RA18-084, Post Accident Monitoring Report

Post Accident Monitoring Report

ML18290A576
Person / Time
Site:	LaSalle
Issue date:	10/17/2018
From:	Washko J Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RA18-084
Download: ML18290A576 (3)

Text

LaSalle County Station Exelon Generation 2601 North 21 " Road Marseilles, IL 61341 815-415-2000 Telephone www.exeloncorp.com RA18-084 October 17, 2018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Unit 2 Renewed Facility Operating License No. NPF-18 NRG Docket No. 50-374

Subject:

Post Accident Monitoring Report The attached report is submitted in accordance with LaSalle County Station, Unit 2 Technical Specifications (TS} 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation,"

and TS 5.6.6, "Post Accident Monitoring (PAM) Instrumentation Report." The report is required due to the inoperability of one testable check valve position indication for a period greater than the 30-day restoration time. Accordingly, this report is due on October 17, 2018.

There are no regulatory commitments contained in this letter. Should you have any questions concerning this letter, please contact Ms. Dwi Murray, Regulatory Assurance Manager, at (815) 415-2800.

Respectfully,

(';('AwJ~

John UkJo Plant Manager LaSalle County Station

Attachment:

LaSalle Unit 2 Post Accident Monitoring Report cc: Regional Administrator - NRG Region Ill NRG Senior Resident Inspector - LaSalle County Station

LaSalle RA 18-084 October 17, 2018 LaSalle Unit 2 Post Accident Monitoring Report This report is submitted for LaSalle County Station, Unit 2, in accordance with Technical Specifications (TS) 5.6.6, "Post Accident Monitoring (PAM) Instrumentation Report."

Additionally, TS 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," requires two channels of Penetration Flow Path Primary Containment Isolation Valve (PCIV) position indication to be operable during plant operations in Modes 1 and 2.

On September 3, 2018, the position indication for the Unit 2 'A' feedwater line outboard testable check valve 2B21-F032A was declared inoperable and TS 3.3.3.1, Required Action (RA) A.1 was entered. Since TS 3.3.3.1, Condition A was not satisfied within 30 days, TS 3.3.3.1, Condition B was entered.

Exelon Generation Company, LLC has determined that the position indication cannot be restored with 30 days. Therefore, TS 3.3.3.1, Condition B requires immediate initiation of action in accordance with TS 5.6.6 to submit a written report within 14 days outlining the pre-planned alternate method of monitoring, the cause of the inoperability and the plans/schedule for restoring the instrument channel of the function to operable status.

Description of Issue On September 3, 2018, the light indication for the Unit 2 'A' feedwater line outboard testable check valve 2B21-F032A at Main Control Room (MGR) panel 2H13-P601 indicated dual position, while the valve's expected position was full open while at full-power conditions.

TS 3.3.3.1 was exited on September 1, 2018 for 2B21-F032A PAM indication due to no longer being in the mode of applicability during maintenance outage L2M20. During the maintenance outage, electrical maintenance technicians adjusted the limits on 2B21-F032A. However, after the unit startup on September 3, 2018, the indication was not restored, and TS 3.3.3.1 was re-entered.

The check valve passed its leak rate tests and checks as required for a primary containment isolation valve (PCIV). However, the valve did not pass its channel check for position indication. Therefore, the valve was declared inoperable for position indication in accordance with TS 3.3.3.1, which requires the valve's position indication to be restored within 30 days.

Feedwater header flows match, indicating 2B21-F032A is full open as expected, and; therefore, its PCIV function is not impacted. Shift operations verified the feed flow by trending the plant process computer (PPG) points for feedwater 'A' and 'B' header flow, with no discrepancies noted. Both loops trended together within tolerance.

Preplanned Alternate Method of Monitoring The alternative method for monitoring the post-accident position of valve 2821-F032A is the PPG Primary Containment Isolation System (PCIS) screen and analog PPG points 8713 and 8714 for Unit 2 A and 8 feedwater line flows, respectively.

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RA18-084 October 17, 2018 Cause of the Inoperable Condition The cause of valve 2B21-F032A position indication malfunction is the limit switches, which require adjustment. Based on the flow indications observed, the valve remains fully functional. However, in order to perform the required surveillances for the closed indication of valve 2B21-F032A, the system is required to have no system flow. Further troubleshooting and repair of the limit switches were precluded while the plant is operating in Mode 1 with the feedwater system in service.

Plans and Schedule for Restoration The repair of the limit switches is scheduled for the first opportunity, in accordance with the station work control process, no later than the upcoming Unit 2 refueling outage (L2R17).

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