05000339/LER-1981-041-03, /03L-0:on 810512,reservoir of Snubber 2-RC-HSS-463-1 Found Empty of Fluid.Caused by Hairline Crack in Lexan Reservoir Tube.Snubber Replaced W/Spare

/03L-0:on 810512,reservoir of Snubber 2-RC-HSS-463-1 Found Empty of Fluid.Caused by Hairline Crack in Lexan Reservoir Tube.Snubber Replaced W/Spare

ML20004D638
Person / Time
Site:	North Anna
Issue date:	06/03/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20004D628	List: 05000339/LER-1981-041, Forwards LER 81-041/03L-0 05000339/LER-1981-041-03, /03L-0:on 810512,reservoir of Snubber 2-RC-HSS-463-1 Found Empty of Fluid.Caused by Hairline Crack in Lexan Reservoir Tube.Snubber Replaced W/Spare
References
LER-81-041-03L, LER-81-41-3L, NUDOCS 8106090603
Download: ML20004D638 (2)

LER-1981-041, /03L-0:on 810512,reservoir of Snubber 2-RC-HSS-463-1 Found Empty of Fluid.Caused by Hairline Crack in Lexan Reservoir Tube.Snubber Replaced W/Spare

Event date:
Report date:
3391981041R03 - NRC Website

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U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK / / / / / / / (1)

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

/O 0/-/0/0/0/0/0/-/0/0/ (3)

/4/1/1/1/1/ (4)

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/V/A/N/A/S/2/ (2) f LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT

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DOCKET NUMBER EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)

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While performing 2-PT-79.2, visual inspection of hydraulic snubbers not

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accessible during reactor operation, the reservoir of snubber 2-RC-HSS-463-1

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was found completely empty of fluid. Since this snubber was changed out with a/

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calibrated shelf spare prior to re-entry into Mode 4 from Mode 5, the health

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and safety of the general public were not affected. This event is reportable /

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pursuant to T.S. 6.9.1.9.b.

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SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

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/C/A/ '(11)__LE/_(12)_LB/ (13) /S/U/P/0/R/T/-_ (14) LD/ (15)

LZ/ (16)

Z SEQUENTIAL OCCURRENCE REPORT REVISION LER/R0 EVENT YEAR REPORT NO.

CODE TYPE NO.

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0 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER LC/ (18) LZ/ (19) LZ/ (20) LZ/ (21) /0/0/0/0/ (22) LY/ (23) /N/ (24) /A/ (25) /G/2/5/5/ (26' CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

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The loss of fluid was due to a hairlir., crack found in tne lexan reservoir

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tube. The damaged snubber was replaced with a spare snabber which was

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previously calibrated and available for service.

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FACILITY METHOD OF STATUS

% POWER OTHER STATUS DISCOE RY DESCRI m 0N (32)

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$/ (28)

/0/0/0/ (29) /

NA LB/ (31)

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VISUAL INSPECTION

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ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35)

LOCATION OF RELEASE (36)

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LZ/ (33)

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NA

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NA

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PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION (39)

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NA

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PERSONNEL INJURIES NUMBER DESCRIPTION (41)

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NA

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LOSS OF OR DAMAGE TO FACILITY (43)

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DESCRIPTION

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PUBLICITY ISSUED DESCRIPTION (45)

NRC USE ONLY

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NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-5151 8106 090 $O3

Virginia Electric and Power Company North Anna Power Station, Unit #2 Attachment: Page 1 of 1 Docket No. 50-339 Report No. LER 81-041/03L-0

Description of Event

With the unit in Mode 5, the snubber supporting reactor coolant loop A cold leg stop valve (MOV-2591) vent line (3/4"-RC-463-1502-Q1) was found empty of fluid during a visual inspection of hydraulic snubbers not accessible during reactor operation.

Probable Consequences of Occurrence The inoperable snubber was replaced with a calibrated shelf spare prior to re-entry into Mode 4 from Mode 5.

Thus the health and safety of the general public were not affected.

i

Cause of Event

The empty fluid reservoir was caused by a hairline crack in the lexan reservoir tube which allowed leakage from the snubber. The cause of the crack is unknown.

Immediate Corrective Action

Upen discovery of the empty snubber, a maintenance report was submitted and the defective snubber was replaced by a calibrated spare.

Scheduled Corrective Action The damaged snubber will be repaired, rebuilt and properly calibrated and made available for service. The surveillance interval for 2-PT-79.2 was changed from 18 months to 12 months 1 25% as required by T.S. 4.7.10.

Actions Taken to Prevent Recurrence No additional action can be taken to prevent recurrence.

Generic Implications There are no generic implications associated with this event.