ML20210K901

Special Rept:On 970701,declared Seismic Monitor Inoperable. Caused by Decision That Procedural Info Re Seismic Monitor Was Insufficient to Confidently Call Seismic Monitoring Equipment Operable.Revised Required Operating Procedures

ML20210K901
Person / Time
Site:	LaSalle
Issue date:	08/15/1997
From:	Dacimo F COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9708200156
Download: ML20210K901 (3)

Text

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'I rl N i ki%"43'O l August 15,1997

- United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

Seismic Monitoring Instrumentation Status Supplemental Report LaSalle County Station, Units 1 and 2 NRC Docket Nos. 50 373 and 50-374

References:

Special Report Pursuant to LaSalle Unit 1 and 2 Operating License NPF 11 and NPF 18, Specification 3.3.7.2 and 6.6.C letter from D.J. Ray, LaSalle Station Manager, to Document Control Clerk, l U.S. NRC, dated November 26,1996.

The reference letter stated that the new seismic monitor would be installed per the design change package, tested and placed in service by Friday, February 28,1997. An attempt was made to install the new seismic monitoring equipment on Tuesday, February 18,1997. Dimensional fitup problems were encountered with the seismic monitor central process components during installation. The installation problems led to the seismic control panel being retumed to the vendor for rework. The reference letter provided a new schedule to retum the seismic monitor to an operable status by June 30,1997.

The vendor retumed the seismic monitor to LaSalle after correcting the dimensional fitup problems. During equipment installation several problems -

were encountered with the intemal wiring as well as an issue involving improperly sized terminal blocks. As a result, the vendor sent a field reprosentative to LaSalle during the last week of May and the first two weeks of June to correct the wiring deficiencies and replace terminal blocks.

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During the last week of June, the vendor's representative retumed to LaSalle to train the Operations and Instrument Maintenance personnel on the specifics of the seismic equipment, and to assist Design and System Engineering with the performance of the final pre operational hardware and software checks. The scheduled training for plant personnel was limited to the cognizant training instructors for instrument Maintenance and Operations because of continued system problems and the need for trouble shooting of the seismic monitoring panel.

Functional testing for the seismic monitor began on Tuesday, June 24,1997, and was successfully completed on Saturday, June 28th. Operations accepted the new seismic monitor as operable.

On Monday, July 1,1997, during Operation's afternoon shift briefing, and following several questions from operating personnel, the Shift Manager decided that the procedural information regarding the seismic monitor was insufficient to confidently call the seismic monitoring equipment operable.

The seismic monitor was therefore declared inoperable at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on July 1,1997.

1 The required operating procedures were revised on Tuesday, July 2,1997.

Additionally, required maintenance procedures were reviewed and revised on Thursday, July 17,1997.

The seismic monitor is currently inoperable pending resolution of a spurious noise signal that was being generated from the accelerometer located at tlie 820 foot elevation of the Unit 1 Reactor Building. This accelerometer, along with a spare, was returned to the vendor for repair. The seismic monitor will be retumed to an operable status following the installation of the accelerometer and the successful functional test of the system. It is anticipated that the seismic monitor will be tested, and placed into service by Sunday, August 31,1997.

While a formal root cause investigation of this event is being performed concurrent with the issuance of this supplemental report, preliminary causal factors surrounding this event indicate a lack of procedural adequacy with regard to operating and maintenance procedures. Those procedures that were required for operators to start up, shut down, or reset the seismic monitor, and for maintenance personnel to functionally test the monitor, were revised prior to the sei smic monitor being declared operable but were not immediately made available to the operators.

iri addition to the procedural availability issue, there was an apparent lack of communications between the training personnel for operations and maintenance, and their respective departments. While the operations and maintenance personnel felt that they were inadequately tralned on the seismic modification, the training department personnel signed off on the modification signature block as having adequate training.

L The root cause of this event, along with recommended corrective actions, will be made available at the site, pending the completion of the formal root cause investigation report, NTS# 373 200 97 CAOD00073.00.

If there are any questions or comments concerning this letter, please refer them to me at (815) 357 6761, extension 3600.

- Respectfully, Fred Dacimo Plant General Manager LaSalle County Station Enclosure cc: A. B. Beach, NRC Region lli Administrator M. P. Huber, NRC Senior Resident inspector LaSalle D. M. Skay, Project Manager - NRR LaSalle F. Niziolek, Office of Nuclear Facility Safety - IDNS