ML20090D252
| ML20090D252 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/17/1975 |
| From: | JERSEY CENTRAL POWER & LIGHT CO. |
| To: | NRC |
| References | |
| AO-50-219-75-19, NUDOCS 8302250453 | |
| Download: ML20090D252 (2) | |
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O Jersey Central Power & Light Company MADISON AVENUE AT PUNCH BOWL ROAD
- MORRISTOWN, N.J. 07960
- 201-539-6111 Uf erme # W FNs
['3~, runne uwa..: corporation cenerai SF5FE W OYSTER CREEK NUCLEAR GENERATING STATION
. --(.7 s Forked River, New Jersey 08731
<3 Abnormal Occurrence
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Report No. 50-219/75-19
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July 17, 1975
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Occurrence Date July 8, 1975 Identification of Occurrence Violation of the Technical Specifications, paragraph 2.3.3, failure of the RE 03A, B, and D Reactor liigh Pressure Sensors to trip at a value correspond-ing to a reactor pressure of 1060 psig. This event is considered to be an abnormal occurrence as defined in Technical Specifications, paragraph 1.15. A.
Conditions Prior to Occurrence l
l The plant was at steady state power with the following major parameters:
Power:
Core, 1625 MWt Electric, 530 MWe 6 lb/hr Flow:
Recirculation, 50.3 x 10 6
l Feedwater, 5.98 x 10 lb/hr Stack Gas:
11,300 pci/sec Description of Occurrence While performing a routine nonthly surveillance test on the Reactor liigh Pressure Scram Sensors, RE 03A, B, C, and D, it was observed that RE 03A, B, and D tripped above the normal trip points of 1068, 1068, and 1066 respectively.
The trip points of RE 03A and B reflect an 8 psig head correction, while RE 03C and D reflect a 6 psig correction. The surveillance test results were as follows:
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9 Abnormal Occurrence Report No. 50-219/75-19 Page 2 "As Found" "As Left"
" Normal" Trip Point Trip Point Trip Point RE 03A 1077 1068 1069 RE 03B 1076 1068 1068 RE 03C 1065 1065 1066 RE 03D 1071 1066 1066 Apparent Cause of Occurrence The cause of this occurrence is switch repeatability.
Analysis of Occurrence Since three of the four Reactor High Pressure Scram Sensors exceeded the normal trip point, a reactor scram due to high reactor pressure would not have been initiated until reactor pressure reached 1065 psig.
(This is equivalent to 1071 psig with the 6 psig head correction; sensors A and C - channel 1, sensors B and D - channel 2.)
The purpose of these sensors is to prevent power operation above 1060 psig and to back up other scrams in order to assure never reaching the reactor coolant system pressure safety limit. The turbine trip with failure of bypass valves is the worst case transient with respect to peak pressure. The additional reactivity contributing to this transient by delay of Reactor High Pressure Scram action is considered to be minimal.
Corrective Action The sensors were recalibrated and returned to service.
As reported previously, efforts are continuing in an attempt to resolve the incompatibilities which exist between the Technical Specification limits and the sensor performance limits.
Failure Data Manufacturer:
Barksdale Type:
Pressure Actuated Switch Switch No.:
B2T - A12SS Previous abnormal occurrence reports:
No. F0-219/75-7 dated January 23, 1974 No. 50-219/74-36 dated July 10, 1974