ML20205F000

Safety Evaluation Supporting Util 831118,840312,0521 & 1227 Responses to Generic Ltr 83-28,Items 4.2.1 & 4.2.2 Re Reactor Trip Sys Reliability

ML20205F000
Person / Time
Site:	Callaway
Issue date:	10/28/1985
From:	NRC
To:
Shared Package
ML20205E995	List: ML20205E991 ML20205F000
References
GL-83-28, NUDOCS 8511040075
Download: ML20205F000 (6)

Text

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ENCLOSURE SAFETY EVALUATION CALLAWAY PLANT, UNIT 1 REACTDlFTRIP SYSTEM RELIABILITY ITEMS 4.2.1 AND 4.2.2 0F GENERIC LErItR 83-28 I. INTRODUCTION OnJuly8,1983,theNuclearRegulatoryCommission(NRC)issuedGeneric

i. Letter (GL)83-28. This letter identified staff positions developed from re-i viewoftheanticipatedtransientwithoutscram(ATWS)eventsattheSalem i Nuclear Power Plant. These positions are related to reactor trip system reli-ability and general management capability. Item 4.2 of GL 83-28 required ll , licensees to submit a description of their preventive maintenance and surveil-

l. lance 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 maintinance, including i lubrication, housekeeping, and other items recommended

. b'y the equipment supplier.

GL, Item 4.2.2 Trending of parameters affecting operation and' measured i

during testing to forecast degradation of operation.

,  ; Union Electric Company, the licensee for the Callaway Plant Unit 1, sub-j f- mitted responses to the Generic Letter on November 18, 1983 March 12, 1984, j !- May 21, 1984, and December 27, 1984. This report presents an evaluation of

!; the adequacy of the licensee's respons:s to Items 4.2.1 and 4.2.2.

I II. EVALUATION CRITERIA

_i A. Periodic Maintenance Program L

r The primary source for periodic maintenance program criteria is l

Westinghouse Maintenance Program Manual for 05-416 Reactor Trip Circuit

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• Breakers, Rev. O. This document was prepared for the Westinghouse Owners 4

P

- i Group and is the breaker manufacturer's recommended maintenance program for i

4 the DS-416 breaker. It provides specific direction with regard to schedule, inspection and testing, cleaning, lubrication, corrective maintenance and recordkeeping. The document was reviewed to identify those items that con-  ;

tribute 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:

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, 1. General inspection to include checking of breaker's cleanliness,

all bolts and nuts, pole bases, arc chutes, insulating link, i wiring and auxiliary switches

2. Retaining rings inspection, including those on the undervoltage ,

tripattachment(UVTA)

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

4. UVTA check as specified by the Westinghouse Maintenance Manual, including replacement of UVTA if dropout voltage is greater than t

60% or lass than 30% of rated UVTA coil voltage ,

5. Shunt trip attachment (STA) check as specified by the Westinghouse

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Maintenance Manual

6. Lubrication as specified by the Westinghouse Maintenance Manual

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

i to service.

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

{ interval basis: >

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l 1. Pre-cleaning insulation resistance measurement and recording

2. RTB dusting and cleaning j ,

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

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

- ness, 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 RT8 response time for the undervoltage trip l

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-7. Functional test of the breaker prior to returning to service as spec-ified by the Westinghouse Maintenance Manual. ,

8. Trending of Parameters 1

l Gener"ic letter Item 4.2.2 specifies that the licensee's preventive main-l tenance 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 parameters are acceptable and recommended trending parameters to forecast breaker operation degradation or failure. If subsequent experience indicates that any of these parameters is not useful as a tool to anticipate failures or degradation, the licensee may, with justification .

and staff approval, elect to remove that parameter from those to be tracked.

III. EVALUATION A. Evaluation of the Licensee's Position on Item 4.2.1 The licensee states that he has incorporated the Westinghouse Owner's Group maintenance document information into his Preventive Maintenance Procedure.

His maintenance program now includes periodic verification of UVTA drop-out

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i voltage, shunt trip attachment (STA) operability under degraded voltage con-ditions (70 VDC vs. 125 VDC design), UVTA trip force (i.e., available force) j and breaker required force. ,

1 The staff finds the licensee's position on Item 4.2.1 acceptable.

I B. Evaluation of the Licensee's Position on Item 4.2.2 ~

i The licensee trends:

a. Insulation resistance

b. Contact clearances i

1 c. UVTA drop-out voltage

d. UVTA trip force and breaker load

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e. Automatic shunt trip response time '

Data is trended to ensure that these measured parameters values are within acceptable bounds for operation. Supplemental maintenance or component replace-I ment may be manifested depending on the nature and severity of the degradation shown by the trending results.

b The staff finds the licensee's position on Item 4.2.2 acceptable.

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4 IV. CONCLUSIONS I Basedonourreview,thestafffindsthelicensee'spositionsonItems4.2[1 l and 4.2.2 of GL 83-28 acceptable. '

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i Mr. D. F. Schnell Callaway Plant Union Electric Company Unit No. 1 cc:

3 Mr. Nicholas A. Petrick Mayor Howard Steffen i Executive Director - SNUPPS Chamois, Missouri 65024 l 5 Choke Cherry Road i Rockville, Maryland 20850 Professor William H. Miller ~

Missouri Kansas Section, American Gerald Charnoff, Esq. Nuclear Society Thomas A. Baxter, Esq. Department of Nuclear Engineering Shaw, Pittman, Potts & Trowbridge 1026 Engineering Building 1800 M Street, N. W. University of Missouri Washington, D. C. 20036 Columbia, Missouri 65211 Mr. J. E. Birk Mr. Robert G. Wright

! Assistant to the General Counsel Assoc. Judge, Eastern District

} Union Electric Company County Court, Callaway County.

i Post Office Box 149 Missouri I- St. Louis, Missouri 63166 Route #1 Fulton, Missouri 65251

{ Lewis'C. Green, Esq.

U. S. Nuclear Regulatory Connission Green, Hennings & Henry Resident Inspectors Office Attorney for Joint Intervenors RR#1 314 N. Br..uway, Suite 1830 Steedman, Missouri 65077 St. Louis, Missouri 63102 Mr. Donald W. Capone, Manager Mr. Earl Brown Nuclear Engincering School District Superintendent Union Electric Company Post Office Box 9 Post Office Box 149 Kingdom City, Missouri 65252 St. Louis, Missouri 63166 Mr. Harold Lottman ..

A. Scott Cauger, Esq. Presiding Judge, Dasconade County Assistant General Counsel for the Route 1 Missouri Public Service Comm. Owensville, Missouri 65066 Post Office Box 360 5

Jefferson City, Missouri 65101 Mr. John G. Reed Route #1

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Ms. Marjorie Reilly Kingdom City, Missouri 65262 -

Energy Chairman of the League of '

Women Voters of Univ. City, M0 Mr. Dan I. Bolef, President 7065 Pershing Avenue Kay Drey, Representative University City, Missouri 63130 Board of Directors Coalition for the Environment Mr. Donald Bollinger, Member St. Louis Region i Missourtans for Safe Energy 6267 Delmar Boulevard 6267 Delmar Boulevard University City, Missouri 63130 University City, Missouri 63130

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Callaway Plant Unit No. I cc:

Regional Administrator U. S. NRC, Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 Mr. Ronald A. Kucera, Deputy Director Department of Natural Resources P. O. Box 176 l Jefferson City, Missouri 65102 Mr. Glenn L. Koester Vice President - Nuclear Kansas Gas and Electric Company 201 North Market Street

• Post Office Box 208 Wichita, Kansas 67201 Eric A. Eisen, Esq.

Birch, Horton, Bittner and Moore Suite 1200 -

1155 Connecticut Avenue, N. W.

Washington, D. C. 20036 -

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