05000395/LER-1983-011, Forwards LER 83-011/03L-0.Detailed Event Analyis Encl

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Forwards LER 83-011/03L-0.Detailed Event Analyis Encl
ML20069D114
Person / Time
Site: Summer South Carolina Electric & Gas Company icon.png
Issue date: 03/09/1983
From: Dixon O
SOUTH CAROLINA ELECTRIC & GAS CO.
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20069D115 List:
References
NUDOCS 8303180258
Download: ML20069D114 (3)


LER-2083-011, Forwards LER 83-011/03L-0.Detailed Event Analyis Encl
Event date:
Report date:
3952083011R00 - NRC Website

text

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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OPPICE 764 CotuusiA. south CAROLINA 29218 /

o. W. DixoN. JR.

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g, viCr paas.oeur NUCLEAR openATIONS March 9, 1983 8 'y,4g of

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Mr. James P. O'Reilly, Regional Administrator

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  • k U.S. Nuclear Regulatory Commission fg2 Region II, Suite 2900 101 Marietta Street, N.W.

Atlanta, Georgia 30303

SUBJECT:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Thirty Day Written Report LER 83-011

Dear Mr. O'Reilly:

Please find attached Licensee Event Report #83-011 for Virgil C.

Summer Nuclear Station. This Thirty Day Report is required by Technical Specification 6.9.1.13.(b) as a result of entry into Action Statements (a) and (c) of Technical Specification 3.6.4,

" Containment Isolation Valves," on February 8 and 17, 1983.

Should there be any questions, please call us at your convenience.

Very truly yours, O. W. Di n, J .

CJM:OWD:dwf/fjc Attachment cc: V. C. Summer G. D. Moffatt T. C. Nichols, Jr. Site QA E. C. Roberts C. L. Ligon (NSRC)

O. W. Dixon, Jr. G. J. Braddick H. N. Cyrus J. C. Miller H. T. Babb J. L. Skolds D. A. Nauman J. B. Knotts, Jr.

M. B. Whitaker, Jr. B. A. Bursey W. A. Williams, Jr. I&E (Washington)

O. S. Bradham Document Management Branch R. B. Clary INPO Records Center C. A. Price NPCF A. R. Koon File pctAL 00d.

8303180258 830309 DR ADOCK 05000 1

F .

Mr. James P. O'Reilly_

LER No.83-011 Page Two March 9, 1983 r

DETAILED DESCRIPTION OF EVENT t

At 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on February 8, 1983, with the Plant in Mode 1, Nuclear Sampling System Valves 9398 A, B, and C failed'to close during the performance of Technical Specification Surveillance Requirement 4.6.4.3. Each affected penetration was isolated with a closed manual valve by 0630 hours0.00729 days <br />0.175 hours <br />0.00104 weeks <br />2.39715e-4 months <br /> in compliance with Action Statement (c) of Technical Specification 3.6.4.

An additional failure occurred to Valve 9398C on February 17, 1983, at 1505 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.726525e-4 months <br />. The inoperable valve was returned to operable status at 1740 hours0.0201 days <br />0.483 hours <br />0.00288 weeks <br />6.6207e-4 months <br /> in compliance with Action Statement (a) of Technical Specification 3.6.4.

PROBABLE CONSEQUENCES No adverse consequences resulted from'either of these events. The compliance with the Action Statements of Technical Specification '

3.6.4 ensured that the possible loss of containment integrity did not occur.

CAUSE(S) OF THE OCCURRENCE The cause of all but one of the failures is attributed to crud

' buildup on the valve seats which inhibited the normal valve stroke. .The exception dealt with Valve 9398C which did stroke on February 8, 1983, but due to limit switch failure, the valve position indication was in error.

IMMEDIATE CORRECTIVE ACTIONS TAKEN The manual isolation valves for 9398 A, B, and C were closed within 30 minutes of the occurrence on February 8, 1983.

Investigation' performed on February 8, 1983, indicated that Valves 9398 A and B failed to stroke because of crud buildup in the valve body. The valves were returned to operable condition by exercising the valves concurrent with tapping on the valve body.

Crud buildup in the valve body was dislodged, and the valves were declared operable at 1355 hours0.0157 days <br />0.376 hours <br />0.00224 weeks <br />5.155775e-4 months <br /> on February 8, 1983, upon the satisfactory performance of surveillance testing.

Mr. James P.-O'Reilly LER No.83-011 Page Three March 9, 1983.

IMMEDIATE CORRECTIVE ACTIONS TAKEN Continued Valve 9398C was found to have faulty limit switches which failed to provide accurate position indication. The limit switches were replaced, and the valve returned to operation upon the completion of a satisfactory surveillance test at 1820 hours0.0211 days <br />0.506 hours <br />0.00301 weeks <br />6.9251e-4 months <br /> on February 9, 1983.

At 1505 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.726525e-4 months <br /> on February 17, 1983, Valve 9398C again failed to operate properly. Crud buildup in the valve body inhibited valve closure. The crud was dislodged when the valve was exercised concurrent with tapping on the valve body. The valve was returned to operable status at 1740. hours on February 17, 1983, upon the satisfactory completion of surveillance testing.

ACTION TAKEN TO PREVENT RECURRENCE The licensee has determined that the type valve presently installed is not suitable for the application, and plans to replace them as soon as an acceptable alternate can be obtained.

A test program has been established which will exercise Valves 9398A, B, and C on a weekly basis in order to preclude future f ailures of a similar nature.

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