ML071140189
| ML071140189 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 04/16/2007 |
| From: | Head S South Texas |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| NOC-AE-07002144 | |
| Download: ML071140189 (5) | |
Text
Nuclear Operating Company South Texas Proect Electnrc Generating Station P0. Box 289 Wadsworth. Texs 77483 lvvv"---
April 16, 2007 NOC-AE-07002144 10CFR50.59 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 10CFR50.59 Summary Report Pursuant to the requirements of 10CFR50.59, the attached report contains a brief description and summary of the 10CFR50.59 evaluations of changes, tests and experiments conducted at the South Texas Project.
There are no commitments in this letter.
If there are any questions regarding this summary report, please contact J. R. Morris at (361) 972-8652 or me at (361) 972-7136.
Scott M. Head Manager, Licensing awh
Attachment:
2007 10CFR50.59 Evaluation Summaries STI:32143330
NOC-AE-07002144 Page 2 of 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Richard A. Ratliff Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756-3189 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission Steve Winn Christine Jacobs Eddy Daniels Marty Ryan NRG South Texas LP Ed Alarcon J. J. Nesrsta R. K. Temple Kevin Pollo City Public Service Jon C. Wood Cox Smith Matthews C. Kirksey City of Austin
Attachment NOC-AE-07002144 Page 1 of 3 Summaries of the following 10CFR50.59 Evaluations are provided in this attachment:
1.
2.
3.
05-15364-10 04-12793-3 05-4840-4 Preheater Bypass Valve Test at Power Change to Failure Modes & Effects Analysis for Auxiliary Feedwater Change to Hot, Full-Power Feedwater Temperature
Attachment NOC-AE-07002144 Page 2 of 3 10CFR50.59 Evaluation Summaries
- 1.
Preheater Bypass Valve Test at Power
==
Description:==
Summary:
This evaluation supports a change to the Preheater Bypass Valve Operability Test procedure, to perform testing required by Technical Specification 4.6.3.1, Containment Isolation Valves.
The valve operability testing will be performed for Containment isolation valve A2FW-FV-7192, Steam Generator 2D Preheater Outside *Reactor Containment Bypass Valve. The test will stroke the valve during at-power operation.
All equipment impacted by the proposed test will stay within its design basis. All code requirements will be satisfied. In addition, the ensuing transient will not result in changing from a Condition I to a Condition II event. This test does not impact accident scenarios and the current dose analysis remains bounding.
- 2.
Change to Failure Modes & Effects Analysis for Auxiliary Feedwater
==
Description:==
Summary:
The change revises the STP UFSAR to reflect revised failure modes and effects analysis (FMEA) for the AFW system electrical components in the isolation valve cubicle (IVC). The change also revises accident analyses to credit faulted steam generator isolation using the safety-grade AFW outside containment isolation valves (OCIV) instead of the AFW regulating valves.
The proposed change replaces the faulted SG isolation function from the operator closing the AFW REG valves to the operator closing the AFW OCIVs. The AFW OCIVs are qualified to "harsh" environment conditions.
The proposed change takes credit for the existing operator actions to isolate the faulted steam generator by closing the AFW OCIV or securing the pump.
No new operator actions, procedure changes or equipment qualification will be performed. The required operator actions already exist in plant procedures No evaluation methodology is changed and no equipment or component needs to be requalified.
No changes will be made to equipment important to safety or to operator actions.
The proposed UFSAR change revises analysis to reflect plant conditions and does not change plant configuration.
The change does not introduce the possibility of a malfunction of an SSC important to safety with a different result because no new failure modes are introduced. This change does not impact accident scenarios and the current dose analysis remains bounding.
Attachment NOC-AE-07002144 Page 3 of 3
- 3.
Change to Hot, Full-Power Feedwater Temperature
==
Description:==
Summary:
The proposed change revises the UFSAR to reflect the observed hot full-power feedwater temperature. This change revises the upper end of the hot full-power feedwater temperature range to 448 'F for all safety analyses described in the UFSAR.
There is no change made to the operating parameters. The results of the evaluation for higher HFP feedwater temperature show that all acceptance limits continue to be met, and the design basis limits for the fission product barriers are not exceeded.