ML19257D015

LER 79-156/03L-0:on 791230,during Visual Insp,Local Lexan Reservoir Tube for Snubber 1-RC-HSS-873 Found Damaged & Empty.Apparently Caused by C Steam Generator Blanket Heat. Snubber Replaced & Equipped W/Stainless Steel Reservoir

ML19257D015
Person / Time
Site:	North Anna
Issue date:	01/29/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19257D008	List: ML19257D007 ML19257D015
References
LER-79-156-03L, LER-79-156-3L, NUDOCS 8001310214
Download: ML19257D015 (2)

Text

N HC F O H M 366 . . L, c (7 77)

LICENSEE EVENT REPORT CON TROL HLOCK: l l l l l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 0 1 lV Al N AlS 1 @l0l0 14 IS

- l 0lLICEN5E 0l 0] 0l 0l - 0l Ol@l 4lLICLN>L NUMdE H .1 26 1l Il 1l 1l@lti LAIl bd @

INPt J1

/ H 9 LICEN5EE COLE CON'T

/

0 i b

["fyj lLl@l 4 5l 0l 0l 0l 3l 31 8l@l Il 21 ll 0l 71 91@ ia0 tv 01 DOCKETNUVuEH fd te > EVENT C AIE 74 Il2lolRIn h HE PORT D ATE EJ EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h o / l During visual inspection of hydraulic snubbers not accessible an H ne ro,ctnr nnn,

• i nn I o 3 l the local lexan reservoir tube for snubber 1-RC-HSS-873 was found damaged and co-nletolly o 4 l enpty of fluid. The health and safety of the veneral public were not affected by thic I o s l event. Paportable pursuant to T.S. 6. 9 .1. 9 . b . I O 6 l l 0 7 l l 0 H l 80 7 8 9 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SU6CCDE COYPONEN T CODE SUSCODE SUWCODE 7

O 9 8

l C l A l@ ]@ J@ l S l Ul P l 0 9 10 11 12 13 R l T lh Wh d h 13 19 20

,_ SE QUEN TI AL OCCU R R E r4CE REPORT REVISION LE R 'RO EVENT YEAR REPORT NO. CODE TYPE NO.

O REPORr l7 9[ l_l l1 5l 6 l/l l 0l 3l lL l- l 0l

_ 21 22 23 24 26 27 23 29 30 31 32 ACTION FUTUHE EFFECT SHUTDOWN A TT AC HV E N T NDRD 4 PRIME COMP. COVPONENT TAKEN ACTION ON PL ANT VETHOD HOUHS SUSYlTTED FORYdVB. SU PP LI E R MANUFACTURER l Clg Z g J3 34

[

35 g l36 Zl@ l 0l 0l 0l 3/ 43 lY g 41 lNl@

42 lAl@ lGl2]5 5l@

43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o l Hea t from "C" steam generator blanket apparently caused the lexan reservoir tube to l

[,)i; distort which resulted in the release of the snubber oil. The damaned snubber war I

, ,  ; replaced with a spare snubber calibrated to the proper environmental zone and oculpped I

,i ;3; l with a remote stainless steel reservoir. l li 141 I l 7 8 9 80 ST S ,SCAER OTHER STATUS DISCOV RY DISCOVERY DESCRIPTION Visual Inspection 7

i 5 8 9 4@ l 100l 0l 0l@l NA 12 11 44 l lBl@l 45 46 80 l

AC TIVITY CON TE NT RFLE ASED OF RELE ASE AYOUNT OF ACTIVITY LOCATION oF RELE ASE i c l Z l @ 10l Zlgl NA l 45 NA 80 7 8 9 11 44 PERSONNE L E x POSURES NUVBER TYPE DESCRIPTION 39 F

l1 l7l 7 8 9 l0 l 0 0l@lZl@l 11 12 13 80 PERSONNE L INJUHtES NUVRE R DESCRIPTION i R l0[0l0lgl 7 8 9 11 12 80 LOSS OF OR OAVAGE TO F ACILITY TYPE D E scrlP rlO N l i l oH l9 I ZI@l10 7

NA 2 0 01310 114 80 PU H UCI T Y c N R C US E ON L Y 2 o ] El10 D@DE ISSU NA SCRIP TION l lllllllllllllj 7 8 0 68 69 80 5 N AME OF PPEPARER D D PHONE:

Nrt'right (7 0 ',) __ ",^ 4 5151

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

Attachment:

Page 1 of 1 Doc ke t No. 50-338 Report No. LER 79-156/03L-0 Description of Event During a visual inspection of hydraulic snubbers not accessible during reactor operation, snubber 1-RC-HSS-873 failed to meet the applicable acceptance criteria due to a lack of oil in the local reservoir and damage to the lexan reservoir tube.

Probable Consquences of Occurrence The af fected snubbe r is located on Loop "C" RTD bypass line 1"-RC-1502-Q1.

Without fluid in the reservoir, it was possible that the snubber could have lost its ability to become a rigid strut when subjected to an excessive rate of movement due to seismic ef fects. The health and safety of the general public were not af fected by this event. No generic implications exist for this occurrence.

Cause of Event The distortion of the lexan reservoir tube and subsequent loss of snubber oil apparently resulted from the neat emitted by the "C" steam generator blanket.

Immediate Corrective Action A spare snubber, calibrated to the proper environmental zone, was installed in place of the damaged snubber and the fluid reservoir for the new snubber was changed from a local lexan reservoir to a remote stainless steel reservoir.

Scheduled Corrective Action No scheduled corrective action is required.

Actions Taken to Prevent Recurrence No further actions are required.

1845 146