ML20083C645
| ML20083C645 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/08/1983 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| RO-83-02T, RO-83-2T, NUDOCS 8312230223 | |
| Download: ML20083C645 (3) | |
Text
GPU Nuclear Corporation
. Nuclear
- =;g;388 Forked River.New Jersey 087310388 609 971-4000 Writer's Direct Dial Number:
December 8, 1983 Dr. 'Ihomas E. Murley, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Dear Dr. Murley:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Special Report 83-02T Fire Suppression Water System Inoperability This letter forwards three copies of the fourteen (14) day follow-up report to Special Report 83-02 in compliance with paragraph 3.12.B.3.b.3 of the 'Ibchnical Specifications.
Very truly yours, e
}L Axv; w >[' J Peter B. Fiedler Vice President and Director Oyster Creek PBF:RPJ: dam Enclosures cc: Director (40 copies)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 Director (3) l Office of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, DC 20555 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 8312230223 831208 PDR ADOCK 05000219 Q
S PDR GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation g
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OYSTER CREEK NUCLEAR GEhTRATING STATION Forked River, NJ 08731 Special Report 83-02T Report Date December 5, 1983 s
Occurrence Date November 19, 1983 Identification of Occurrence While fire pump 1-1 was out of service for inspection and rebuilding of the pump, fire pump 1-2 failed to start on low system pressure during a demand for fire water to fill an isolated portion of the underground fire suppression loop. With both pumps 1-1 and 1-2 inoperable, the fire suppression water system is inoperable.
Conditions Prior to Occurrence Plant is in an outage condition with no fuel in the vessel.
Description of Occurrence On November 19, 1983, at 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, the fire suppression water system at Oyster Creek was declared inoperable based on the following conditions:
1.
Fire pump 1-1 had been taken out of service for inspection and rebuilding of the pump.
2.
At 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br /> on November 19, 1983, fire pump 1-2 was declared inoperable after failing to start on low fire water system pressure due to an overspeed trip signal received on 1-2 fire diesel.
Apparent Cause of Occurrence he apparent cause of fire pump 1-1 failure to meet the requirements of Technical Specifications paragraph 4.12.B.I.e.1 (360 feet head at 2000 GPM) was attributed to the impeller wear rings being out of tolerance on the high end of the clearance limits and the pump internals being heavily coated with cedar residue and sap from the supply pond. Eis condition decreased the pump's performance.
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. The apparent cause of fire pump 1-2 failure to start on low fire water system pressure was diesel engine related. S e overspeed trip (OT) switch is the location of the problem. Were are two possible causes, one being a malfunction of the switch itself, and the other possibility being that the setpoint of the overspeed trip switch was set too close to the setpoint for the diesel engine speed governor.
Corrective Action As an immediate corrective action, the overspeed trip switch on fire diesel 1-2 was removed and functionally tested; it was proven to be functioning.
This Or switch was then placed on fire diesel 1-1, which was idle while fire pump 1-1 was undergoing inspection and repairs. Fire diesel 1-1 was then started and stopped several times as a test. When the next start was attempted, the diesel cranked but did not run. Se or switch, when inspected, was found to be in the tripped position. The W switch was again removed, functionally tested and the M setroint was reset allowing a greater margin between the Or trip setpoint and the engine speed governor setpoint. 21s will prevent overspeed trip signal conditions when not needed. We setpoint of the Or switch is well below the maximum design limit for the diesel engine speed. The or switch that was originally on fire diesel 1-1 was placed on fire diesel 1-2 and has been operating without incident since fire pump 1-2 was returned to operable status at 2110 hours0.0244 days <br />0.586 hours <br />0.00349 weeks <br />8.02855e-4 months <br /> on November 19, 1983.
Fire pump 1-1 rebuilding and cleaning efforts have been completed and the pump was returned to operable status on November 24, 1983. W e post-maintenance fire pump functional test recorded the pump discharge pressure at 159 psig at 2006 GPM which is above Technical Specification requirements.
To finally determine whether the cause of fire diesel 1-2 trip was an OT switch malfunction or due to the Or setpcint being too close to the engine speed governor's setpoint tests will be run over the next ten (10) days that will pinpoint the cause of this incident. Should the cause be Or switch malfunction, both switches (1-1 and 1-2) will be replaced; should the cause be that the setpoints were too close together, both OT switch setpoints will be adjusted to the new setting for future operation.
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