ML19105A220

LER 1975-012-00 for Surry 2 Re Sudden Closure of Main Steam Trip Valve in B Steam Line, Causing Closure of a & C Trip Valves & Reactor Trip

ML19105A220
Person / Time
Site:	Surry
Issue date:	07/15/1975
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Moseley N NRC/RGN-II
References
Serial No. 598 LER 1975-012-00
Download: ML19105A220 (3)

Text

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• ... * ** .v~*Ro1N1.A. EiECTRIO* .A.No *:rbwEii coMPAri

• • * *-RrnHM~Ni>:ViRGINIA. 23261 *

.*. July'. 15, 19.75

• . Mr.** Noman c/ Moseley, Director*. * -Serial No.

• 598 -* ..

_:_ Offic*e 'of.. Inspection and- .Enforce¢ent . . PO&M/JTB:ciw ':_ '

United States Nuclear Reguiatory*coriimission*

• Region II - Suite 818 * . .. *

• Docket No~ *50...:281 230 Peac,ht:ree. Street,. Northwest* License No. DPR..:.37

• • _Atla:nta , .. Georgia -. 30303

Dear 'l:

1r .:*.*Moseley: .*.

I .***

P~rauant: to. Surry Power St~tion*::;~chnical .Specification *6. 6. B. l ~ *

• the Virginia -Electric and* Power Company hereby: submit.a. f6rty *-(40) copies 1- . -. of Ab.nol:Dlal O~currence Report No. Ab-sz..:.75-12~ . . *., ...

" .. The. sub.stance.*o*f th.1~ report has been. r~vie,ed hy_.th~ Station Nuclear

• Safety *and :operating Committ*ee and 'will be. placed on the agenda fo_~ t_he :- .

.: next meetfo.g ~f th~ System *Nuclear. Sc3:fety: and- Operating Committee.

Very_ *truly yours, .

I_ , . ' -' .*

. *, .. "* . / 1f;:P?lxf?ac4~

. C. M. *Stallings*

' Vice President-Power Supply

,,. , - and: Production. Opet:ations :

'. '* .. . : *,:. -.~ , :  :: ' [ ',  :.~ '.*, ~ ,.

....... ,'}**I' En~losures* -,-. -,_

40 cpp.ies .of AO-:,:sz..:.75'.""12 * *.

. cc*:* . Hr .* K. -;R*. Goller**/* . ' ~.  ; '

.782B*

. ..~ ....

LICENSEE EVENT F!EPORT AO*-S2-75-12 CONTROL BLOCK:j .

• LICENSEE NAME 1

I I 6

LICENSE NUMBER

.EASE PRINT ALL RE:~Ulf.U:IJ lruFORMfl.TION]

LICENSE TYPE EVENT TYPE

@J2J I vi Ajs Jr I I oI o1-1 01 o I oI oI o1-1° Io25l 14!1!1!1101 I31O I 132I 7 B9 15 26 30 REPORT REPORT CATEGORY TYPE. SOURCE DOCKET NUMBER EVENT DATE REPORT DATE

@El CON'T IP jO I LU L!J 101s101-101 2 181 1 1 1011101617 IS! L0!711!417 ISi 7 B 57 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION

@Jg] !During full power operation, the main steam trip valve in B steam line suddenly closed j 7 8 9 80 jojsj !causing the closure of A and C trip valves and a reactor trip. While at hot shutdown I 7 8 9 BO

@El !testing revealed that the A and C main steam trip valves would not close following I 7 B 9 BO

@:@] !reopening. This event is considered an abnormal occurrence since the failure of the J

7 8 9 80)

@]§] jtrip valves to close during testing is an engineered safeguard system malfunction ( cong 7 8 9 PRIME 80 SYSTEM CAUSE COMPONENT COMPONENT CODE CODE COMPONENT CODE SUPPLIER MANUFACTURER VIOLATION

@El IHI Bl L!£..J 1v JA!LI vJE Jx J ~ s l o 11 I s L2:J 7 B 9 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION

~ I Investigation revealed a faulty piston 0-ring in one of the operating cylinders on B 7 8 9 80 IC?]3] l trip valve and trash in the solenoid valve supplying air to the cylinder. Adequate _ _ JI 7 8 9 80

~ I air pressure was not maintained due to blockage in the solenoid valve and leakage (cons) 7 8 9 80 FACILITY METHOD OF STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION EE]

7 8

~

9 Io l oI oj12 10 IN/A 13 44

~

45 46 N/A 80 FORM OF ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 12.@J lu l~ l N/A N/A _J 7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION

[ill I olo Io I lLJ N/A 7 8 9 11 12 13 80 PERS'or',JNEL INJURIES NUMBEH DESCRIPTION 12EJ lo jo, Io II~_N_;_/A_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

7 8 9 11 12 80 OFFSITE CONSEQUENCES E:@J N/ A JBO 7 8 9 LOSS DR DAMAGE TD FACILITY TYPE DESCRIPTION

[ilil *L~ 10I N/A ,_____________________J

• 7 8 9 80 PUBLICITY ill?) N/ A 7 8 9 BO ADDITIONAL FACTDRS-r

[i_@] I N/A I 7 8 9 80

[ill.._[-

7 8 9 80 NAME: E. M. Sweeney, Jr. PHDNE:SS04) 357-3184 .

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GPO OB t

• CG 7

4- .....

EVENT ~ESCRIPTION: (can't) which could render the system incapable of performing its intended function (TS 1.1.6). AO-S2-75-12 CAUSE DE§CRIPTION: (can't) past the 0-ring causing the valve to trip. The 0-ring was replaced and the air lines cleared of all debris. A and C trip valves would not close due to binding between the back of the valve discs and valve body. Non-destructive testing re-vealed no component failures on any valves. The chamfer corner on the edge of the valve discs was rounded by grinding in the area where binding occurred. The corners were ground sufficiently on all valves to allow the disc to be opened approximately two degrees higher than the movement when connected to the operating cylinders.

The load carrying capacity of the discs is not changed by this modification.

(