ML20238E058

Forwards Request for Addl Info Re Util Response to Generic Ltr 83-28,Item 4.2 (Parts 3 & 4).Requests Info within 60 Days of Ltr Receipt

ML20238E058
Person / Time
Site:	Callaway
Issue date:	09/08/1987
From:	Alexion T Office of Nuclear Reactor Regulation
To:	Schnell D UNION ELECTRIC CO.
References
GL-83-28, NUDOCS 8709140092
Download: ML20238E058 (4)

Text

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.t Docket No. 50-483- DISTRIBUTION:

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.NRC PDR OGC-Bethesda PDIII-3 r/f. EJordan Mr. Donald F. Schnell DWigginton JPartlow Vice President - Nuclear TAlexion ACRS(10)

Union Electric Company P0'Connor-Post Office Eox 149 St. Louis, Missouri 63166

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 83-28 ITEM 4.2(PARTS 3&4)

The staff is continuing its review of your responses to Item 4.2 (Parts 3 & 4) of Generic Letter 83-28 and finds that the additional information identified in the Enclosure is needed to continue the review.

Please provide the requested information within 60 days of your' receipt of this latter.

This request for information affects fewer than 10 respondents; therefore, OMB clearance is not required under Pub. L.96-511.

Sincerely, Js/

Thomas W. Alexion, Project Manager Project Directorate III-3 Division of Reactor Projects

Enclosure:

As stated cc: See next page

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Mr. D. F.-Schnell Callaway Plant Union Electric Company Unit No I cc:

Dr. J. O. Cennack Mr. Bart D. Withers CFA Inc. .

President and Chief

- 4 Professional Dr., Suite 110 Executive Officer Gaithersburg, MD 20879 Wolf Creek Nuclear Operating Corporation Gerald Charnoff, Esq. P. O. Box 411

. Thomas A. Baxter, Esq. Burlington, Kansas 66839

.Shaw, Pittman, Potts & Trowbridge 2300 N Street, N. W. Mr. Dan I. Bolef, President Washington, D. C. 20037 Kay Drey, Representative Board of Directors Coalition Mr; T. P. Sharkey for the Environment Supervisor, Ccmpliance St. Louis Region Union Electric Company 6267 Delmar Boulevard Post Office Box 620 University City, Missouri 63130 Fulton, Missouri 65251 U. S.; Nuclear. Regulatory Commission Resident Inspectors Office RRf1 Steedman, Missouri. 65077 Mr. Alan C. Passwater, Manager Licensing and Fuels Union Electric Company Post Office Box 149

.St. Louis, Missouri 63166 Manager - Electric Department Missouri Public Service Comission 301 W. High Post Office Box 360 Jefferson City, Missouri 65102 Regional Administrator U. S. NRC, Region III 799 Roosevelt Road Gtca Ellyn, Illinois 60137 Mr. Ronald A. Kucera, Deputy Director Department of Natural Resources P. O. Box.176 Jefferson City, Missouri 65102 J

ENCLOSURE .)

REQUEST FOR ADDITIONAL INFORMATION ITEM 4.2 (PARTS 3 & 4) 0F GENERIC LETTER 83-28 CALLAWAY PLANT, UNIT 1 Item 4.2 of Generic Letter 83-28 requires licensees or applicants to describe their preventive maintenance.and surveillance program for ensuring reliable reactor trip breaker operation. Parts 3 and 4 of Item 4.2 pertain to life testing'of an acceptable sample size of the breakers, and periodic replacement of the breakers or components consistent with demonstrated life cycles. The licensee submitted responses to Item 4.2 (Parts 3 & 4) by letters dated November 18, 1983, May 21, 1984, and December 27, 1984. The licensee referred to the life cycle testing program conducted by Westinghouse for the Owners Group, and as a result has established a service list of 1250 operations for the undervoltage trip attachments (UVTA's). No service life was assigned'to the shunt trip attachments or to the reactor trip breakers (RTB's) themselves.

Westinghouse has- presented the results of cyclic testing on the DS-416 RTB in WCAP-10835 " Report of the DS-416 Reactor Trip Breaker Undervoltage and Shunt Trip Attachments Life Cycle Tests." 'WCAP-10835 addresses only cyclic tcsting i on RTB trip attachments. It neither addresses life qualification of the RTB's I nor noneyclic life-limiting or performance-degrading phenomena (e.g., aging) for the trip attachments. Therefore, WCAP-10835 does not constitute an acceptable response to the concern of the generic letter.

If it can be demonstrated that the qualified life of the RTB exceeds the life of the plant, then the specific qualified life need not be identified. In a practical sense, the intent of the life testing requirement of the generic letter would be satisfied by demonstrating that the qualified life of the breaker (for the tripping function) exceeds the expected use projected to the next refueling. Cycle testing by the various owners groups, although it does not consider the effects of aging, may provide evidence to support continued use of the RTB's for one additional refueling cycle, provided that the individual breaker has not shown a sign of degradation based on the licensee's Parametric Trend Monitoring Program. In this approach, the actual qualified life is not specifically identified, but is only demonstrated to be adequate.

Ongoing life testing is an acceptable alternative to formal life testing for the purpose of establishing a specific qualified life for RTB's. Ongoing life testing will demonstrate that the qualified life, though not specifically known, is longer (in terms of cycles and time) than the integrated service that will be accumulated through the next refueling interval. The description of an ongoing qualification program should include the following:

(1) estimate of the number of demands between refueling outages to which the RTB must respond, and the basis for the estimate.

(2) definition V celevant, end-of-life related failures (Note that random failures occurring during the constant hazard rate portion of the "bathtubcurve"(plotoffailureratevs. time)arenotrelevanttoa 1

ij.

S lifetest). The licensee should. (a) identify the possible failure modes, (b)categorizeeachfailuremodeasanend-of-lifetypeornot,and(c) present a general methodology for categorizing future failure modes that may not be included in (a).

(3) the action to be taken upon any failure.

The staff finds that the licensee has not committed to a life testing program. The' licensee should qualify their breakers by (1) actual life testing of the breakers, including aging, on an acceptable sample size; or (2) establishing an ongoing life testing program. If the first alternative is selected, the licensee should present the results of the life testing to the staff for review. If the second alternative is selected, the licensee should describe its ongoing life testing program, including the three items listed above.

The licensee should also present for staff review a replacement program for the breaker and breaker components based on the results of its life qualification program. For ongoing qualification, the licensee should describe how the ongoing qualification results will be used to establish replacement cycles and times.

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