ML021050113
| ML021050113 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 04/01/2002 |
| From: | Lagergren W Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| WBN-TS-01-04 | |
| Download: ML021050113 (6) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 William R. Lagergren, Jr.
Site Vice President, Watts Bar Nuclear Plant WBN-TS-01-04 10 CFR 50.4 APR- 0 1 2002 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 In the Matter of the
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Docket No. 50-390 Tennessee Valley Authority
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WATTS BAR NUCLEAR PLANT (WBN) - TECHNICAL SPECIFICATION CHANGE TS-01-04, DIESEL GENERATOR (DG) RISK INFORMED ALLOWED OUTAGE TIME (AOT) EXTENSION - ADDITIONAL INFORMATION TVA submitted a letter on August 7, 2001, requesting an amendment to the Technical Specifications for Limiting Condition for Operation (LCO) 3.8.1, "AC Sources Operating."
The proposed amendment revises the AOT for one DG from three days to 14 days.
Additional information regarding the proposed amendment was provided in a letter to NRC dated December 14, 2001. NRC's review of the proposed amendment resulted in a teleconference February 19, 2002, to discuss whether the DG's from one train can be, if required, interconnected to the opposite train. Based on the teleconference TVA agreed to clarify and submit the information discussed. The information on the capabilities of the onsite electrical system is provided in Enclosure 1 to this letter and indicates that a means exist to interconnect the DGs to provide one train of power. Enclosure 2 list the commitment to update appropriate site procedures to reflect this capability.
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U.S. Nuclear Regulatory Commission Page 2 APR 0 1 L'OOZ If you have any questions about this request, please contact P. L. Pace at (423) 365-1824.
Sincerely, W. R. Lag rgren I
Subscribed and sworn to before me on this day of 0 0____
Notary PuCE_
My Commission Expires 3
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U.S. Nuclear Regulatory Commission Page 3 APR 0 1 2002 cc (Enclosures):
NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr. L. Mark Padovan, Senior Project Manager U.S. Nuclear Regulatory Commission MS 08G9 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. Lawrence E. Nanny, Director Division of Radiological Health 3rd Floor L & C Annex 401 Church St.
Nashville, Tennessee 37243 WBN Technical Specification Change 01-04, Diesel Generator (DG)
Risk Informed Allowed Outage Time (AOT) Extension - Additional Information A teleconference was held with NRC on February 19, 2002, to discuss the capabilities of the onsite/DG electrical system. During the discussion TVA outlined the breaker alignment required to tie a DG from one train to the opposite train. TVA also clarified that no credit is taken for this capability in the design or licensing basis for the plant even though the DGs may be aligned in this manner. In order to clarify the information presented in the teleconference, a listing of the various DG/breaker configurations is provided on the following page. This information indicates that one train of DGs can be made available when one DG is available in a train and a second DG is available in the opposite train.
TVA discussed during the teleconference that the alignment of a DG to an opposite train is a manual action that must be performed outside the main control room by the operations staff. A review of the activities required for the alignment of a DG in this manner and a walkdown of the associated equipment indicated that the required actions can be performed in less than an hour.
Based on this, TVA will develop appropriate revisions to affected site procedures to incorporate a cross-train alignment process for contingency purposes. These procedures will ensure appropriate safe shutdown loads are available, and aligned or locked out to support availability of a complete train. The procedures will be formally approved and released for use in conjunction with the incorporation of the amendment into the Technical Specifications.
6.9KV Start Bus To Watts Bar Hydroelectric 161KV Switchyard, Bay 4 To CCST D H
Common Station Service
" Y Transformer A NO 1514 NC ) 1512 sA
- ý-
Commnon Station Service Bus A I
I6.9KV Start Bus B NO 13 6.9KV Unit Board 2C Diesel Generator 2B-B NC
)1822 P
NO 1826 NO 1924 6.9KV Shutdown Board 2B-B; NO ) 1632 6.9KV Unit Board 2B Diesel Generator NC 1814 NO 1818 NO S1922 6.9KV Shutdown Board 2A-A NO ) 1524 6.9KV Unit Board IC Diesel Generator 1B-B NC)7 2 2 (P NO ) 726 NO ) 1914 6.9KV Shutdown Board lB-B NO ) 1622 6.9KV Unit Board I B Diesel Generator S
IA-A NC )171 NO )1718 NO 1l912 6.9KV Shutdown Board IA-A Simplified Schematic for WBN Diesel Generators (DGs)
Information Extracted from UFSAR Figures 8.1-2 and 8.1-2A El-i I
I
Breaker Alignment for a DG to Supply Opposite Train Based on the Above Schematic E1-2 DG Available for Realignment 1A-A 2A-A 1B-B 2B-B Align to Supply Align to Supply Align to Supply Align to Supply Shutdown Board Shutdown Board Shutdown Board Shutdown Board 1B-B 2B-B lB-B 2B-B 1A-A 2A-A 1A-A 2A-A Breakers Closed Breakers Closed Breakers Closed Breakers Closed 1912 1912 1922 1922 1914 1914 1924 1924 1718 1718 1818 1818 1726 1726 1826 1826 1714 1714 1814 1814 1722 1722 1822 1822 1622 1622 1632 1632 1524 1524 1534 1534 1514 1514 1514 1514 1512 1512 1512 1512 1512 1512 1512 1512 1514 1514 1514 1514 1524 1534 1524 1534 1622 1632 1622 1632 1722 1822 1722 1822 1714 1814 1714 1814 1726 1826 1726 1826 1718 1818 1718 1818
ENCLOSURE2 TECHNICAL SPECIFICATION CHANGE TS-01-04 DIESEL GENERATOR (DG) RISK INFORMED ALLOWED OUTAGE TJIME (AOT) EXTENSION COMMITMENT LIST TVA will develop appropriate revisions to affected site procedures to incorporate a cross-train alignment process for contingency purposes. These procedures will ensure appropriate safe shutdown loads are available, and aligned or locked out to support availability of a complete train. The procedures will be formally approved and released for use in conjunction with the incorporation of the amendment into the Technical Specifications.
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