ML20064H877

/01T-0 on 781205:during Refueling Outage 6 Msiv'S Exceeded Leakage Limits.Caused by Degradation of Valve Seating Surfaces Thru Normal Oper

ML20064H877
Person / Time
Site:	Browns Ferry
Issue date:	12/18/1978
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20064H876	List: ML20064H869 ML20064H877
References
LER-78-034-01T, LER-78-34-1T, NUDOCS 7812270269
Download: ML20064H877 (2)

Text

NRC FORM 366 U. S. NUCLEAR REOULATORY COMMISSl!N CL77)

LICENSEE EVENT REPORT

~

s.

(PLEASE PRINT OR TYPE ALL REQUIREO INFORMATIONI CONTR"Ot BLOCK: l 1

l l

! l I 6

lh lo l1l l Al Ll Bl Rl Fl 1l@dj 0 l -l 0 lLICENSE Ol 0lNW'.tdER 010 l -l O l O l@l 4UCENSE 23 26 l ll ll TYPE 1l 1l@l JJ l

67 GT $$

l@

7 8 9 UCENSEE CCCE 14 :S CON'T IOI1l TRc, S

lL ]@l 01 5l O! 0l 0121519 6d@l 6911210 l Sl 7 l 8 l@l 1l 2 REPORT EVENT QATE 24 7S l 118QATE l 7 l 830l@

7 8 60 61 OCCKET NUM8ER EVf NT DES RIPTION AND PROBABLE CONSEQUENCES h '

IO I2l l During a refueling outage, while performing local leak rate tesCing, six MSIV's, FCV's IO ia i l 1-14,1-15,1-51,1-52,1-37, and 1-38, exceeded the leakage limits of T.S.4.7. A.2.1. l 10141 l FCV's 1-14,1-15,1-51, and 1-52 leakage was greater than 2,196 SCFH.FCV's 1-37 and 1-38 i i lo Isl I leakage was greater than 1,986 SCFH. Redundant systees were not applicable since the l l o is i l reacter was in the refueling mode. There was no hazard to the public health or safety.l l

LO W [ Previcus occurrence: BFRO-50-259/7723.

I I'O ITl i E CODE SU C E COMPONENT CODE Sus E S E

[0_[9_l 7 8 l Cl Dlh Wh l B lh lV l A l L l V l E I X lh lF lh [G_] h 9 10 11 12 13 18 19 20 REPORT REylSION SEQUENTIAL CCCURRENCE EVENT YEam REPORT NO. CODE TYPE N O.

LE R a

O sgo,/RO g 17181 1-1 Lo l 3141 1-1 10 11 I I Tl I-I lo l

_ 21 22 23 24 26 27 28 29 30 31 J2 T K N CT ON ONP 47 1 O MOURS 2 38 I E FO 8. SUP*L MA FA TURER lZl@lBl@

3J 34 l3hZ l@ lZl@

36 l0l0l0l0l 37 40 l41Y l@ lN[g 42 lNl@

43 lAl5l8l5l@

44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS l i l 0 l l The defective valves were 26-inch Atwood-Morill giche valves, pneumatic a ctuation, I i i l operating pressure rating of 1,250 psig at 575 F. The cause of the occurret*ce was  !

[ 71 l degradation of valve seating surfaces through normal operation. I i a l l I

l i i 41 1 80 7 ae ST  %>OWER OTMER STATUS 015 O RY DISCOVERY OESCRIPTION I i i s 1 [_JJjh l 0 l 0 l 0 l@l NA l lBl@l Surveillance Test l ACTIVITY CO TENT RELE ASED OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RELEASE NA l l NA l W [Z_]

7 8 9

@ l Zl @ l1t10 44 45 80 i

PERSONNEL EXPOSURES Nuv8E R TYPE DESCRIPTION 4-NA l

lTTTl 10 l0 l0 'l@l zl@l

' ' ' ,ERSONu'LINau'4ES NLveER oESCniPTiONh I

li le 8l 9l0 l010 l@l 7 11 12 NA

$4 LOSS OF 09 04 MAGE TO FACILITY Q TYPE DESCRIPTION  %/

NA l li' 191 ' '

IZ l@l '

PUeusTv issuEn oESCRiPriON 781227C&4 D NRc UsE ONov t

12 i a l [,N_j@l NA l IIIlIIllll lIII

, , 3 io se e, so 2 vants ns Pncoanco _ . . . PHONE:

Farm BF-17 BF 15.2

• 6/09/78 i LER SUPPLDIENTAL INFORMATION "BFRO 259 / 7834 Technical Specification Involved 4.7.A.2.1 Reported Under Technical Specification 6.7.2.a (3) 12/5/78 unknown Unit 1 Date of Occurrence Time of Occurrence .

Identification and Descriotion of Occurrence: -

Six MSIV's, FCV's 1-14, 1-15, 1-51, 1-52, 1-37, and 1-38, exceeded the leak rate allowed by T.S. 4.7.A.2.1 during local leak rate testing. The following are the leak rares:

FCV's 1-14, 1-15, 1-51,and 1-52 indicated a leak rate greater than 2,196 SCFH.

FCV's.1-37 and 1-38 indicated a leak race greater than 1,986 SCFH.

Conditions Price to Occurrence: - ,

Unit shutdown for refueling. The' reactor head was off. ,

Action specified in the Technical Specification Surveillance Requirements met due to inoperable eauioment. Describe .

Repair and retest to be completed. .

Apparent Cause of Occurrence:

Degradation of valve seating surface due to normal wear.

Analysis of Occurrence:

Nond Corrective Action:

Valves will be repaired and satisfactorily retested prior to return to service of the unit.

Failure Data:

BFRO-50-259/7723 Tennessee Valley Authority - Browns. Ferry Nuclear Plant l

t l

,