ML20084D026

AO 50-219/74/38:MSIV NS04B Failed to Close in Less than 10 S.Cause Under investigation.Four-way Valve in Pilot Valve Assembly Cleaned & Relubricated

ML20084D026
Person / Time
Site:	Oyster Creek
Issue date:	07/16/1974
From:	Carroll J JERSEY CENTRAL POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-219-74-38, NUDOCS 8304080450
Download: ML20084D026 (3)

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} m~19 To: Jaros Utrectorato of Repilatory Operations Rogica I 631 Park Avenue King of Prussia, Pennsylvania 19406 1:ron: Jersey Central Power g 1.ight co repany Oyster Creek Nuclear Generating Station Doclot 650-219 Poyked River, New Jersey 08731 subject: Abnornal Occurrence Report No. 50-219/74/38 l

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'Iho following i:; a pre 11'ainary report being submitted in corpliuneu with the Tedinical Specifications, l'arnBraph 6,6,2 .

PrelirinaIy Approval:

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L /& n d [ ( 7/16/74 hT. Carroll, Jr. Dato cc: Mr. A. Giarhtuso 1

I1 8304080450 740716 PDR ADOCK 05000219 ~~ ~~

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• ' OYSThT'JUK 1;UChEAR GENUBATING STATIO FORKED RIVER, NEW JERSliY 08731 N>nortul Occurrence i P.eport No. 50-219/74/ g i IDEh'TIFIC ATIO:1 Violation of the Tec;mical Specifications, paragraph l

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OF OCCURREMCE:

4.5.1.2, failure of !!aln Steau 19013 tion Valve NSO.in to  !

close in less then ten seconds.

'Ihis event is considered to be on abnorr.a1 occurrence as de-fined in the TecJmical Specifications, paragrnphs 1.150 and E.

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l L Steady State Power Routine Shutdown ";

OXiDITIONS PRIOR l TO OCCURIOlCE: X llot Stcndby Operation f Load Gian get. During i l Cold Ehutdown i l __ _ Refueling Shutdown Routine Power Operation Routine Startup other (Specify) ,

Operation _ _ _ _ _ _ _

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I At the tice of the full clonure surveillance of the unin stena  !

isolation valves, the reactor was shut do,n with all ec.ntrol i rods fully inserted and a reactor coolant temperature of approxi-nately 160%.  ;

D:iSCatPTION During the routine full closure surveillance test of the main OF OCOJius:m:

steau' isolation valves, perforced as part of the routine p1;:nt {

startup operation, it was obseric'd tihat !4in Steam isolation i Valve N504B closed jn 13.0 ccond Two subsequent trials re- f sulted in ti m of 8.0 and 8.S $cconds. The valve test resulth ]

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Kn v ~ Full clornro Tir:a o

NS03A 6.5 s c..

NSO4/s 8.0 sec.

NS038 4.5 soc.

NSO4B 13.0 see APPAFENT CW.I! _

pesi m _ Procedure OF OCCURRL::CE: Manufa ture .

Unusual Service Condition Installation / Inc. Environnental Construction Co'eponent Failure j Operator __ Other (Specify) l - .. -

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We cause of this occurrence is tmder investigation.

NJMXSIS OF 'ihe ten seco :d carinun tino for full closure of the nain sicua OCCURRENCB:

icolation vntvos is to provide a safety cargin in the event of a rain steam line bred.. Clo.ture of thoso valves minimizos the radioact vc dosc to the envions and provide: for caintaining a coolant Icvel above the fuel .r.r.cthlies in the reactor with-out consideration of coolant n% cup systems. The failure of one main stera isolation valve to close in the required tine remover, the safety system redundancy. If a stoaa lino braak had occurred, NS03D would have isolated the systen in the required tire.

CORRECTIi'E The four-way valve in the pilot valvo assorbly was cicaned and ACTION:

relubri ent ed. 1he valve was ratested with satisfactory results.

FAllE t Df.TA: Not applicabic..

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Jersey Central Power & Light Company f'

MADISON AVENUE /sT PUNCH BOWL ROAD e MORRISTOWN, N.J. 07960

• 201533-G111

.a ..u a r-a cerera: jffjjjj"', Pubhc Ut.hties Corpornen - _._ _ _ _____

$ > S TE M July 23, 1974 f\,P OLLill)4

n. gr,n Mr. A. Giambusso f- -

h?j f:[g Deputy Director for Reactor Projects V; c~ //'A -

Directorate of Licensing IM United States Atomic Energy Coccission Washington, D. C. 20545 h ',, y,7 m A%3t(( lh_:l k //

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Dear t!r. Gianbusso:

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Subject:

Oyster Creek Station Dc40 ':e. 50 210 Abnormal Occurrence Report No. 50-219/74/38 The purpose of this letter is to fon ard to you the attached Abnormal Occurrence Report in compliance with paragraph 6.6.2.a of the Technical Specif cations.

Enclosed are forty copies of this submittal.

Very truly yours, c ,- ,

's M/( h (I . } c S~ ~ O Donald A. Ross Manager, Nuclear Generating Stations ..

cs Enclosures cc: !!r. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region I t

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COPY SFNr REGION X_ p

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1 Jersey Central Power & Light Company "

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' ]o MADICON AVENUE AT PUNCH BOW 1. ROAD

• MORRISTOWN, N.J. 07900

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OYSTER CREEK NUCLEAR GENEPATIN6 STATION FORKED R1VER, NEW JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/38 Report Date

. July 23,1974 1

i Occurrence Date i

July 14, 1974 Identification of Occurrence Violation of the Technical Specifications, paragraph 4.5.I.2, failure of the main stean isolation valve NSOIB to close in less than 10 seconds. This event is considered to be an abnormal occurrence as defined in the Technical Specifi-cations, paragraphs 1.15D and E.

Conditions Prior to Occurrence The reactor was shut down and reactor coolant temperature was approximately 160*F.

i Description of Occurrence During the routine full closure surveillance test of the main steam isolation ,

valves, performed as part of the prerequisites to a plant startup, it was observed that main steam isolation valve NSO4B closed in 13.0 seconds. 'lho subsequent trials resulted in times of 8.0 and 8.5 seconds.

Apparent Cause of Occurrence As a result of installation of the new pilot control system for the main steam isolation valves' air operators, throttling of the hydraulic speed control valves to some degree greater tluin with the former system appears to be necessary to control the closing speed for the valves. The increased throttling appears to have decreased somewhat the sensitivity ot? the hydraulic valves themse]ves.

Consequently, repeatability of the closing speeds is not as firm as it has becn in the past.

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O Abnormal Occurrence No. 50-219/74/38 Page 2 Analysis of Occurrence The 10 second maximum time for full closure of the main steam isolation valves is to provide a safety margin in the event of a main stean line break. Closure of these valves minimizes the radioactive dose to the environs and provides for naintaining a coolant level above the fuel assecblics in the reactor without consideration of coolant makeup systems. The failure 'of one main steam isolation valve to close in the required time renoved the system redundancy. If a stcan line break had occurred, NS03B would have isolated the system in the required tire.

Corrective Action In order to clininate any question as to the operability of the new main steam isolation valve pilot modifications, the four-way valve in the pilot valve assenbly was inspected, cleaned and relubricated. Following reinstallation, the valve uns retested but still did not close within the required time. The hydraulic needle valves were then adjusted to give the required closing speed. Action had previously been initiated to purchase nore sensitive hydraulic valve stems to permit better throttling characteristics. However, the valve stems purchased were not sized properly for the actual hydraulic valves installed. Since installation of the modified pilot assemblies, new hydraulic valves have been ordered. Current plans are te inct:11 there t' nite di' ring tha +1rst anuronvn eynaro nryweit onrry , s allewed) following receipt of the new valves.

Failure Data Not applicabic.

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