ML17346A814

Forwards Response to Request for Addl Info Re Generic Ltr 83-28,Items 4.2.1 & 4.2.2 on Reactor Trip Breakers Periodic Maint Program & Parameters to Forecast Degradation of Operability

ML17346A814
Person / Time
Site:	Turkey Point, 05000351
Issue date:	01/18/1985
From:	Williams J FLORIDA POWER & LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
CON-FIN-A-6814 GL-83-28, L-85-31, NUDOCS 8501230357
Download: ML17346A814 (11)

Text

REGULATORY I>>.

RMATION DISTRIBUTION SYST (RIDS)

ACCESSION NBR:8501230357 DOC ~ DATE! 85/01/18 NOTARIZED! No DOCKET'- 0 FACIL:50 250 Turkey Point Planti Unit 3iFlor ida.Pawer

=and Light-C>>

05000250 50 251 Tur key Point Plant~

Unit-4~ Florida Power =and Light C

05000251 AUTH BYNAME AUTHOR AFFILIATION*.

WILLIAMS'OW, Florida-Power L Light Co, REC IP ~ NAME.

RECIPIENT AFFILIATION VARGAi'ST Ae Operating Reactors-Branch 1

SUBJECT; Forwards -response to request for. addi: info re-" Genr ic,Ltr>>

83. 28g Items 4 ~ 2;1 8

4 ~ 2,2 on reactor tr,ip br eaker s-pe'r iodic maint program I>>'arameters to forecast. degradation of operability, DISTRIBUTION CODE:

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TITLEs OR/Licensing Submittal:

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FLORIDAPOWER & LIGH7 COMPANY January 18, 1985 L-85-31 Office of Nuclear Reactor Regulation Attention:

Mr. S.

A. Varga, Chief Operating Reactors Branch InI1 Division of Operating Reactors U.

S. Nuclear Regulatory Commission Washington, D.

C.

20555

Dear Mr. Varga:

Re:

Turkey Point Units 3 and 4

Docket Nos.

50-250 and 50-251 Generic Letter 83-28 Items 4.2. 1 and 4.2.2 Florida Power 5 Light Company has reviewed the subject request for additional information and a response is attached.

Very truly yours, J.

W. Williams, Jr.

Group Vice President Nuclear Energy JWW/JA/msK26 Attachment cc:

J.

P. O'Reilly, Region II Harold F.

Rei s, Esquire S50l230357 8Ml 28 PDR AoaCV OaOOO2Sa P

PDR PEOPLE SERVING PEOPLE

ATTACHMENT Re:

Turkey Point Units 3 and 4 Docket No. 50-250, 50-251 Request For Additional Information on GL 83-28 Items 4.2.1 and 4.2.2 Task A6814

~RE UEST:

Item 4.2.1 - Periodic Maintenance Program for Reactor Trip Breakers.

1.1 Criteria for Evaluatin Com liance with Item 4.2.1 The Turkey Point Units 3 and 4 Reactor Trip Systems utilize Westinghouse DB-50 circuit breakers.

The primary criteria for an acceptable maintenance program for this breaker are contained in Maintenance Pro ram for DB-50 Reactor Tri Switch ear Rev.

0, dated October 14, 1, by Westinghouse.

The NRC Staff, 'quipment Qualification

Branch, has reviewed and endorsed the Westinghouse Maintenance Program for DB-50 Switchgear.

Speci fi cal ly, the cr>teri a used to evaluate compl iance include those items in the Westinghouse program that relate to the safety functi on of the

breaker, suppl emented by those measures that must be taken to accumulate data for trending.

1.2 Issues Relatin to Item 4.2.1 The licensee response states that "Every 6 months, each circuit breaker is

cleaned, lubricated as

required, checked for alignment, checked for proper operation of shunt and undervoltage trip devices, and tested on the bench and in-place.

Every refueling overhaul operability of the shunt trip is checked via the manual trip pushbuttons."

The response identifies, but does not include, the procedures governing reactor trip breaker periodic maintenance.

Does the Turkey Point Units 3 and 4 periodic maintenance program for the reactor trip breakers

include, on a six month basis:

1.

Verification of trip bar freedom; 2.

Verification of operating mechanism alignment and

freedom, using the procedure identified in the Westinghouse program; 3.

Retaining ring verification, 33 places; 4.

Verification of nut and bolt tightness; 5.

Verification of pole bases physical condition; 6.

Verification of arcing and main contacts physical condition, using the procedure identified in the Westinghouse program; 7.

Verification of insulating link's physical condition;

Re:

Generic Letter 83-28 Items 4.2.1 and 4.2.2 Task A6814 Page 2

8.

Verification of wiring insulation and termination physical condition;.

9.

Verification of arc chute physical condition; 10.

Verification of breaker cleanliness; 11.

Undervoltage Trip Attachment (UVTA) dropout voltage test and lubrication, using the procedure identified in the Westinghouse program; 12.

Shunt Trip Attachment (STA) operation verification; 13.

Verification of operation of auxiliary switches; S

14.

Inspection of positioning 1 ever condition, using the procedure identified in Westinghouse program; 15.

Functional test of the breaker prior to returning it to service, using the procedure identified in the Westinghouse program.

Does the Turkey Point Units 3

and 4 periodic maintenance program for the reactor trip breakers

include, on a refueling interval basis:

1.

Verification of cell interlock operation; 2.

Measurement of trip force required, using the, procedure identified in the Westinghouse program; 3.

Breaker response time for undervoltage trip; 4.

Functional test of the breaker prior to returning it to service, using the procedure identified in the Westinghouse program.

The licensee is to confirm that the periodic maintenance program includes these 19 items at the specified intervals or commit to their inclusion.

RESPONSE

Item 4.2. 1 - Periodic Maintenance Program for reactor trip breakers requi res that 19 items as contained in Maintenance Program for DB-50 Reactor Trip Switchgear, Rev.

0, dated October 14, 1983 by Westinghouse be implemented.

Our present program contains the items as listed and we are in full compliance.'

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Re:

Generic Letter 83-28 Items 4.2.1 and 4.2.2 Task A6814 Page 3

REQUEST:

Item 4.2.2 Trending of Reactor Trip Breaker Parameters to Forecast Degradation of Operability.

2.1 Criteria for Evaluatin Com liance with Items 4.2.2 Four parameters have been identified as trendable and are included in the criteria for evaluation.

These are (1) undervoltage trip attachment dropout

voltage, (2) trip

force, (3) breaker response time for undervoltage trip, and (4) breaker insulation resistance.

2.2 Issues Relatin to Item 4.2.2 The licensee submittal states that "No specific trending of reactor trip breaker opening times is peformed."

The response does not describe any trending program as being in place at Turkey Point or planned.

.The licensee is to commit to inclusion of trip force, breaker response time and dropout voltage for undervoltage trip and breaker insulation resistance as trending parameters.

The licensee should also identify the organization which will perform trend analysis, how often the analysis will be performed and how the information derived from the analysis will be used to affect periodic maintenance.

RESPONSE

Item 4.2.2 -

FPL commits to inclusion of trip force, breaker response time; and dropout voltage for undervoltage trip into a periodic trending program.

The Trip Force Measurement will be plotted on a refueling basis.

The trip force required will be linearly extrapolated using the two most recent data points to ensure that the acceptance limit of 31 oz. is not exceeded prior to the next maintenance interval.

The maintenance interval will be rescheduled if trends indicate that the limit may be exceeded prior to regularly scheduled refueling checks.

The Dropout Yoltage Test data will be trended on a

6 month initial interval.

The acceptance for trending information'ill be in accordance with the Westinghouse Instructions for DB-50 Reactor Trip Switchgear.

Additionally if the pre-lubrication dropout voltage vs service time plot shows that the acceptance criteria wi 11 not be met prior to the next scheduled 6

month interval the service interval wi 11 be adjusted downward to the predicted interval.

This trending plot wi 11 also be.used to adjust the 6 month interval to 9 or 12 months if the pre-lubrication trend predicts that the acceptance criteria will not be exceeded during that interval.

Turkey Point Plant staff will be responsible for performing the trend analysis.

Breaker

Response

Time will be trended on a monthly interval.

The response time plot will be linearly extrapolated to adjust the maintenance interval upward or downward from 6 months initially so long as predicted response time does not exceed 167 milliseconds.

k t

0 Re:

Generic Letter 83-28 Items 4.2.1 and 4.2.2 Task A6814 Page 4

FPL does not intend to include insulation resistance checks in a trending program.

Insulation resistance is not checked on the DB-50 trip breaker per the Westinghouse Maintenance Guidelines.

Due to the reduced voltage

'application of the breakers (ce do not believe that any prediction could be obtained from a trend plot of Insulation Resistance.

The trending Programs will be implemented by August 1, 1985.

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