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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 55955 | 22 June 2022 02:40:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Control Room Ventilation and Control Area Chilled Water System Inoperable | The following information was provided by the licensee via email: At 2240 on 06/21/2022, it was discovered that both required trains of Control Room Ventilation and Control Area Chilled Water System were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(v)(d). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The 'B' train was restored at 2315. | ||
| ENS 53160 | 10 January 2018 00:28:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Both Trains of Containment Air Return Fans Inoperable | During normal power operations at 100 percent power on Unit 2, both trains of Containment Air Return Fans (CARF) were declared inoperable at 19:28 (EST) on January 9, 2018 due to a common issue with control power fuses. The fuses potentially could not handle the in-rush current upon re-energizing the circuits. This condition resulted in a loss of a reasonable expectation that the Unit 2 Containment Air Return Fans would meet their design safety function and mitigate an accident. This loss of safety function is reportable under 10CFR50.72(b)(3)(v)(D), 8 hour report. The site entered T.S. 3.0.3 at 19:28 and exited at 20:54 when repairs to 2B CARF were completed. 2A CARF repairs are complete. There was no impact on the health and safety of the public or plant personnel. The senior NRC Resident Inspector has been notified. The licensee verified this problem does not affect unit-1.
A subsequent evaluation determined that the fuses for the Containment Air Return Fans (CARFs) would be able to perform their safety function and were operable at the time of discovery. The limiting safety condition for the fuses is the return to power following a Loss of Offsite Power (LOOP). The evaluation determined that the fuses would satisfy their safety function upon re-energizing the circuits if a LOOP occurred and would not impact the ability of the CARFs to perform their safety function. The subject fuses were replaced on January 9, 2018." The Licensee notified the NRC Senior Resident Inspector. Notified the R2DO (Musser). | ||
| ENS 46557 | 20 January 2011 16:10:00 | 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Technical Specification Required Shutdown | The 1B and 2B trains of Nuclear Service Water Systems (Raw Water Nuclear RN) were declared inoperable on 1/18/11 at 0423 EST due to fouling of the respective suction strainers when aligned to the Standby Nuclear Service Water Pond (SNSWP). Tech. Spec. 3.0.3 was entered at 1110 EST on 1/20/11 due to the lack of reasonable assurance of operability pertaining to 1A and 2A RN trains in the event of a potential realignment to the SNSWP due to a seismic event. The licensee plans to reduce power and place both Units in Mode 5. Unit 1 has been reduced to 90% and Unit 2 is holding at 100% and will begin reducing power later. The fouling is being caused by fish being sucked into the RN train suction strainers. The licensee has been back-flushing the strainers to clear the fouling. The pond was chemically treated approximately 1 year ago to eliminate the fish. The licensee notified the NRC Resident Inspector.
McGuire Units 1 & 2 entered Technical Specification 3.0.3 with a requirement to be in Mode 5 in 37 hours. A Notification of Enforcement Discretion was verbally approved by the Nuclear Regulatory Commission on 1/20/11 at 2336 EST, therefore both Unit 1 & 2 will remain in Mode 3. The licensee notified the NRC Resident Inspector. Notified R2DO (Sykes), NRR EO (Thomas), and IRD MOC (Gott)
This is an amendment to Event Notification #46557 to include the following 8 hour non-emergency notifications previously omitted by the NRC from the event report: 50.72(b)(3)(v)(A) POT UNABLE TO SAFE S/D 50.72(b)(3)(v)(B) POT RHR INOP 50.72(b)(3)(v)(D) ACCIDENT MITIGATION The licensee will notify the NRC Resident Inspector. | Service water |