05000348/LER-2016-003

LER-2016-003, Pressurizer Safety Valve Setpoint Pressure Outside of Technical Specification Tolerance Band

Joseph M. Farley Nuclear Plant
Event date:	10-13-2016
Report date:	12-12-2016
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
LER closed by
IR 05000348/2017001 (1 May 2017)
3482016003R00 - NRC Website

LER 16-003-00 for Farley, Unit 1, Regarding Pressurizer Safety Valve Setpoint Pressure Outside of Technical Specification Tolerance Band

ML16347A116
Person / Time
Site:	Farley
Issue date:	12/12/2016
From:	Gayheart C A Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-16-2478 LER 16-003-00
Download: ML16347A116 (6)

internal e-mall to Inlocollects.Resourceenic gov, and lo the Desk 0111cer, Office of Information and Regulatory Attains, NE06-10202, (3150.0101), Oltice of Management and Budget, Washington. DC 20503 II a moans used to Impose en information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person Is not required to respond to the Intonation collection,

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2016 - O03 - Joseph M. Farley Nuclear Plant, Unit 1 05000- 348 00 NA ItRATIvE

A. PLANT AND SYSTEM IDENTIFICATION

Westinghouse - Pressurized Water Reactor

B. DESCRIPTION OF EVENT

During the Unit 1 October 2016 refueling outage (1R27) the Pressurizer Safety Valve (PSV) was removed as part of the routine inservice inspection testing program and sent to an offsite testing facility. The as found lift pressure for this PSV was discovered to be 2443 psig which was outside of Technical Specification (TS) 3.4.10 allowable lift settings of 2 2460 psig and S. 2510 psig.

During cycle 27 there were no indications of seat leakage from this PSV as evidenced by tailpipe temperature indication. However, during 1R27 a small amount of boric acid was evident when the valve was removed for valve testing and dismantled during the outage, indicating some leakage had occurred during the cycle. Data from the plant trip on 10/1/2016 was reviewed and there was no indication that any of the pressurizer safety valves lifted during the transient. The primary system response was considered to be normal following the plant trip. There were also no transients during the cycle that would have caused the PSVs to lift.

C. UNIT STATUS AT TIME OF EVENT

Unit 1, Defueled Unit 2, Mode 1, 100 percent power

D. CAUSE OF EVENT

Seat leakage of the PSV is the most likely cause of the setpoint drift.

E. REPORTABILITY ANALYSIS AND SAFETY ASSESSMENT

This failure constitutes a condition that is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications." Based upon a review of relevant information (e.g., equipment history and the cause of failure), there is no firm evidence of when the failure to meet the lift setting requirements occurred prior to the time of discovery at the test facility.

The setpoint could have drifted below the allowable value at any time between startup from 1R26 and the time of discovery.

Since the as found lift setpoint was lower than the allowed value in the Technical Specifications, the condition did not have an adverse impact on over pressurization, and the valve continued to perform its overpressure protection function. The as found lift pressure was 2443 psig and the valve reclosed following the lift. This is within the safety analysis assumptions that are credited for Pressurizer Safety Valves, and the plant remained bounded by the accident analyses in the FSAR. Therefore, this condition had no significant effect on the health and safety of the public.

The inservice testing (1ST) requirement of plus or minus 3% of 2485 psig (2411 — 2559 psig) was met.

Reported lessons learned are incorporated Into the licensing process and ted back to industry Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T

• 5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555.0001, or by Internet e-mall to Infocollects,Resourceenrc,gov, and to the Desk Officer, Office of Information and Regulatory ;Maks, NEOB-10202, (3150-0104), 011ice of Management and Budget, Washington, DC 20503. If a means used to Impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the Information collection.

SEOuENTIAL REV YEAR NUMBER NO Joseph M. Farley Nuclear Plant, Unit 1 05000- 348

F. CORRECTIVE ACTION

The PSV was replaced during the October 2016 refueling outage. An additional PSV that was removed for routine 1ST requirements was tested satisfactorily. The setpoints were left at plus or minus 1% tolerance.

G. ADDITIONAL INFORMATION

1) Failed Components: Pressurizer safety valve 2) Previous Similar Events: A similar event was reported for Unit 1 LER 2015-004-00. For that event, there had been indication of seat leakage during the previous operating cycle based on elevated tailpipe temperatures. This was not seen in this event.

3) Other system affected: No systems other than those mentioned in this report were affected by this event.

4) Commitment Information: This report does not create any licensing commitments 5) Energy Industry Identification System Code:

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