cover plate (OTCP) to shell weld on dry shielded canister (DSC)-16. This was a re-examination of a linear indication identified on January 24, 2014. The results of the re-examination identified a 1.6 inch linear indication that remained after surface conditioning. This indication had not been previously detected by nonconforming nondestructive examination previously reported by TriVis Inc. Xcel Energy is evaluating the condition and will remedy prior to moving the cask to the ISFSI (Independent Spent Fuel Storage Installation) pad. The associated DSCs loaded during the current campaign successfully passed their helium leak tests. Helium leak checks are performed to demonstrate confinement and boundary integrity. Thus, public health and safety is not affected. Since the licensee communication plan also notified other government agencies, this report is being made pursuant to 10CFR50.72(b)(2)(xi) and 72.75(b)(2). The above referenced dry shielded canister is currently located on the refuel floor in the reactor building. The licensee notified the NRC Resident Inspector. | ||
| ENS 49741 | 18 January 2014 09:38:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Discharge Canal Temperature Drop | At 0338 CST, Xcel Energy Environmental Services made a report to the State of Minnesota due to cooling water return to the Mississippi River via the plant's discharge canal dropping by more than 5 deg F per hour. The cause of the temperature drop was due to a required time limited reactor shut down. The reactor is currently shut down with all systems responding as expected. This notification is being made under 10 CFR 50.72(b)(2)(xi) based on a notification to another government agency. The NRC Resident Inspector has been notified
At 1130 EST on 1/20/2014, XCEL Energy Environmental Services made a report to the State of Minnesota (Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources) due to the recorded total fish loss (207) as a result of the Monticello Plant's discharge canal temperature change per above. This is an update notification only and has no safety significance and no impact on the health and safety of the general public. The licensee notified the NRC Resident Inspector. Notified the R3DO (Skokowski). | ||
| ENS 49714 | 11 January 2014 07:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Decreasing Discharge Temperature | At 0205 CST (on 1/11/14), Xcel Energy Environmental Services made a report to the State of Minnesota due to cooling water return to the Mississippi River via the plants discharge canal dropping by more than 5 degrees F in an hour. The cause of the temperature drop was due to an emergent reduction in reactor power and generator load in response to a degrading condenser vacuum. This notification is being made under 10 CFR 50.72(b)(2)(xi) based on a notification to another Government Agency. The NRC Resident Inspector has been notified. | ||
| ENS 49181 | 8 July 2013 22:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Sodium Hypochlorite Spill | On July 8th, 2013, at approximately 1730 CDT, the Minnesota State Duty Officer was notified of an approximately 50 gallon sodium hypochlorite spill onsite. The spill has been contained and clean-up is in progress. There was no actual or potential impact on the environment and no impact on the health and safety of the public or onsite personnel. The licensee will also be notifying Wright County. The NRC Resident Inspector has been informed. | ||
| ENS 49010 | 8 May 2013 11:23:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Emergency Siren Spurious Actuation | On 5/8/2013 at 0623 (CDT) MNGP was informed by Wright County Sheriffs Department of a spurious actuation of one emergency response siren in Wright County (for about 2 seconds). This activation was confirmed by vendor system monitoring. The source of the activation has not been determined. At this time all aspects of the public notification system are functional. The licensee notified the NRC Resident Inspector and will notify the state and local governments. | ||
| ENS 48805 | 4 March 2013 15:27:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to a Fish Kill | At 0927 CST on March 4, 2012, XCEL Energy Environmental Services made a report to the State of Minnesota regarding 475 fish killed from the discharge canal temperature transient following reactor shutdown on March 2, 2013. Monticello was in the process of performing a planned shutdown in preparation for a refueling outage. The NRC Resident Inspector, Wright County Sheriffs Department and Sherburne County Sheriffs Department have been notified by the licensee. | ||
| ENS 48754 | 14 February 2013 23:10:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Release of Amertap Balls Into the Mississippi River | On 2/14/2013, Xcel Energy personnel determined that approximately 44% of the Amertap balls recently used were not recovered. Monticello Nuclear Generating Plant is required to report to the Minnesota Pollution Control Agency (MPCA) when greater than 20% of the Amertap balls are not recovered. This is based on an agreement with the MPCA dated September 12, 2008. The MPCA was notified at 1710 CST on 2/14/2013. The licensee has notified the NRC Resident Inspector.
Update for 50.72 non-emergency notification number 48754: The referenced report number was made at 1831 EST on 2/14/2013. This report stated the Minnesota Pollution Control Agency (MPCA) was notified that 44% of Amertap balls recently used were not recovered at 1710 CST on 2/14/2013. Due to a miscommunication between the Monticello Nuclear Generating Plant Chemistry Department and the Xcel Energy Corporate Environmental Services contractor, the actual MPCA notification was not made until 0930 CST on 2/15/2013. This update report is to ensure the correct time of the MPCA notification was documented. The licensee notified the NRC Resident Inspector. Notified R3DO (Pelke). | ||
| ENS 48681 | 18 January 2013 18:40:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Pans System False Activation of 58 Sirens | There was a false activation signal applied for 3 seconds to site emergency sirens. The licensee notified the State of Minnesota and local government agencies. The licensee will notify the NRC Resident Inspector. | ||
| ENS 48343 | 25 September 2012 20:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Hydraulic Leak | On September 25, 2012 at 1055 CDT, a road grader developed a hydraulic leak on a steering hose. This resulted in a light mist of approximately 20 gallons of oil being sprayed for a quarter mile. Three hundred feet of that was on gravel and the rest on blacktop. There is no actual or potential impact to the environment. There is no impact to plant operation. At 1500 CDT, (the licensee was) notified by Xcel Energy Environmental Services that the State has been notified. The licensee has notified the NRC Resident Inspector. | ||
| ENS 47948 | 22 May 2012 22:13:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Loss of Amertap Balls | On May 22, 2012 it was determined that more than 20% (3 of 8 barrels) of the Amertap balls used for condenser cleaning on May 18, 2012 were not able to be recovered by normal means. Observers were stationed at the discharge structure during the process and it is not believed that balls were released to the river. The current agreement with the Minnesota Pollution Control Agency dated September 12, 2008, requires XCEL Energy to make a report to the MPCA whenever more than 20% (1.5 barrels or approximately 7,500 balls) of the Amertap balls are not recovered. The MPCA was notified May 22, 2012. Approximately, 15,000 Amertap balls have not been recovered by the normal strainer system and may be in the discharge canal. The licensee is investigating the cause of the event. The NRC Resident Inspector, Wright County Sheriffs Department, and Sherburne County Sheriffs Department have been notified. | ||
| ENS 47782 | 28 March 2012 21:48:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification of Potential Release of Amertap Balls to Mississippi | On 3/28/2012, Xcel Energy Personnel determined that approximately 50% of the Amertap balls recently used were not recovered. A survey of the Mississippi River bank downstream of the plant by site personnel recovered an additional 3 Amertap balls, indicating that the balls were not released to the river. Monticello Nuclear Generating Plant (MNGP) is required to report to the Minnesota Pollution Control Agency (MPCA) when greater than 20% (1 .5 barrels or approximately 7,500) of the Amertap balls are not recovered. This is based on an agreement with the MPCA dated September 12, 2008. The MPCA was notified at 1648 CDT on 3/28/12. The NRC Resident Inspector has been notified. | ||
| ENS 47725 | 8 March 2012 15:54:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Notification of the Minnesota Pollution Control Agency for Release of Amertap Balls | At 0954 on 3/8/12 Xcel Energy notified the Minnesota Pollution Control Agency of an Amertap ball release exceeding 1.5 barrels per agreement. Three barrels of Amertap balls are unaccounted for. Plant operational personnel are inspecting the site water system for unaccounted Amertap balls. A survey of the river performed by personnel only produced 4 of the missing balls. The licensee notified the NRC Resident Inspector. | ||
| ENS 47664 | 15 February 2012 14:25:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Inadvertent Manual Siren Activation | At 0825 CDT on 2/15/2012, the Monticello Nuclear Power Generating Plant (MNGP) received a report from the Sherburne County Sheriff Dispatcher that there had been an inadvertent manual initiation of Emergency Preparedness sirens in the county while performing siren testing. All plant conditions/parameters are normal. A total of 48 emergency sirens were on for approximately one minute before being secured. All sirens are currently functional. Sherburne County and the site NRC Resident Inspector have been notified The licensee also notified the Wright County offices. | ||
| ENS 47464 | 21 November 2011 22:06:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Fish Kill | At 1606 Central Standard Time, Xcel Energy Environmental Services made a report to the State of MN regarding 190 fish killed from the discharge canal temperature transient during the reactor scram on 11/20/11. The report was made verbally with a follow-up email message detailing the species of fish killed. This is a notification being made under 50.72(b)(2)(xi) as an event related to the environment for which notification to other government agencies have or will be made. The licensee has notified the NRC Resident Inspector and the State and will notify local authorities of this event. | ||
| ENS 47460 | 20 November 2011 05:12:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | Automatic Reactor Scram While Performing Turbine Bypass Valve Testing | While performing a regularly scheduled Turbine Bypass Valve surveillance, prior to Turbine Bypass Valve movement, a 'B' half scram (signal) was received. Operators immediately suspended testing. Approximately 10 seconds later, a full Reactor Protection System actuation occurred. Following the reactor scram, reactor water level lowered below the Group II isolation initiation setpoint of +9 inches, (resulting in containment valve isolations). There were no radioactive releases associated with this event. No other alarms were received prior to the RPS actuation. The cause of the reactor scram is under investigation at this time. Also, due to the reactor scram, discharge canal temperature rate of change exceeded plant requirements. As a result, the State of Minnesota, and appropriate local agencies will be notified. All control rods inserted and the scram is considered uncomplicated. The plant is in a normal shutdown electrical configuration. The licensee notified the NRC Resident Inspector. | Reactor Protection System Control Rod | |
| ENS 47364 | 21 October 2011 17:50:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | Automatic Reactor Scram Due to Lockout of Auxiliary Power Transformer | The station experienced a lockout of the 2R Auxiliary Power Transformer. The resulting transient caused an automatic actuation of the RPS system. All control rods fully inserted. A Group 2 Primary Containment isolation occurred. Both 11 and 12 Emergency Diesel Generators started on a loss of voltage signal. Equipment response was that the 11 ESW (Emergency Service Water) pump (cooling for the #11 Emergency Diesel) failed to develop required pressure. The #13-4160V non-safety related bus failed to restore after the transient (and feed the Division 1 Essential Bus). Additionally, the #15 bus transferred to the 1AR transformer (and is feeding the Essential Bus). The #11 Emergency Diesel Generator is currently tagged out of service. Electrical supply is being provided by offsite power. Reactor heat is being removed through the main steam line to the main condenser and reactor water inventory is being provided by the feedwater system. The SRVs lifted and reseated. The HPCI system was manually place into a pressure control mode. The Minnesota Pollution Control Agency is being notified due to the licensee violating the site discharge canal temperature rate of change limit. The licensee notified the NRC Resident Inspector.
Prior to this event the 'B' Control Room Emergency Filtration (CREF) and 'B' Control Room Ventilation (CRV) Systems were inoperable for planned maintenance. On 10-21-11 at 1325 CDT, the #11 EDG ESW Pump was declared inoperable due to low cooling water pump flow, resulting in the #11 EDG being inoperable, which in turn resulted in the 'A' CREF and 'A' CRV being inoperable. Contrary to reporting requirements this condition was not identified and reported pursuant to 10 CFR 50.72(b)(3)(v)(D) as required within 8-hours in the previous event notification. This condition resulted in a loss of safety function for both divisions of CREF and CRV. This update amends the 10-21-11 event notification to include this as an 8-hour non-emergency event pursuant to 10 CFR 50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector. Notified the R3DO (Nick Valos) | Feedwater Emergency Diesel Generator Primary containment Main Steam Line Main Condenser Control Rod | |
| ENS 46657 | 5 March 2011 16:45:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Related to Fish Kill | At 1045 the Monticello Nuclear Generating Plant (MNGP) control room was notified by an Xcel Energy environmental specialist that a fish kill count was conducted on the morning of 3/5/11 following reactor shutdown. In accordance with the MNGP water appropriations permit for fish kill in the Mississippi river, the environmental specialist will be notifying the State of Minnesota Department of Natural Resources and Minnesota Pollution Control Agency. Notifications made to above government agencies meet the reporting criteria established in 10CFR50.72(b)(2)(xi) as an event or situation related to the protection of the environment for which a notification to government agencies has been or will be made. Total fish kill was determined to be approximately 100 fish downstream of the plant's discharge canal. Fish kill was the result of cooldown of water being discharged to the river from the plant's discharge canal. All temperature limits specified in the plant's water appropriation permit were met throughout the shutdown. There was no release of any chemical or radioactive materials to the environment. The licensee has notified the NRC Resident Inspector and will be notifying appropriate state and local authorities. | ||
| ENS 46407 | 9 November 2010 17:39:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification - Violation of the Discharge Permit | The Minnesota Pollution Control Agency was notified (on 11/9/10) at 1139 hours (CST) today that at Monticello, the Circulating Water and Service Water Streams were simultaneously chlorinated for a duration of approximately one (1) hour. Simultaneous chlorination of these two water streams is a violation of the National Pollutant Discharge Elimination System (NPDES) Permit. Chapter 4, Section 2.3, states, 'The condenser cooling water and the service water shall not be chlorinated simultaneously.' Upon discovery of this event, both the Service Water and the Circulating Water bleach injection skids were secured. This event did not result in bleach discharge concentration in excess of the 0.038 ppm concentration set forth in the NPDES permit. The licensee notified NRC Resident Inspector. | Service water | |
| ENS 46113 | 21 July 2010 13:16:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Inadvertent Manual Initiation of Emergency Alert Sirens | At 0816 (CDT) on 7/21/2010, the Monticello Nuclear Power Generating Plant (MNGP) received a report from the Sherburne County Sheriff Dispatcher that there had been an inadvertent manual initiation of Emergency Preparedness sirens in the county while performing siren testing. All plant conditions/parameters are normal. A total of 48 emergency sirens were on for approximately 1 minute before being secured. The inadvertent initiation of the sirens was determined to be reportable under 10 CFR 50.72(b)(2)(xi), 'News Release or Notification of Other Government Agency.' Sherburne County, the State of Minnesota, and the site NRC Resident Inspector have been notified. | ||
| ENS 46023 | 17 June 2010 15:45:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Inadvertent Initiation of Emergency Preparedness Sirens | At 1045 (CDT) on 6/17/2010, the Monticello Nuclear Power Generating Plant (MNGP) received a report from the Sherburne County Sheriff Dispatcher that there had been an inadvertent manual initiation of Emergency Preparedness sirens in the county while performing siren testing in preparation for inclement weather anticipated later this evening. All plant conditions/parameters are normal. A total of 48 emergency sirens were on for approximately 1 minute before being secured. The inadvertent initiation of the sirens was determined to be reportable under 10 CFR 50.72(b)(2)(xi), 'News Release or Notification of Other Government Agency.' Sherburne County, the State of Minnesota, and the site NRC Resident Inspector have been notified. | ||
| ENS 45338 | 10 September 2009 14:13:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | State Offsite Notification Due to Not Meeting Permit Requirements | The Minnesota State Pollution Control Agency and State Department of Emergency Management were notified today, September 10, 2009, that Monticello did not meet the National Pollutant Discharge Elimination System (NPDES) Permit. Samples from a new monitoring well near the reactor building showed low levels of tritium greater than normal background but below Environmental Protection Agency drinking water standards. The concentration of tritium is below any radiological reporting levels established in station procedures. No elevated levels have been detected in any of the other permanent plant monitoring wells. Therefore, we have no indications that there has been a release of tritium beyond the site from this source. The station will continue to monitor, sample and investigate the source of the tritium. The licensee notified the NRC Resident Inspector.
A subsequent water sample from a new monitoring well near the reactor building indicated a level of 21,300 picocuries/liter of tritium which is slightly above the Environmental Protection Agency drinking water standard for tritium of 20,000 picocuries/liter. No elevated levels have been detected in any of the other permanent plant monitoring wells. Therefore, (the licensee has) no indication that there has been a release of tritium beyond the site from this source. The station will continue to monitor, sample and investigate the source of the tritium. This poses no immediate safety concern for plant employees or the general public. The licensee notified the NRC Resident Inspector. Notified the R3DO (Ring). | ||
| ENS 44907 | 16 March 2009 14:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Fish Kill During Routine Shutdown | The licensee notified state and local authorities of a fish kill that occurred during a routine plant shutdown for refueling. The fish kill, in the Mississippi River, was monitored for a two day period. Notifications were made to the State of Minnesota Emergency Management Agency, Wright County Sheriff's Office, and Sherburne County Sheriff's Office. The licensee has notified the NRC Resident Inspector. | ||
| ENS 44633 | 6 November 2008 17:15:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification of a Discharge to the Mississippi River | On November 6, 2008 at 11:15, Operations was notified that results of an October 20, 2008 oil and grease weekly sample from a plant sump discharge to the Mississippi River exceeded the National Pollution Discharge Elimination System (NPDES) daily maximum allowable value of 15ppm. The October monthly average oil and grease NPDES of 10ppm was also exceeded. The Minnesota Pollution Control Agency is being notified. The licensee notified the NRC Resident Inspector. | ||
| ENS 44498 | 17 September 2008 15:17:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(a)(1)(i), Emergency Class Declaration 10 CFR 50.72(b)(3)(iv)(A), System Actuation | Unusual Event Due to Loss of Shutdown Cooling | Monticello lost the 1R offsite power transformer due to an industrial accident that grounded the bus and resulted in a fatality of an employee onsite. At the time of this event, the 2R offsite transformer was already out of service due to a previous event (see EN #44484). This effectively resulted in a loss of all normal offsite power. The 1AR safety related offsite power source remained available and the safety related buses are energized and diesels are available. However, shutdown cooling was lost during the event due to a Group 2 isolation and cannot be restored. The shutdown cooling suction isolation valves #2020 and #2030 have power but until the Group 2 logic can be reset the valves cannot be reopened. The licensee needs to repower the RPS bus to reset the logic. Based on the uncertainty in reestablishing shutdown cooling an Unusual Event was declared based on Emergency Director judgment (EAL HU5.1). Current reactor coolant temperature is approximately 110 degrees with a heatup rate of about 20 degrees an hour. State and local authorities and the NRC resident inspector have been notified. The licensee will likely be making a press release.
On Wednesday, September 17, 2008 Monticello Nuclear Generating Plant (MNGP) experienced a loss of power to the station transformer resulting in a valid actuation of the following systems: Reactor Protection System (with the reactor shutdown), Containment Isolation, and Emergency Diesel Generators. The cause of the loss of power was due to contact of a 115kV transmission line by a manlift. A vendor employee was electrocuted. On-site Medical Emergency Response personnel responded until the individual was transported to North Memorial Medical Center. The individual was pronounced dead at North Memorial Medical Center. Notifications of offsite agencies and a media press release are in progress. 'This notification is being made in accordance 10CFR50.72(b)(2)(xi) and 10CFR50.72(b)(3)(iv)(A).' Licensee notified the NRC Resident Inspector." Notified R3IRC (Garza)
This is a follow-up to Event notification #44498. The station has completed notifications to off-site agencies and to the media. The station continues to troubleshoot and restore plant equipment and respond to media inquiries. NUE update - As of 1113 CDT shutdown cooling was restored." Notified R3 IRC.
Monticello Nuclear Generating Plant exited their Notification of Unusual Event at 1100 CDT on 9/21/08. The exit criteria is supported on the following information: (1) This event did not result in the loss or potential loss of a fission product barrier and did not change the status of the current fuel condition. All three fission barriers are intact and were maintained throughout the event. (2) There were no radiation releases as a result of the event. (3) Restoration of plant loads including shutdown cooling onto a normal offsite power source (the 1R transformer) has been completed. (4) The 1R transformer offsite power source was recovered and is being protected. Protection of the 1R transformer will continue until availability of the other offsite power source supplied from the 2RS/2R transformers has been restored. (5) Shutdown cooling is in service. (6) The site organization challenges in response to the injury event and loss of decay heat removal are no longer present. The licensee has notified the NRC Resident Inspector, as well as state and local agencies. A media release will be issued. Notified R3DO (Stone), NRR EO (Galloway), IRD MOC (Clark), OPA (Burnell), DHS (S. Moore), and FEMA (D. Fuller). | Reactor Protection System Emergency Diesel Generator Shutdown Cooling Decay Heat Removal | 05000263/LER-2008-007 |
| ENS 43174 | 20 February 2007 14:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite State Notification Required by Npdes Permit | Notification to NRC following notification to the following government agencies on 02/20/2007 at 0830 (CST): State of Minnesota Pollution Control Agency - Water Control Quality, State of Minnesota Department of Emergency Management - State Duty Officer. Notifications made to above government agencies in accordance with Monticello NPDES permit for a collapse of cooling tower panels which resulted in a diversion of circulating flow overland to the discharge canal, resulting in washing of soil and gravel into the canal. The licensee informed the NRC Resident Inspector. | ||
| ENS 43114 | 23 January 2007 19:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Press Release Issued | The purpose of this notification is to inform the NRC that Nuclear Management Company (NMC) will be issuing a press release approximately two hours (CST) after this notification to the NRC on January 23, 2007, concerning an event previously reported to the NRC on January 10, 2007, via EN# 43088. The event in question involved an automatic reactor scram at 3:26 PM on January 10, 2007. As reported in that notification, all safety systems operated correctly. The scram occurred following the unexpected opening of the main turbine control valves. There was no release of radioactivity during the event. The purpose of the press release is to provide information to the media and the public regarding the results of NMC's investigation as to the cause of the January 10 event and the status of remedial actions. The licensee notified the NRC Resident Inspector. The licensee will notify State and Local authorities. | ||
| ENS 43095 | 11 January 2007 23:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification to State Agencies | Notification to NRC following notification to the following government agencies: State of Minnesota Pollution Control Agency State of Minnesota Dept of Natural Resources Enforcement State of Minnesota Dept of Natural Resources Area Fisheries Office State of Minnesota Dept of Natural Resources Local Conservation Office Notifications made to above government agencies in accordance with Monticello Nuclear Plant water appropriations permit for fish kill in Mississippi river following Rx scram on 1-10-07. The licensee will notify the NRC Resident Inspector. | ||
| ENS 40518 | 13 February 2004 13:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Loss of Offsite Communications | At 0730, Monticello Nuclear Generating Plant became aware of the loss of incoming phone call capability. Investigation determined loss of ENS, HPN (FTS) lines were inoperable as well as the State of MN dedicated line. Commercial incoming calls (inoperable) out calls were operable. By 0930 CST all phone system were restored and determined operable. NRC Operations Center was notified of inoperable ENS phone via backup commercial line. NRC Resident Inspector was notified of this by the licensee. |