ML020650010
| ML020650010 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/04/2002 |
| From: | Sheppard J South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-02001282 | |
| Download: ML020650010 (4) | |
Text
Nuclear Operating Company South Texas Pro/ect Electric Generattng Station PO. Box 289 Wadsworth, Texas 77483 March 4, 2002 NOC-AE-02001282 File No.: G25 10CFR50.90 STI:31413746 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units I & 2 Docket Nos. STN 50-498, STN 50-499 Additional Information to Support the Request for Approval of Power UDrate and a Revision to the Technical Specifications
Reference:
AAAA Letter from J. J. Sheppard to NRC Document Control Desk, "Proposed Amendment to Facility Operating Licenses and Technical Specifications Associated with a 1.4-% Core Power Uprate," August 22, 2001 (NOC-AE-01001162)
The referenced letter requested approval of increasing the plant operating power level by 1.4 percent and submitted a license amendment supporting associated revisions to Technical Specifications. As the result of a phone conversation with the NRC on February 27, 2002, additional information to support review of the licensing application is provided in the attachment to this letter.
There are no licensing commitments in this letter. If you should have any questions concerning this matter, please contact Mr. Ken Taplett at (361) 972-8416 or me at (361) 972-8757.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on:
31 J. J. Sheppard Vice President, Engineering & Technical Services KJT/
Attachments: Additional Information
NOC-AE-02001282 Page 2 Ellis W. Merschoff Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mohan C. Thadani Project Manager U. S. Nuclear Regulatory Commission 1 White Flint North, Mail Stop: O-7D1 11555 Rockville Place Rockville, MD 20852-2738 Cornelius F. O'Keefe U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code MN1 16 Wadsworth, TX 77483 A. H. Gutterman, Esquire Morgan, Lewis & Bockius 1111 Pennsylvania Avenue, NW Washington, DC 20004 M. T. Hardt/W. C. Gunst City Public Service P. 0. Box 1771 San Antonio, TX 78296 A. Ramirez/C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Jon C. Wood Matthews & Branscomb 112 East Pecan, Suite 1100 San Antonio, Texas 78205-3692 Institute of Nuclear Power Operations - Records Center 700 Galleria Parkway Atlanta, GA 30339-5957 Richard A. Ratliff Bureau of Radiation Control Texas Department of Health 1100 West 49th Street Austin, TX 78756-3189 R. L. Balcom/D. G. Tees Reliant Energy, Inc.
P. 0. Box 1700 Houston, TX 77251 C. A. Johnson/A. C. Bakken, I AEP - Central Power and Light Company P. 0. Box 289, Mail Code: N5022 Wadsworth, TX 77483 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Attachment NOC-AE-02001282 Page I of 2 NRC Requested Information:
Demonstrate that the operation of the South Texas units remains consistent with the basis for the ATWS Mitigation System required by 10CFR50.62 following a 1.4-percent power uprate.
Response
The generic Westinghouse analysis that is the basis for the ATWS Mitigation System is provided in Westinghouse Letter NS-TMA-2182 "ATWS Submittal", December 1979.
South Texas conducted a study to compare the results of the referenced four-loop plant in the generic analysis with the South Texas design at the uprate conditions. Design values for South Texas were compared with values for the four-loop plant with Model F steam generators. Of the steam generator models that were analyzed, the tube design and secondary side volume of the Model F design is the closest comparison to the Delta 94 steam generator design at South Texas.
In addition, the nominal reactor coolant system conditions and steam generator secondary fluid mass for the Model F plant most closely resembles the South Texas plant. For the comparative study, sensitivities were used for the Model 51 steam generator analysis because sensitivities for the Model F do not appear in the letter report. These sensitivities should bound the predicted reactor coolant system peak pressure for the South Texas plant. The tables below provide a listing of the compared parameters and the resulting peak reactor coolant system pressure. The primary safety concern from the two transients is the potential for high pressure within the reactor coolant system. The results of the study demonstrate that the South Texas units compare favorably with the American Society of Mechanical Engineers (ASME) stress level C limit of 3200 psig.
Case 1: Loss of load without a reactor trip transient Parameter Model F South Texas Sensitivity Adjustment referenced Delta 94 difference plant plant Referenced plant reactor 2902 coolant system pressure Pressurizer water level 60 56 6.67
-0.5
-3
(%)___
Steam generator water 107,850 151,856 40.80 0
0 mass (Ibm)
Feedwater enthalpy 419.6 419.6 0.00 0
0 (Btu/lbm)
Reactor coolant system 12,049 15,075 25.11 4.2 105 volume (cubic feet)
Auxiliary feedwater flow 1760 2160 22.73
-1.1
-25 (gpm)
Core thermal power 3423 3853 12.56 22 276 (MWt)
Pressurizer power-210,000 210,000 0.00 0
operated relief valve capacity (lbm/hr)
Pressurizer safety relief 420,000 501,000 19.29 Note 1 0
valve capacity (lbm/hr)
South Texas reactor 3255 coolant system pressure
Attachment NOC-AE-02001282 Page 2 of 2 Case 2: Loss of feedwater without a reactor trip transient Parameter Model F South Sensitivity Adjustment referenced Texas difference plant Delta 94 plant Referenced plant reactor 2830 coolant system pressure Pressurizer water level 60 56 6.67
-0.4
-3
(%)
Steam generator water 107,850 151,856 40.80 0
0 mass (Ibm)
Feedwater enthalpy 419.6 419.6 0.00 0
0 (Btu/lbm)
Reactor coolant system 12,049 15,075 25.11 1.8 45 volume (cubic feet)
Auxiliary feedwater flow 1760 2160 22.73
-0.3
-7 (gpm)
Core thermal power 3423 3853 12.56 13 163 (MWt)
Pressurizer power-210,000 210,000 0.00 0
operated relief valve capacity (lbm/hr)
Pressurizer safety relief 420,000 501,000 19.29 Note 1 0
valve capacity (lbm/hr)
South Texas reactor 3028 coolant system pressure Note 1:
No sensitivity is presented in the generic analysis. The larger capacity of the South Texas pressurizer safety relief valves would result in a lower reactor coolant pressure than that presented in the above two tables.
Reference:
NS-TMA-2182, Letter from T. M. Anderson (Westinghouse) to Dr. S. H. Hanauer (NRC) dated December 30, 1979, "ATWS Submittal".