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| Entered date | Event description | |
|---|---|---|
| ENS 48937 | 17 April 2013 05:20:00 | The Perry Nuclear Power Plant is reporting an event or condition pursuant to 10 CFR 50.72(b)(3)(v)(D). On April 16, 2013, at 2323 EDT, it was identified that Emergency Service Water (ESW) pump 'A' was inoperable due to an inability to maintain minimum flow requirements. As a result, ESW 'A' and the supported Division 1 Emergency Diesel Generator (EDG) were declared inoperable. Coincident with this discovery, a test of the Division 2 emergency systems was in progress with the associated ESW 'B' pump and Division 2 EDG inoperable. Division 2 EDG was available to support the Shutdown Defense In-Depth Strategy. Division 3 EDG was operable and could supply High Pressure Core Spray system injection, if needed. Both EDGs were inoperable simultaneously and Technical Specification 3.8.2 'AC Sources-Shutdown' was entered and required actions taken. These actions included immediately suspending core alterations and immediately initiating actions to restore the required EDG. The test of Division 2 emergency systems was suspended and ESW 'B' and the Division 2 EDG were restored to operable status at 0135 EDT on April 17, 2013. The failure of ESW 'A' minimum flow is currently under investigation. The Resident Inspector has been notified.
Engineering personnel performed an immediate investigation of the ESW 'A' minimum flow condition. The investigation results showed that the ESW 'A' pump flow exceeded the minimum flow requirement to protect the ESW 'A' system. Therefore, continued operation of ESW 'A' was acceptable and the minimum flow condition originally reported did not cause the Division 1 Emergency Diesel Generator to be inoperable. The condition would not have prevented the fulfillment of a safety function to mitigate the consequences of an accident. Reporting is not required under 10 CFR 50.72(b)(3)(v)(D) and this notification is retracted. The NRC Resident Inspector has been notified. Notified R3DO (Orth). |
| ENS 48415 | 17 October 2012 07:40:00 | At approximately 0800 hours EDT on October 17, 2012, computer engineering personnel will be taking the plant integrated computer system (ICS) out-of-service for planned maintenance. During the time ICS is out-of-service, the Safety Parameter Display System (SPDS) and the Emergency Response Data System (ERDS) will be unavailable. The computer outage is scheduled for twelve hours. In the event of an emergency, plant parameter data will be communicated to the facilities through the Status Board Ring Down circuit with back-up by the Private Branch Exchange, Off Premise Exchange, and various redundant intra-facility circuits throughout the emergency facilities. The dose assessment function will be maintained during the out-of-service time period by manual input of data into the Meteorological Information and Dose Assessment System (MIDAS). The ability to open and maintain an 'open line' using the Emergency Notification System will not be affected and will be the primary means of transferring plant data to the NRC as a contingency until the ERDS can be returned to service. This event is being reported in accordance with 10 CFR 50.72(b)(3)(xiii). A follow-up notification will be made when the maintenance activities are complete and the equipment is restored. The (NRC) Resident Inspector has been notified.
As of 2140 EDT on 10/17/12, the ERDS system was tested and restored to service. The licensee notified the NRC Resident Inspector. Notified the R3DO (Orth). |
| ENS 47901 | 6 May 2012 20:53:00 | This event is being reported in accordance with 10 CFR 50.72(b)(2)(xi). On May 6, 2012, during daily chlorination activities, it was identified that the National Pollutant Discharge Elimination System (NPDES) permit limit for Total Residual Chlorine was exceeded between approximately 0935 hours (EDT) and 0947 hours (EDT) when the noncompliance was corrected. The maximum measured value was 0.29 mg/L, which exceeded the NPDES Maximum Concentration Limit of 0.2 mg/L. On May 6, 2012, at approximately 1930 hours (EDT), a 'Noncompliance Notification for Exceedance of a Daily Maximum Discharge Limit' was made to the Ohio Environmental Protection Agency. The cause of the NPDES permit noncompliance is under investigation. Chlorination evolutions have been suspended pending investigation results. At the time of the event, the plant was in Mode 1 at 100 percent rated thermal power. This event is also being reported in accordance with the plant's operating license, appendix B, Environmental Protection Plan, which states, in part, that any occurrence of an unusual or important event that indicates or could result in environmental impact causally related to plant operation shall be recorded and reported to the NRC within 24 hours followed by a written report. The licensee notified the NRC Resident Inspector. |
| ENS 47024 | 5 July 2011 20:35:00 | On July 5, 2011, at 1815 hours, it was determined that a design deficiency at the Perry Nuclear Power Plant (PNPP) constituted a fire protection program concern which could adversely affect the ability to achieve and maintain safe shutdown of the plant in the event of a control room fire. (Reference event notification numbers 46811 and 46997). In the event of a postulated control room fire, the potential exists that two 4160 VAC breakers could trip open under a hot-short condition. PNPP's Appendix R design vulnerability only affects Breakers EH1106, which supplies the Emergency Service Water Pump A and EH1107, which supplies the Control Complex Chiller A. Specifically, the current transformers used in these breakers for the 50/51 instantaneous and time over current protective relays are in line with the component control room ammeters. Therefore, a hot-short-to-ground in the associated control room ammeters could actuate the 50/51 relays and trip the component breaker. Actions are in progress to isolate the control room ammeters for the Emergency Service Water Pump A in breaker EH1106 and the Control Complex Chiller A in breaker EH1107. Isolating these ammeters would isolate the affected circuitry from the described Appendix R failure mechanism. Control room amperage indication for the pump and chiller would be lost while this Temporary Modification is installed. PNPP will pursue a permanent resolution to the hot-short-to-ground fault for the EH1106 and EH1107 breakers. This event is being reported in accordance with 10 CFR 50.72(b)(3)(ii)(B), as a condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety. A follow-up licensee event report will be made in 60 days. The resident inspector has been notified. |
| ENS 46370 | 28 October 2010 07:59:00 | Beginning at approximately 0800 hours EDT on October 28, 2010, Perry Plant personnel will be taking the plant Integrated Computer System (ICS) out of service for planned maintenance. During the time ICS is out of service, the Safety Parameter Display System (SPDS), the Emergency Response Data System (ERDS), and the automatic mode calculation of the Computer Aided Dose Assessment Program (CADAP) will be unavailable. The computer outage is scheduled for six hours. In the event of an emergency, plant parameter data will be orally transmitted to the facilities through the Status Board Ring Down circuit with back-up (using) the Private Branch Exchange, Off-Premise Exchange, and various redundant intra-facility circuits throughout the emergency facilities. The dose assessment function will be maintained during the out of service time period by manual input of data into CADAP and, if required, by manual calculation. The ability to open and maintain an 'open line' using the Emergency Notification System will not be affected and will be the primary means of transferring plant data to the NRC as a contingency until the ERDS can be returned to service during the period of unavailability. This event is being reported in accordance with 10 CFR 50.72(b)(3)(xiii), as a condition that results in a major loss of offsite communications capability. A follow-up notification will be made when the maintenance activities are completed and the equipment is restored. The NRC Resident Inspector has been notified.
At 1100 EDT, the plant ICS has been returned to service and functioning normally. The NRC Resident Inspector has been informed. Notified R3DO (Skokowski). |