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On November 22, 2017, at 2043 (CST), Unit I MCC (Motor Control Center) 18/19-5 overvoltage relay target was found actuated and would not reset. MCC 18/19-5 was powered from the normal feed, Bus 19. Bus 19 voltages were verified to be normal. The overvoltage relay actuation would result in MCC 18/19-5 being de-energized in the event of a DBA LOCA (Design Basis Accident Loss of Coolant Accident) in which the 1/2 Emergency Diesel Generator fails to energize Bus 18, therefore rendering both divisions of the Low Pressure Cooling Injection (LPCI) mode of Residual Heat Removal (RHR) system inoperable. Technical Specification 3.5.1 Condition E was entered, requiring restoration of LPCI in 72 hours. The overvoltage target was subsequently able to be reset at 2114 (CST), restoring the LPCI function of RHR. Technical Specification 3.5.1 Condition E was exited at that time. This event is reportable under 10 CFR 50.72(b)(3)(v)(D) as an event or condition that could have prevented fulfillment of a safety function. The licensee notified the NRC Resident Inspector.

• * * RETRACTION FROM RONALD SNOOK TO STEVEN VITTO ON 01/11/18 AT 1913 EST * * *

The purpose of this notification today (01/11/18) is to retract the ENS Report made on November 23, 2017 at 0248 hours EST (ENS Report #53089). Upon further review, it was determined that the Unit 1 MCC 18/19-5 overvoltage relay target that was found actuated and would initially not reset was caused only by intermittent degraded DC control power. During this event, MCC 18/19-5 remained powered from the normal feed Bus 19, and Bus 19 voltages were verified to be normal. It was further determined from plant drawings that under this condition the degraded DC control power to the Unit 1 MCC 18/19-5 overvoltage relay has no impact to the Technical Specification 3.5.1 required capability to auto transfer power from the normal Bus 19 to the alternate Bus 18 should Bus 19 lose power such as during a DBA LOCA. This overvoltage relay was installed in the early 1990's only to support enhanced reliability of the power supply to the LPCI injection valves, and its actuation due to degraded DC control power would not impact the ability to auto transfer to alternate Bus 18. Therefore, both divisions of the Low Pressure Cooling Injection (LPCI) mode of Residual Heat Removal (RHR) system would have remained fully operable under the as-found relay condition, and Technical Specification 3.5.1 Condition E was not required to be entered. On December 6, 2017, it was determined that a loose fuse clip terminal had caused the DC control power to the overvoltage relay to become degraded which in turn caused the relay target and its reset to become erratic. This fuse clip terminal was repaired on December 6, 2017. Based on the subsequent reviews of this event, the LPCI system was not required to be declared inoperable in accordance with Technical Specifications 3.5.1 during the period of the MCC 18/19-5 overvoltage relay actuation (i.e., 31 minutes on 11/22/17), and hence was not required to be reported under 10CFR 50.72(b)(3)(v)(D) as an event or condition that could have prevented fulfillment of a safety function. Therefore, based on this information, ENS Report #53089 is being retracted. The NRC Resident Inspector has been notified. R3DO(Jeffers) has been notified.

On October 31, 2016, at 0239 hours (CDT), a defect (minor audible through-wall leak) was identified on the steam line drain valve 1-2301-55, HPCI Steam Line Drain Line Steam Trap Outlet Valve. The defect was identified by Operations personnel traversing through the HPCI room as part of normal rounds. HPCI was declared inoperable under Tech Specs 3.5.1, Condition G. The Reactor Core Isolation Cooling (RCIC) system was verified operable. HPCI remains available (but not operable). The leak has been isolated. The 1-2301-55 is a manual valve downstream of the HPCI steam line drain trap. In a standby line-up, this line drains condensation from the HPCI steam supply line to the main condenser. During operation in an accident scenario, this line drains condensation from the HPCI steam supply line to the Torus via a drain pot. The location of the defect is in class 2 safety related piping. HPCI is a single train safety system and this notification is being made in accordance with 10CFR50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified. Technical Specification 3.5.1, condition G requires that HPCI be Operable within 14 days.

• * * RETRACTION ON 12/05/2016 AT 1505 EST FROM MARK BRIDGES TO STEVEN VITTO * * *

The purpose of this notification is to retract the ENS Report made on October 31, 2016, at 0239 hours CDT (ENS Report #52334). Upon further investigation, a pinhole through-wall leak was discovered in the body of the 1-2301-55 valve (HPCI Steam Line Drain Line Steam Trap Outlet Valve). The defect was characterized as a 1/32-inch rounded hole due to a manufacturing defect in the casting located on the downstream side of the valve near the piping connection. A subsequent evaluation performed by Quad Cities Station considering the defect size, location, and characterization, confirmed the Unit 1 High Pressure Coolant Injection (HPCI) system would have performed its safety function when required. Based on this subsequent evaluation, ENS Report 52334 is being retracted. Note: On November 1, 2016, at 1624 hours CDT, the 1-2301-55 valve (HPCI Steam Line Drain Line Steam Trap Outlet Valve) was successfully repaired and HPCI was returned to Operable status. The NRC Resident Inspector has been notified. Notified R3DO (Stone).

At 0723 (CST) hours on January 15, 2014, the 2A Drywell Radiation Monitor was declared inoperable after exhibiting erratic performance. This monitor provides the input into one division of the primary containment isolation logic for a Group II isolation. As a result, the channel was placed in a tripped condition in accordance with Technical Specification 3.3.6.1, Condition B. Given both divisions are required to complete the Group II isolation logic, this condition is reportable in accordance with 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented the fulfillment of a safety function. The 2A Drywell Radiation Monitor has been repaired and restored to an operable condition. The NRC Resident Inspector has been notified.

• * * RETRACTION FROM JAMES BURKE TO JOHN SHOEMAKER AT 1447 EST ON 2/7/14 * * *

The purpose of this notification is to retract the ENS notification made on January 15, 2014 (ENS 49727). Upon further investigation it was verified that the Drywell Radiation Monitors do not mitigate the consequences of an accident as discussed in Chapters 6 and 15 of the Updated Final Safety Analysis Report and the Technical Specifications Bases for 3.3.6.1. Therefore, the threshold for reporting the issue as an event or condition that could have prevented the fulfillment of a safety function was not met (NUREG 1022 Revision 3 - Event Report Guidelines Section 3.2.7). The NRC Resident Inspector has been notified. Notified the R3DO (Orlikowski).

On April 11, 2013, at 1300 hours, during the performance of On-Line Automatic Depressurization System (ADS) Blowdown Logic Testing, two poor wiring connections were identified (the electrical leads were not properly compressed at their termination point). The electrical leads are associated with the B and C ADS valves. Quad Cities has five ADS valves which can be used to depressurize the Reactor Pressure Vessel under accident conditions. While the solenoids of these valves were actuated successfully during the recent Unit 1 refueling outage (which ended on April 8, 2013), the less than optimum configuration could have prevented the valves from actuating under design basis conditions. The degraded wiring for both valves was restored at 1741 hours (CDT). Given the potential impact on the ADS depressurization function, this event is reportable under 50.72(b)(3)(v)(D) as an event or condition that could have prevented the fulfillment of a safety function. The licensee notified the NRC Resident Inspector.

• * * RETRACTION ON 6/3/13 AT 1138 EDT FROM FRED SWIHART TO DONG PARK * * *

The purpose of this notification is to retract the ENS Report made on April 11, 2013, at 2110 EDT (ENS Report # 48916). Further evaluation performed by Quad Cities Station confirms the Unit 1, 3B and 3C Automatic Depressurization System (ADS) valves would have performed their safety functions when required. Based on this subsequent evaluation, ENS Report # 48916 is being retracted. Note: On April 11, 2013, at 1741 CDT the degraded wiring for the Unit 1, 3B and 3C ADS valves was repaired and both valves were returned to operable status. The licensee notified the NRC Resident Inspector. Notified R3DO (Orth).

On February 20, 2007 at 1720 hours, the High Pressure Coolant Injection (HPCI) system was declared inoperable. During a system walkdown the HPCI Motor Speed Changer (MSC) was discovered energized. The MSC controls HPCI turbine speed during system startup and shutdown, and should not have been energized at the time of the walkdown. Additional troubleshooting determined the MSC was not functioning properly, rendering the HPCI system inoperable. This event is being reported as a condition that could have prevented fulfillment of a safety function in accordance with 10CFR50.72(b)(3)(v)(D) because the HPCI system is a single train system and the loss of HPCI could impact the plant's ability to mitigate the consequences of an accident. In accordance with Technical Specification Action 3.5.1.F, the Reactor Core Isolation Cooling (RCIC) system was confirmed operable. Further troubleshooting and engineering evaluations are continuing. The licensee informed the NRC Resident Inspector.

• * * RETRACTION AT 1146 ON 3/5/2007 FROM ERIK MARKS TO MARK ABRAMOVITZ * * *

The purpose of this report is to retract the ENS report made on February 20, 2007 at 1720 hours (ENS #43177) under 10CFR50.72(b)(3)(v)(D), a condition that could have prevented fulfillment of a safety function. The initial report was made when the Unit 2 High Pressure Coolant Injection (HPCI) system was declared inoperable following a system walkdown that discovered the HPCI Motor Speed Changer (MSC) was energized. The MSC controls HPCI turbine speed during system initiation, and should not have been energized at the time of the walkdown since the system was not in operation. During troubleshooting the MSC responded slower than expected. Due to this unexpected behavior, it was not certain if HPCI could have met its design basis requirements. However, a subsequent engineering evaluation has determined that at the time of discovery, the HPCI system injection time would have been sufficient to meet its safety function. Repairs to HPCI were completed and the system was declared operable on February 22, 2007 at 0036 hours. The licensee notified the NRC Resident Inspector. Notified the R3DO (Orth).

At 1150 on June 27, 2005 Quad Cities Station was notified that the calculated post-LOCA switchyard voltage is below the minimum acceptable value required to ensure offsite power will remain available following a design basis accident. The appropriate Technical Specification Actions have been taken for both Units. The ability of the Emergency Diesel Generators to fulfill their design function is not affected by this condition. This event is being reported in accordance with 10CFR50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of a safety function given the predicted post-LOCA switchyard voltage. Actual Switchyard voltage at the time of this notification is 356 Kv. The required minimum post-accident switchyard voltage for current conditions is 352.9 Kv for Unit-1 and 351 Kv for Unit-2, while the projected post-accident voltage which prompted this notification is 349.8 Kv. At 1320 hrs on June 27, the projected post-accident voltage was 351.3kV. This prediction satisfies the minimum Unit 2 voltage requirement, but is still below the minimum voltage for Unit 1. This notification is similar to the condition reported on April 29, 2005 (EN #41652) and June 11, 2005 (EN #41766). The licensee notified the NRC Resident Inspector.

• * * RETRACTION FROM J. COX TO W. GOTT 1906 ET 08/09/05 * * *

The purpose of this report is to retract ENS report #41652 (April 29, 2005), ENS report 41766 (June 11, 2005), and ENS report #41801 (June 27, 2005). The reports were made following notification that the switchyard predicted voltage was below the required value necessary to ensure that offsite power would remain available following a design basis accident. For each event, both sources of offsite power were declared inoperable, the appropriate Technical Specification required actions were taken for the units, and an ENS notification was made for a condition that could have prevented the fulfillment of a safety function. Each Quad Cities unit has two sources of off-site power. For a specific unit, one source is from the switchyard through the unit's Reserve Auxiliary Transformer (RAT) and the second source is from the switchyard through the opposite unit's RAT. Following further analysis of the loading on the RATs during an accident, it was determined that only one source of offsite power to each unit should have been considered inoperable. The analysis determined that because the RAT for the non-accident unit (i.e., the offsite source supplied through the opposite unit) would be carrying a much smaller load, it would not be subject to a degraded voltage condition and resultant isolation from the grid. Therefore, an accident on one unit would not affect the operability of the source of offsite power supplied through the opposite unit's RAT. As a result, only the source of offsite power supplied through the unit's RAT was inoperable. With one source of offsite power available at all times, there was no condition present that could have prevented fulfillment of a safety function, and therefore, these events are not reportable. The licensee notified the NRC Resident Inspector. Notified R3 DO (R. Lanksbury)

At 0732 (CDT) on April 29, 2005 Quad Cities Station was notified that the calculated post-LOCA switchyard voltage was below the minimum acceptable value required to ensure offsite power would remain available following a design basis accident. As a result, both offsite power sources were declared inoperable and the appropriate Technical Specification Actions were taken for both Units. The ability of the Emergency Diesel Generators to fulfill their design function was not affected by this condition. This event is being reported in accordance with 10CFR50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of a safety function given the predicted post-LOCA switchyard voltage. The condition was exited at 0836 (CDT) on April 29, 2005. The required minimum post-accident switchyard voltage is 352.9 KV (Unit 1) and 351.0 KV (Unit 2) while the projected post accident voltage, which prompted this notification, was 347.9 KV. During this timeframe, actual switchyard voltage was approximately 358 KV. The licensee notified the NRC Resident Inspector.

• * * RETRACTION FROM J. COX TO W. GOTT 1906 ET 08/09/05 * * *

The purpose of this report is to retract ENS report #41652 (April 29, 2005), ENS report 41766 (June 11, 2005), and ENS report #41801 (June 27, 2005). The reports were made following notification that the switchyard predicted voltage was below the required value necessary to ensure that offsite power would remain available following a design basis accident. For each event, both sources of offsite power were declared inoperable, the appropriate Technical Specification required actions were taken for the units, and an ENS notification was made for a condition that could have prevented the fulfillment of a safety function. Each Quad Cities unit has two sources of off-site power. For a specific unit, one source is from the switchyard through the unit's Reserve Auxiliary Transformer (RAT) and the second source is from the switchyard through the opposite unit's RAT. Following further analysis of the loading on the RATs during an accident, it was determined that only one source of offsite power to each unit should have been considered inoperable. The analysis determined that because the RAT for the non-accident unit (i.e., the offsite source supplied through the opposite unit) would be carrying a much smaller load, it would not be subject to a degraded voltage condition and resultant isolation from the grid. Therefore, an accident on one unit would not affect the operability of the source of offsite power supplied through the opposite unit's RAT. As a result, only the source of offsite power supplied through the unit's RAT was inoperable. With one source of offsite power available at all times, there was no condition present that could have prevented fulfillment of a safety function, and therefore, these events are not reportable. The licensee notified the NRC Resident Inspector. Notified R3 DO (R. Lanksbury)

The following information was obtained from the licensee via facsimile (licensee text in quotes): On April 4, 2005, at 1607 hours (CDT), Quad Cities was notified that the switchyard voltage was below that required to ensure that offsite power would remain available following a design basis accident. Both sources of off site power were declared inoperable. The appropriate Technical Specification required actions were taken for both units. The ability of the Emergency Diesel Generators to perform their design function is not affected by this condition. This event is being reported in accordance with 10 CFR 50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of a safety function given the predicted post-LOCA switchyard voltage. This notification report is similar to the condition reported on March 24, 2005 (reference EN#41524 for additional information). Technical Specification minimum switchyard voltage is 348.4 KV. Switchyard voltage at 1607 hrs. was approximately 343.7 KV. Switchyard voltage at the time of NRC notification was 358 KV which is above the Technical Specification minimum. The licensee has notified the NRC Resident Inspector.

• * * RETRACTION FROM C. STEFFES TO M. RIPLEY 1556 EDT 04/13/05 * * *

The purpose of this report is to retract the following ENS reports: 1) ENS # 41524 on March 24, 2005; 2) ENS # 41562 on April 4, 2005; and 3) ENS # 41587 on April 11, 2005. These reports were made following notification to Quad Cities that the switchyard voltage was below the required value necessary to ensure that offsite power would remain available following a design basis accident. For each event, both sources of offsite power were declared inoperable, the appropriate Technical Specification required actions were taken for both units, and an ENS notification was made for a condition that could have prevented fulfillment of a safety function. The events occurred when Unit 1 was in a refueling outage and Unit 2 was operating at 85% power. Subsequent Engineering analysis has determined that with a unit shutdown, and the large 4 Kv loads on that unit not running, the required minimum post-accident switchyard voltage is reduced to 339.3 kV (for the shutdown unit). Given the new minimum post-accident switchyard voltage, it was confirmed that there was a source of off-site power available to the Station. Specifically for all three events, the projected post-accident switchyard voltage (which ranged between 343 kV to 347.5 kV) was higher than the required minimum post-accident switchyard voltage (339.3 kV) for the shutdown unit. As a result, there was no condition present that could have prevented fulfillment of a safety function, and thus these events are not reportable. The licensee notified the NRC Resident Inspector. Notified R3 DO (J. Madera)

On October 19, 2004 at approximately 1830 hours CDT, Unit One was performing QCOS 2300-05, Quarterly HPCI Pump Operability Test. This was being performed to prove operability following maintenance work on various valves and the turning motor gear unit. At this time when the HPCI turbine was rolled, the HPCI Signal Converter Trouble alarm was received. The HPCI Flow Controller demand controlled at approximately 7250 gpm instead of controlling at the desired 5600 gpm. HPCI was determined not to be operable and was shutdown per procedure. Due to the unexpected behavior of the HPCI Flow Controller, at this time it is not certain if the HPCI will meet its safety function. Therefore, we are reporting this event under 10 CFR 50.72 (b)(3)(v). Licensee entered Tech Spec 3.5.1.(f) 14 day Limiting Condition of Operation (LCO) for HPCI. Reactor Core Isolation Cooling (RICI) is operable. All other Emergency Core Cooling Systems (ECCS) and the Emergency Diesel Generators (EDG) are fully operable if needed. The NRC Resident Inspector was notified of this event by the licensee.

• * * RETRACTION J. DAVIS TO W. GOTT AT 1819 ON 10/28/04 * * *

The purpose of this report is to retract the ENS report made on October 19, 2004 at 2237 CDT (ENS #41139). The initial report was made following HPCI operability testing in accordance with QCOS 2300-05, Quarterly HPCI Pump Operability Test. When the HPCI turbine was rolled, the HPCI Signal Converter Trouble alarm was received. The HPCI Flow Controller failed to control at the desired 5600 gpm (instead, the system ramped to 7250 gpm). Due to the unexpected behavior, it was not certain at the time if HPCI could have met its design basis requirements. However, a subsequent review of this event has determined that HPCI would have performed its safety function. The Signal Converter failed in a manner that prevented automatic flow control, but did not prevent HPCI from initiating and ramping to full flow (i.e., the turbine high speed stop). In this condition, HPCI would have met corresponding Technical Specifications and Accident Analysis requirements. The circuit board was replaced and the Signal Converter and flow controller feedback loop were re-calibrated. The Unit 1 HPCI turbine's automatic flow control was successfully tested on October 20, 2004. The Licensee notified the NRC Resident Inspector. Notified R3DO (R. Garner)