ML20153D223

Forwards Interim Rept & Request for Addl Info Re Items 4.2.1 & 4.2.2 of Generic Ltr 83-28 Concerning Preventive Maint & Parameter Trending Associated W/Reactor Trip Breaker Operation.Response Unacceptable

ML20153D223
Person / Time
Site:	McGuire
Issue date:	02/17/1986
From:	Youngblood B Office of Nuclear Reactor Regulation
To:	Tucker H DUKE POWER CO.
References
GL-83-28, NUDOCS 8602240047
Download: ML20153D223 (7)

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..o Docket Nos.: 50-369 and 50-370 FEB 171986 Mr. H. B. Tucker, Vice President Nuclear Production Department Duke Power Company 422 South Church Street Charlotte, North Carolina 28242

Subject:

Interim Report Regarding Maintenance and Trending for Reactor Trip Breakers - McGuire Nuclear Station, Units -1 and 2 By letters dated November 4, 1983 and May 24, 1985, you responded to Items 4.2.1 and 4.2.2 of NRC Generic Letter 83-28 for McGuire Nuclear Station, Units 1 and 2.- These items regard preventive maintenance and parameter trending associated with reactor trip breaker operation.

The NRC staff has reviewed your responses to Items 4.2.1 and 4.2.2 with the technical assistance of Idaho National Engineering Laboratory (INEL). Enclosed is our combined report in which we find your re-sponses unacceptable and request additional information or other actions.

l You reply to Sections 3.1 and 3.2 of the enclosed report is requested

within 60 days of this letter. Contact your Project Manager, Darl i

Hood,at(301)492-8060 if you have questions.

l Sincerely, B. J. Youngblood, Director PWR Project Directorate #4 Division of PWR Licensing-A

Enclosure:

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1'c Mr. H. B. Tucker Duke Pcwer Company McGuire Nuclear Station cc:

,Mr. A. Carr Dr. John M.Barry -

Duke Power Company Department of Environmental Health P. O. Box 33189 Mecklenburg County -

422 South Church Street 1200 Blythe Boulevard Charlotte, North Carolina 28242 Charlotte, North Carolina 28203 Mr. F. J. Twogood- County Manager of Mecklenburg County Power Systems Division 720 East Fourth Street Westinghouse Electric Corp. Charlotte, North Carolina 28202 i P. O. Box 355 Pittsburgh, Pennsylvania 15230 Chairman, North Carolina Utilities Commission Mr. Robert Gill Dobbs Building Duke Power Company 430 North Salisbury' Street Nuclear Production Department Raleigh, North Carolina 27602 i . P. O. Box 33189 Charlotte, North Carolina 28242 Mr. Dayne H. Brown, Chief Radiation Protection Branch 4

J. Michael McGarry, III, Esq. Division of Facility Services Bishop, Liberman, Cook, Purcell Department of Human Resources and Reynolds P.O. Box 12200

1200 Seventeenth Street, N.W. Raleigh, North Carolina 27605 Washington, D. C. 20036 Senior Resident Inspector c/o U.S. Nuclear Regulatory Commission Route 4, Box 529 Hunterville, North Carolina 28078 Regional Administrator, Region II U.S. Nuclear Regulatory Commissicn, 101 Marietta Street, N.W., Suite 2900 -

. Atlanta, Georgia 30323 L. L. Williams Operating Plants Projects

! Regional Manager

. Westinghouse Electric Corporation - R&D 701 P. O. Box 2728 Pittsburgh, Pennsylvania 15230 d

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, V INTERIM REPORT McGUIRE NUCLEAR SlATION, UNITS'1 AND 2 REACTOR TRIP SYSTEM RELIABILITY ITEMS 4.2.1 AND 4.2.2 0F GENERIC LETTER 83-28 -

1. INTRODUCTION  ;

On July 8,1983, the Nuclear Regulatory Commission (NRC) issued GenericLetter(GL)83-28. This letter addressed intermediate-term actions to be taken by licensees and applicants aimed at assuring that a f comprehensive program of preventive maintenance and surveillance testing is ,

implemented for the reactor trip breakers (RTBs) in pressurized water reactors. In particular, Item 4.2 of the letter required licensees and applicants to submit a description of their preventive maintenance and surveillance program to ensure reliable reactor trip breaker operation.

The description of the submitted program was to include the following:

GL, Item 4.2.1 A planned program of periodic maintenance, including lubrication, housekeeping, and other items recommended by the equipment supplier.

GL, Item 4.2.2 Trending of parameters affecting operation and measured

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, during testing to forecast degradation of operation.

, Duke Power Company, the licensee for McGuire.1 and 2, submitted responses to the Generic Letter on November 4,1983, and May 24, 1985.

This report presents an evalu3 tion of the adequacy of the licensee's responses and of his preventive maintenance and surveillance programs for RTBs.

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v 2. EVALUATION CRITERIA 2.1 Periodic Maintenance Program The primary source for periodic maintenance program criteria is Westinghouse Maintenance Program Manual for 0S-416 Reactor Trip Circ 0it Breakers, Rev. O. This document was prepared for the Westinghouse Owners i

Group and is the breaker manufacturer's recommended maintenance program for the DS-416 breaker. It provides specific direction with regard to schedule, inspection and testing, cleaning, lubrication, corrective maintenance and record keeping. The document was reviewed to identify those items that contribute to breaker trip reliability consistent with the generic letter. Those items identified for maintenance at six month

, intervals (or when 500 breaker operations have been counted, whicheve'r comes f1rst) that should be included in the licensee's RTB maintenance program are: l

1. General inspection to ir.clude checking of breaker's cleanliness, all bolts and nuts, pole bases, arc chutes, insulating link, wiring and auxiliary switches;

2. Retaining rings inspection, including those on the undervoltage trip attachment (UVTA);

3. Arcing and main contacts inspection as specified by the Westinghouse Maintenance Manual;

4. UVTA check as specified by tha Westinghouse Maintenance Manual, 3 including replacement of UVTA if dropout voltage is greater than 60% or less than 30% of rated UVTA coil voltage;

5. Shunt Trip Attachment (STA) check as specified by the Westinghouse Maintenance Manual;

6. Lubrication as specified by the Westinghouse Maintenance Manual; 2

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7. Functional check of the breaker's operation prior to returning it to service.

The licensee's RTB periodic maintenance should also include, on'a refueling interval basis: ,

1. Pre-cleaning insulation resistance measurement and recording;

2. RTB dusting and cleaning;

3. Post-cleaning insulation resistance measurement and recording, as specified cy the Westinghouse Maintenance Manual;

. 4. Inspection of main and secondary disconnecting contacts, bolt

.... tightness, secondary wiring, mechanical parts, cell switches, instruments, relays and other panel mounted devices;

5. UVTA trip force and breaker load check as specified by the Westinghouse Maintenance Manual;

6. Measurement and recording of RTB response time for the undervoltage trip;

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7. Furictional test of the breaker prior to returning to service as specified by the Westinghouse Maintenance Manual.

2.2 Trending of Parameters Generic Letter Item 4.2.2 specifies that the licensee's preventative maintenance and surveillance program is to include trending of parameters affecting operation and measured during testing to forecast degradation of operation. The parameters measured during the maintenance program described above which are applicable for trending are undervoltage trip attachment dropout voltage, trip force, response time for undervoltage trip and breaker insulation resistance. The staff position is that the above 3

r s parameters are acceptable and recommended trending parameters to forecast breaker operation degradation or failure. If subsequent experience inoicates that any of these parameters is not useful as a tool to anticipate f ailures or degradation, the licensee may, with justification and NRC approval, elect to remove that parameter from those to be tracked.

3. EVALUATION 3.1 Evaluation of the Licensee Position on Item 4.2.1 The licensee states that his periodic maintenance program for RTBs includes those six-month interval items listed above, but does not specify whether they are performed at six-month intervals or during refueling

, outages, nor does he provide any justification for an interval longer than six mont_hs.

The responses also indicate that the licensee performs UVTA trip force and breaker load check, RTB response time for undervoltage trip and functional test on at least a refueling interval basis. However, the licensee's periodic maintenance program does not include pre-cleaning insulation resistance measurement, RTB cleaning and dusting, post-cleaning insulation resistance measurement, or inspection of main and secondary contacts. The licensee contends that these items are not related to the

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safety function of the breaker and that Westinghouse "may consider revising"' their maintenance manual for the DS-416~ RTBs to " reflect the

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.. clarification provided" by the licensee. The staff finds the licensee's

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justification inadequate in view of the lack of substantiation and concurrence by Westinghouse.

The staff considers the licensee position on Item 4.2.1. to be unacceptable. The licensee must specify the frequency with which he performs that maintenance recommended for six-month intervals. and provide justification if that interval is greater than six months. The licensee must also include pre- and post-cleaning insulation resistance measurem'.ots, RTB cleaning and dusting, and inspection of 4

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l i- main and secondary contacts in his maintenance program. If the licensee declines to include these: maintenance procedures in his program, he must provide written technical justification.

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l 3.2 Evaluation of the Licensee's Position on Item 4.2.2 ,,

The licensee has stated that McGuire currently records data for (a) undervoltage trip dropout voltage, (b) trip force, and (c) breaker response time for undervoltage trip. McGuire does not measure or record insulation resistance. The licensee.has not identified the organization which will perform treno analysis, how often it will'be performed or how the information derived from the analysis will be used to affect periodic ,

maintenance. Rather, the licensee has taken the position that a formal

. trending program of the RTB parameters is not necessary or beneficial to

. predict. degradation of operation. This position is based on operating and

- maintenance experience at McGuire and the results of life cycle tests soon to be released by the Westinghouse Owners Group. .. ,

The staff finds the licensee position on Item 4.2.2 to be unacceptable without additional justification. The licensee must implement a formal trending program as described in Section 2.2. of this SER and provide the staff with a description of his trending program. Alternatively, the

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licensee must demonstrate that a parametric trending program is of no value in predicting degradation or failure of RTBs due to both aspects of component' life, cycling and aging. '

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4. CONCLUSIONS i

Based on a review of the licensee responses, the staff finds the licensee positions on Items 4.2.1 and 4.2.2 of Generic Letter 83-28 to be unacceptable.

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