ML20090D114
| ML20090D114 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/17/1975 |
| From: | Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20090D121 | List: |
| References | |
| AO-75-27, GN-75-032, GN-75-32, NUDOCS 8302240067 | |
| Download: ML20090D114 (4) | |
Text
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GN-75-032
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Jersey Central Power & Light Company MADISON AVENUE AT PUNCH BOWL ROAD
- MORRISTOWN. N.J. 07960
- 201-539-6111
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Public Utahties Corporation General SF$f a.
0YSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Abnormal Occurrence Report No. 50-219/75-27 Report Date October 17, 1975 Occurrence Date October S, 1975 1
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Identification of Occurrence I
Violation of Technical Specifications, paragraph 3.1.1.D.3, Low Reactor
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Pressure Core Spray Valve Permissive Pressure Switches RE17B and D were
[ound to t_rin at pressures less than the minimum required value of 285 psig.
7 rhis event is considered to be an a'bnormal occurrence as defined in the Technical Specifications, paragraph 1.15.B.
Conditions Prior to Occurrence The plant was at steady state power with the following major parameters:
l Power:
Core, 582.6 FMt i
Elect ric, 155 FMe 4
Flow:
Recirculation, 6.0 x 10 Feedwater, 1.77 x 106 lb/hr Stack Gas:
3090 pei/sec 1
Description of Occurrence 1
4 On Wednesday, October 8, 1975, at approximately 1130, while performing quarterly surveillance testing on the four (4) I,ow Reactor Pressure Core Spray Valve Permissive Pressure Switches, it was discovered that RE17B and D tripped at 275 psig and 277 psig, respectively. These values are less than the Technical Specification limit of 285 psig.
Pressure switches RE17B and D were immediately recalibrated.
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GN-75-032 j '..,
Abnormal Occurrence Report No.~ 50-219/75-27 Page 2 The "As Found" and "As Left" switch settings were:
"As Found" Settings "As Left" Settings RE17A 285 psig 285 psig RE17B 275 psig 287 psig RE17C 285 psig 285 psig RE17D 277 psig 289 psig Apparent Cause of Occurrenc.e The cause of this occurrenca is switch repeatability.
Analysis of Occurrence The core spray system parallel isolation valves open when a low-low reactor water level and/or high drywell pressure condition exists in addition to a low reactor pressure condition (285 psig). The four (4) low reactor pressure core spray valve permissive pressure switches sense the low reactor pressure condition and provide signals to the valve opening logic. Two (2) of these switches (RE17A and B) are associated with Core Spray System 1 and the other two (2) switches (RE17C and D) are associated with Core Spray System 2.
A trip of one switch in each core spray system is required to effect parallel isolation valve opening in that system. A review of the "as found" switch settings indicates that parallel isolation valves in both core spray systems would have opened at reactor pressure of 285 psig had a reactor low-low water level and/or high drywell pressure condition existed concurrently. The safety significance of this event is considered to be the loss of switch redundancy.
Corrective Action Immediate corrective action involved the recalibration of pressure switches RE17B and D.
There are continuing efforts to resolve the incompatibilities between the Technical Specification setpoint limits and the sensor performance limits.
It is felt that the conservative design margins associated with the derivation of the plant safety' limits will permit a change in the Technical Specifications to be made whicl' will take into account the expected sensor performance variations. This will eliminate instances of abnormal occurrence repcrts caused by the normal variation in a sensor setpoint within the design margins of the plant safety limits.
Failure Data Manufacturer:
Barksdale Type:
Pressure Actuated Switch Range:
50-1200 psig Switch No.:
32T-A12SS (RE17B)
B2T-A12SS (RE17D)
l GN-75-032 l
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Abnormal Occurrence' Report No. 50-219/75-27 Page 3
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Previous abnormal occurrence reports involving these switches are:
1.
' Abnormal Occurrence Report No. 50-219/74-9 2.
Abnormal Occurrence Report No. 50-219/74-10 3.
Abnormal Occurrence Report No. 50-219/74-12 4.
Abnormal Occurrence Report No. 50-219/74-22 5.
Abnormal Occurrence Report No. 50-219/74-35 6.
Abnormal Occurrence Report No. 50-219/74-37 7.
Abnormal Occurrence Report No. 50-219/74-41 8.
Abnormal Occurrence Report No. 50-219/74-42 5
9.
Abnormal Occurrence Report No. 50-219/74-43 10.
Abnormal Occurrence Report No. 50-219/74-51 11.
Abnormal Occurrence Report No. 50-219/75-12 I
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'GN-75-032 u
J Jersey Central Power & Light Company MADISON AVENUE AT PUNCH BOVA. ROAD
- MORRISTOWN, N.J. 07960
- 201-539-6111 NLNE6 R Of 1NL s
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Octobec 17, 1975 l
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- gU.3dIUT Mr. R. Boyd, Acting Director g
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Division of Reacter Licensing 0[$ff, Office of Nuclear Reactor Regulation
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s, United States Nuclear Regulatory Commission rG Washington, D. C. 20555
Dear Mr. Boyd:
EFILE COPY
Subject:
Oyster Creek Station Docket No. 50-219 Abnormal Occurrence Report No. 50-219/75-27 l
The purpose of this Ictter is to forward to you the attached abnormal occurrence report in compliance with paragraph 6.6.2.a of the
.l Technical Specifications.
Vo truly yours,
/
/
Donald A. Ross, Manager Generating Stations-Nuc1 car es Enclosures cc:
Mr. J. P. O'Reilly, Director Office of Inspection and Enforcement, Region 1 COPY SENT REGION 3w I 'a Fr m c)
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