ML20207K018
| ML20207K018 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/21/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8809280216 | |
| Download: ML20207K018 (4) | |
Text
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7 TENNESSEE VALLEY AUTHORITY CH ATTANOOG A. TENNESSEE 37401 SN 1578 Lookout Place SEP 211988 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket Nos. 50-259 Tennessee Valley Authority
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50-260
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50-296 BROWhS FERRY NUCLEAR PLANT (BFN) - SEISMIC PROGRAM INTERIM OPERABILITY CRITERIA - SAFETY EVALUATION OPEN ITEMS AND COMMENTS
Reference:
TVA letter, August 23, 1988,' BFN Response to Seismic Program Interim Operability Criteria Safety Evaluation Open Items and Concerns.
This submittal documents commitments made between TVA and NRC (T. Cheng) to resolve comments on the referenced letter.
Reference letter items not included in the following discussion have been resolved to the satisfaction of the NRC inspectors.
While they may still be subject to inclusion in future inspection, answers presented previously adequately serve to address NRC questions.
Open Issue 1 - Electrical Conduit and Conduit Supports - Use of (2.0 x Fy)/(0.75 x 2.3) Interim Allowable Stress Criteria.
NRC comment - Justification provided by TVA for use of this higher allowable stress criteria is inadequate. Comparisons of conduit to piping are not sufficient as support systems for each are not equivalent.
Unless TVA can offer sufficient justification which does not reference a piping equivalence, this higher allowable will not be accepted.
TVA agreed to provide discussion and justification for this higher allowable stress value on condult.
TVA's response in the referenced letter will be revised and resubmitted.
Open Issue 2 - Electrical Conduit and Conduit Supports - Buckling Criteria for Aluminum Conduits NRC comment - While it is understood that buckling may not be a critical failure mode for aluminum conduit, NRC would like a calculation justifying aluminum conduit resistance to buckling.
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% SEP 211988 U. S. Nuclear Regulatory Commission TVA agreed to generate this calculation and make available for NRC review and inspection.
Open Issue 3 - HVAC Ouctwork and Supports.
NRC coment - While buckling of HVAC ductwork might not have been an original design requirement, NRC would like justification that either buckling with HVAC cracking will not occur at BFN, or if cracking does occur, that leakage will not impact plant operation.
TVA agreed to provide such justification and make available for NRC review and inspection.
Open Issue 4 - Drywell Access Steel Platforms - Use of absolute summation fer interim operability and phasing for long term.
NRC comment - TVA wording of response in reference letter implies not that TVA can use phasing where justified for long term evaluation, but will utilize phasing.
TVA will revise and resubmit this response to clarify that use of phasing in long term is an acceptable analysis option where properly justified.
Enclosure i summarizes the TVA commitments contained in this letter.
Items 1 and 4 will be submitted to NRC by October 14, 1988, items 2 end 3 will be i
available for NRC inspection presently scheduled to begin on October 31, 1988.
If there are any questions, please telephone M. J. May at BFN (205) 729-3570.
g Very truly yours, TENNESSEE VALLEY AUTHORITY
\\qJM q
k R. Gridley, Manag p
Nuclear Licensing and Regulatory Affairs i
I Enclosures cc:
See page 3 t
t e-U.S. Nuclear Regulatory Commission h $1 MO cc (Enclosures):
Ms. S. C. Black, Assistant Director for Projects TVA Projects Olvision U.S. Nuclear Regulatory Commtssion One'Whlte Flint North
'11555 Ror.kville Pike L
Rockville, Maryland 20852 i
Mr. F. R. McCoy, Assistant Director for Inspection Programs TVA Projects Olvision U.S. Nuclear Regulatory Comission l
Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Browns Ferry Resident Inspector Browns Ferry Nuclear P1&nt l
Route 12, Box 637 Athens, Alabama 35611 i
I
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ENCLOSURE 1 LISTING OF COMMITMENTS 1.
TVA will provide discussion and justification for use of a higher allowable stress criteria on electrical condult. Due date 10/14/88.
2.
TVA will generate a calculation justifying aluminun conduit resistance to buckling.
This calculation will be available for NRC review and inspection.
Due date 10/31/88.
3.
TVA will provide justification for buckling acceptability of HVAC ductwork.
Either buckling with HVAC cracking will not occur or cracking will not cause leakage which will impact plant operation.
Due date 10/31/88.
4.
TVA will revise and resubmit its original response on drywell access steel platforms, to clarify that use of phasing in long term evaluations is an acceptable analysis option where properly justified.
Due date 10/14/88.
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