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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 50870 | 7 March 2015 17:55:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Declared Inoperable Due to Containment Fan Coil Leak | At 1155 CST on March 7, 2015, a small cooling water leak was identified on the 21 Containment Fan Coil Unit east face u-bend on the north east corner bottom bundle. Unit 2 Containment was declared inoperable, which required entry into Technical Specifications (TS) LCO 3.6.1, Condition A, Containment inoperable, applicable in MODES 1, 2, 3, and 4. Immediate actions were taken to isolate the Fan Coil Unit within 1 hour from the initial identification of the leak. 21 Containment Fan Coil Unit was isolated, Containment was declared operable and TS 3.6.1 Condition A was exited at 1220 CST on 3/7/15. This condition is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. The plant remains in a safe condition and there was no effect to the health and safety of the public. The licensee has notified the NRC Resident Inspector. | 05000306/LER-2015-001 | |
| ENS 50808 | 11 February 2015 04:05:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Declared Inoperable Due to Containment Fan Coil Leak | At 2205 CST on February 10, 2015, a cooling water leak of approximately 60 to 90 drops per minute was identified on the 14 Containment Fan Coil Unit Cooling Water face gasket. As a result, Unit 1 Containment was declared inoperable. This required entry into Technical Specifications (TS) LCO 3.6.1 Condition A, Containment inoperable, applicable in MODES 1, 2, 3, and 4. Immediate action was taken to isolate the fan coil unit within 1 hour from the initial identification of the leak. After isolating the cooling water leak to 14 Containment Fan Coil Unit, containment was declared operable and TS 3.6.1 Condition A was exited at 2232 CST. A Work Request (WR) has been initiated to restore 14 Containment Fan Coil Unit to an operable condition. This condition is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. The plant remains in a safe condition and there was no effect to the health and safety of the public. The licensee has notified the NRC Resident Inspector. | ||
| ENS 50630 | 20 November 2014 16:22:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Declared Inoperable Due to Containment Fan Coil Leak | At 1022 CST on November 20, 2014, a cooling water leak of approximately 20 to 30 drops per minute was identified on the 14 Containment Fan Coil Unit NW side lower face gasket. Unit 1 Containment was declared inoperable, which required entry into Technical Specifications (TS) LCO 3.6.1 Condition A, containment inoperable, applicable in MODES 1, 2, 3, and 4. Immediate actions were taken to isolate the Fan Coil Unit within 1 hour from the initial identification of the leak. 14 Containment Fan Coil Unit was isolated and Containment was declared operable and TS 3.6.1 Condition A was exited at 1109 CST. A Work Request (WR) was initiated and 14 Containment Fan Coil Unit has been restored to an operable condition. This condition is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. The plant remains in a safe condition and there was no effect to the health and safety of the public. The licensee has notified the NRC Resident Inspector. The licensee verified the other Unit 1 Containment Fan Coil Units did not have the same problem. | ||
| ENS 50123 | 19 May 2014 17:36:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Containment Declared Inoperable Due to Containment Fan Coil Leak | At approximately 1236 CDT on May 19, 2014, a cooling water leak was identified on 23 Containment Fan Coil Unit flange. Unit 2 Containment was declared inoperable, which required entry into Technical Specifications (TS) LCO 3.6.1 Condition A, Containment inoperable, in MODES 1, 2, 3, and 4. Immediate actions were taken to isolate the Fan Coil Unit and was isolated within 1 hour from the initial identification of the leak and TS 3.6.1 Condition A was exited. This restored Containment to an Operable status. A Work Request (WR) was initiated to repair the leak, and to restore the 23 Containment Fan Coil Unit to an operable condition. This condition is reportable under 10 CFR 50.72(b)(3)(v)(C), Event or Condition that Could Have Prevented Fulfillment of a Safety Function. The plant remains safe, and this condition does not pose any additional risk to the public. Additionally, our defense in depth strategies are relied upon to take actions to protect the health and safety of the public. The licensee has notified the NRC Resident Inspector. | ||
| ENS 50004 | 7 April 2014 11:00:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Control Room Special Vent Boundary Inoperable | At approximately 0600 CDT on April 7, 2014, Units 1 and 2 Control Room Special Vent System (CRSVS) Boundary was declared inoperable when a Control Room door handle fell off. Air could be felt flowing through the hole, causing an opening in the Control Room Envelope (CRE) Boundary. An opening reduces the protection of the Control Room Envelope provided to the operators in the event of a Design Basis Accident. The CRSVS Boundary was declared Inoperable, which required entry into Technical Specifications (TS) LCO 3.7.10. Condition B, one or more CRSVS trains inoperable, in MODES 1, 2, 3, or 4. Actions were immediately initiated to implement mitigating actions. A Work Request (WR) was initiated to repair the door, and work is in progress to restore the Control Room Boundary to an operable condition. This condition is reportable under 10CFR50.72(b)(3)(v)(C), Event or Condition that Could Have Prevented Fulfillment of a Safety Function. The plant remains safe, and this condition does not pose any additional risk to the public. Additionally, our defense in depth strategies are relied upon to take actions to protect the health and safety of the public. The licensee has notified the NRC Resident Inspector."
Engineering evaluation has determined that the door would still fulfill its safety function of maintaining the integrity of the Control Room Envelope while the door handle was broken. The Control Room Special Vent System Boundary remained operable with the door handle off, therefore, there was no loss of safety function. The licensee has notified the NRC Resident Inspector." Notified R3DO (Riemer). | Control Room Envelope | |
| ENS 49495 | 1 November 2013 17:06:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Trains of Auxiliary Building Special Ventilation System Declared Inoperable | During Unit 2 refueling outage (currently defueled) preventative maintenance on CV-31117, Loop B Main Steam Isolation Valve (MSIV), an opening in the valve was discovered without direct administrative controls to ensure the opening could be closed within 6 minutes following a Loss of Coolant Accident on Unit 1. Addition of this opening to other openings created a total of greater than 10 square feet of non-closable openings and required declaring the Auxiliary Building Special Ventilation System (ABSVS) boundary inoperable. The inoperable ABSVS boundary caused both trains of ABSVS to be declared inoperable and required entry into Technical Specification (TS) 3.7.12, Condition B. This could have prevented the ability to control the release of radioactive material and is considered a potential loss of safety function per 10CFR50.72(b)(3)(v)(C). Administrative controls in the ABSVS Boundary were re-established by installing a closure device in the opening on CV-31117 at 1246 CDT. The ABSVS boundary and both trains of ABSVS were declared operable at that time. During the time that the ventilation system was out of service, no evolutions were in progress that could have resulted in an unmonitored release.
After further evaluation, the non-closable boundary openings for the Auxiliary Building Special Ventilation Zone (ABSVZ) including CV-31117, Loop B Main Steam Isolation Valve (MSIV), at the time of discovery is calculated to be 9.48 square feet. This is below the 10 square feet required in TS 3.7.12, thus both trains of ABSVS were operable and no loss of safety function existed. The licensee has notified the NRC Resident Inspector. Notified the R3DO (Cameron). | Main Steam Isolation Valve | |
| ENS 49261 | 10 August 2013 01:28:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Inoperable Control Room Envelope | In 2010, Control Room Envelope testing was conducted to satisfy SR 3.7.10.5 (this surveillance testing is required each 6 years). At that time, as a prerequisite, the surveillance procedure contained a step to add water to two floor drain loop seals that penetrated the Control Room Envelope; this practice was determined to be unacceptable preconditioning. Because the 2010 surveillance test was the first performance of this surveillance, the unacceptable preconditioning resulted in the following: a never-performed surveillance, failure to meet the associated surveillance requirement, and an inoperable Control Room Envelope. At 2028 CDT the station entered LCO 3.7.10, Condition B. The station has taken action to periodically add water to the loop seals; this practice validates the loop seals will remain full of water. This action ensures, through Engineering judgment, that the loop seals will perform their function and the Control Room Envelope will provide adequate protection to the plant operators. The NRC Resident Inspector was notified. The floor drains are located inside the control room envelope near the control room chillers. Prior to this report, filling the loop seal was performed sporadically. The loop seal is now filled daily. * * * UPDATE FROM STEVEN SKOYEN TO PETE SNYDER AT 2019 EDT ON 9/10/13 * * * On 9/10/13, the Tracer Gas Test of Control Room failed to meet its acceptance criteria for the surveillance test. The failure was due to three (3) doors with minor seal leaks and/or test uncertainty. The station is evaluating door repairs and test uncertainty. The actions for the test failure to offset the consequences of the inoperable Control Room Envelope have been modified to protect the operators with the use of SCBA's and Potassium Iodine (KI) in the event of a DBA. The NRC Resident Inspector was notified. The R3DO (Lipa) was notified. | Control Room Envelope | |
| ENS 48870 | 31 March 2013 04:44:00 | 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Both Trains of Auxiliary Building Special Ventilation System Declared Inoperable | During testing of the Auxiliary Building Ventilation System it was discovered that the outlet damper of one of the normal make-up fans did not close. This created a non-closable opening in the Auxiliary Bldg Special Vent System (ABSVS) boundary of greater than 10 square feet and required entry into TS (Technical Specification) 3.7.12, Condition B, for two ABSVS trains inoperable due to inoperable ABSVS boundary. This is considered a potential loss of safety function to control the release of material. The licensee has notified the NRC Resident Inspector. * * * RETRACTION FROM MARK LOOSBROCK TO PETE SNYDER ON 5/13/13 AT 1639 EDT * * * This notification is being made to retract Event Notification (EN) #48870, which reported a non-closeable opening in the Auxiliary Building Special Vent System (ABSVS) boundary of greater than 10 square feet. This required entry into TS 3.7.12 Condition B for two ABSVS trains inoperable due to an inoperable ABSVS boundary. This was considered a potential loss of safety function to control the release of radioactive material. Engineering evaluation and analysis identified that there was not a loss of safety function because the ABSVS started on demand during the performance of SP 1172 and that the ABSVS Boundary never exceeded the Tech Spec value of 10 square feet per TS 3.7.12. Review of the work order for CD-34042 validated that the system would have performed its safety function during the failure of CD-34042. In the event of a Design Basis Accident the ABSVS would have received a signal to actuate, the system would have performed as designed and drawn a negative differential pressure in the Aux Bldg within 6 minutes with the identified opening of 9.62 square feet that was observed during the failure of CD-34042. The licensee notified the NRC Resident Inspector. Notified R3DO (Riemer). |