ML20082E718
| ML20082E718 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 11/18/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-83 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8311280292 | |
| Download: ML20082E718 (2) | |
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TENNESSEE VALLEY. AUTHORITY CHATTANOOGA, TENNESSEE 374ot 400 Chestnut Street Tower II M g 2l A9 l $ November 18, 1983 U.S. Nuclear Regulatory Commission Region II
' Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
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Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - FAILUEZ OF MAIN STEAM LINES BECAUSE OF MLIN FEEDWATER OVERFILL - NCR BLN NEB 8004 - ELEVENTH INTERIM REPORT On March 19, 1980, Bruce Cochran, NRC-0IE Region II, was informed that the subject nonconformance was determined to be reportable in accordance with 10 CFR 50.55(e). This was followed by our interim reports dated April 17, September 23, and December 29,1980; June 25 and December 28, 1981; March 31, August 27, and November 18, 1982; and March 24 and July 14, 1983. Enclosed is our eleventh interim report. We expect to submit our next report by February 29, 1984 We consider 10 CFR Part 21 to be applicable to this nonconformance.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY n
I L. M. Mills, l{anager Nuclear Licensing Enclosure oc (Enclos a ):
Mr. Ric1ard C. DeYoung, Director Office of Inspection and Enforcement U.S. N clear Regulatory Commission Washirston, D.C.
20555 Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, _ Georgia 30339 Babcock & Wilcox Company P.O. Box 1260 Lynchburg, Virginia 24505 Attention:
Mr. H. B. Barkley OFFICIAL COPV r
0311280292 831118 _
DR ADOCK 05000438:
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.983-TVA SOTH ANNIVERSARY g
An Equal Opportunity Employer
J ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS.1 AND 2 FAILURE OF MAIN STEAM LINES BECAUSE OF MAIN FEEDWATER OVERFILL NCR BLN NEB 8004.
ELEVENTH INTERIM REPORT.
Description of Deficiency A preliminary safety concern, PSC 35-79, was initiated within B&W, Lynchburg, Virginia, which presents the concern that a potential exists for overfilling steam generators by excessive addition of main feedwater (MFW) or auxiliary feedwater (AFW).
Excessive feedwater addition, as used here, is defined as a condition which would exist if feedwater (main or auxiliary) is continually added to.the steam generators.in an unplanned fashion at a rate greater than the core heat generation capability for converting it to steam. Overfill, the condition addressed in this preliminary safety concern, may be defined as a
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limiting case of excessive feedwater addition which allows ' liquid spillage into the steam lines.
It is estimated that the time to overfill the integral economizer once-through steam generators (IEOTSG) provided on the Bellefonte Nuclear Plant is approximately 2.to 4 minutes with MFW and between 7 to 15 minutes with AFW.
Potential results of overfill could be:
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- 1. - Steam line deformation and failure because of water accumulation.
- 2. ' Steam generator blowdown because of steam line failure with the potential for core return to power from a safe shutdown condition, excessive steam generator tube stress, exceeding reactor vessel NDT limits, or containment overpressurization.
Interim Progress TVA is still in the process of reviewing and approving the analysis which shows that the main steam line piping can withstand the MFW
, overfill event, and thus, no failure problem would exist. The preliminary analysis' appears to be acceptable, and TVA's Nuclear Engineering Support Branch is awaiting verification and approval of the final analysis by the Civil Engineering Support Branch (CEB). CEB has completed the verification and approval of four of six analysis problems associated with this item. Problems N4-1(2)SM-K,L,M,N have been completed; problems N4-1(2)SM-A,C are not yet finished.
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