ML13336A139: Difference between revisions

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{{Adams
#REDIRECT [[SVP-13-080, Technical Specifications Section 5.6.6 Post Accident Monitoring Instrumentation Report]]
| number = ML13336A139
| issue date = 11/26/2013
| title = Quad Cities, Unit 2, Technical Specifications Section 5.6.6 Post Accident Monitoring Instrumentation Report
| author name = Hanley T
| author affiliation = Exelon Generation Co, LLC
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000265
| license number = DPR-030
| contact person =
| case reference number = SVP-13-080
| document type = Letter
| page count = 3
}}
 
=Text=
{{#Wiki_filter:AExeton Generation.
SVP-13-080 November 26, 2013 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Quad Cities Nuclear Power Station, Unit 2 Renewed Facility Operating License No. DPR-30 NRC Docket No. 50-265
 
==Subject:==
Technical Specifications Section 5.6.6 Post Accident Monitoring Instrumentation Report The purpose of this letter is to submit the Post Accident Monitoring (PAM) Instrumentation Report as required by Quad Cities Nuclear Power Station (QCNPS) Technical Specifications (TS) Section 5.6.6, "Post Accident Monitoring (PAM) Instrumentation Report." On October 14, 2013, during normal panel monitoring, Operations personnel identified the'open' light indication for the Unit 2 1A (inboard)
Main Steam Isolation Valve (MSIV) was extinguished.
The most likely cause of the inoperable indication is high resistance on the associated position limit switch located in the Unit 2 drywell (i.e., inside primary containment).
This discrepancy required entry into TS Section 3.3.3.1, "Post Accident Monitoring (PAM)Instrumentation," Condition A, due to an inoperable indication channel for Function 6 in Table 3.3.3.1-1, "Penetration Flow Path PCIV Position." Condition A requires restoration of the required indication channel to an operable status within 30 days, or initiate reporting requirements in accordance with TS Section 5.6.6.Resolution of this issue within the 30-day requirement was not feasible due to the significant power reduction and potential containment entry required to complete the necessary repairs (see Attachment).
For this reason, QCNPS is submitting this report in accordance with TS Section 5.6.6. Accordingly, the attached report outlines the preplanned alternate method of monitoring and the apparent cause of the inoperability along with the plans and schedule for restoring the instrument channel to an operable status.
SVP-13-080 U. S. Nuclear Regulatory Commission Page 2 Should you have any questions concerning this letter, please contact Mr. Wally J. Beck, Regulatory Assurance Manager, at (309) 227-2800.Respectfully, Tim 4HanI Site Vice President Quad Cities Nuclear Power Station
 
==Attachment:==
 
Post Accident Monitoring Instrumentation Report Inoperable Channel for Penetration Flow Path PCIV Position cc: Regional Administrator
-NRC Region III NRC Senior Resident Inspector
-Quad Cities Nuclear Power Station ATTACHMENT Post Accident Monitoring Instrumentation Report Inoperable Channel for Penetration Flow Path PCIV Position Preplanned Alternate Method of Monitorinq An alternate method of monitoring the isolation function for the Unit 2 1 A inboard Main Steam Isolation Valve (MSIV) has been implemented.
The alternate method requires Operations personnel, following an isolation signal, to verify that flow indication for the 'A' Main Steam Line on main control room panel 902-5 is indicating zero flow.This guidance has been communicated to Operations personnel and is included with station procedure QCOS 1600-05, "Post Accident Monitoring Instrumentation Outage Report." This alternate method provides an acceptable means of indication to ensure the MSIV isolation function has been accomplished.
In addition, the Unit 2 1A MSIV indication anomaly has been entered into the Unit 2 Degraded Equipment List, as well as the Corrective Action Program for final resolution.
It should be noted that the position indication for the outboard MSIV on the 'A' Main Steam Line is fully functional.
Apparent Cause of the Inoperability The most likely cause is a faulty limit switch which provides the open indication (i.e., red lamp) for the inboard MSIV. This limit switch is located inside the Unit 2 drywell and is positioned closest to the valve, which subjects the switch to a high radiant heat load. Limit switch contact contamination from heat up of non-metallics in the switch assembly, resulting in elevated contact resistance, is the most likely cause of the loss of indication.
Efforts have not been made to attempt to burnish this set of contacts with increased current flow, as the cycling of the switch is important to the burnishing effort because it allows some measure of arcing as the contacts open or close. This would require the MSIV to be cycled near the closed position to actuate the limit switch, which is not feasible without a significant power reduction.
Plans and Schedule for Returning Function to Operable Status A modification to move the subject limit switch further away from the source of heat has been performed on the outboard MSIVs, and will be performed on the inboard MSIVs during the next Unit 2 refuel outage scheduled for Spring 2014 (Q2R22).Page 1 of 1}}

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