ML030770532

Special Report - Seismic Monitoring Instrumentation Inoperability

ML030770532
Person / Time
Site:	Limerick
Issue date:	03/10/2003
From:	Levis W Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TRM 3.3.7.2
Download: ML030770532 (2)

Text

ExelI e n SM Exelon Nuclear www exeloncorp coM Nuclear Limerick Generating Station TRM 3.3.7.2 PO Box 2300 Sanatoga, PA 19464 March 10, 2003 U.S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555 Limerick Generating Station (LGS) Units 1 and 2, Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353 Subject Special Report - Seismic Monitoring Instrumentation Inoperability This Special Report is being submitted pursuant to the requirements of Limerick Generating Station (LGS), Unit1 ha-nd Ufit2 Updated FirinaSafety Analysis Report (UFSAR) section 3.7.4.5, Technical Specifications 6.9.2 and Technical Requirements Manual 3.3.7.2. With one or more of the seismic monitoring instruments inoperable for more than 30 days, a Special Report shall be prepared and submitted to the Nuclear Regulatory Commission pursuant to Specification 6.9.2 of the Technical Specifications within the next ten days outlining the cause of the malfunction and the plans for restoring the instrument(s) to operable status" On January 31, 2003, with both units operating at full power, Operations personnel determined that 'D' channel of the seismic monitor was not functional. Attempts to reset the channel were not successful.

The Seismic Monitoring System consists of 6 tri-axial time history accelerometers, 1 response spectrum analyzer, 4 digital recorders and a playback unit. At this time, the Seismic Monitoring System can detect and record data from a seismic event, and can provide a light indicating that a seismic event occurred. The system is currendy incapable of processing data to determine the spectral response to an earthquake. A station procedure is in place \to take compensatory action for this issue until the system is returned to service.

Subsequent attempts to repair the Seismic Monitoring System have been unsuccessful and are hampered by equipment obsolescence and parts issues. The fault appears to be within the computer's hard drive associated with the spectral analyzer. Replacement drives are not available. Two refurbished hard drives were procured from the manufacturer. The first was not an identical replacement and was incompatible. The second was installed on 2128/03; however, the disk boot errors did not allow the seismic monitor software to be installed. The hard drive has been sent to the vendor.

The seismic monitor will be repaired, tested, and returned to operable status by April 30, 2003.

If you have any questions or require additional information, please do not hesitate to contact us.

William Levis Vice President, LGS cc: H. J. Miller, Administrator Region I, USNRC A. L. Burritt, USNRC Senior Resident Inspector, LGS

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bcc: C. Pardee - KSA 3N W. Levis - GML 5-1 R. Braun - GML 5-1 E. Callan - GML 5-1 C. Mudrick - SSB 3-1 A. Wasong - LTC 1-1 J. Perry - GML 3-3 M. Gallagher - KSA 3G T. Dougherty - GML 4-1 M. Kaminski - SSB 2-4 R. Kreider- GML 3-3 J. Lauro - GML 3-3

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D. Dyckman - PA DER BRP Inspector SSB 2-4