ML18107A354

LER 99-006-00:on 990501,HHSI Flow Balance Discrepancy Was Noted During Surveillance.Caused by Sticking of Check Valve in SI Discharge Line to 21 Cold Leg.Valve 21SJ17,was Cut Out of Sys & Replaced.With 990601 Ltr

ML18107A354
Person / Time
Site:	Salem
Issue date:	06/01/1999
From:	Garchow D, Nagle J Public Service Enterprise Group
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
LER-99-006, LER-99-6, LR-N990266, NUDOCS 9906080284
Download: ML18107A354 (4)

Text

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• Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit LR-N990266 Regional Administrator U.S. Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406-1415 Gentlemen:

LICENSEE EVENT REPORT 99-006-00 SALEM GENERATING STATION-UNIT 2 FACILITY OPERATING LICENSE NO DPR 75 DOCKET NO. 50-311 This Licensee Event Report entitled " High Head Safety Injection Flow Balance Discrepancy Noted During Surveillance " is being submitted on a voluntary basis and is not required under the reporting requirements of 10CFR50.73

• I David F. Garchow General Manager-Salem Operations Attachment C U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

/JCN Distribution:

LER File 3.7 Cqa l ,..,

y The power is in your hands.

95-2168 REV. 6/94

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NRt:-PORfv1'366 U.S. NUCLEAR REGULAT.OMMISSION APPROVEDr.MB NO. 3150-0104 EXPIRES 06/30/2001 (6-1998) Estimated bur er response to comply with this mandatory information collection request: 50 hrs. Reported lessons learned are incorporated into the LICENSEE EVENT REPORT (LER) licensing process and fed back to industry. Forward comments regarding burden estimate to the Records Management Branch (T-6 F33), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, and to the Paperwork (See reverse for required number of Reduction Project (3150-0104), Office of Management and Budget, Washington, DC 20503. If an information collection does not display a currently digits/characters for each block) valid OMB control number, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.

FACILITY NAME 111 SALEM GENERATING STATION UNIT 2 DOCKET NUMBER 121 05000311 l"G' f:I OF 3 I TITLE (4)

High Head Safet11 Injection Flow Balance Discrepancy Noted During Surveillance.

EVENT DATE (5) LER NUMBER (6) REPORT DATE 171 OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER I REVISION NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 FACILITY NAME DOCKET NUMBER 05 01 99 99 006 00 06 01 99 05000 OPERATING Tl-llC:: *~

IC:: C::l IRM TTJ:n Pl IDCl IJ\l\IT Tn Tl-Ii: Ri:n1 **--* ---*-::: ni: 1 n ri:R n. rrh~~*- *-~ nr -..,rol 111 I MODE (9) 5 20.2201 (b) 20.2203(a)(2)(v) 50. 73(a)(2)(i) 50. 73(a)(2)(viii)

I POWER I I 20.2203(a)( 1) 20.2203(a)(3)(i) 50. 73(a)(2)(ii) 50. 73(a)(2)(x) 1t*'~I 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50. 73(a) (2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50. 73(a)(2)(iv) x OTHER i *, 20.2203(a)(2)(iii) 50.36(c)(1) 50. 73(a)(2)(v)

Specify in Abstract below

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• 20.2203(a)(2)(iv) 50.36(c)(2) 50. 73(a)(2)(vii) or in NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

John C. Nagle Senior Licensing Engineer 609-339-31 71 rnnnPI J:T~ nl\li: I Ill.Ii: i:nR "l\,l"l-I rn11.nPn11.1i:r 1T i:1111 (ID<: nJ:C!l"'RIRJ:n 11\1 rUIC '1':l\

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REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX B BO ISV 147E y  ?!

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EXPECTED IYES SUBMISSION (If ves, complete EXPECTED SUBMISSION DATE). I x I No DATE(15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On April 30, May 1, 1999, during performance of a surveillance on the safety injection system throttling valves to balance injection flow, it was determined that there was no flow in one of the four injection legs (21 leg). U~on throttling the valves in the remaininl legs the flow was re-established to the 1 lel. It is believed that the 21SJ 7 (safety injection line to cold leg) check va ve had been stuck closed. The four legs were subsequently flow balanced successfully.

The 21SJ17 was cut out of the system and replaced in kind. Subsequent inspection of the valve found no evidence of malfunction which would have rendered the valve inoperable. The valve seats were in specification and the internal clearances were at the low end of the manufacturer's (Edwards) recommendation. It is suspected that there may have been foreign material which jammed the valve in the closed position.

This voluntary relort is being submitted in order to provide a record of the failure which was initial y communicated in a 4-hour report to the NRC under 10CFR50.72. In accordance with NUREG 1022, Revision 1 guidance, which states that the out of service time is calculated using the "time of discovery unless there is firm evidence based on a review of relevant information (e.g. the equipment history and cause of failure) to believe the discrepancy existed previously," this event is not reportable. Technical specification requirements for this system were satisfied for the mode of operation at the time of discovery and the event is bounded by current analyses.

NRC FORM 366 (6-1998)

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NRC FORM 366A U.S. NUCLEAR RE TORY COMMISSION (6-1998)

LICENSEE EVENT REPORT CLER)

TEXT CONTINUATION DOCKET 121 FACILITY NAME (1) NUMBER (21 LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER I REVISION NUMBER Salem Generating Station Unit 2 05000311 99 06 00 2 OF 3 TEXT (If more space is required, use additional copies of NRG Form 366AJ ( 171 PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Safety Injection system/Isolation Valve {SI/ISV}*

• Energy Industry Identification System (EIIS) codes and component function identifier codes appear as {SS/CCC} in the text.

CONDITIONS PRIOR TO OCCURRENCE The unit was shutdown for refueling prior to the event.

DESCRIPTION OF OCCURRENCE During the performance of the 18 month high head injection test S2.0P-ST.SJ-0016, the 21 cold leg showed no flow until flow into the other cold legs was throttled. Flow began with an audible indication, possibly associated with a stuck check valve unseating. The flow balance of the injection pathways was subsequently performed successfully.

CAUSE OF OCCURRENCE The cause of the occurrence is believed to be sticking of the check valve (21SJ17) in the safety injection discharge line to the 21 cold leg due to close tolerances and possible foreign material in the valve. Inspection of the valve revealed no evident failure mechanism. The internal clearances were close to the minimum manufacturer's tolerance range thus there may have been sticking caused by foreign material. The replacement valve had greater clearance, more in line with optimal tolerances.

While there have been no similar failures with these types of valves in the safety injection system, there have been 2 instances of problems with valves of this family in the closed cooling system. In addition, this specific valve did initially experience difficulty seating during the surveillance testing for RCS pressure isolation valve leakage (S2.0P-ST.SJ-0020) prior to the start-up from the extended outage in 1997. A review of industry data revealed no instances of similarly sticking closed valves although there were several other types of failures identified.

NRC FORM 366A (6-1998)

NRC FORM 366A U.S. NUCLEAR RE TORY COMMISSION (6~1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION DOCKET (2)

FACILITY NAME (1) NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR I SEQUENTIAL NUMBER I REVISION NUMBER SALEM GENERATING STATION UNIT 2 05000311 99 06 00 3 OF 3 TEXT (If more space is required, use additional copies of NRG Form 366A) (17)

SAFETY CONSEQUENCES AND IMPLICATIONS If the valve had been stuck during operations, the plant would have been in a condition prohibited by technical specifications and the appropriate Action would have been taken. There are two accidents which are potentially impacted by this high head safety injection system discrepancy, namely small break LOCA and main steam line break (UFSAR sections 15.3.1 and 15.4.2). The assumptions for these accidents include the loss of a single train of Safety Injection thus there would be only a single pump injecting into the cold legs. With a stuck check valve there would only be three legs available.

Preliminary review indicates that the accident analyses bound the current event. A review of the analysis must be completed prior to making the final determination of significance. If further review does not support the preliminary determination a separate report will have to be made regarding operation outside of design bases.

CORRECTIVE ACTIONS

1) The 21SJ17 valve, an Edwards 1.5 inch Model # D36274, was cut out of the system and replaced in kind. The flow balance was successfully re-performed and the system returned to available status.

2) The potential generic implications of foreign material in the system will be reviewed under the corrective action system.

NRC FORM 366A (6-1998)