ML20059G264

Rev 1 to Monthly Operating Rept for Nov 1993 for Sequoyah Nuclear Plant,Consisting of Revised Unit Shutdowns & Power Reductions Tables

ML20059G264
Person / Time
Site:	Sequoyah
Issue date:	11/30/1993
From:	Hollomon T TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20059G256	List: ML20059G253 ML20059G259 ML20059G264
References
NUDOCS 9401240077
Download: ML20059G264 (3)

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ENCLOSURE 2 TENNESSEE VALLEY AUT110RITY NUCIEAR POWER GROUP -

SEQUOYAH NUCLEAR FIANT N WTELY OPERATING REPORT TO THE NUCLEAR REGUIATORY CGWIISSIGE IgNERSER 1993 REVISIGt 1 UNIT 1 DOCKET NtBIBER 50-327 LICENSE NIMBER DPR-77 UN,IT 2 DOCKET NIMBER 50-328 LICENSE NUMBER DPR-79 9401240077 940118- T PDR ADOCK 05000327 'E R PDR X

DOCKET NO: 502328 UNIT SKU7 DOWNS AND POWER REDUCTIG2S UNIT NAME: Two DATE: 12/03/93 REPORT MONTH: November 1993 COMPLETED BV:T. J. Hollomon TELEPHONE:(615) 843-7528 . .

Method of Licensee Cause and Corrective Duration Shutting Down Event System Comp nent Action to No. Date Type l (Hours) Reason 2 Reactor 3 Report No. Code 4

Code Prevent Recurrence ,

5 931101 F r, 4 N/A N/A N/A At the beginning of November, Unit 2 was increasing power af ter an outage for voltage regulator repairs.

Unit 2 reached 100 percent power on November 5 at 0545 EST.

6 931105 F 32.93 B 5 N/A At 2115 EST on November 5, a reactor power decrease to 30 percent was iritiated to allow excitation system repairs to be performed. On November 8 at 1921 EST, the Unit 2 generator was removed from the grid for exciter work. Problems with the compensator card, minimum excitation limitor card, transformer card, and logic drawer were identified. These components were replaced, and the system was tested and determined to be operable. Unit 2 was returned to service an November 10 at 0417 EST when the generator was once again tied to the grid. Reactor power level was at approximately 25 per-cent. Unit 2 reached 100 percent reactor power on November 12 at 0557 EST.

7 331116 F 154.59 B 1 327/93029 CC 1SV On November 16 at 0913 EST, a reactor shutdown to Mode 4 was initiated as a result of a thermal barrier check valve issue. Seven of the eight check valves were stuck in the open position. The cause of the condition was oxide wedging (iron oxide corrosion build-up) between valve components (piston and bonnet). The valves were 2 3 #

I:F Forced Reason: Method: Exhibit G-Instructions S Scheduled A-Equipment Failure (Explain) 1-Manual for Preparation of Data B-Maintenance or Test 2-Manual Scram Entry sheets for Licensee C-Refueling 3-Automatic Scram Event Report (LER) File D-Regulatory Restruction 4-Continuation of Existing Outage (NUREG-lC22)

E-Operator Training and License Examination 5-Reduction F-Admi ni strati ve 9-Other 5

G-Operational Error (Explain) Exhibit I-Same Source H-Other (Explain)

DOCKE7 NO: 50-328 ,

UNIT SHUTDOWNS AND POWER REDUCTIONS UNZT NAME: Two DATE: 12/03/93 ,

REPORT MONTH:_Nay. ember 1993 COMPLETED BY:L J. Hollagen TELEPHONE:(615) 843-7528 . -

Method of Licensee Cause and Corrective Duration ,

Shutting Down Event Systgm Component Action to No. Date Type l (Hours) Reason' Reactor 3 Report No. Code Code 5 Prevent Recurrence 7 931116 F B 1 327/93029 CC 1SV disassembled, cleaned, repaired, and cont. returned to service. A long-term action plan is being develop?d to ensure continued check valve oper-aoility. Unit 2 entered Mode 1 on November 23 at 0256 EST and was returned to service.

2 Reason: 3 Method: #

I F:-Forced Exhibit G-Instructions 5: Scheduled- A-Equipment Failure (Explain) 1-Manual for Preparation of Data B-Haintenance or Test 2-Manual Scram Entry sheets for Licensee C-Refueling 3-Automatic Scram Event. Report (LER) File D-Regulatory Restruction 4-Continuation of Existing Outage (NUREG-1022)

E-Operator Training and License Examination 5-Reduction F-Administrative 9-Other G-Operational Error (Ex' plain) 5 Exhibit I-Same Source H-Other (Explain)

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