ML20155C368

Part 21 Rept Re Deviation in Westinghouse Type Ds 206 & 416 Circuit Breakers.Crimp Connections Repaired

ML20155C368
Person / Time
Site:	Calvert Cliffs
Issue date:	09/20/1988
From:	Tiernan J BALTIMORE GAS & ELECTRIC CO.
To:	Russell W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
REF-PT21-88, REF-PT21-88-129-000 PT21-88-129, PT21-88-129-000, NUDOCS 8810100014
Download: ML20155C368 (5)

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S A LTIMORE GAS AND ELECTRIC a

CHARLES CENTEA P. 0.9CX 1475 BALTIMORE. MARYLAND 21203 JostpH A.TscowAN Vgg Datsittet Nwest.aa cages, September 20, 1988 U. S. Nuclear Regulatory Commission Regior,1 475 Aller. dale Road King of Prussia PA 19406 ATTENTION: W. T. Russell Regional Administrator

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & $0 318 Notification of a Defect in Westinghouse Type DS Circuit Dreakers per 10 CFR 21 Gentleinen:

We have identified a deviation in Westinghouse Type DS 206 and DS 416 circuit breakers.

We enluated the deviatiori, and determined such deviation can be considered a defect as defined in 10 CFR 21. This defect was reported to me on September 15,1988, and we e notified Mr. David Limroth by telephone on September 16, 1938. Attathed is our writte..

report M required by 10 CFR 21.21(bX2). The report contains the informatiori required by 10 CfR 21.21(bX3).

Should you have any further questions regarding this matter, we will be pleased to )"

discuss them w!th you.

Very truly yours JAT/ WPM / dim Attachment 8010100014 000920 POR 8 ADOCK 05000317 pg %b I

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'. - . ATTACHMEPR A t .

The length of time that was taken to comple.te the action:

Breakers were taken out of service, tested, and repaired, if necessat y, from Octoeer 1947 to July 1988, as operating conditions permitted. This work was done while we were inspecting pole snef' assemblies, as required by NRC Bulletin 68-01.

(viii) Any advice related to the detect that has been, is being, or will be given to purchasers or licensees:

We have informed Westinghouse of the results of our investigation, and will send them a copy of this letter.

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• 4 hir. W. T. Russell September 30,'1988 Page 2 1

cc: D. A. Brune, Esquite l i J. E. 5;1 berg, Esquire j T. E. Murley, NRC (3 copies)

R. A.Capra, NRC l S. A.McNeil,NRC W. T. Russell, NRC D. C.Trimble, NRC T. Masette, DNR  !

P. Morris, Westinghouse ,

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ATTACHMENT A 1

The forrrist of this Attachment conforms to the list of information required per  ;

< 10 CFR 21.21(bX3),

j (i) Name and address of the individual informing the Commission.

Joseph A. Tiernan j Vice President Nuclear Energy i Baltimore Gas and Electric Comoany  !

P. O. Box 1535 Lusby, MD 20657 (ii) Identification of the basic componen* which contains a defect.

Westinghouse Type DS 206 and OS 416 Circuit Breakers (iii) Identification of the firm supplyir. the bule component which contains a defect.

Westinghouse Electric Corporation 4

(iv) Nature of the defect and the sar. sty hazard which could be created by such defect, i Inadequate crimps on insulated Amp closed-end splices have been found in power operated circuit breakers. We identified the deviation while :

investigating the failure of a reactor cavity cooling fan 480 volt breaker to close. A crimped connector fell off during inspection. The cono;ctor was crimped at the end of the barrel and did not contain the ier.ds. The following day, a second connector fell off a charging pump breater dtiring maintenance.

After conferring with Amp, the supplier of the connecto,s, we tension-i tested all crimped connectors in Clus I E, 480 volt breakers. An extremely conservative acceptance criteria was applied to the tension i

test. This criteria was based on the manufacturer's recommended limiu for wire installation. Pulling tention for la AWG wire was 20 pounds, t

Test results are given in Item (vi) below. Ninety-two breakers were te;ted. Two breakers contained connectors that fell off before the tension test. Ten of the remaining ninety breakers contained oat or more connectors that did not meet the tension test criteria. in all, out of nir.ety-four breakers, four breakers contained a connector that fell off and ten other breakers contained one or more connectors that did not meet i

, the tension test criteria.

Of the fourtten breake s that had inadequate crimps, only one breaker had l lost a function and that function was non tafety-related. An inadequate j crimp an the reactor cavity cooling fan breaker led to a failure of that i l

. . . . ATTACHMEVT A

. I breaker to close. The safety-related function of that breaker is to trip, or open. This function was not affected by the inadequate crimp. All of the other 13 breakers had operated properly up to when they were taken out of-service for the tent on i test. Nonetheless, we have conservatively concluded that, had the deviation occurred on another one of the crimp connectors, it could have prevented a breaker from performing its safety-related function. We are reporting this deviation to notify others of a potential problem. Our evaluation indicated that a signifiennt safety hazard did not exist.

l (v) The date on which the information of such defect was obtained:

September 15, 1988

/ (vi) The number and location of all such defective components identified in use at Calvert Cliffs Units I and 2: '

No. of Failed l Breaker No. Eaulement Connectors 52-1101 11 Cavity Cooling Fan 1 (1) 52-1413 Load Center 14B Main 3 i

52-1415 13 Charging Pump I (1) 52-1416 13 Component Cooling Water Pump 2 (2)

! 52-1430 12 Pressurizer Proportional Heater 2 52-2109 MCC 20l AT Feeder Breaker 1 52 2113 Load Center 21B Main 1 52-2413 Load Center 24B Main 2 52-2419 MCC 201BT Feeder Breaker 3 52-2422 22 Hydrogen Recombiner 2 52-1106 Il Component Cooling Water Pump 2 52-1115 11 Charging Pump 1 (1) ,

89-1116 13 Component Cooling Water Pump Disconnect t 49-1416 13 Component Cooling Water Pump Disconnect 1

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.; NOTES: (1) Connector fell off prior to a tension test.

(2) One of the two connectors fell off prior to a tension test. {

I (vii) The corrective action which has bee taken:

I We reptired all crimp connections that failed our test criteria.

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j The name of the organization respo sible for the corrective action:

! Baltimore Gas and Electric Compaty  !

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