ML20235U736
| ML20235U736 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 02/24/1989 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8903090351 | |
| Download: ML20235U736 (2) | |
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' Duke Ibuer Company HAL B Tuche
- PO Bin 33198 '.'
VicePresident Charlotte, NC 28242 Nuclear l'roduction '
(704)373 4531 DUKEPOWER c
- February 24, 1989.'
LDocument Control Desk U. S.' Nuclear Regulatory Commission-m" Washington, D. C.
.20555
Subject:
Catawba Nuclear Station, Unit 1 Docket No.'50-413 Special Report'
. Gentlemen:'
Pursuant to Technical Specifications 6.9.2 and 3/4.3.3.3,.please find attached a Special Report concerning the inoperability.of the Unit 1 seismic monitoring; instrumentation in excess of:30 days.
Very truly yours,.
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H. B. Tucker
'JGT/2/SR89-15.
Attachment
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Mr. M. L. Ernst
' Acting Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta St., NW, Suite 2900 Atlanta, Georgia.30323 Mr. W. T.-Orders NRC. Resident Inspector Catawba Nuclear Station 9
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.6-P CATAWBA NUCLEAR STATION, UNIT 1 q
SPECIAL REPORT INOPERABLE SEISMIC MONITORING INSTRUMENTATION On December 8, 1988 while performing the 18 month Channel Calibration on Unit 1 Triaxial Peak Accelograph IMIMT5010, it was discovered that the recorder was damaged due to vibrations on the Auxiliary Feedwater (CA) line near the top of Steam Generator ID.
The same problem was discovered in 1987 during the end of cycle 2 refueling outage and at that time was assumed to be an isolated occurrence. However, failure analysis and trending alerted responsible personnel that this was a recurring failure that required diagnostic attention. The component was replaced and returned to service on December 12, 1988.
A Duke Power Design Engineering's Operability Evaluation indicates that the newly installed monitor which replaced the damaged monitor is operable and would remain operable until it is exposed to process induced vibrations during and after unit startup.
It also states that if the new monitor is not moved to a new location before startup, the component should be declared inoperable at the time of startup and the Technical Specification 3.3.3.3 Action Statement followed.
Plans for Restoring the Instrument to Operable Status Catawba personnel determined that the instrument should be removed from the CA line near the top of Steam Generator ID and relocated to another allowable location not subjected to vibrations from normal operations. The instrument was removed from its location in the Steam Generator cavity on January 16, 1989 during the latter portion of the Unit 1 end of Cycle 3 refueling outage. The Steam Generator cavity is inaccessible at power. Duke Power personnel are in the process to relocate the instrument to the cold leg accumulator 1A lifting lug at elevation 586', 3, 3/4".
This new location is on top of the cold leg accumulator tank and it satisfies the requirements of Regulatory Guide 1.12 for " equipment" type locations.
A Technical Specification change that will indicate the new location for this monitor will be submitted. The technical basis for the change will be provided at such time. Since the equipment will be at a location different from the present Technical Specification location, the monitor will be considered technically inoperable until the Technical Specification change is issued by the NRC.
The process induced vibrations, which caused the damage to instrument 1MIMT5010, do not represent an operability concern with respect to the piping and equipment.
This problem does not affect Catawba Unit 2 since the same type of monitor is not installed near the top of the Unit 2 Steam Generators.
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