ENS 48916
ENS Event | |
|---|---|
18:00 Apr 11, 2013 | |
| Title | Degraded Electrical Connections |
| Event Description | On April 11, 2013, at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, 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 hours0.0202 days <br />0.484 hours <br />0.00288 weeks <br />6.624505e-4 months <br /> [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.
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). |
| Where | |
|---|---|
Quad Cities  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+3.17 h0.132 days <br />0.0189 weeks <br />0.00434 months <br />) | |
| Opened: | Kevin Holle 21:10 Apr 11, 2013 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Jun 3, 2013 |
| 48916 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |