ML20009F715

Revised Final Deficiency Rept Re Inoperable 480-volt Motor Control Ctr Transformer Fuses,Originally Reported on 800808. Replacement of Type J Fuses W/Type RK5 Fuses Will Be Completed by 810901.Also Reported Per Part 21

ML20009F715
Person / Time
Site:	Bellefonte
Issue date:	06/26/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21- 10CFR-050.55E, 10CFR-50.55E, NCR-1234, NUDOCS 8107310447
Download: ML20009F715 (2)

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. ONFICIAL COPY e.:- a i n g0C-400 Chestnut Street Tower II June 26, 1981 U

//gfrMj,%,I I '~t\f .r N fl U u f_J 3 Mr. James P. O'Reilly, Director ~

ggg , 01981 * -

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 6; "d" % 'iE'$* " '4 Region II - Suite 3100 ,

101 Marietta Street g' Atlanta, Georgia 30303 Gi

Dear Mr. O'Reilly:

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - 480V MCC CONTROL TRANSFORMER FUSES - NCR 1234 - REVISED FINAL REPORT The subject nonconformance was initially reported to NRC-0IE Inspector M. Thomas on August 8,1980 in accordance with 10 CFR 50.55(e). This was followed by our interim reports dated September 8 and October 24, 1980 and our fir.al report on December 16, 1980. We consider 10 CFR Part 21 to be applicable to this nonconformance. As dicussed with R. V. Crlenjak by telephone on June 24, 1981, enclosed is our revised final report. The reason for the revision is to change the expected completion date of the corrective action. The date for completion has been delayed because of equipment delivery.

If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 857-2581.

Very truly yours,

. s TENNESSEE VALLEY AUTHORITY

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v L.M.Mi}ls, Manager, Nuclear Regulation and Safety Enclosure cc: Mr. Victor Stello, Jr., Director (Enclosure)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission g Washington, DC 20555 pgf/

Sill 8107310447 810626 PDR ADOCK 05000 S

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o' ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 880V MCC CONTROL TRANSFORMER FUGES

, NCR 1234 10 CFR 50.55(e) -

REVISED FINAL REPORT _

Description of Deficiency The motor control centers (MCC) at Bellefonte were supplied by Gould-Brown Boveri, Westminster, Maryland. The 5 kVA and 10 kVA control transformers for these MCC's utilize 15- and 30-amp type J fuses, respectively. These fuses have operated when the control circuit is energized. These fuses were not properly chosen to coordinate with the inrush current.

Safety Implications The transformerb supply power to 120V Class IE control circuits. If the fuses operate, any equipment that is controlled by those circuits is inoperable. The fuses operate when the circuit is initially energized or when energized after an outage. Therefore, if these circuits are required to energize to mitigate an accident, the associated equipment may not be available, which could adversely affect plant safety.

Corrective Action TVA and Gould-Brown Boveri have reevaluated the design of the control circuits and have determined that type "K5 fuses should be used instead of type J fuses in order to ccordinate with the inrush current. The fuses will be replaced to eliminate fuse operation when the circuit is energized. TVA anticipates that replacement will be completed by September 1,1981. ~/

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