ML11318A190
| ML11318A190 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 11/01/2011 |
| From: | - No Known Affiliation |
| To: | Division of Operating Reactor Licensing |
| References | |
| Download: ML11318A190 (7) | |
Text
1 WBN2Public Resource From:
Boyd, Desiree L [dlboyd@tva.gov]
Sent:
Tuesday, November 01, 2011 8:30 AM To:
Epperson, Dan; Poole, Justin; Raghavan, Rags; Milano, Patrick; Campbell, Stephen Cc:
Arent, Gordon; Hamill, Carol L; Boyd, Desiree L
Subject:
TVA letter to NRC_10-31-2011_WBN U2 Hydrology Analysis Results - FSAR 2 4 Commitment Attachments:
10-31-2011_WBN U2 Hydrology Analysis Results - FSAR 2 4 Commitment_Final.pdf Please see attached TVA letter that was sent to the NRC today.
Thank You,
~*~*~*~*~*~*~*~*~*~*~*~
Désireé L. Boyd WBN 2 Licensing Support Sun Technical Services dlboyd@tva.gov 423-365-8764
Hearing Identifier:
Watts_Bar_2_Operating_LA_Public Email Number:
574 Mail Envelope Properties (7AB41F650F76BD44B5BCAB7C0CCABFAF24C68D2B)
Subject:
TVA letter to NRC_10-31-2011_WBN U2 Hydrology Analysis Results - FSAR 2 4 Commitment Sent Date:
11/1/2011 8:30:26 AM Received Date:
11/1/2011 8:30:42 AM From:
Boyd, Desiree L Created By:
dlboyd@tva.gov Recipients:
"Arent, Gordon" <garent@tva.gov>
Tracking Status: None "Hamill, Carol L" <clhamill@tva.gov>
Tracking Status: None "Boyd, Desiree L" <dlboyd@tva.gov>
Tracking Status: None "Epperson, Dan" <Dan.Epperson@nrc.gov>
Tracking Status: None "Poole, Justin" <Justin.Poole@nrc.gov>
Tracking Status: None "Raghavan, Rags" <Rags.Raghavan@nrc.gov>
Tracking Status: None "Milano, Patrick" <Patrick.Milano@nrc.gov>
Tracking Status: None "Campbell, Stephen" <Stephen.Campbell@nrc.gov>
Tracking Status: None Post Office:
TVANUCXVS2.main.tva.gov Files Size Date & Time MESSAGE 296 11/1/2011 8:30:42 AM 10-31-2011_WBN U2 Hydrology Analysis Results - FSAR 2 4 Commitment_Final.pdf 79494 Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 October 31, 2011 10 CFR 100 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 Docket No. 50-391
Subject:
Results of the Hydrology Analysis Without Use of Sand Baskets
Reference:
TVA to NRC letter dated April 20, 2011, Response to Request for Additional Information Regarding Final Safety Analysis Report Section 2.4 (TAC NO. ME3945)
By the Reference letter, the Tennessee Valley Authority (TVA) committed to provide the results of the hydrology analysis without crediting the use of sand baskets at Fort Loudoun dam for the seismic dam failure and flood combination or the seismic test of the sand baskets to the Nuclear Regulatory Commission by October 31, 2011. TVA performed the hydrology analysis without use of the sand baskets under TVA Calculation CSQ000020080080, Flood Levels at WBN and SQN from Seismic Dam Failures. The hydrology analysis confirms the sand baskets are not required to be in-place during and following the seismic events defined in Section 2.4.4 of the WBN Final Safety Analysis Report (FSAR). Testing to demonstrate stability of the sand baskets during a seismic event is not required. Enclosure 1 provides the WBN flood levels and warning time of the revised hydrology analysis.
This submittal addresses SSER 24, Appendix HH, Item 133. Enclosure 2 provides the list of commitments for this submittal.
U.S. Nuclear Regulatory Commission Page 3 October 31, 2011 bcc (Enclosures):
Stephen Campbell U.S. Nuclear Regulatory Commission MS 08H4A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Patricia Holahan, Acting Deputy Regional Administrator for Construction U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257
ENCLOSURE 1 RESULTS OF THE HYDROLOGY ANALYSIS WITHOUT USE OF SAND BASKETS TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-391 In the Reference letter, TVA committed to perform either a hydrology analysis without crediting the use of the sand baskets at Fort Loudoun dam for the seismic dam failure and flood combination or perform a seismic test of the sand baskets. This commitment was made because Fort Loudoun dam was the only location where credit for sand baskets was taken during a seismic event.
To address the commitment, TVA re-performed the hydrological analysis (Calculation CDQ000020080080) for the seismic failure combinations which utilized sand baskets to increase the elevation of embankments at the dams. In this reanalysis, the sand baskets were not credited to increase the height of the Fort Loudoun embankment. As a result of this re-analysis, the flood elevation at Watts Bar Nuclear Plant (WBN) increased from 731.11 feet to 731.17 feet, and the flow discharge past the plant increased from 977,618 cubic feet per second to 979,385 cubic feet per second. The flood wave warning time decreased from 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br />, which is still greater than the controlling warning time of 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />. These elevation, flow, and warning time changes will be provided in the next update of the WBN Unit 2 FSAR.
E1-1
ENCLOSURE 2 LIST OF COMMITMENTS
- 1. These elevation, flow, and warning time changes will be provided in the next update of the WBN Unit 2 FSAR.
E2-1