IR 05000327/1993002
| ML20058N328 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/07/1993 |
| From: | Gibson A NRC Office of Inspection & Enforcement (IE Region II) |
| To: | Medford M Tennessee Valley Authority |
| References | |
| NUDOCS 9310130278 | |
| Download: ML20058N328 (3) | |
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SEP 7 1993
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Docket Nos. 50-327, 50-328 License Nos. DPR-77, DPR-79 t
Tennessee Valley Authority ATTN: Dr. Mark 0. Medford Vice President, Technical
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Support
3B Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Gentlemen:
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SUBJECT: REQUEST FOR EVALUATION OF EMERGENCY RAW COOLING WATER SYSTEM ADEQUACY i
The purpose of this letter is to request information to assist us in resolving a concern identified in Nuclear Regulatory Commission (NRC) Inspection Report Nos. 50-327/93-02 and 50-328/93-02. The concern was contained in inspector
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follow-up item 93-02-05, regarding the capability of the Emergency Raw Cooling
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Water (ERCW) to provide sufficient flow rate while one unit is in refueling with a simultaneous loss of coolant accident on the other unit. While reviewing this postulated event, the inspectors reviewed a preliminary calculation that suggested the ERCW system could provide sufficient flow for these circumstances if certain nonessential heat loads are removed. During l
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their review, however, the inspectors did note that some initial conditions
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assumed in this evaluation were questionable.
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We understand that your subsequent review of the evaluation shows that the reactor coolant temperature would not exceed 151.3 Degrees Fahrenheit in the refueling reactor; however, we remain concerned whether the initial conditions assumed in this evaluation encompass all applicable conditions.
In particu-lar, we are interested in TVA's assumptions regarding ERCW inlet temperature and the specific nonessential heat loads which are assumed to be removed.
Therefore, we request that you provide us with your approved evaluation of the heat loading and ERCW removal capacity for this situation.
Further, this approved evaluation should include an assessment of the ability of the shutdown unit to remain in a cold shutdown condition and identification of any inhibiting conditions that might prevent safe cessation of fuel movement.
Mr. Charles Casto of my staff discussed this matter with Mr. Russell Thompson of your staff.
In that discussion, Mr.-Thompson indicated that the preliminary evaluation could be finalized within several weeks. We
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request that TVA provide the final evaluation, including a description of all compensatory actions, if any, to the NRC within 30 days of this letter.
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9310130278 930907
PDR ADOCK 05000327
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SEP 7 1993 Tennessee Valley Authority
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I The responses requested by this letter are not subject to the clearance
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procedures of the Office of Management and Budget as required by the Paperwork Reduction Act of 1980, Pub. L. No.96-511.
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Sincerely,
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Original signed by
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Johns P. Jaudon/for
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Albert F. Gibson, Director Division of Reactor Safety
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cc:
W. H. Kennoy, Director i
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Tennessee Valley Authority M
l ET 12A 400 West Summit Hill Drive Knoxville, TN 37902
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R. M. Eytchison, Vice President Nuclear Operations
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Tennessee Valley Authority 3B Lookout Place
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1101 Market Street i
Chattanooga, TN 37402-2801
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B. S. Schofield, Manager Nuclear Licensing and Regulatory Affairs Tennessee Valley Authority
5B Lookout Place
1101 Market Street
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Chattanooga, TN 37402-2801
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Robert Fenech, Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Soddy-Daisy, TN 37379 TVA Representative
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Tennessee Valley Authority
Rockville Office
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11921 Rockville Pike
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Suite 402 r
Rockville, MD 20852-(cc cont'd - See page 3)
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SEP 7 1993 Tenn.es'ee Valley Authority
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Ralph H. Shell
Site Licensing Manager Sequoyah Nuclear Plant
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P. O. Box 2000 l
Soddy-Daisy, TN 37379
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Michael H. Mobley, Director Division of Radiological Health
3rd Floor, L and C Annex
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401 Church Street Nashville, TN 37243-1532 i
General Counsel Tennessee Valley Authority ET 11H i
400 West Sumit Hill Drive Knoxville,-TN 37902
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County Judge
Hamilton County Courthouse
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Chattanooga, TN 37402
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Bill Harris
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Route 1, Box 26 Ten Mile, TN 37880
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bec: E. Merschoff, RII-J. Johnson, RII i
P. J.' Kellogg, RII
S. E. Sparks, RII
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B. Bordenick, OGC
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D. E. LaBarge, NRR Document Control Desk NRC Resident Inspector U.S. Nuclear Regulatory Commission 2600 Igou Ferry Soddy-Daisy, TN 37379 RII:DRS RI P
CCaho CJulian PKellodg'
08/gQ/93 c06/ /93'
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