ML18152B418

LER 99-002-00:on 990425,MSSVs Tested Out of Tolerance for as Found Setpoint.Caused by Minor Setpoint Drift.No Immediate Action Required.Deviation Rept Submitted for Each Valve.With 990518 Ltr

ML18152B418
Person / Time
Site:	Surry
Issue date:	05/18/1999
From:	Grecheck E VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
99-284, LER-99-002-02, LER-99-2-2, NUDOCS 9905240126
Download: ML18152B418 (7)

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'7'~ REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

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ACCESSION NBR:9905240126 DOC.DATE: 99/05/18 NOTARIZED: NO DOCKET#

FACIL:50-281 Surry Power Station, Unit 2, Virginia Electric & Powe 05000281 AUTH.NAME AUTHOR AFFILIATION GRECHECK,E.S. Virginia Power (Virginia Electric & Power Co.)

GRECHECK,E.S. Virginia Power (Virginia Electric & Power Co.)

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 99-002-00:on 990425,MSSVs tested out of tolerance for as C found setpoint,was revealed.Caused by minor setpoint drift.

No immediate action required.Deviation rept submitted for A each valve.With 990518 ltr.

T DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR l_ ENCL j_ SIZE: /_p TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. E NOTES: 05000201 G 0

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL R PD2-1 PD 1 1 EDISON,G. 1 1 y

INTERNAL: ACRS 1 1 AEOD/SPD/RRAB 1 1 1 1 1

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NRR/DSSA/SPLB 1

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1 NRR/Dil?M/IOLB NRR/DRIP/REXB RES/DET/EIB 1

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1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LMITCO MARSHALL 1 1 D NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 0 NOTES: 1 1 C u

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T NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION .415-2083 1 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 18 ENCL 18 I

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10CFR50.73 Virginia Electric And Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 May 18, 1999 U.S. Nuclear Regulatory Commission Serial No.: 99-284 Attention: Document Control Desk SPS: JCS*

Washington, D. C. 20555 Docket No.: 50-281 License No.: DPR-37

Dear Sirs:

Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the*

following Licensee Event Report applicable to Surry Power Station Unit 2.

Report No. 50-281/1999-002-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be forwarded to the Management Safety Review Committee for its review.

Very truly yours,

• ~

E. S. Grecheck Site Vice President Enclosure Commitments contained in this letter: None 9905240126 99051a PDR ADOCK 05000281:

r S PDR.

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cc: U. S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303 Mr. R. A.. Musser NRC Senior Resident Inspector Surry Power Station

I APPROVED BY 0MB NO. 3150-0104

~)RC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION EXPIRES 06/30/2001

$*1998)

Estimated burden per response to comply with this mandatory information collect1on request* 50 hrs Reported lessons learned are incorporated into the hcensmg process and fed back lo 1ndus1ry Forward comments regarding burden eslimate lo lhe Records LICENSEE EVENT REPORT (LER) Management Branch (T-6 F33). U.S. Nuclear Regulalory Comm1ssron.

Washington. DC 20555-0001, and to lhe Papel"NOrk ReduchOn ProJect (3150-0104), Office al Management and Budge\. Washington. DC 20503. If an information collecllOn does not display a currenlly vahd (See reverse for required number of digits/characters for each block) 0MB control number. the NAG may not conducl or sponsor. and a person is not required to respond to, the 1nlormauon collec11on FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3)

SURRY POWER STATION , Unit 2 05000 - 281 1 OF4 TITLE (4)

Main Steam Safety Valves Tested Out of Tolerance for As Found Setpoint I EVENT DATE (5) II LER NUMBER (6) I REPORT DATE (7} I OTHER FACILITIES INVOLVED (8) I FACILITY NAME DOCUMENT NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REVISION DAY YEAR MONTH NUMBER NUMBER 05000-FACILITY NAME DOCUMENT NUMBER 04 25 99 1999 -- 002 -- 00 05 18 99 05000-OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more) (11)

MODE (9) NA 20.2201(b) 20.2203(a)(2)(v) X 50.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 20.2203(a)(1) 20.2203(a)(3)(i) 50.73(a)(2)(ii) 50. 73(a)(2)(x)

LEVEL (10) 0 '7c 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) OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v) Specify in Abstract below 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 E. S. G recheck, Site Vice President I ( ; ; ; ) N ; ; ; : ; ~ ; l ; e kea Code)

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

! l ....~.,:.-:

I CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX TO EPIX I

SUPPLEMENTAL.REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR I (IfYESyes, complete EXPECTED SUBMISSION DATE).

IX I NO SUBMISSION DATE I ABSTRACT (Li~it to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On April 25, 1999, April 27, 1999, and April 28, 1999, with unit 2 in Refueling Shutdown, setpoint testing of Unit 2 Main Steam Safety Valves (MSSVs) revealed that the lift settings for three valves were outside of the as found setpoint tolerance (+/- 3%) that is allowed by Technical Specification (TS) 3.6.A. The event is reportable pursuant to 10CFR50.73(a)(2)(i)(B) for conditions prohibited by TS 3.6.A.

The safety valves were overhauled, adjusted, and tested to verify that they were within the i correct as left setpoint tolerance (+/- 1%) allowed by TS.

I I The event posed no significant safety implications because the safety valves would have still performed their safety function in the event of an overpressure condition. The health and iI safety of the public were not affected at any time.

NRC FORM 366 (6-1998)

NRC FORM 366A . . NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET LER NUMBER/Bl PAGE (3)

YEAR SEQUENTIAL I REVISION Surry Power Station Unit 2 I NUMBER NUMBER 05000 - 281 1999 -- 002 -- 00 2 OF 4 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

1.0 DESCRIPTION

OF THE EVENT On April 25, 1999, Unit 2 was in Refueling Shutdown. As part of the outage scope, the five Main Steam Safety Valves (MSSVs) [EIIS-SB,RV] from "C" header were setpoint tested at Wyle Laboratories. The MSSVs were tested in accordance with a station testing procedure developed pursuant to the Surry Power Station ASME Seqtion XI Testing Program. The as found setpoint of valve 2-MS-SV-203C was 1143.8 psig, outside the acceptable range of 1077 psig - 1143 psig. Due to this failure; two valves from "A" header were selected for expansion of test scope.

On April 27, 1999, the as found setpointof valve 2-MS-SV-201C was 1127 psig, outside the acceptable range of 1053 psig - 1117 psig. Due to this failure, two more valves from "A" header were selected for scope expansion. .

On April 28, 1999, the as found setpoint of valve 2-MS-SV-204A was 1084.6 psig, outside the acceptable range of 1087 psig - 1153 psig. Due to this failure, all remaining MSSVs were tested for a total of fifteen valves. No additional failures were found during the testing.

The event is reportable pursuant to. 10CFR50.73(a)(2)(i)(B) for conditions prohibited by Technical Specifications (TSs) 3.6.A.

2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS The MSSVs provide overpressure protection for Main Steam Supply System piping upstream of. the main steam trip valves [EIIS-SB,ISV]. The as found lift pressure settings for the MSSVs are bounded by the safety analysis for overpressure transients that are part of the current licensing basis.

Each steam line has five associated safety valves. For the valves whose as found lift pressures were* above the design lift (2-MS-SV-201 C and 203C) there is no safety concern. The valves had as found lifts of 3.88% and 3.05% above the design lift setpoint, respectively. From a safety point of view, the order in which the valves open is not a concern, as long as there is adequate discharge before the upper limit of the pressure band is reached.

A valve that opens below its lower limit (2-MS-SV-204A) is not a safety concern. This 11 valve had an as found lift pressure of 1084.6 psig, 3.16% below the design lift setpoint.

This valve opening first in this header would not lead to a safety concern because it would continue to provide relief capacity and its setpoint was sufficiently above the operating range for steam line pressure.

NRC FORM 366A (6-1998)

NRC FORM 366A . . UCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) . DOCKET LER NUMBER (61 r PAGE (3)

YEAR .SEQUENTIAL I REVISION Surry Power Station Unit 2 I NUMBER NUMBER 05000 - 281 1999 -- 002 -- 00 3 OF 4 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 3.0 CAUSE The MSSVs experienced minor setpoint drift which can be expected under normal operating conditions. Although the specific cause of such setpoint drift is not known, its occurrence is well documented in the industry.

4.0 IMMEDIATE CORRECTIVE ACTION(S)

Unit condition at the time of discovery did not require any immediate actions to be performed. A Deviation Report was submitted for each valve to document this condition.

1 5.0 ADDITIONAL CORRECTIVE ACTIONS.

The MSSVs with the As Found lift pressures outside the setpoint allowed by TS 3.6.A were inspected and overhauled by the manufacturer, Dresser Industries, at the Wyle Testing Laboratory. The MSSVs were as left tested in accordance with procedure 2-MPT-0427-02, "Main Steam Safety Setpoint Verification," to verify that the setpoint was within the +/- 1% as left requirement of TS 3.6.A.

• 6.0 ACTIONS TO PREVENT RECURRENCE Safety valve setpoint drift is a recognized phenomenon. Periodic testing and maintenance will continue *to be performed in accordance with Virginia Power ASME Section XI Testing Program for Pumps and Valves to ensure that the valves are maintained as required by TS.

7.0 SIMILAR EVENTS Unit 2 LER 95-002-00, "Main Steam and Pressurizer Safety Valves As Found Lift Settings Out of Tolerance" Unit 1 LER 97-004-00, "Main Steam Safety Valves Out of Tolerance Due to Minor Setpoint Drift."

Unit 2 LER 97-003-00, "Main Steam Safety Valves As Found Setpoint Found Out of Tolerance."

NRC FORM 366A (6*1998)

NRC FORM 366A U. UCLEAR REGULATORY COMMISSION (6-1998) i LICENSEE EVENT REPORT (LER)

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

Surry Power Station Unit 2 YEAR I SEQUENTIAL NUMBER I REVISION NUMBER 05000 - 281 1999 -- 002 -- 00 4 OF4 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 8.0 MANUFACTURER/MODEL NUMBER Consolidated Dresser Industries/Type 3700 9.0 ADDITIONAL INFORMATION Unit 1 was operating at 100% and was not affected by this event.

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II 1J NRG FORM 366A (6-1998)