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Provides Addl Info in Response to 850130 Request Re Items 4.2.1 & 4.2.2 of Generic Ltr 83-28 Concerning Salem ATWS Events.Reactor Trip Breaker Maint Performed Per Maint Procedure MP 1405.5
	ML20100F532
Person / Time
Site:	Davis Besse
Issue date:	03/29/1985
From:	Crouse R; TOLEDO EDISON CO.
To:	Stolz J; Office of Nuclear Reactor Regulation
References
	1130, GL-83-28, TAC-53120, NUDOCS 8504040351
	Download: ML20100F532 (4)
	v • d • e

s Docket No. 50-346 TOLEDO License No. NPF-3 !!!)!kI(I!N Serial No. 1130 Rcaso P.CA16E

w. emum Nucses March 29, 1985 mea 3#wa Director of Nuclear Reactor Regulation Attn.: Mr. John F. Stolz Operating Reactor Branch No. 4 Division of Licensing United States Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Stolz:

By letter dated November 7, 1983 (Serial No. 1000), Toledo Edison Company submitted the Davis-Besse Nuclear Power Station, Unit No. I response to Generic letter 83-28 (Log No. 1322), entitled " Required Actions Based on Generic Implications of Salem ATWS Events." Within that submittal, Toledo Edison provided detailed responses to each specific item identified in Generic Letter 83-28.

In your letter, " Reactor Trip Breaker's Preventative Maintenance Program; Items 4.2.1 and 4.2.2, Generic Letter 83-28", (Log No. 1685), dated January 30, 1985, additional information was requested to continue your review. Per telecon with Mr. A. DeAgazio on February 28, 1985, Toledo Edison received an extension to March 29, 1985, to submit the requested information.

Within your letter (Log No. 1685), for Generic Letter Item 4.2.1, it was stated the Davis-Besse, Unit 1 periodic maintenance program for the re-actor trip breakers should include the 13 items listed on a six month interval basis. Your letter further stated the licensee is to confirm that the periodic maintenance program includes these 13 items at the specified interval or commit to their inclusion.

As stated in our letter of November 7,1983, reactor trip breaker mainte-nance is performed in accordance with Maintenance Procedure MP 1405.05, 480V Type AK Circuit Breaker Maintenance and Testing, which is presently based on the General Electric Instruction GEI-50299, Service Advice 175-9.3S and Service Advice 175-9.20. Attachment I provides a response to the 13 items relating to a periodic maintenance program for Davis-Besse.

In your letter of January 30, 1985, for Generic Letter Item 4.2.2, it was stated the licensee is to commit to inclusion of (1) trip torque, (2) breaker' response time. (3) dropout voltage for undervoltage trip, and (4) breaker insulation resistance as trending parameters. The licensee should f s THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652 j

OA 8504040351 850329 :

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D ckst No. 50-346 License No. NPF-3 Serial No. 1130 March 29, 1985 Page 2 also identify the organization which will perform trend analysis, how of ten the analysis will be performed, and how the information derived from the analysis will be used to affect periodic maintenance.

At Davis-Besse, data has been accumulated since July,1982, for trending of breaker response time from loss of signal to the undervoltage device, trip shaft operating torque, undervoltage device pickup voltage, and undervoltage device dropout voltage. As a participant in the B&W Owners Group Reactor Trip Reliability Monitoring Program, data from these para-met,ers has been included in the program since January, 1984. Breaker insulation resistance data is taken and used as acceptance criteria during prevautative maintenance, however, breaker insulation resistance was not selected as a trending parameter that provides useful information for the Re?.iability Monitoring Program.

The Davis-lesse Maintenance Department is assigned to collect the data from these parameters on a six month interval, per MP 1405.05. Data from these parameters is given to the B&W Owners Group Availability Group for trending and analysis for the duration of the Reliability Monitoring Program.

Upon completion of the Reliability Monitoring Program, an analysis will be performed to evaluate the interval for performing periodic maintenance.

If the analysis indicates a period greater than 12 months is warranted.

TED will perform breaker periodic maintenance using the 12 month interval recommended by General Electric, the breaker manufacturer, and B&W, the breaker supplier. If analysis indicates a period less than 12 months is warranted, we will then determine the appropriate conservative interval for performing this maintenance.

Toledo Edison recognizes the importance of the reliability of the reactor trip breakers and contends the actions outlined above are sufficient to ensure their reliability.

Very truly yours, f]PC - h RPC:DLM:JSH:SGW:nif

encl. cc: DB-1 NRC Resident Inspector

r Dock t No. 50-346 License No. NPF-3 Serial No. 1130 Attachment 1 Page 1 Reactor Trip Breaker Periodic Maintenance Request: The licensee is to confirm that the periodic maintenance program includes the following 13 items at the specified interval or commit to their inclusion:

1. Verification of breaker cleanliness and insulation structure; all foreign materials, such as paint, dust, or oil, should be removed to prevent electrical breakdown between points of different poten-tial.

Response: MP 1405.05 includes inspections in accordance with General Electric Instruction GEI-50299.

2. Verification of breaker physical condition, including wiring insula-tion and termination, all retaining rings, pole bases, are quencher, stationary and movable contacts, and tightness of nuts and bolts.

Response: MP 1405.05 includes a verification of breaker physical condition.

3. Verification of proper manual operation of the breaker, including checks for excessive friction, trip bar freedom, latch engagement, operating mechanism alignment and freedom, and undervoltage trip (UVT) device armature freedom.

Response: MP 1405.05 includes inspections in accordance with General Electric Instruction GEI-50299.

4. Verification of the optimum freedom of the armature as specified in General Electric Service Advice 175-9.3S, item #S1.