ML20084D031

AO 50-219/74/37:on 740712,main Steam Line Low Pressure Switches RE23A,B,C & D Found to Trip at Pressures Less than Min Value of 860 Psig.Caused by Switch Repeatability. Corrective Actions Continuing

ML20084D031
Person / Time
Site:	Oyster Creek
Issue date:	07/12/1974
From:	Carroll J, Rone A JERSEY CENTRAL POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-219-74-37, NUDOCS 8304080452
Download: ML20084D031 (5)

Text

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• 50-219 To: James P. O'Reilly Directorate of Regulatory Operations Region 1 , cp'gy, 631 Park Avenue , # /'t King of Pru.<sia, Pennsylvania 19406 i' Ti fc:9(7ik $(f '~;.

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From: Jersey Cent ral I!ower S Light Company

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Oyst er Creck Nuclear Generating Station Docket #50-219 . "' "'

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Forked River, New Jersey 08731 Stbject: Abnormal Occurrence 'leport No. 50-219/74/37 inc f ollowing is a prelininary report being submitted in conpliance with the l'echnical Specifications, i

paragraph 6.6.2.

Preliminary Approval:

I c<wo r 7/12/74 J. T. Carroll, Jrk Date cc: Mr. A. Gianbusso i

g,gy REGION ,

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8304080452 740712 l' PDR ADOCK 05000219 r S PDR

Iqitiaa Telephone Report Date:

O//12/ 74 ~

nete er O Occurrence: 7/12/74 . e i

Initial 11ritten Time'of [

Occurrence: 1000 7/12/74 Report Date:

OYSTER CRiiEr NUCLEAR GENERATING STATION FORKl!D RIVER, NEli JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/ 37 II)ENTIFICATION Violation of the Technical Specifications , paragraph 2.3.7, OF OCCURRENCE

• Main Steam Line Low Pressure Switches RE23A, B, C, and D, found to trip at pressures Icss than the minimum required value of f i

860 psig. ,

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

CONDITIONS PRIOR x Steady State Power Routine Shutdown To occiumn. ~ !!ot Standby Operation Cuid Ghadc.:c.  !"31 < >. ang w n; .-i n g Pefueling Shutdown Routine Power Operation Routine Startup Other (Specify)

Operation Power: Reactor, 1893 MWt Elec. , 640 hide Flow : Recirc. , 16.0 x 10'+ gpm Feed. , 7.07 x 10 6 lb/hr Reactor Pressure: 1020 psig Stack Gas: 15,000 pCi/sec 1)ESCRIPTION OF On Friday, July 12, 1974, at 1000, while performing a routine OCCURRENCE:

surveillance test on the four Main Steam Line Low Pressure l Switches, it was discovered that switches RE23A, B, C, and D l tripped at S42, 848, 846, and 850 psig, respectively. These values are below the minimum required trip point of 860 psig which is derived by adding to the Technical Specification l limit of 850 psig a 10 psig head correction factor.

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I Abiformal OccurrenceO

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Report No. 50-219/74/37 Page 2 i

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. 'Ihe "as found" and "as left" switch settings were- '

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l "As Found" Settings "As Left" Settings .

RE23A '842 psig 860 psig  !

RE2311 848 psig 860 psig  ;

lui23C 846 psig 860 psig i-I RE23D 850 psig 860 psig ,

i i APPARENT CAUSE x Design Procedure i 0F OCCURRENCE: Manufact ure Unusual Service Condition

! Installation / Inc. Environmental  !

Construction Component Failure j Operator Other (Specify) i l l' 4

The cause of this occurrence is switch repeatability, which  !

i is a recognized prob 1cm.  ;

i ANALYSIS OF As indicated in the bases of the Technical Specifications, j l OCCURRENCE.

l "The 10 pressure inclation cf thc Li.i Otenin Li ne:, a i. a3G '

psig was provided to give protection against fast reactor depressurization and the resultant rapid cooldown of the a

l vessel. Advantage was taken of the scram feature which I occurs when the Main Steam Isolation Valves are closed to .

[ provide for reactor shutdown so that high power operation at l low reactor pressure does not occur, thus providing protec- l l

' tion for the fuel cladding integrity safety limit."  ;

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O The adverse consequences of reactor isolation occurring at i a

l l reactor pressure approximately 18 psig belcw the specified minimum value of 860 psig is limited to those effects atten-l dont to a greater than nomal reactor cooldown rate. The l fuel cladding integrity safety limit only comes into effect

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• _- . i Abnomal Occurrence Report No. 50-219/74/37 Page 3 ,

for power operation at reactor pressures less than 600 psig or for power operation greater than 354 FMt with less than 10*a recirculation flow. Therefore, the consequences of a 18 psig lower than normal reactor isolation and scram set-point has no threatening effect whatsoever on the fuel cladding integrity.

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l The effects of a too rapid cooldown due to the lower isola- t I

tion pressure are inconsequential since there is less than j t

2 r difference between the saturation temperr.ture for 850  !

psig and 832 psig. ,

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C0llRFCTI VE Continuing corrective action on this matter is as stated -

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in previous abnormal occurrence reports. {

FAILURE D.iTA:  !!anufacturer data pt ztinent to these switches are as follows: j bleletron Corp. (subsidiary of barksdale)  ;

1.os Angeles , Cali fomia  ;

Pressure Actuated Switch  !

Flodel 372 I Catalog # 372-6SS49A-293 '

Range 20-1400 psig Proof Psi. 1750 G l, Previous Abnormal Occurrence !!cperts involving these switches i

are:

1. Letter to F!r. A. Giambusso from Ftr. D. A. Ross, dated December 24, 1973.

2. '

Abnormal Occurrence Report No. 74-1

3. Abnormal Occurrence Report No. 74-9.

4 Almormal Occurrence Report No. 74-10.

• db'ho'ri:a1 Occurrence o -

Report No. 50-219/74/37 Page 4 I

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. 5. Abnormal Occurrence Report No. 74-12.

6. Abnormal Occurrence Report No. 74-22.

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7. Abnormal Occurrence Report No. 74-35.

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