ML20070D417
| ML20070D417 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 02/27/1991 |
| From: | Wallace E TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9102280259 | |
| Download: ML20070D417 (4) | |
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Tennesbee Va%y Authonty.1101 Ma+et Streter. Chananoega Tennessee 37432 FEB 27 B31 U.S. Nuclear Regulatory Cotanission ATTN:
Document Control Desk Washington, D.C.
20555 Centlemen:
In the Matter of
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Docket Nos. 50-259 Tennessee Valley Authority
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50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - ACTION PLAN TO DISPOSITION CONCERN!:
RECARDINC THE SEISMIC QUALIFICATION OF UNITS 1 AND 3 INSTRUMENT TUBINC
Reference:
TVA letter, dated January 9,1991, plans for the Return to Service of BFN Units 1 and 3 As part of the referenced lettor TVA committed to provide the NL; staf f with the action plan for dispositioning concerns regarding the seismic qualification of instrument tubing at BFN Units 1 and 3.
Enclosu'o 1 to this letter provides a summary of the concerns, a review of the U it 2 resolution, a discussion of lessons learned, and a description of how these concerns will be resolved on Unita 1 and 3.
This submittal is provided for informational purposes only. No NRC action is spee!fically requested.
A su1mnary list of commitments contained in this letter is prov.ded in.
If you have any questions, please contact Joseph E. McCarthy, Manager of Unit 3 Licensing, at (205) 7'9-3604.
Very truly yours, TENNESSEE VALLEY AUTit0RITY 1
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E. G Walla Mana 'r Nucl e Licensing a d Regulatory Affairs Enclosures cc:
See page 2 9102280259 91022y PDR ADOCK 05000259 P
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f-U.S. Nuclear Regulatory Comission k
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Ms. S. C. Black,' Dr puty Director _
Project Directoratt.11-4 U.S. Nuclear Regulatory Commission One White Flint,= North 11555 Rockville Pike, Rockville, Maryland 20852 NRC Resident Inspector
. Browns Ferry Nuclear Plant-Route 12, Box 637-Athens, Alabama 35609-2000-Mr. Thierry M. Ross,- Project Manager U.S. Nuclear Regulatory Commission One White Flint, North -
-11555 Rockville' Pike Rockville, Maryland 20857.
Mr. B. A. Wilson, Proje.t Chief U.S. Nuclear Regulatory Curunission Region-II' 101 Marietta Street, NW, Ailte - 2900 Atlanta, Georgia'.30323-a i
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4 ENCLOSURE 1 BROWNS FERRY NUCLEAR PLANT - UNITS 1 AND 3 INSTRUMENT TUBING CORRECTIVE ACTION PLAN The program for seismic qualification of Unit 2 and common instrument tubing-was developed to address concerns identified with the lack of design criteria for the support of tubing and for the consideration of thermal stresses.- The l
details of the Unit 2 program were submitted by TVA letter,-dated June 13, 1989.. Implementation of the program was evaluated as documented in-Inspection Reports 89-36, dated September 21, 1989, 89-44, dated i
D9cember 11, 1989, and 90-13, dated August 10, 1990.
Approval of TVA's instrument tubing program was documented in Section 2.2.3.4 of Supplement 2 to NURICM 232, Volume 3, dated January 23, 1991.
The program to resolve the instrument tubing concerns for Unit 2 restart involved the rigorous analysis of a sample of the Unit 2 and common safety related instrument tubing which wae within the Design Baseline Program Safe Shutdown Restart Boundary *. This prc, gram was sim').ar to the program which was used to noismically qualify Unit 2 and common _cmall bore piping. Generic attribstes which contributed to an overstressed condition were identified. - A subseqtent screening walkdown of the romaining tubing _was performed.-
The t @ ing which was-identified as potential outliers during the screening ravies, were further evaluated. The Unit 2 and common' tubing, which did 'not' i
.eet interim operability criteria (which was approved for one cycle of Unit 2 operation), was modified to meet the design criteria. TVA committed to modify the Unit 2 and common safety related tubing which:-
- 1) Was outside the safe shutdown restart boundary, or
- 2) Het the interim criteria, but did not meet the: final desig'n criteria :
tc, meet the final design criteria during the next Unit 2 refueling outage.
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l Discussion of the design baseline and verification program was'inc}uded in TVA letter, dated March'25, 1988.
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.j Page 2 of 2 ENCLOSURE 1 (CONTINUED)
BROWNS FERRY NUCl. EAR PLANT - UNITS 1 AND-3 INSTRUMENT TUBING CORRECTIVE ACTION -PL AN Based upon the lessons learned from the Omplementation of the Unit 2 and instrument tubing program, TVA will implement a similar program on Unite 1 and 3.
TVA will perform a walkdown the Units-1 and 3 safety related instrument tubing.
This walkdown will be based on the' generic. attributes which were developed in the Unit 2 program and will use procedures and checkliste similar to the ones de<reloped for Unit 2...The use of the Unit 2 generic attributes, procedures, and checklisto for the seismic qualification of the Unite I and 3 instrument tubing la acceptable since The almilarity between the instrument ttbing installations for_ Unite 1, 2, and 3, The analyste parameterc (e.g., operating modee, seismic spectra, etc.)
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Unite 1 and 3 safety related tubing will be celemi.cally; qualified to meet the final design criteria prior to the restart of each respective unit.' Interim operability criteria will not be used.
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ENCLOSURE 2 BROWNS FERRY. NUCLEAR PLANT - UNITS-1 AND 3~
SUMMARY
OF COMMITMENTS Units 1 and 3 safety related instrument tubing will be seismically qualified to meet the final design criteria prior to the restart of each respective unit.
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