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| Entered date | Event description | |
|---|---|---|
| ENS 49002 | 5 May 2013 01:45:00 | At 0112 EDT on May 5, 2013, the plant commenced a shutdown due to water leakage from the SIRW (Safety Injection Refueling Water) Tank exceeding the operational decision-making issue process trigger point of 34 gallons per day, causing it (the SIRW) to be declared inoperable and requiring entry into Technical Specification LCO 3.5.4 Condition B. LCO 3.5.4 Condition B requires the SIRW Tank to be returned to Operable status within one hour or entry into Condition C which requires the plant to be in Mode 3 within 6 hours and Mode 5 within 36 hours. This event had no impact on the health and / or safety of the public. The NRC Resident has been notified. The exact location of the leakage has not been determined at this time. The Plant will be taken to Mode 5. The licensee has been operating with SIRW leakage at a rate of less than 34 gallons per day. The leakage has increased for unknown reasons to a calculated value of approximately 90 gallons per day. See EN #48018 dated 06/12/12 for similar report on a technical specification shutdown for the SIRW tank leakage. |
| ENS 48478 | 4 November 2012 14:52:00 | At 1115 EST on November 4, 2012, primary coolant loop #2 was declared inoperable due to a small un-isolable steam leak on a drain valve of an atmospheric steam dump valve on the secondary side of the 'B' Steam Generator. The valve is ASME Class II high energy piping and the non-conforming condition could not be evaluated with the steam generator pressurized. Based on the condition of the valve and the inability to evaluate, Technical Specification 3.4.4, PCS loops - Modes 1 and 2, Required Action A.1 was entered which requires the plant to be placed in Mode 3 in 6 hours. Repair of the valve may require cooldown to Mode 5. At 1230 EST on November, 2012, Palisades initiated a shutdown in accordance with Technical Specification 3.4.4. The licensee has notified the NRC Resident Inspector. |
| ENS 48182 | 12 August 2012 11:05:00 | Following a planned shutdown to investigate the source of elevated Primary Coolant System (PCS) Unidentified Leakage, the Mode 3 PCS walk-down identified a steam leak on CRD-24, Control Rod Drive Mechanism (CRD), pressure housing. The leak is ~ 1 foot above the CRD to Reactor Head flange. The leak was observed from the Refueling floor deck and appears to be coming from an area of the CRD with no bolted connections. Leakage from this area is unexpected and the mechanism of failure is not understood at this time. Closer examination of the leak is expected to occur in parallel with plant cool-down. The plant entered T.S. 3.4.14 (PCS Operational Leakage) Condition B. at 0418 EDT hours this morning and this requires the plant to be placed in Mode 5 within 36 hours. The leakage is considered Pressure Boundary Leakage. Operations is in progress of performing the plant cool-down from Mode 3 to Mode 5. The licensee discovered this condition following a shutdown the morning of 8/12/12 to investigate unidentified primary coolant leakage of about 0.3 gpm that had been recently trending upwards. Plant conditions are currently 400 degrees F with primary system pressure at about 1000 psi. The licensee has notified the NRC Resident Inspect |
| ENS 43832 | 10 December 2007 22:21:00 | Five new ground water monitoring wells were recently installed at Palisades Nuclear Plant in support of the Nuclear Energy institute (NEI) ground water initiative. The initial sampling of one of these wells displayed a level of tritium that triggered the communication protocol of the NEI initiative on ground water protection. On December 10, 2007, at 1830 hours, Entergy confirmed that the tritium concentration for this well was 22,000 picoCuries per liter (pCi/l). The threshold for initiating the communication protocol is 20,000 pCi/l (Offsite Dose Calculation Manual limit for drinking water). This well is located inside the owner controlled area and inside the protected area. This well is not a drinking water source. Entergy is continuing to investigate the source of tritium identified in this well. Samples from the remaining four wells are below minimum detectable activity levels. There is no indication that tritium has migrated off the Palisades site. The licensee plans to notify the State of Michigan, Van Buren County Office of Domestic Preparedness, City of South Haven, Covert Township, and the South Haven Charter Township. The licensee has notified the NRC Resident Inspector. |
| ENS 43351 | 8 May 2007 15:23:00 | On May 8, 2007 at 1322 hours, the reactor automatically tripped from approximately 100% power due to low level in the 'B' Steam Generator. The low level condition resulted from spurious closure of the 'B' feedwater regulating valve. The feedwater regulating valve closure appears related to an instrument and control troubleshooting work activity that was in progress at the time of the event. Investigation into the cause is continuing. In additions an automatic actuation of the auxiliary feedwater system occurred, as designed, to restore steam generator levels. All systems functioned as designed. Decay heat is being removed via steaming through the turbine bypass valve to the main condenser. All control rods fully inserted. The licensee informed the NRC Resident Inspector. |