ML19308D054

Third Interim Deficiency Rept Re Excessive Output Fluctuations of Foxboro Instrumentation.New Voltage Inverters Installed at Unit 1 to Reduce Voltage Fluctuations.Rept on Permanent Solution Forwarded by 800811

ML19308D054
Person / Time
Site:	Sequoyah
Issue date:	02/05/1980
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:
References
NCR-SWP-79-S-5, NUDOCS 8002250554
Download: ML19308D054 (1)

Text

TENNESSEE VALLEY AUTHORITY l I

CHATTANOOGA. TENNESSEE 374ot 400 Chestnut Street Tower 11 1 February 3, lWU

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l l Hr. James P. 'Reilly, Director l Office of Insp tion and Enforcement U.S. Nuclear Re latory Commission Rebion II - Suite 3100 101 Marietta Stree Ac.?anta, Georgia 3 03

Dear Mr. O'Railly:

SEyUOYAH NUCLEAR PLAliT UNITS 1 AND 2 - EXCESSIVE OUTPUT FLUCTUATIONS OF FOXSudO INSTRUMENTATION - hCR SWP-79-S THIRD INTERIM REPohT l

l The sulifect deficiency was initially reported to NRC-OIE Inspector M. J. Gouge on August 2d,1979, in accordance with 10 CFR 50.55(e).

7 Interim reports were submitted on Eeptember 26, 1979, and October 30, l 1979.

l Tne new voltage inverters have been installed at Sequoych Nuclear Plant unit 1 to reduce the voltage fluctuations seen by the Fotboro modules.

Tests have verified enat these new inverters guarantee a closely regulated voltage to tne Foxboro module and that the Foxboro module will therefore l

perform acceptably for Sequoyah Nuclear Plant unit 1.

1 We are still pursuing redesign of the Foxboro module which would ensure an acceptable permanent solution to the original design problem with tais module. We expect to submit a report on the permanent solution by August 11, 1980.

If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 854-2581.

Very truly yours, TENNESSEE VALLEY AUTh0d1TY l

l L

L. M. Mills, Manager Nuclear Regulation and Safety cc: Mr.VictorStallo,Jr., Director [

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission gj9 Washington, DC 205SS N 0

! 8002250 L, L An Equal Oppos Employer f