ML19305A332

LER 79-009/03L-0 on 790212:during Normal Operation,Snubber Support for C Steam Generator Atmosphere Discharge Line Found Damaged.Caused by Use of Support as Anchor for Chain Fall.Support Replaced

ML19305A332
Person / Time
Site:	North Anna
Issue date:	03/08/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19305A323	List: ML19305A322 ML19305A332
References
LER-79-009-03L, LER-79-9-3L, NUDOCS 7903130310
Download: ML19305A332 (2)

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T.i HEPOR T D ATE e '3 LVLNT DESCHIPTION AND PROU ABLE CONSEQUENCES h FoV] Louring normal power opprations, a snubber support for "c" steam aenerator atmosohere i o 3 l discharge line was found to be damaged. The support was replaced and the snubber I o 4 [ reinstalled. This event did not . jeopardize the health and safety of the general I n ., [public. Reportable pursuant to T.S. S.9.1.9.b. l c l

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Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Paqe 1 of 1 Dcrket No: 50-338 Report No: LER/R0 79-009/03L-0 Description of Event On February 12, 1979 during normal power onerations snubber suoport H-238, to wnich snubber 1-SAE-HSS-238 is connected, was found to be damaged. Snubber 1-SAE-HSS-238 restrains a ten inch main steamline, which is atmospheric discharge line for "C" steam generator.

Probable Consequences of Event The consequences of this event were limited. The damage to the snubber support made its behavior unpredictable in a seismic event. The amount of angular deflection was only three degrees, significantly less than the maximum five degrees alloweo. However, in accordance with the plant Technical Specification 3/4.7.10., Surveillance Requirements, supports to which snubbers are connected are classified as part of the snubber. Therefore, it was necessary to classify the snubber as Inoperable, even though the possibility of it performing unsatisfactorily was remote. Also, the damaged support was reolaced and the snubber reinstalled within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, well within the T.5. 3/4.7.10 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time limit. Therefore, the pt+1ic health and safety were not endangered.

Cause Examination of the snubber support indicated that a person or persons unknown had used the support as an anchor for a chain fall. This caused the support, which is L-shaped, to be twisted 3 degrees about its longest leg.

Immediate Corrective Action The damaged snubber support was replaced with a new, identical suoport and the snubber reinstalled. Since the snubber, itself, was operable per the appropriate T.S. surveillance requirements, the appropriate surveillance interval is unaffected.

Scheduled Corrective Action None required.

Action Taken To Prevent Recurrence None required.