ML19324C214

Responds to Suppl 1 to NRC Bulletin 88-010 Re Nonconforming Molded Case Circuit Breakers (Mccbs).Results of Testing of Twelve Nontraceable MCCBs Discussed.Util Basis for Position That Responses to Actions 4 & 5 Unnecessary Provided

ML19324C214
Person / Time
Site:	Farley
Issue date:	11/06/1989
From:	Hairston W ALABAMA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-88-010, IEB-88-10, NUDOCS 8911150219
Download: ML19324C214 (3)

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Alabama Power Company

-t 40 inverness Center Pail <way feet Offee Box 1295

, . Birmingham, Alabama 35201 o >. Te!ephone 205 8604581

, f W. G. Hal*ston, lit

~, Senior Vt6 President

• • ' "" "* November 6, 1989 AlabamaPower o

Docket Nos. 50-348 I 50-364

.U. S. Nuclear Regulatory Commission ATTN Document Control Desk Washington, D. C. 20555 i

Gentlemen: ,

Joseph M. Farley Nuclear Plant - Units 1 and 2 Nonconforming Holded-Case Circuit Breakers (NRC Bul_letin 88-10)

By letter of June 14, 1989, Alabama Power Conipany submitted to the NRC a complete response to NRC Bulletin 88-10 for Farley Nuclear Plant.- As discussed in the response, six (6) breakers purchased from Exide Power Systems on one purchase order vere not traceable to the manufacturer

, however, the remainder of the 115 molded-case circuit breakers (MCCBs) being mair.tained as stored spares for future use in safety related applications were considered traceable to the manufacturer. On August 3, 1989, the NRC issued Supplement 1 to NRC Bulletin 88-10 which stated that visual inspection and physical examination by the circuit breaker manufacturer _(CBH) is not considered adequate to meet the traceability provisions of NRC Bulletin 88-10. Since the June 14, 1989 response had )

relled upon a visual inspection by the manufacturer to demonstrate the traceability of six (6) MCCBs, Supplement 1 to NRC Bulletin 88-10 required that Alabama Power Company consider an additional six MCCBs as non-traceable.

Consequently, 103 of the 115 HCCBs identified at the time of inventory I and being maintsined as stored spares for safety related use are  ;

considered traceable to the CBM. Therefore, more than 80% of the MCCBs '

identified in Action 1 of the bulle tin are traceable to the CBM. In accordance with the bulletin, Alabama Power Company is requested to test l the twelve non-traceable MCCBs in accordance with the testing program described in Attachment 1 to the bulletin and continue with Action 4 if more than 10 percent of the HCCBs tested fail any of the tests. j It should be noted that the twelve non-traceable MCCBs have been tested in accordance with the program described in Attachment 1 of Bulletin  !

88-10. As noted in the June 14, 1989 letter, the six breakers purchased from Exide Power Systems were shipped to Wyle Laboratories for Testing in  !

accordance with Vyle Test Procedure No. 6110-26, Revision C, " Test '

Procedures for Holded Case Circuit Breakers." Results of the testing by o

Vyle demonstrate that five of the six breakers successfully completed the test program (See Attachment I for the discrepancies of the one breaker that did not successfully complete the test program). Subsequent to the issuance of Supplement 1 to NRC Bulletin 88-10, the six additional MCCDs t .

'\\ ,

U. S. Nuclear Regulatory Commission

• • + Page 2 November 6, 1989 now required to be considered non-traceable were shipped to Vyle Laboratories for testing in accordance with Vyle Test Procedure No.

6110-26 Revision F, " Test Procedures for Holded Case Circuit Breakers.d Results of the testing by Vyle demonstrate that all six HCCBs successfully completed the Vyle test program. One of these additional MCCBs tested was manufactured by Seimens (Model HE3B20). The remaining i

five MCCBs were manufactured by Heinemann (1 Model JA2-A3-A and 4 Hodel AM2-A3-A). These five are magnetic-trip HCCBs, and the manufacturer's specified curves vary dramatically from traditional MCCB trip curves.

Consequently, one of these five breakers (Hodel AM2-A3-A) passed the rated current hold-in test (test section 2.3 of Attachment 1 to NRC Bulletin 88-10) at 95.3% of the rated current, which deviates from the test requirements in section 2.3 but is in accordance with the Vyle test program which includes the manufacturer's specification. In addition, Alabama Power Company has evaluated the circuits for which this breaker was purchased as a potential / replacement. Therc exists a vide margin of safety.between the actual current draw in these circuits and the verified test performance as well as the nominal rating of the breaker. Based on the above, Alabama Power Company considers that this test result indicates that this breaker has not been tampered with or refurbished since original manufacture and is in conformance with the manufacturer's specification for current interrupting capability.

It is-the position of Alabama Power Company that eleven of the twelve non-traceable breakers were successfully tested according to the intent of Action 3 of the bulletin. Since less than 10 percent of the MCCBs failed the testing requirement of Action 3 to Bulletin 88-10, Alabama Power Company is not required to respond to actions 4 and 5 of the bulletin and no additional actions are planned in response to NRC Bulletin 88-10. Accordingly, this letter and the letter of June 14, 1989 provide the complete response to NPC Bulletin 88-10 including Supplement I for Farley Nuclear Plant.

If you have any questions, please advise.

Respectfully submitted, s

w.h./L,1 .x 1

V. G. flairston, III VGil,III/DHC:mV.1218 Attachment SVORN TO AND SllBSCRIBED BEFORE HE l- cc: Mr. S. D. Ebneter

l. Mr. E. A. Reeves 'IllIS /p DAY OF YBMNtIe .1989 i

Hr. G. F. Maxwell l - JA O4 1A I

NpJaryPublic My Commission Expires: U i

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1 Attachment 1

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• Molded Case Circuit Breaker (MCCB) Response to NRC Bulletin 88-10 .

Manufacturer ITE Circuit Breaker Company Part No.: KM Frame ET 9690 I

ID Number FNP 40640-1 i

Breaker Rating: 800 Amps 600 Volts AC 250 Volts DC 2 Pole Rated Current Hold-In Test:

Breaker did not trip.after 2.06 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. (135% of rated current)

L Instantaneous Trip Test:

Trip times for Pole one of the circuit breaker exceeded 0.10 seconds.

Time Delay Overcurrent Trip Pole one of the circuit breaket tripped in 388.72 seconds with 2410

. amperes applied.

Pole two of the circuit breaker did not trip with 2420 amperes applied for 520.55 seconds.

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