ML20044B992
| ML20044B992 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/04/1993 |
| From: | Ebneter S NRC Office of Inspection & Enforcement (IE Region II) |
| To: | Medford M Tennessee Valley Authority |
| References | |
| CAL-2-93-03, CAL-2-93-3, CAL-II-93-03, CAL-II-93-3, NUDOCS 9303160078 | |
| Download: ML20044B992 (4) | |
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f f-e MAR 4 1993 Docket No. 50-327, 50-328 License _No. DPR-77, DPR-79 CAL No. 2-93-003 Tennessee Valley Authority ATTN:
Dr. Mark 0. Medford, Vice President Nuclear Assurance, licensing & Fuels 3B Lookout Place i
1101 Market Street Chattanooga, TN 37402-2801 i
Gentlemen:
SUBJECT:
CONFIRMATORY ACTION LETTER On March 1, 1993, Sequoyah Unit P
.s manually tripped from full power.
The Unit was tripped when operators noticed an increase in main generator voltage.
Subsequent to the trip, a steam leak was discovered in an extraction steam line to a feedwater heater. The Unit 2 generator voltage regulator cubicles were discovered to be wetted due to the steam leak. The leak was believed to be caused by erosion of the piping. Unit 2 was taken to Mode 3 after the trip.
Based on the unknown condition of the Unit I extraction steam piping, licensee plant management directed that Unit I be shut down for inspection.
It is our understanding that you will take all the actions identified in Mr. Kingsley's letter dated March 4,1993 with special emphasis on the following actions prior to restart of either unit:
Perform a complete review of the event, including a determination of the piping failure mechanism Complete permanent repairs to piping that is currently under temporary repairs due to erosion / corrosion (E/C) effects Review your E/C program to identify any weaknesses, including a third party evaluation of the E/C program Conduct field measurements of piping to assess the state of piping subject to E/C effects Resolve all overvoltage issues which occurred as a result of the transient, including conducting surveillancer of selected solid state devices Assess the impact of plant equipment in the vicinity of the ruptured pipe and assure there is no damage that could affect safe i
plant operation 1
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Tennessee Valley Authority 2
Meet with the NRC staff to discuss the above activities and the event prior to restart of either unit Pursuant to Section 182 of the Atomic Energy Act, 42 U.S.C. 2232, and 10 CFR 2.204, you are required to:
1)
Notify me immediately if your understanding differs from that set forth above, 2)
Notify me if for any reason you cannot complete the actions specified above, and advise me in writing of your modified schedule in advance of the change, and 3)
Notify me in writing when you have completed the actions addressed in this Confirmatory Action Letter.
Issuance of this Confirmatory Action Letter does not preclude issuance of an order formalizing the above commitments or requiring other actions on the part of the licensee; nor does it preclude the NRC from taking enforcement action for violations of NRC requirements that may have prompted the iss ance of this letter.
In addition, failure to take the actions addressed in this Confirmatory Action Letter may result in enforcement action.
The responses directed by this letter are not subject to the clearance procedures of the Office of Management and Budget as required by the Paperwork Reduction Act of 1980, Pub. L. No.96-511.
In accordance with 10 CFR 2.790 of the NRC's " Rules and Practice," a copy of this letter will be placed in the NRC Public Document Room.
Sincerely, (Original signed S. Ebneter)
Stewart D. Ebneter Regional Administrator cc:
(See page 3)
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I Tennessee Valley Authority MAR 4 1993 3
- cc:
Mr. John B. Waters, Director Tennessee Valley Authority Mr. M. J. Burzynski
'3 ET 12A 400 West Summit Hill Drive Nuclear Licensing an,dManager Regulatory Affairs Knoxville, TN Tennessee Valley Authority 37902 SB Lookout Place TVA Representative 1101 Market Street Tennessee Valley Authority Chattanooga, TN 37402-2801 Rockville Office 11921 Rockville Fike Suite 402 Mr. Michael H. Mobley Director Rockville, MD 20852 Division of Radiological Health General Counsel T.E.R.R.A. Building, 6th floor Tennessee Valley Authority 150 9th Avenue North ET llH Nashville, TN 37218-5404 400 West Summit Hill Drive Knoxville, TN 37902 County Judge Hamilton County Courthouse Mr. J. R. Bynum, Vice President Chattanooga, TN Nuclear Operations 37402 Tennessee Valley Authority bec:
(See page 4) 3B tookout Place 1101 Market Street Chattanooga, TN 37402-2801 Ms. Marci Cooper Site Licensing Manager Sequoyah Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Soddy-Daisy, TN 37379 Mr. Robert fenech, Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Soddy-Daisy, TN 37379
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l MAR 4 1993 Tennessee. Valley Authority 3
cc: Mr. John B. Waters, Director Mr. M. J. Burzynski, Manager l
Tennessee Valley Authority Nuclear Licensing and ET 12A Regulatory Affairs 400 West Summit Hill Drive Tennessee Valley Authority Knoxville, TN 37902 SB Lookout Place 1101 Market Street TVA Representative Chattanooga, TN 37402-2801 Tennessee Valley Authority Rockville Office Mr. Michael H. Mobley 11921 Rockville Pike Director Suite 402 Division of Radiological Rockville, MD 20852 Health T.E.R.R.A. Building, 6th Floor General Counsel 150 9th Avenue North Tennessee Valley Authority Nashville, TN 37218-5404 ET 11H 400 West Summit Hill Drive County Judge Knoxville, TN 37902 Hamilton County Courthouse Chattanooga, TN 37402 Mr. J. R. Bynum, Vice President Nuclear Operations bcc:
(See page 4)
Tennessee Valley Authority 3B Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Ms. Marci Cooper Site Licensing Manager Sequoyah Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Soddy-Daisy, TN 37379 Mr. Robert Fenech, Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Soddy-Daisy, TN 37379 i
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Tennessee Valley Authority 4
FAR 4 1993 bec:
J. H. Sniezek, EDO J. Lieberman, OE S. A. Varga, NRR J. R. Johnson, DRP/RII G. C. Lainas, NRR F. J. Hebdon, NRR i
G. R. Jenkins, EICS/RII C. F. Evans, ORA /RII P. J. Kellogg, DRP/RII S. Sparks, DRP/RII D. E. LaBarge, NRR NRC Document Control Desk NRC Resident Inspector U.S. Nuclear Regulatory Commission 1
2600 Igou Ferry Road Soddy-Daisy, TN 37379 l
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