ML20084D013

AO 50-219/74/39:on 740714,electromatic Relief Valve Pressure Switches IA83A,B,C & E Found to Trip at Pressures in Excess of Max Allowable Value of 1070 Psig.Caused by Setpoint Repeatability.Switches Reset

ML20084D013
Person / Time
Site:	Oyster Creek
Issue date:	07/16/1974
From:	Carroll J, Lang R JERSEY CENTRAL POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-219-74-39, NUDOCS 8304080446
Download: ML20084D013 (4)

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To: James P. O'Reilly Directorate of Regulatory Operations h- I r-" .,.,, [',^ Q bp :% ,)

A'l Region I  %..@lf*'; D,/ '

631 Park Avenue -x\lY King of Prussia, Pennsylvania 19406 b8I Y .

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From: Jersey Central Power G Light Co:apany Oycter Creek Nuclear Generating Station Docket #50-219 "

Forked River, New Jersey 08731

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Subject : Abnormal Occurrence Report No. 50-219/74/39 ,

The following is a preliminary report being submitted  ;" [;

in compliance uith the Technical Specifications, 5

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paragraph 6.6.2. - '

Preliminary Approval:'

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b. T. Carroll, Jr. - 'Dat e' cc: Mr. A. Gianhusso r

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8856 8304080446 Y40716 C Oi+Y M f M N .

PDR ADOCK 05000219 S PDR . . ,

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nitial Telephone Date of O -

' Report Date: 7/15/74 Occurrence: 7 /14 / 74

! Initial Written Time of Report Date: 7/16/74 Occurrence: 2300 i

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OYSTER CREEK NUCLEAR GENERATING STATION

, , FORKED RIVER, NEW JERSEY 08731 Abnormal Ocenrrence

, Report No. S0-219/74/ 39 1

IDENTIFICATION Violation of the Technical Specifications, paragraph 2.3.4, OF,0CCURRENCE:

1 Electromatic Relief Valve Pressure Switches 1A83A,1A83B,

! 1A83C, and 1A83E were found to trip at pressures in excess of

, the maximum allowabic value of 1070 psig, i

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This event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.15A.

• l CONDITTONS PRIOR Steady State Power Routine Shutdown

! TO OCCURRENCE: llot Strmdby Ope ration l Cold $ht:td~stn Lead Chang:::: During i ~

Refueling Shutdown Routine Power Operation l Routine Startup X Other (Specify) l _

Operation t

Re reactor mode switch was in the REFUEL position with reactor coolant temperature approximately 150 F.

DESCRIPTION On Sunday, July 14, 1974, while performing surveillance on 0F OCCURRENCE:

the five Electromatic Relief Valvo Pressure Switches,-it was found that 1AS3A,1AS3B,1A83C, and 1A83E tripped at 1083

, psig,1094 psig,1085 psig, and 1089 psig, respectively.

.; %ese values are in excess of the maximum allowabic trip l

points indicated below, which are derived by adding appropriate head correction factors to the Technical Specification limit of 1070 psig. The Electromatic' Rolief Valve Pressure Switches were immediately recalibrated to their correct setpoints, as 9

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Abnormal Occurrence Report No. 50-219/74/39 Page 2 indicated below:

I Associated " Desired" "As Found" "As Left" Switch Valve . Setting Setting Setting 1A83A NR108A 1079 psig 1083 p % 1079 psig 1A83B NRIOSB 1084 psig 1094 psig 1084 psig 1A83C NR108C 1077 psig 1085 psig 1077 psig j 1A83D NR108D 1082 psig 1080 psig 1082 psig j 1A83E NR10SE 1082 psig 1089 psig 1082 psig APPARENT CAUSE Design Procedurc jl OF OCCURRENCE: Manufacturer Unusual Service Condition Installation / Inc. Environmental Construction , Component Failurc Operator X Other (Specify)

Sctpoint repeatability has been tentatively identified as the cause of this occurrence.

ANALYSIS OF The relief valves are provided to remove sufficient energy OCCURRENCE:

from the primary system to prevent the safety valves from listing during a transient. The limiting pressure transienti is that which is produced upon a turbine trip from rated design power with a failure of the bypass system to function. Under these conditions, the five (5) *clief valves are required to operate in order to pre"-9 tb >ressure excursion from reaching the lowest setpoint of u.e p. .sy system safety valves. It should be noted that a 25 psi margin exists between the result-ing peak pressure and the lowest safety valve setpoint as added assurance that the safety valves will not lift during this transient. With valves NR108A, NR10SB, NR10SC, and NR108E actuating at from 4 psig to 10 psig above the maximum allouabic trip point of 1070 psig, and assuming the most limiting pressure

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' Abnormal Occurrence l Report No. 50-219/74/39 Page 3 1

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l transient had occurred, the lowest setpoint safety valve or valves may have been required to actuate in order to limit the pressure transient. Since the safety valve capacity is l based upon providing sufficient vessel over-pressure protec-l tion upon failure of all pressure relieving devices, in addi-tion to a failure of the reactor to scram, over-pressurization of the vessel would not have occurred.

l COP, RECTI VE To be provided following Plant Operations Review Committee ACTION :

review of this event, l

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FAILURE DATA: Manufacturer data pertinent to these switches:

Manufacturer - Dresser Type - 1;3;VY Serial Nurrbers - 1 A83A - BK3337

, 1A83B - BK3339 l

1A83C - BK3340

, IA83E - BN7126 l

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Reference:

Abnormal Occurrence Report No. 50-219/74/29, dated April 23, 1974, l

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Prepared by: f '# tg - Date: 7/15/74 9

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• 2 Jersey Central Power & Light Company  ;

MADISON AVENU!i AT F'UNCH COWL ROAD

• MORRISTOWN,N.J. 07900

• 201-539 6111 pf WEI 4 (I f nf

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svarr v July 23, 1974 f,

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Nr. A. Giambussa Deputy Director for Reactor Projects q , .? ' '01?ls(f) , %. /c!

Directorate of Licensing 6'.

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United States Atomic Energy Commission

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1lashington, D. C. 20545 J -A'\

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Dear Mr. Gianhusso.

Subject:

Oyster Creek Station Docket No. 50-219 Abnornal Occurrence Report No. 50-219/74/39 The purpose of this letter is to forward to you the attached Abnormal Occurrence itcrort in compliance with paragraph 6.6.2.a of the Technical Specifications.

Enclosed are forty copies of this submittal.

Very truly yours ,

%:%LbfL.f :;*dA'E" Donald A. Ross Manager, Nuclear Cencrating Stations es ..

Enclosures cc: Mr. J. P. O'Reilly, Di. rector Directorate of Regulatory Operations, Region I

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-t COPY SENT REGION Mc ' ' 'l J

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.n o, Jersey Central Power & Light Company / j'

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MADISON AVENUE AT PUNCH DOWL ROAD

• MORRISTOWN,it J. 07560

• 201-539-6111 m , e, r ~,

- ._ ._ __ _ _ _ _ _ ce ne r ai EQ g;g;.;. ,, rubw uwines corporation __.__.__ __

Sr$?4 at OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEh' JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/39 Report t, ate July 23, 1974 Occurrence Date July 14, 1974 Identi fication of Occurrence _

Violation of the Technical Specifications, paragraph 2.3.4, electromatic relief valve pressure switches 1A83A, 1AS3B, IA83C, and 1AS3E were found to trip at pressures in excess of the naximun allowabic value of 1070 psig. This event is considered to be an abnormal occurrence as defined in the Technical Specifi-cations, paragraph 1.15A.

Conditions Prior to Occurrence The reactor modo switch was in the REFUEL position with reactor coolant temper-ature approxicately 130 F.

1)escription of Occurrence On Sunday, July 14, 1974, while perforning surveillance on the five electromatic relief valve pressure switches , it was found that suitches 1A83A,1A83B,1 A33C, and 1AS3E tripped at 1083 psig,1094 psig,1085 psig, and 1089 psig, respectively.

'Ihese values are in excess of the maximun allowabic trip points indicated below which are derived by adding appropriate head correction factors to the Technical Specification limit of 1070 psig. These trip point values are within the design limitations of the switch. The electromatic relief valve pressure switches ucre in. mediately recalibrated to their correct set points as indicated below:

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o Abnormal Occurrence No. 50-219/74/39 Page 2 l

Associated " Desired" "As Found" "As 1.cf t" Switch Valve Setting Setting Setting 1A83A NR108A 1079 psig 1083 psig 1079 psig 1A83B NR108B 1084 psig 1094 psig 1084 psig 1A83C NRIOSC 1077 psig 1085 psig 1077 psig 1AS3D NR10SD 1082 psig 1080 psig 1082 psig 1A83E NR108E 1082 psig 1089 psig 1082 psig Apparent Cause of Occurrence The cause of this occurrence is the lack of allowance for set point tolerances in the Technical Specifications.

Analysis of Occurrence The relief valves function to remove sufficient energy from the primary system to prevent the safety valves from lifting during a transient. The limiting pressure transient is that which is produced upon a turbine trip from rated design pcuer with a failure of the bypass systcm to function. . Under these conditions, the five relief valves are required to operate in order to prevent the pressure excursion from reaching the lowest set point of the primary system safety valves.

It shculd bc noted that a 5 pai margin :::ict; b ucen the resulting pod preocure and the lowest safety valve set point as added assurance that the safety valves will not lift during this transient. With valves NRIOSA, NR108D, NR10SC, and NR108E actuating at from 4 psig to 10 psig above the maximum allowabic trip pcint of 1070 psig, and assuming the most limiting pressure transient had occurred, the lowest set point safety valve or valves may have been required to actuate in order to limit the pressure transient. Since the safety valve capacity is based upon providing sufficient vessel overpressure protection upon failure of all pressure relieving devices, in addition to a failure of the reactor to scram, overpressuriza-tion of the vessel would not have occurred.

Corrective Action These switches were reset and surveilled satisfactorily. Jersey Central Power G Light Company, GPU Service Corporation, and General Electric Company personnel, ."

as stated in Abnormal Occurrence Report No. 50-219/74/35, are continuing to investigate this generic problem of set point tolerance.

t Failure Data Manufacturer data pertinent to these switches:

I Manufacturer - Dresser I Type - 1539VX Serial Numbers - 1AS3A - BK3337 1AS3B - BK333t?

1A83C - BK3340 1A83E - BN7126 1

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Reference:

Abnormal Occurrence Report No. 50-219/74/29 dated April 23, 1974 I