U-604243, Special Report: Inoperable Post Accident Monitoring Instrumentation

Special Report: Inoperable Post Accident Monitoring Instrumentation

ML15272A493
Person / Time
Site:	Clinton
Issue date:	09/25/2015
From:	Newcomer M Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
U-604243
Download: ML15272A493 (2)

Text

ExeotonGenerationo clinton Power Station 8401 Power Road Clinton, IL 61727 U-604243 10OCFR50.4 September 25, 2015 SRRS 5A.108 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Special Report: Inoperable Post Accident Monitoring Instrumentation In accordance with Clinton Power Station (CPS) Technical Specification (TS) 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation, Required Action B.1, Exelon Generation Company, LLC (EGC) is submitting the following Special Report concerning the inoperability of a limit switch associated with Reactor Water Cleanup System inboard primary containment isolation valve, lWX019.

Description of Event On August 13, 2015, at 0925 hours0.0107 days <br />0.257 hours <br />0.00153 weeks <br />3.519625e-4 months <br />, Operations declared the position indication inoperable for primary containment inboard isolation valve, 1WX019, in accordance with TS 3.3.3.1, Table 3.3.3.1-1, Function 7, Penetration Flow Path, Automatic Primary Containment Isolation Valve (PCIV) Position. This instrumentation was declared inoperable following a 10 CFR Part 21 notification made by NAMCO Controls (NAMCO) identifying thee possible malfunction of safety related EA170 and EA180 limit switches.

Cause of Inoperability On July 31, 2015, NAMCO issued a 10 CFR Part 21 notification to the NRC associated with an anomaly that limit switches manufactured between March 25, 2014 and December 30, 2014 may not provide reliable indication due to a performance degradation of a compression spring in the limit switch assembly.

Action Taken CPS Issue Report (IR) 2537305 was initiated on August 4, 2015 following NAMCO's Event Notification Report (#51 260) to the NRC made on July 31, 2015. NAMCO provided Technical Bulletin TB1 501 to its customers on August 7, 2015 describing the possible operational anomalies associated with the EA1 70/1 80 limit switches. IR 2541236 was generated at CPS on August 13, 2015 following review of the NAMCO technical bulletin.

CPS traced the serial numbers and concluded the lWX01 9 limit switch Was impacted by the NAMCO technical bulletin.

The CPS review identified that the 1WX01 9 limit switch functioned properly. However, on *..Ti- ,,

August 13, 2015, based on the 10 CFR Part 21 notification associated with the EA 170/180

• U-604243 Page 2 of 2 limit switches, it declared the position indication for valve 1WX01 9 inoperable. As a result, EGO entered TS 3.3.3.1 Required Action A.1 to restore the indication to an operable status in 30 days. If not restored within 30 days, Required Action B.1 required action to be initiated to prepare and submit a Special Report within 14 days. On September 12, 2015, the 30 day Required Action A.1 was not completed and Required Action B.1 was entered. Position indication for lWX01 9 was declared inoperable but the containment isolation function remained operable. The limit switch does not impact the capability of the valve to open or close when demanded. Position indication for 1WX020 remained operable since it was not impacted by the NAMCO technical bulletin.

Work Order 1854355 will replace the current degraded limit switch and restore the valve position indication to an operable status. Due to the valve being located inside the containment steam tunnel and not being accessible with the unit on line, EGO plans on replacing the limit switch in the Spring 2016 refueling outage.

There are no regulatory commitments contained in this report.

Should you have any questions concerning this report, please contact Mr. Mark Friedmann, Acting Regulatory Assurance Manager, at (217) 937-4833.

Respectfully, Site Vice President Clinton Power Station J LP/cas cc: Regional Administrator - NRC Region Il1 NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - Illinois Emergency Management Agency