ML20057B605
| ML20057B605 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/16/1993 |
| From: | Hood D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9309220325 | |
| Download: ML20057B605 (16) | |
Text
{{#Wiki_filter:l e , h A}\S4 ! k l 8 ! l G UNITED STATES - l l'id@. i I NUCLEAR REGULATORY COMMISSION ) (
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/ WASHINGTON, D.C. 20555-0001 Septenber 16, 1993 j
I Docket Nos. 50-424 i and 50-425 LICENSEE: Georgia Power Company, et al. j i l l FACILITY: Vogtle Electric Generating Plant, Units 1 and 2 l
SUBJECT:
SUMMARY
OF AUGUST 31, 1993, MEETING REGARDING POTENTIAL ELECTRICAL ]' MODIFICATIONS l On August 31, 1993, the NRC staff met in Rockville, Maryland, with Georgia Power Company, et al., to discuss two potential modifications currently being considered to enhance the Vogtle electric power system. Meeting attendees are listed in Enclosure 1. Enclosure 2 is a copy of the presentation handouts l used during the meeting. , I Mr. W. Shipman of Southern Nuclear, Inc., identified the two potential ! enhancements to be (1) the addition of another Class IE, 4.16 kilovolt (KV) ; supply breaker with interlocks to preclude closing if the existing breaker is l closed, and (2) the addition of another offsite power source from neighboring ! Plant Wilson. l Mr. L. Ward of Southern Nuclear, Inc. reviewed the history and advantages for the additional breaker. During the review of the FSAR, before issuance of the operating license, the NRC questioned the potential for compromising the independence of offsite power sources to Vogtle (see NRC Question 430.60 and licensee's response in FSAR Revisions 7 and 39) with breakers installed in both the normal feed and alternate feed to the 4.16 KV bus. To preclude this potential, the breaker for the alternate feed was physically removed. Now, when the 4.16 KV bus needs to be transferred from the normal feed to the alternate feed source, the single breaker is removed and transported from one breaker cubical to the other, and the emergency diesel generator (EDG) is used to keep the bus energized during the transfer. The transfer is time consuming and precludes a fast transfer of power sources when needed. Mr. Shipman noted that if the extra breaker had been available on March 20, 1990, there would have been no Vogtle loss-of-power event because the extra breaker would have been in use, powering the 4.16 KV bus through the B reserve auxiliary transformer (RAT) that had already been repaired. Mr. Shipman noted that Plant Wilson is less than one mile from the Vogtle site and consists of 6 combustion peaking units of 50 megawatts each. The licensee is considering an underground line to use Plant Wilson as an additional source of offsite power. The extra breaker (discussed above) would also be used with the Plant Wilson offsite source to energize the 4.16 KV buss. Plant Wilson i would be used as an offsite power source during shutdown or when maintenance needs to be performed on a RAT. The licensee envisions that the modifications would provide for a transfer between offsite power sources that would be independent of EDGs, and would enable RAT and EDG maintenance at power.
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9309220325 930916
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t t f Septaber 16, 1993 [ I ; I Mr. Snipman estimates that, with the modifications, Vogtle could be ! transferred to the Plant Wilson source during a station blackout in about ; I hour if Plant Wilson were operating at the time. Otherwise, the transfer [ could require an additional hour. Preliminary estimates for severe accidents . (i.e., individual plant evaluations) indicate the modifications could reduce ' the core damage frequency for Vogtle from 4.87 E-5 to about 3.33 E-5, with the major contributor, station blackout, decreasing from 69.9% to about 55.2%. Mr. Shipman noted that purchase orders are ready to be placed for the i breakers, which are proposed to be installed in the next 18 months for. Unit 1 l and during the spring of 1995 for Unit 2. By early next year, designs for the ' electrical connection to Plant Wilson and a decision regarding implementation of the design will be available. Further discussions with the NRC are planned
- at that time.
Original signed by: Darl Hood, Senior Project Manager l Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation i
Enclosures:
j As stated j cc w/ enclosures: l See next page ! Distribution: caesbstkMie OGC 15/B/18 - NRC & Local PDRs E. Jordan HNBB3701 ; PD 11-3 R/F A. Herdt RII ! F. Miraglia 12/G/18 B. Bonser RII J. Partlow 12/G/13 ACRS (10) P-315 , S. Varga 14/E/4 'R. Borchardt 11H3 ! G. Lainas 14/H/3 D. Hood i D. Matthews 14/H/25 J. Starefos D. Thatcher 7E4 R. Jones 8E23 M. Caruso SE23 C. Thomas 10H5 PDII-3:LA PD-II3:PM D:PDIILhdp LBERRY Q DH00D:cwbifj att.h Ws , y//$/93 }/g/93 ////93 0FFICIAL RECORD COPY Document Name: G:\Vogtle\MeetSum i i i
4 Georgia Power Company Vogtle Electric Generating Plant ! cc: l Mr. J. A. Bailey Harold Reheis, Director l Manager - Licensing Department of Natural Resources 1 Georgia Power Company 205 Butler Street, SE. Suite 1252 P. O. Box 1295 Atlanta, Georgia 30334 Birmingham, Alabama 35201 Attorney General l Mr. J. B. Beasley Law Department ' General Manager, Vogtle Electric 132. Judicial Building Generating Plant Atlanta, Georgia 30334 P. O. Box 1600 Waynesboro, Georgia 30830 Mr. Alan R. Herdt Project Branch #3 Regional Administrator, Region II U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission 101 Marietta Street, NW. Suite 2900 ; 101 Marietta Street, NW., Suite 2900 Atlanta, Georgia 30323 ! Atlanta, Georgia 30323 , Mr. Dan H. Smith, Vice President l Office of Planning and Budget Power Supply Operations Room 615B Oglethorpe Power Corporation , , 270 Washington Street, SW. 2100 East Exchange Place ) Atlanta, Georgia 30334 Tucker, Georgia 30085-1349 ' Office of the County Commissioner Charles A. Patrizia, Esquire. Burke County Commission Paul, Hastings, Janofsky & Walker Waynesboro, Georgia 30830 12th Floor ! 1050 Connecticut Avenue, NW. ! Mr. J. D. Woodard Washington, DC 20036 i Senior Vice President - ! Nuclear Operations Arthur H. Domby, Esquire . Georgia Power Company Troutman Sanders j P. O. Box 1295 NationsBank Plaza ; Birmingham, Alabama 35201 600 Peachtree Street, NE. l
- Suite 5200 l Mr. C. K. McCoy Atlanta, Georgia 30308-2216 i Vice President - Nuclear Vogtle Project Resident Inspector Georgia Power Company U. S. Nuclear Regulatory Commission P. O. Box 1295 P. O. Box 572 Birmingham, Alabama 35201 Waynesboro, Georgia 30830 l
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l l . \ l Enclosure 1 Meeting Attendees August 31, 1993 l l NRC D. Thatcher M. Caruso C. Thomas J. Starefos l R. Jones, Jr. I D. Hood Southern Nuclear /Georoia Power ComDanY W. Shipman J. Bailey L. Ward l R. Moye l S. Swanson H. Oglesby l A. Streetman i 1 l
ENCLOSURE 2 i i l Introductions : Bill Shipman- ! l Purpose and scope of meeting Bill Shipman ; Proposed modifications Lewis Ward- ! Addition of Class lE 4.16 supply breaker ! Existing Design Proposed Modification ! t New offsite source . l Existing Design Proposed Modification Comments Questions All I
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Current IPE contributors to CDF i 4.87 E-5 a LOSP SBO 69.9% I ISLOCAs o.1% Transient 6.8% SGTR 3.6% Special o.5% LOCAs 19.0% e W - -----_M'M--_ _ _____ ,- W"W'"W%'TDW'4-M'1W'*WW+'WW"WW"'T"T-Nh& 't*WP-*N@ww 'w w e'mw e N-*vmNYw'WewM* ' *NN" "-'WD4 "in7"'""'N --- T* Net'M'-N"ww-"""'Mi "D-*"'t l-B +'P W""-' s'*4-
l Estimated CDF with additional offsite feed 3.33 E-5 l l LOSP SBO 55.2% i \ . ISLOCAs o.1% Transient 10.2% SGTR sA% Speciaa o.7% LOCAs 28A% , i
Intended Uses Transfer between offsite sources independent of EDGs Utilize as an offsite power source during shutdown Enable RAT maintenance at power Enable EDG maintenance at power (Future) .}}