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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.

EN Revision Text: UNANALYZED CONDITION FOR TORNADO GENERATED MISSILES On March 1, 2018, during evaluation of protection for Technical Specifications (TS) equipment from the damaging effects of tornado generated missiles, Quad Cities Station identified a non-conforming condition in the plant design such that specific TS equipment is considered to not be adequately protected from tornado generated missiles. Tornado generated missiles could strike the Unit l, Unit 1/2, and Unit 2 Emergency Diesel Generator intake and exhaust stacks, day tank vents, and main fuel oil tank vents. This could result in crimping of the intake/exhaust stacks and vents, which would affect the ability of the Emergency Diesel Generators to perform their function if a tornado would occur. This condition is reportable 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, and 10 CFR 50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. This condition is being addressed in accordance with NRC enforcement guidance provided in Enforcement Guidance Memorandum (EGM) 15-002, 'Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance,' Revision 1, and DSS-ISG-2016-01, 'Clarification of Licensee Actions in Receipt of Enforcement Discretion per Enforcement Guidance Memorandum EGM 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance,' Revision 1. Compensatory measures have been implemented in accordance with these documents. The NRC Resident Inspector has been informed of this notification.

• * * RETRACTION FROM NICK JOHNSON TO HOWIE CROUCH AT 1900 EST ON 11/7/19 * * *

The purpose of this notification today (11/07/19) is to retract event notification #53235 made on March 1, 2018, for Quad Cities Station. Additional review determined that the current design of all three Emergency Diesel Generators and associated Day Tanks and Main Fuel Oil Storage Tanks Vents is consistent with the licensing basis for Quad Cities Station. There was no non-conformance of Quad Cities' tornado missile protection design, and the EDGs were operable at the time the event notification was made. Therefore, this event does not meet the criteria of 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v)(D) and ENS report #53235 is being retracted. The NRC Resident Inspector has been informed of this notification. Notified R3DO (Peterson).

On September 26, 2018 at 1908 CDT. an automatic scram was received on U1 following main generator 345 kV output breaker 7-8 trip with 345 kV output breaker 6-7 already opened for maintenance on line 0401. Following the reactor scram, reactor water level decreased to approximately minus 15 inches, which resulted in automatic Group II and Group Ill isolations (expected response). Reactor pressure rose to approximately 1083 psig, and the 3B and 3C low set relief valves opened briefly to control reactor pressure. Reactor water level and reactor pressure have been restored to their normal bands. All systems responded properly to the event. Unit 1 remains in Mode 3, with reactor pressure being controlled on the turbine bypass valves. The cause and details of the event are under investigation.

Unit 2 was unaffected by the event and remains at 100% power. This report is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A)." All control rods inserted. Decay heat is being removed via the main condenser. The licensee notified the NRC Resident Inspector.

The following information was provided by the licensee via fax: At 1359 CDT on May 10, 2022, the 1B LPCI Loop Upstream Injection valve (1-1001-28B) was found to have a motor operated torque switch issue and inadequate lubrication. This issue called into question the ability of the valve to close when required. At 1746 CDT on May 10, 2022, both trains of Unit 1 LPCI were made simultaneously inoperable. TS 3.6.1.3 Condition A required de-activation of 1B LPCI Loop Downstream Injection valve (1-1001-29B) which was completed at 1746 CDT. Because of the de-activation of the 1B LPCI Loop downstream injection valve and LPCI Loop select logic, both trains of LPCI were made inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(V). Unit 1 HPCI and both loops of Core Spray are operable. After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

• * * UPDATE AT 12:32 EDT ON 05/11/22 FROM MARK HUMPHREY TO BRIAN P. SMITH * * *

The following information was provided by the licensee via phone call and email: The last sentence in the second paragraph, "After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required," has been deleted. The licensee is continuing to follow up on the issue and believes that sentence to be unclear and premature. Notified R3DO (Skokowski).