ML18152B074

LER 88-022-00:on 880710,unit Ramped Down to Shutdown.Caused by MOV-CS-101B Leakage Due to Lost Motion in Shaft & Linkage Between Motor Operator & Shaft.Valve Disassembled & Valve Seat & O-rings replaced.W/880808 Ltr

ML18152B074
Person / Time
Site:	Surry
Issue date:	08/08/1988
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-036, 88-36, LER-88-022, LER-88-22, NUDOCS 8808160245
Download: ML18152B074 (4)

Text

POW 28-06-01 NnC Form 381! U.S. NUCLEAR REGULATORY COMMISSION (9-831 APPROVED 0MB NO. 3160-0104

'** EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LER)

FACILITY NAME 111 OOCKET NUMBER 121 I PAGE 131 TITLE 141 Surry Power S'tation, Unit 1 Io Is I o Io I o 12 18 D 1 loF O I 3 Unit Rampdown To Cold Shutdown Due To MOV-CS-1018 Leakage EVENT DATE 151 LER NUMBER 161 REPORT DATE 171 OTHER FACILITIES INVOLVED 181 MONTH DAY YEAR YEAR t:t SE~~~~~~L tt: ~~~i~ MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Cht1ek on* or mor* of th* fol/oV(ing) 1111 OPERATING MODE 191 N 20.402(b)

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LICENSEE CONTACT FOR THIS LER 112)

S0.731oll2llvlll)IB) 50.731oll211xl NAME TELEPHONE NUMBER AREA CODE D. L. Ben son . Station Manaaer 8 10 14 3 I 51 71 -I 3 11 18 I 4 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 113)

MANUFAC- MANUFAC-CAUSE SYSTEM COMPONENT TURER TURER X B IE I rs rv I P 13 IO 14 y I I I I I I I I I I I I I I ii!i!:!i!iii!i!i!i!i!i!ilili!ili!iiiiii:iiiiiii:iiiii I I I I I I I 'j////////lil///lililiii!iiiii///i!////////iijj/j/i/

SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR EXPECTED n ~

SUBMISSION DATE 115)

YES /If yo1, compl*to EXPECTED SUB~ISSIDN DATE/ NO I I I ABSTRACT /Limit to 1400 1p,,cM, i.o., oppro,c/moto/y fiftnn 1/nglo-1poc* rypowr/mn linM) 118)

On July 10, 1988 at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, Unit 1 was at intermediate shutdown conditions with the Reactor Coolant System at 490 degrees and 1900 _psig. While investigating observed refueling water storage tank level decrease and recirculatiqn spray sump level increase, a leakage test performed on the 'A' containment spray pump discharge isolation valve indicated high leakage through the valve. At 0455 hours0.00527 days <br />0.126 hours <br />7.523148e-4 weeks <br />1.731275e-4 months <br /> on July 11, 1988, a unit cooldown to less than 200 degrees was commenced to repair the valve and a Notification of Unusual Event (NOUE) was declared.

At 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on July 11, 1988, the unit reached cold shutdown conditions and the NOUE was terminated. The cause of the valve leakage was the lost motion in the shaft and linkage between the motor operator and the valve. A contributing factor was the improper "close" limit switch setting. The valve was disassembled and the valve seat and "O" rings were replaced and the valve to motor shaft was welded. The limit switch settings were adjusted and the valve was tested satisfactorily.

8808160245 880808 PDR ADOCK 05000280 S PNU NRC Form 3811 19-83)

NRCrfarm 368A (9-83.J FACILITY NAME (11 LICENSEE .T REPORT (LER) TEXT CONTINUA DOCKET NUMBER (21 N

POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION LER NUMBER (61 APPROVED 0MB NO. 3150-0104 EXPIRES: B/31 /88

SEQUENTIAL ::::::::::: REVISION PAGE (31 YEAR -:::::::::: NUMBER  ::;:;::::: NUMBER Surry Power Station, Unit 1 01s101010121a10 a,s -01212-010 012 oFO 13 TEXT /ff more $/JIIC9 is required, use *dditiona/ NRC Form 36/iA'a/ (171 1.0 Description of the Event On July 10, 1988 at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, Unit 1 was at intermediate shutdown with the Reactor Coolant System (RCS) at 490 degrees and 1900 psig. In an attempt to determine the cause of an observed refueling water storage tank level decrease and recirculation spray sump level increase, a leakage test was performed on the 'A' containment spray (CS) pump {EIIS-BE} discharge valve {EIIS-ISV} 1-MOV-CS-lOlB. The type 'C' containment valve leakage test requires blank flanges to be installed on the cs lines within containment.

This leakage test provided valve leakage data in the reverse direction, e.g. leakage into containment. The test indicated that there was high leakage through the valve. After some adjustments to the valve, the test was repeated and indications of high leakage remained.

Based on the test results, a decision was made to commence a unit cooldown to less than 200 degrees (CSD) in order to facilitate repair of the valve. A Notification of Unusual Event (NOUE) was declared on July 11, 1988 at 0455 hours0.00527 days <br />0.126 hours <br />7.523148e-4 weeks <br />1.731275e-4 months <br />. At 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, that same day, the unit reached CSD and the NOUE was terminated.

With the unit at CSD, flanges were installed on the cs lines in containment and a satisfactory type 'C' test was performed. However, the decision was made to disassemble the valve and inspect it.

2.0 Safety Consequences and Implications The CS pump discharge valve, 1-MOV-CS-lOlB, along with its parallel valve 1-MOV-CS-lOlA and an upstream check valve (1-CS-13) in containment, serve to provide containment isolation, during an accident, for the 'A' train of the CS system if required. Since the leakage test performed on MOV-CS-101B was not designed to quantify containment out leakage through the valve, the status of the valve as a containment boundary could not be determined. Therefore, the decision was made to repair the valve and the unit was ramped to CSD within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> of the event. At CSD a satisfactory type 'C' test was performed. In addition, the check valve, 1-CS-13, upstream of the parallel MOVs, remained operable to serve as a containment isolation boundary.

Therefore, the health and safety of the public were not affected.

NRC FORM 366A *u.s. GPO, 1988-520-589*00070 (9-831 1--

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N Rl Form 366A (9-83)

LICENSEE NT REPORT (LER) TEXT CONTINUA I N POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150-0104 EXPIRES: 8/31 /88 FACILITY NAME (1) DOCKET NUMBER (21 LER NUMBER (61 PAGE (31 Surry Power Station, Unit 1 o Is , o , o , o , 2 , s 10 aa - o 12 12 - o Io o , 3 oF o13 TEXT /ff more space is required, uStl additional NRC Form 366A's) (17) 3.0 Cause During the investigation of the failure, the valve seat was noted to be slightly damaged. The cause of the valve leakage was determined to be the lost motion in the shaft and linkage between the motor operator and the valve. A contributing factor was the improper setting of the "close" limit switch. The combination of the limit switch setting and the lost motion in the shaft and linkage resulted in the valve failing to completely close.

4.0 Immediate Corrective Action(s)

Following the performance of the leakage tests, the unit was ramped to cold shutdown and a NOUE was declared.

5.0 Additional Corrective Action(s)

While at cold shutdown, the valve was disassembled and the valve seat and "O" rings were replaced. The valve to motor shaft was welded to ensure rigidity and to remove the lost motion. The limit switch settings were adjusted. The valve was retested satisfactorily per 10CFR50 appendix J requirements.

6.0 Action(s) Taken to Prevent Recurrence A review of the design of this valve is being conducted.

7.0 Similar Events None.

8.0 Manufacturer/Model Number CS-MOV-101B: Posi-Seal Int'l Inc.

DWG. 22462-02.

NRC FORM 3eeA *u. s. GPO, 1988-520-5891 00010 (9-831

'j e

VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 316 Surry, Virginia 23883 August 8, 1988 U.S. Nuclear Regulatory Commission Serial No.: 88-036 Docmnent Control Desk Docket No.: 50-280 016 Phillips Building Licensee No.: DPR-32 Washington, D.C. 20555 Gentlemen:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Coapany hereby submits the following Licensee Event Report for Surry Unit 1.

REPORT NUMBER 88-022-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control.

Very truly yours, t~

David L. Benson Station 11.a.nager Enclosure cc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323