ML13018A072
| ML13018A072 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/18/2013 |
| From: | Farideh Saba Plant Licensing Branch II |
| To: | James Shea Tennessee Valley Authority |
| Saba F NRR/DOLR/LPL2-2 301-415-1447 | |
| References | |
| TAC ME6615, TAC ME6616, TAC ME6617 | |
| Download: ML13018A072 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20555-0001 January 18, 2013 Mr. Joseph W. Shea Corporate Manager-Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street LP 3D-C Chattanooga, TN 37402-2801
SUBJECT:
BROWNS FERRY NUCLEAR PLANT. UNITS 1, 2, AND 3, REQUEST FOR ADDITIONAL INFORMATION RELATED TO CORE PLATE BOLT STRESS ANALYSIS (TAC NOS. ME6615, ME6616, AND ME6617)
Dear Mr. Shea:
By letter dated June 15, 2011, as supplemented by a letter dated October 25, 2012, the Tennessee Valley Authority (TVA or the licensee), submitted a report on the plant-specific stress analysis of the Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, core plate hold down bolts. This report was submitted in accordance with Commitment 47 in Appendix A to NUREG-1843, whereby TVA committed to perform a plant-specific stress analysis of the BFN core plate hold down bolts, as described in Boiling Water Reactor Vessel Internals Program (BWRVIP)-25, and submit the results of this analysis 2 years prior to the period of extended operation.
A response to the enclosed Request for Additional Information is needed before the Nuclear Regulatory Commission staff can complete the review. This request was discussed with Mr. Tom Hess of your staff on January 10, 2013, and it was agreed that TVA would respond within 30 days of issuance of this letter.
If you have any questions, please contact me by phone at (301) 415-1447 or email at Farideh.Saba@nrc.gov.
Sincerely,
~r- ~
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Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296
Enclosure:
Request for Additional Information cc: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION REQUEST FOR ADDITIONAL INFORMATION REGARDING CORE PLATE HOLD DOWN BOLT STRESS ANALYSIS PERFORMED TO ADDRESS LICENSE RENEWAL COMMITMENT TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50- 259, 50-260, AND 50-296
- 1.
Core plate bolts are prone to intergranular stress corrosion cracking (IGSCC). Since the visual examination currently performed at Browns Ferry Nuclear Plant cannot find IGSCC due to an accessibility issue, the licensee should address the potential extent of cracking that could occur in these bolts in its analysis. Clarify whether the core plate bolt stress analysis account for some portion of the core plate bolts being either completely or partially cracked due to IGSCC or irradiation assisted stress corrosion cracking. If this assumption is included in the analYSiS, describe how the cracking was accounted for in the analysis. If cracking was not accounted for in the stress analysis, provide a technical justification that demonstrates that cracking need not be considered in the analysis.
- 2.
In the October 25, 2012, Request for Additional Information (RAI) response, the licensee presented the results of the analysis of the core plate bolts for Scenario 1 (defined in General Electric Report NEDC-33632P) and provided a justification for calculating the stresses in the core plate bolts using average horizontal and vertical forces. These results are presented in Figure 1 of the licensee's October 25,2012, RAI response and include the effect of preload on the vertical forces applied to the core plate bolts; the horizontal load applied to the bolts was omitted for clarity. However, based on the information provided, the Nuclear Regulatory Commission staff is unable to determine whether the limiting core plate bolt(s) satisfy the allowable stress limits outlined in Table 4-1 of NEDC-33632P. Please provide a comparison of the calculated stresses in the limiting core plate bolt(s), depicted as the bolts to which the highest loads are applied in Figure 1 of the October 25,2012, RAI response, to the stress limits provided in Table 4-1 of NEDC-33632P.
January 18, 2013 Mr. Joseph W. Shea Corporate Manager-Nuclear Licensing Tennessee Valley Authority 3R lookout Place 1101 Market Street lP 3D-C Chattanooga, TN 37402-2801
SUBJECT:
BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3, REQUEST FOR ADDITIONAL INFORMATION RELATED TO CORE PLATE BOLT STRESS ANALYSIS (TAC NOS. ME6615, ME6616, AND ME6617)
Dear Mr. Shea:
By letter dated June 15, 2011, as supplemented by a letter dated October 25,2012, the Tennessee Valley Authority (TVA or the licensee), submitted a report on the plant-specific stress analysis of the Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, core plate hold down bolts. This report was submitted in accordance with Commitment 47 in Appendix A to NUREG-1843, whereby TVA committed to perform a plant-specific stress analysis of the BFN core plate hold down bolts, as described in Boiling Water Reactor Vessel Internals Program (BWRVIP)-25, and submit the results of this analysis 2 years prior to the period of extended operation.
A response to the enclosed Request for Additional Information is needed before the Nuclear Regulatory Commission staff can complete the review. This request was discussed with Mr. Tom Hess of your staff on January 10, 2013, and it was agreed that TVA would respond within 30 days of issuance of this letter.
If you have any questions, please contact me by phone at (301) 415-1447 or email at Farideh.Saba@nrc.gov.
Sincerely, IRA by Siva Lingam forI Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296
Enclosure:
Request for Additional Information cc: Distribution via Listserv DISTRIBUTION:
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