ML20084D031
| 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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,N 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'
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Oyst er Creck Nuclear Generating Station Docket #50-219 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, paragraph 6.6.2.
i Preliminary Approval:
I c<wo r 7/12/74 J. T. Carroll, Jrk Date cc:
Mr. A. Gianbusso i
6 67o g,gy REGION e
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Occurrence:
7/12/74 e
Report Date:
//12/ 74 i
Time'of
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Initial 11ritten Report Date:
7/12/74 Occurrence:
1000 OYSTER CRiiEr NUCLEAR GENERATING STATION FORKl!D RIVER, NEli JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/ 37 Violation of the Technical Specifications, paragraph 2.3.7, II)ENTIFICATION 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 6
Feed., 7.07 x 10 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 Switches, it was discovered that switches RE23A, B, C, and D 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 limit of 850 psig a 10 psig head correction factor.
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Abiformal Occurrence a
Report No. 50-219/74/37 Page 2 i
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'Ihe "as found" and "as left" switch settings were-t t
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
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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."
l
}.
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 3.CrlU.M :
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in previous abnormal occurrence reports.
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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.
o
- db'ho'ri:a1 Occurrence Report No. 50-219/74/37 Page 4 1
i 5.
Abnormal Occurrence Report No. 74-12.
6.
Abnormal Occurrence Report No. 74-22.
i 7.
Abnormal Occurrence Report No. 74-35.
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