ML20078F477

Responds to NRC Re Violation Noted in Insp Repts 50-327/94-43 & 50-328/94-43.Corrective Actions:Procedures Associated W/Maint of Arrow-Hart Contactors Revised

ML20078F477
Person / Time
Site:	Sequoyah
Issue date:	01/23/1995
From:	Adney R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9502020120
Download: ML20078F477 (4)

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RA Tenressee Vaney Authonty Post ONe f3on 2000 S003y Decy. Tennessee 37370 January 23, 1995 U.S. Nuclear Regulatory Commission '

ATTN Document Control Desk Washington, D.C. 20555 Gentlemen In the Matter of ) Docket Nos. 50-327 Tennessee valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - INSPECTION REPORT NOS. 50-327, 328/94 REPLY TO NOTICE OF VIOLATION (NOV) 50-327, 328/94-43-01 Enclosed is TVA's reply to Charles A. Casto's letter to Oliver D. Fingslej, Jr., dated December 23, 1994, which transmitted the subject NOV. The NOV pertains to a failure to follow the procedure during the performance of maintenance activities.

The enclosure to this letter is TVA's reply to the NOV, including any applicable commitments relative to the violation.

If you have any questions concerning this submittal, please telephone l R. H. Shell at (615) 843-7170. .

Sincerely _

l -

R. J. Adney ..

Site Vice President Enclosure ec See page 2 l

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l (9(C;1T' 9502020120 DR 950123 ff0 g ADOCK 05000327 d}

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. U.S. Nuclear Regulatory Commission Page 2 January 23, 1995 cc (Enclosure):

Mr. D..E. LaBarge, Project Manager

'U.S.. Nuclear Regulatory Commission

'One White Flint, North 11555 Rockville. Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Scquoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711 5

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e ENCLOSURE F3 PLY TO NOTICE OF VIOLATION NRC INSPECTION REPORT NOS. 50-327, 328/94-43 CHARLES A CASTO'S LETTER TO OLIVER D. KINGSLEY, JR.

DATED DECEMBER 23, 1994 Violation 50-327, 328/94-43-01 I

" Technical Specification 6.8.1 requires, in part, that written procedures be established, implemented and maintained for activities recommended in Appendix A of Regulatory Guide 1.33, Quality Assurance Program Requirements, Revision 2, February 1978.

" Contrary to the above, on September 28, 1994 and October 22, 1994, Centrifugal Charging Pumps suction valves failed to open due to maintenance pract1ces not being implemented as required by Technical Specification 6.8.1. Specifically, failure to follow Maintenance Instruction, 0-MI-EPM-317-040.0 on the Arrow-Hart Motor starter contactors resulted in improper use of cleaning solvents and tools. This caused the failure of the contactors and subsequently the valves to operate.

"This is a Severity Level IV violation (Supplement I)."

3eason for the Violation The cause for the improper implementation of the maintenance procedure was the failure to follow the procedure as a result of personnel error.

Workers used inappropriate cleaning tools to perform maintenance activities.

Revision 15 of Maintenance Instruction 0-MI-EPM-317-040.0, " Arrow-Hart Magnetic Contactor/ Starter Maintenance," introduced the use of abrasive material (fine emery or crocus cloth) for cleaning the auxiliary contacts of Arrow-Hart contactors. However, workers used an electrical contact cleaner (burnishing tool) to clean the auxiliary contacts. The workers incorrectly believed that the burnishing tool would be less abrasive and l therefore less detrimental to the contacts. By using the burnishing tool to clean the auxiliary contacts, the contact surfaces were contaminated with residue from the burnishing tool, resulting in a loss of electrical j continuity (high resistance) across the contacts. i Maintenance Instruction 0-MI-EPM-317-040.0 specifies alcohol as the required cleaning solvent. A corrective action document was initiated on i June 7, 1993, to address sticking components on the Arrow-Hart contactors. The cause of the condition that existed before 1993 was determined to be the result of the failure to follow the procedure in that inappropriate cleaning solvents were used during maintenance activities. Walkdowns performed for the corrective action document identified chemical residue on the plastic components of the auxiliary

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• contacts. Testing determined that cleaning solvents containing the chemical'1,1,1 trichloroethane would result in the observed residue and that'this chemical is incompatible with the plastic components contained in the Arrow-Hart contactor. It was theorized that maintenance activities performed before the development of preventive maintenance instructions associated with motor control centers may have used cleaning solvents that contained 1,1,1 trichloroethane. At that. time, the work documents on the motor control centers may not have specified the cleaning solvents. However, TVA has found no evidence that cleaning solvents, other than alcohol, have been used since the implementation of corrective actions for the 1993 condition.

Corrective Steos That Have Been Taken and the Results Achieved Electrical Maintenance management has reinforced management expectations to workers relative to procedure compliance.

The procedure associated with the maintenance of Arrow-Hart contactors has been revised to no longer allow the use of abrasive cleaners on the auxiliary contacts. The procedure provides guidance on the use of alcohol and an ultra-sonic bath for cleaning the auxiliary contact supplemented with the use of silver polish to minimize wear and damage to the contacts. ' Individuals performing maintenance on Arrow-Hart contacters have received specific instructions on the cleaning methodology cor.sistent with the procedure. The review of worker performance by electrical maintenance foremen and oversight of the maintenance activities by the responsible component engineer have found the procedure being properly implemented.

Corrective Steos That Will be Taken to Avoid Future Violations No additional actions are required.

Date When Full Como11ance Will be Achieved TVA is in full compliance in that burnishing tools and 1,1,1 trichloroethane solvents are no longer utilized to clean Arrow-Hart contactors.

Commitments None.