ML13336A139

Quad Cities, Unit 2, Technical Specifications Section 5.6.6 Post Accident Monitoring Instrumentation Report

ML13336A139
Person / Time
Site:	Quad Cities
Issue date:	11/26/2013
From:	Hanley T Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SVP-13-080
Download: ML13336A139 (3)

Text

AExeton Generation.

SVP-13-080 November 26, 2013U. S. Nuclear Regulatory Commission ATTN: Document Control DeskWashington, D.C. 20555-0001 Quad Cities Nuclear Power Station, Unit 2Renewed Facility Operating License No. DPR-30NRC Docket No. 50-265

Subject:

Technical Specifications Section 5.6.6Post Accident Monitoring Instrumentation ReportThe 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) wasextinguished.

The most likely cause of the inoperable indication is high resistance on theassociated 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 Table3.3.3.1-1, "Penetration Flow Path PCIV Position."

Condition A requires restoration of therequired 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 TSSection 5.6.6. Accordingly, the attached report outlines the preplanned alternate method ofmonitoring and the apparent cause of the inoperability along with the plans and schedule forrestoring the instrument channel to an operable status.

SVP-13-080 U. S. Nuclear Regulatory Commission Page 2Should you have any questions concerning this letter, please contact Mr. Wally J. Beck,Regulatory Assurance

Manager, at (309) 227-2800.

Respectfully, Tim 4HanISite Vice President Quad Cities Nuclear Power Station

Attachment:

Post Accident Monitoring Instrumentation ReportInoperable Channel for Penetration Flow Path PCIV Positioncc: Regional Administrator

-NRC Region IIINRC Senior Resident Inspector

-Quad Cities Nuclear Power Station ATTACHMENT Post Accident Monitoring Instrumentation ReportInoperable Channel for Penetration Flow Path PCIV PositionPreplanned Alternate Method of Monitorinq An alternate method of monitoring the isolation function for the Unit 2 1 A inboard Main SteamIsolation 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 onmain control room panel 902-5 is indicating zero flow.This guidance has been communicated to Operations personnel and is included with stationprocedure QCOS 1600-05, "Post Accident Monitoring Instrumentation Outage Report."

Thisalternate method provides an acceptable means of indication to ensure the MSIV isolation functionhas been accomplished.

In addition, the Unit 2 1A MSIV indication anomaly has been entered intothe 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 isfully functional.

Apparent Cause of the Inoperability The most likely cause is a faulty limit switch which provides the open indication (i.e., red lamp) forthe inboard MSIV. This limit switch is located inside the Unit 2 drywell and is positioned closest tothe 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, isthe 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 ofarcing as the contacts open or close. This would require the MSIV to be cycled near the closedposition to actuate the limit switch, which is not feasible without a significant power reduction.

Plans and Schedule for Returning Function to Operable StatusA modification to move the subject limit switch further away from the source of heat has beenperformed on the outboard MSIVs, and will be performed on the inboard MSIVs during the nextUnit 2 refuel outage scheduled for Spring 2014 (Q2R22).Page 1 of 1