ML19289E556

Technical Specification 5.6.8 Special Report: Inoperable Containment Isolation Valve Indication

ML19289E556
Person / Time
Site:	Prairie Island
Issue date:	10/16/2019
From:	Sharp S Northern States Power Company, Minnesota, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-Pl-19-044
Download: ML19289E556 (3)

Text

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RESPONSIBLE BY NATURE 1717 Wakonade Drive Welch, MN 55089 October 16, 2019 L-Pl-19-044 10 CFR 50.36 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant, Unit 2 Docket No. 50-306 Renewed Facility Operating License No. DPR-60 Technical Specification 5.6.8 Special Report: Inoperable Containment Isolation Valve Indication Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits a special report per Technical Specification (TS) 3.3.3 "Event Monitoring (EM) Instrumentation" and TS 5.6.8 "EM Report". This report is included as Enclosure 1.

This event was not considered risk significant and did not adversely affect the health and safety of the public.

If there is any question or if any additional information is needed, please contact Steve Sollom at 612-342-8982.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

Scott Sharp Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure

ENCLOSURE 1 PRAIRIE ISLAND NUCLEAR GENERATING PLANT L-Pl-19-044 SPECIAL REPORT EVENT DESCRIPTION On 09/19/2019, while investigating a separate issue with increased Unit 2 Reactor Coolant System (RCS) letdown flow, Operations placed control valve (CV) CV-31348,

• 21 Letdown Orifice Isolation CV B, into service. At approximately 1616 hours0.0187 days <br />0.449 hours <br />0.00267 weeks <br />6.14888e-4 months <br />, it was noted that there was "no positive verification that CV-31348 was full open", although an additional 40 gallons per minute (gpm) of Letdown flow indicated that the valve CV-31348 was full open.

After some troubleshooting efforts, at approximately 1735 hours0.0201 days <br />0.482 hours <br />0.00287 weeks <br />6.601675e-4 months <br /> on 09/19/2019, Operations re-closed CV-31348 and removed control fuses to maintain the valve in the closed position. Closing the valve and removing the fuse met limiting condition for operation (LCO) Technical Specification (TS) 3.3.3 Condition A 1, "if a normally active CIV is known to be closed and deactivated, position indication is not needed to determine status, therefore the position indication for the valve in this state is not required to be Operable".

On 10/3/2019 an evaluation was completed which reviewed the plant process computer information and determined that all three indications likely failed on 07/21/2018 and only one EM instrumentation for this containment penetration flow path was operable from 07/21/2018 until the fuse was pulled on 09/19/2019. TS 3.3.3 Function 9, requires two EM instrumentation per flow path.

There is diverse indication used to validate the valve position of CV-31348 and only one method is required to meet TS 3.3.3:

o The Control Switch red light (open valve) and green light (closed valve).

o The Containment Isolation Panel's white "sugarcube" light (lit signifies closed valve).

o Computer display: Safety Parameter Display System (SPDS) indication of an open or closed valve.

• SPDS parameters are processed by the Safety Assessment System (SAS) that in turn is part of the plant's ERGS (Emergency Response Computer System).

The Technical Specifications (TS) 3.3.3's limiting condition for operation (LCO) required action A.1 (Restore required channel to OPERABLE status) was not completed within the required Completion Time of 30 days.

TS 3;3.3's LCO Condition C, required to be entered when Condition A's required Completion Time is not met, is to immediately initiate an action in accordance with TS 5.6.8.

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ENCLOSURE 1 PRAIRIE ISLAND NUCLEAR GENERATING PLANT L-Pl-19-044 SPECIAL REPORT TS 5.6.8 directs: "a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status".

PREPLANNED ALTERNATE METHOD OF MONITORING As noted above, TS 3.3.3 is not applicable when a Containment Isolation Valve is closed and deactivated and CV-31348 will be closed and deactivated until it is needed for shutting down Unit 2 for refueling outage 2R31, beginning the week of October 1, 2019. While in the mode of applicability the Operations crew's logging of manipulations of CV-31348 and observance of pressure and flow indications, will provide a Preplanned Alternate Method of Monitoring.

CAUSE OF INOPERABILITY The cause is unknown at the present time. A work order has been scoped into the Refueling Outage 2R31 for performing troubleshooting and repairs.

A Supplement to this Special Report will be submitted once the Cause of lnoperability has been firmly established.

PLANS AND SCHEDULE FOR RESTORING OPERABILITY The results from the work order will likely determine the cause of the inoperability and the means to achieve future operability of the CV-31348 indication.

The Supplement to this Special Report will provide the details of how and when operability will be restored.

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