ML20209J194

SER Accepting Licensee 831104 & 850422 Responses to Items 4.2.1 & 4.2.2 of Generic Ltr 83-28 Concerning Preventative Maint Program & Trending Parameters for DS-416 Type Reactor Trip Breakers,Respectively

ML20209J194
Person / Time
Site:	Farley
Issue date:	10/24/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20209J184	List: ML20209J177 ML20209J194
References
GL-83-28, NUDOCS 8511110381
Download: ML20209J194 (5)

Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIO JOSEPH M. FARLEY N CLEAR PLANT, 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 Generic Letter (GL) 83-28. This letter addressed intermediate-term actions to be taken by Itcensees and applicants aimed at assuring that a ,

comprehensive program of preventive maintenance and surveillance testing is implemented for the reactor trip breakers (RTBs) in pressurized water ,g -

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 gaintenance, including l * ~

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lubrication, housekeeping, and other items recommended by the equipment suppiter.'

GL, Item 4.2.2 Trending of parameters affecting operation and measured

"^ during testing to forecast degradation of operation.

Alabama Powef Company, the licensee for Farley 1 and 2, submitted responses to the Generic Letter'on November 4, 1983, and Apr!1 22, 1985.

- This report presents an evaluation of the adequacy of the ifcensee's responses aiid of his preventive maintenance and surveillance programs for RTBs. ,

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2. EVALUATION CRITERIA 2.1 Periodic Maintenance Program The primary. source for periodic maintenance program criteria is Westinghouse Maintenance Program Manual for 05-416 Reactor Trip Circuit Breakers, Rev. O. This document was prepared for the Westinghouse Owners 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, whichever comes first) that should be included in the licensee's RTB maintenance , ,

program are:

1. General inspection to include checking of byeaker's cleanliness, all bolts and nuts',. pole.

bases, are chutes, insulating link, wiring and' auxiliary switches; . 1

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

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3. Arcing and main contacts inspection as specified by the Westingh5bseMaintenanc,eManual;

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4. UVTA check as specified by the Westinghouse Maint'enance Manwal, including replacement of UVTA if dropout voltage is greater than 6Q% or less than 30% of rated UVTA coil voltage;

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

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6. Lubrication as specified by the Westinghouse Maintenance Manual;

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 resis.tance measurement and recording;

2. RTB dusting and cleaning; ,

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

4. Inspectionofmainandsecondarydisconnectingcontacts, bolt-'I tightness, secondary wiring, mechanical parts, cell switches, instruments, relays and other panel mounted devices;

5. UVTA trip' force and b'reak'er load check as specified by the Westinghouse Maintenance Manual;

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

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

2.2 Trending of Parameters Generic Letter 83-28. Item 4.2.2 specifies that the licensee's preventative maintenance and surveillance program is to include trending of parameters I affecting operation and measured during testing to forecast de' gradation of operation. The parameters measured du' ring the maintenance program described above which are applicable for trending are undervoltage trip 3

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b attachment drepout voltage, trip force , response time for undervoltage trip The staff position is that the above and breaker insulation resistance.

- parameters are acceptable and recommended trending ' parameters to forecast If subsequent experience breaker operation degradation or failure.  :

indicates that any of these parameters is not useful as a tool to anticipate failures or degradation, the licensee may, with justification and NRC approval, elect to remo,ve 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 preventative maintenance program for RTS's is being revised and, by the end of the current Unit I refueling' outage, will contain all the elements detailed ~in Section 2.1 of this SER; '

however, the licensee states that his undervoltage trip force and breaker ',

load check and his functional test of the breaker prior to return to service are similar to, rather than identical to, those specified in the Westinghouse Maintenance Manual.- As ,the.. licensee's procedures yield parametric data whil'h are to be 'used'in the Farley trending program, the staff finds the maintenance procedures acceptable.

The licensee performs all periodic maintenance on the breakers on a refueling interval basis. The licensee states that the extended interval for that part of the maintenance program specified for performance at six-month intervall'is justified based on previous satisfactory inspections i

- and on ,a desire to avoid the potential for degradation of safety due to additional breaker wear caused by unnecessary cycling.

The itaff finds this justification adequate and the Itcensee maintenance frequency to be acceptable, ,

I The staff finds the licensee pocition on Item 4.2.1 to be acceptable. ,

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3.2 Evaluation of the Licensee's position on Item 4.2.2 The licensee has committed to performance of trend analysis of trip force, breaker response time, undervoltage trip dropout voltage and The licensee has identified the organization which insulation resistance.

w111 perform trend analysis, how often it will be performed and how the information derived from the analysis will be used to affect periodic maintenance.

The staff finds 'ttur licensee position on Item 4.2.2 to be acceptable.

4. CONCLUSION! .

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

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