ML20070D418
| ML20070D418 | |
| 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 9102280261 | |
| Download: ML20070D418 (5) | |
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knressee va*v Mwy 1 tot Mom spect chaw, as tenname 3202 FEB 171991 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.
20555 Centlement In the Matter of
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Docket Nos. 50-259 Tennescoo Valloy Authority
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50-296 BROWNS FERRY NUCLEAR PLANT (UPN) - ACTION PLAN TO DISPOSITON CONCERNS RELATED TO UNITS 1 AND 3 SMALL BORE PIPING
Reference:
TVA lotter, dated January 9, 1991, Plans for the Return to Service of BFN Units 1 and 3 Ar part of the referenced letter, TVA committed to provido the NRC staff with the action plan for dispositioning small bore piping concerns at BFN Units 1 and 3. to this letter providos a summary r the l
concerns, a review of the Unit 2 resolution, a discussion of Itasons learned, and a description of how these concerns will be resolved on Units 1 and 3.
This submittal is provided for informational purposes only. No NRC action is specifically requested.
A summary list of commitments contained in this letter is provided in.
If yru have any questions, please contact Joseph E. McCarthy, Manager of Unit 3-Licensing, at (205) 729-3604.
Very truly yours, s
TENNESSEE val. LEY AUTHORITY 0
Ah W E. G(,Jalla
, Ma ger Nuclehr Licensing nd Regulatory Affairs Enclosures cc See pago-2 f,h22h s_
9-
2 U.S. Nuclear Regulatory Commission FEB 271991 1
cc (Enclosures):
Ms. S. C. Black, Deputy Director Project Directorate 11-4 U.S. Nuclear Regulatory Commission One White (lint, North 11555 Rockville Pike, Rockville, Maryland 20852 NRC Resident inspector Browns Ferry Nuclear Plant a
Route 12. Box 637 Athens, Alabama 35609-2000 Mr. Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One While Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Coorgia 30323 i
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ENCLOSURE 1 BROWNS FERRY NUCLEAR PLANT - UNITS 1 AND 3 SMALL BORE PIPING CORRECTIVE ACTION PLAN The program for qualification of Unit 2 and common small boro piping (less than 2 inch dLamoter) was developed to address concerne identified with the application of design criteria, incomplete support detaile, and missing back-up calculations for typical supporte.
Separate Unit 2 programs were used to qualify control rod drive insert and withdrawal, torus attached piping, and come small boro piping which branched off large bore piping and was qualified as part of the Bulletina 79-02 and 79-14 programs.
Tbo details of the Unit 2 program were submitted by TVA letters, dated March 10, 1988, April 29, 1988, Juno 00, 1989, and November 6, 1989.
Review of the interim operability and final doelgn critoria was documented in Inspection Reporte 89-15, datou May la,1989, and Inspection Reporte 89-36, dated September 21, 1989.
Implementation of the program was evaluated as documented in Inspection Reporte 89-36, dated September 21, 1989, and 89-44, dated December 11, 1989. Approval of TVA's small boro piping program was documented in Section 2.2.3.2 of Supplement 2 to NUREG-1232, Volume 3, dated January 23, 1991.
The program to resolve the small bore piping concerne for Unit 2 restart involved the rigorous analysis of a cample of the Unit 2 and common Soiemic Class I emall bore piping which was within the Design Baseline Program Sale Shutdown Restart Boundary"'.
Generic attributes which contributed to an overstressed condition were identified.
Using these attributes, a screening walkdown of the romaining piping was performod.
Further evaluations were performed when a field docinion regarding the adequacy of piping or a pipe support could not be made due to the complexity of the configuration. The Unit 2 and common piping, which did not meet interim operability criteria (which was approvod for one cycle of Unit 2 operation), was modified to moet the final design critoria. TVA committed to modify the following Unit 2 and common seismic class I piping to moet the final design criteria during the next Unit 2 refueling outage:
- 1) Piping which was outside the safe shutdown restart boundary, and 2)
Piping which mot the interim operability critoria, but did not meet the final design crittria.
Discussion of the design baseline and verification pcogram was included in T/A letter, dated March 25, 1988.
4 Page 2 of 2 ENCLOSURE 1 (CONTINUED)
BROWNS FERRY NUCLEAR PLANT - UNITS 1 AND 3 SMALL BORE PIPING CORRECTIVE ACTION PLAN An additional 100 pipe supports were rigorously analyzed to achieve approximately a 10 percent sample of the Unit 2 and common restart scope.
No new attributes were identified as a result of this additional analysis.
Based upon the lessons learned from the implementation of the Unit 2 and l
cvmmon small bore piping prograno, TVA will implement a similar program on Units 1 and 3.
TVA will perform a walkdown of the Units 1 and 3 Seismic class 7 email bore piping. This walkdown will be based on the generic attributes which were developed in the Unit 2 program and will use procedures and cht.cklists similar to the ones developed for Unit 2.
The use of the Unit i generic attributes, procedures, and checklists for the qualification of tne Units 1 and 3 small bore piping is acceptable since:
Small bore piping fue all three units was field routed and supported using the same design criteria and construction methods, and The analysis parameters (e.g., operating moues, seismic spectra, etc.)
e are the same for all three units.
As previously perfor.ned on Unit 2, complex pipe or pipe support configurations will be evaluated on a case by case basis.
Unita 1 and-3 Seismic class I small bore piping will be 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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i ENCLOSURE 2 BROWNS FERRY NUCLEAR-PLANT - UNITS 1 AND 3
SUMMARY
OF COMMITMENTS Units 1 and 3 seismic Class I small bore-piping will be qualified to meet the final design criteria prior to the restart of each respective unit.
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