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| Entered date | Event description | |
|---|---|---|
| ENS 55311 | 16 June 2021 23:41:00 | On June 16, 2021, at 1550 EDT, Palisades Nuclear Plant was operating in Mode 1 at 100% power. At that time, operations identified an acrid odor in the control room. Investigation revealed that the steam dump control relay had failed, rendering all four atmospheric steam dump valves inoperable. The loss of function of all four atmospheric steam dump valves is reportable in accordance with 10 CFR 50.72(b)(3)(v)(D) as 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 mitigate the consequences of an accident. Troubleshooting and replacement of the relay are in progress. The plant remains stable in Mode 1 at 100% power. The NRC Resident Inspector has been notified. Unit 1 is in a 24 hour LCO for Tech Spec 3.7.4.b, atmospheric steam dump valve inoperability. The Unit is in a normal offsite power line-up. |
| ENS 54867 | 31 August 2020 08:28:00 | A contract employee supervisor had a confirmed positive for alcohol during a fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector. |
| ENS 50907 | 19 March 2015 16:44:00 | On February 26, 2015, as a result of routine monitoring well sampling, Palisades Nuclear Plant identified tritium in temporary wells 7 and 8, located within the plant protected area. Tritium concentrations were less than the threshold value (20,000 pCi/L) for initiating voluntary communications in accordance with Nuclear Energy Institute Ground Water Protection Initiative. The station promptly isolated and rerouted the likely source. Subsequent sample concentrations from samples obtained on March 18, 2015, have resulted in concentrations of tritium less than the minimum detectable activity. The wells are currently used only for on-site sampling and not for drinking water. There is no threat to public health and safety. These results confirm that a leak from the pipe that runs from the turbine sump oil separator to the turbine building drain tank was the likely cause. The volume of the leak cannot be determined but is potentially greater than 100 gallons. Therefore, voluntary communications have been made to state and local stakeholders. The Licensee has notified the Michigan Department of Environmental Quality, Van Buren County Administrator, the Township Supervisors in Covert, Geneva, and South Haven Townships, as well as the City of South Haven Mayor and City Manager. The licensee has notified the NRC Resident Inspectors. The tritium is suspected to be migrating through the steam generator tubes to the turbine building waste water. |
| ENS 49796 | 5 February 2014 16:17:00 | On February 5, 2014, during planned inspections, an ultrasonic examination performed on weld PCS-6-PRS-1C1-1 (RV-1041) revealed two axial indications in the root area of the weld. The weld containing the indications is the nozzle to safe end dissimilar metal weld on the flange for pressurizer safety valve RV-1041. These two indications do not meet applicable acceptance criteria under ASME, Section XI, IWB-3600, 'Analytical Evaluation of Flaws,' or ASME Section Xl, Table IWB-3410, 'Acceptance Standards,' and will require a repair or replacement activity in order return the weld to an acceptable condition. The plant was in cold shutdown at 0% power for a planned refueling outage at the time of discovery. Replacement or repair actions will be completed prior to plant startup from the outage. This condition has no impact to the health and safety of the public. The licensee notified the NRC Senior Resident Inspector. This report is being made in accordance with 10 CFR 50.72(b)(3)(ii)(A), since indications were found that did not meet acceptance criteria referenced in ASME Code, Section XI. |
| ENS 44385 | 5 August 2008 22:27:00 | On August 5, 2008, a planned shutdown was in progress to repair a control rod drive mechanism due to excessive leakage (within Tech Spec identified leakage limits). During the shutdown, the site experienced excessive unidentified leakage of approximately four gallons per minute for short periods following charging pump starts, due to leakage past the letdown relief valve. (this first occurred at 1629) As a result of the plant shutdown, and not being in a steady state condition, PCS leakage is unable to be definitively determined. Limiting Condition of Operation 3.4.13 was entered at 1629 hrs. The plant was in Mode 3 at 1955 hrs. The Tech Spec requirement is to restore leakage to within limits within 4 hours. If not within limits within 4 hours, be in Mode 3 within 6 hours (August 6, 2008 at 0229 hours) and be in Mode 5 within 36 hours (August 7, 2008 at 0829 hrs). This event is being reported as a 4-hour non-emergency report in accordance with 10 CFR 50.72(b)(2)(i), Tech Spec required shutdown. The licensee will notify the NRC Resident Inspector. |
| ENS 42317 | 7 February 2006 14:46:00 | This report is being made in accordance with 10 CFR 50.73(a)(1), which states in part, 'in the case of an invalid actuation reported under 10 CFR 50.73(a)(2)(iv), other than the reactor protection system (RPS) when the reactor is critical, the licensee may, at its option, provide a telephone notification to the NRC Operations Center within 60 days after discovery of the event instead of submitting a written LER. On December 14, 2005, at 0616 hours EST, a failure of the left channel load sequencer resulted in an invalid actuation of components associated with the left channel design basis accident (DBA) sequencer. Components in the emergency core cooling system were among the components actuated. Therefore, this event constitutes a partial actuation of the emergency core cooling system, which is reportable under 10 CFR 50.73(a)(2)(iv)(A). All components actuated by the event functioned satisfactorily as would be expected for this equipment failure and operating status of the plant at the time of the event. The licensee notified the NRC Resident Inspector. |
| ENS 41263 | 15 December 2004 09:36:00 | On November 4, 2004, at 0917 hours EST, an inadvertent actuation of the left train of the safety injection system was initiated. The invalid actuation occurred during a system surveillance test, when a screwdriver that was being used to lift a lead slipped, causing a short circuit between the terminal being disconnected, and an energized terminal directly in front of it. As a result, all left train safety injection system equipment activated as expected for existing plant conditions. The resident inspector was notified of this event. |