NOC-AE-09002384, Nine-Month Supplemental Response to Generic Letter 2008-01
| ML090330142 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 01/22/2009 |
| From: | Gerry Powell South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-09002384, STI 32424172, TAC MD7881, TAC MD7882 | |
| Download: ML090330142 (5) | |
Text
Nuclear Operating Company South Texas Project Electric Geneiating Station PC. Box 289 Wadsworth. Temas 77483 ,
January 22, 2009 NOC-AE-09002384 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket No. STN 50-498, STN 50-499 Nine-Month Supplemental Response to Generic Letter 2008-01 (TAC Nos. MD7881 and MD7882)
Reference:
- 1. NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008
- 2. Letter from Mohan C. Thadani to Edward C. Halpin dated September 22, 2008, "South Texas Project, Units 1 and 2 - Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and-Containment Spray System." Proposed Alternative Course of Action and Request for Additional Information (TAC Nos. MD7881 and MD7882).
- 3. Letter from G. T. Powell to NRC Document Control Desk dated October 13, 2008, "Nine-Month Response to Generic Letter 2008-01". (NOC-AE-08002355)
The Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01 (Reference 1) to request that each licensee evaluate the licensing basis, design, testing, and corrective
.actions for the emergency core cooling (ECCS), decay heat removal (DHR), and containment spray systems to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.
As requested in Reference 4 and committed to in Reference 5, please find attached the South Texas Project (STP) supplemental response to the nine month response letter (Reference 5).
In summary, STP Nuclear Operating Company (STPNOC) has concluded that based on the previous reviews of the current design basis (drawing reviews, piping walkdowns), plant specific operating experience, and procedure reviews the subject systems/functions are in compliance with the current licensing and design bases and applicable regulatory requirements. System piping walkdowns and slope determinations performed to date have not yielded any information to alter this conclusion. All identified systems are capable of performing their design function.
The enclosure to this letter contains the STP nine-month supplemental response to NRC GL 2008-01.
STI 32424172
NOC-AE-09002384 Page 2 There are no new commitments in this letter.
If there are any questions or if additional information is needed, please contact Mr. Wayne Harrison at 361-972-7298.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on January 22, 2009.
G.T. Powell Vice President, Engineering
Enclosure:
Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems"
NOC-AE-09002384 Page 3 cc:
(paper copy) (electronic copy)
Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Morgan, Lewis & Bockius LLP 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Mohan C. Thadani U. S. Nuclear Regulatory Commission Senior Resident Inspector Kevin Howell U. S. Nuclear Regulatory Commission Catherine Callaway P. 0. Box 289, Mail Code: MNl 16 Jim von Suskil Wadsworth, TX 77483 NRG South Texas LP C. M. Canady Ed Alarcon City of Austin J. J. Nesrsta Electric Utility Department R. K. Temple 721 Barton Springs Road Kevin Polio Austin, TX 78704 City Public Service Richard A. Ratliff Jon C. Wood Bureau of Radiation Control Cox Smith Matthews Texas Department of State Health Services 1100 West 49th Street C. Kirksey Austin, TX 78756-3189 City of Austin Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 7 D1) 11555 Rockville Pike Rockville, MD 20852
Enclosure NOC-AE-09002384 Page I of 2 Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" This enclosure provides the Nine-Month Supplemental (Post Outage) Response to Generic Letter 2008-01 for actions that were deferred until after the refueling outage as requested by the NRC in Reference 4 of the cover letter.
Provided in this enclosure is a description of the results of evaluations that were performed pursuant to Generic Letter 2008-01 on the previously incomplete activities, such as system piping walkdowns, at the South Texas Project (STP).
The original conclusions documented in the 9 month response with respect to the licensing basis evaluation, testing evaluations, and corrective action evaluations have not changed. This supplement will only discuss the results of design evaluation reviews conducted since the October 13, 2008 submittal (Reference 5).
A. EVALUATION RESULTS
- 1. Design Basis Documents No changes have been made to any STP design basis documents as a result of evaluations performed for this GL response.
- 2. Confirmatory Walkdowns In our 9-month response (Reference 5), STP committed to complete the following by January 30, 2009:
Unit 2 confirmatory walkdowns and any additional Unit 1 walkdowns determined necessary, Units 1 and 2 piping slope survey and evaluation of accessible piping STP Units 1 and 2 confirmatory walkdowns are complete. This included the Fuel Handling Building ECCS pump cubicles, the Mechanical Auxiliary Buildings Refueling Water Storage Tank room, and the Reactor Containment Buildings. No discrepancies were found between the as-built field conditions and the drawings, relevant to gas accumulation issues. All vent valves were found to be installed at the proper location circumferentially as well as at the proper location along the length of the pipe. The horizontal piping was found to be nominally level with no discernible change in elevation detected through visual inspection.
STP Units 1 and 2 piping slope survey and evaluation of accessible piping are also complete. This activity involved both un-insulated accessible piping and insulated accessible piping. Results of the surveys and the evaluations were found to be acceptable.
The piping slope survey was performed using conventional surveying tools (level and gauge). On insulated piping, the insulation was temporarily removed as necessary to gain access to the pipe. The Pressurized Water Reactor Owner's Group (PWROG) guidance was used to assess the data. For example, for pump suction
Enclosure NOC-AE-09002384 Page 2 of 2 Nine-Month Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" piping, the interim pump gas ingestion limits shown in Reference 5 were used for the acceptance criteria.
- 3. Vent Valves No new vent locations or modifications to existing vent valves have been identified as a result of the confirmatory walkdowns or the slope surveys.
- 4. Procedures No additional procedures or additional procedure revisions have been identified.
B. DESCRIPTION OF NECESSARY ADDITIONAL CORRECTIVE ACTIONS
- 1. Additional Corrective Actions No additional corrective actions have been identified as a result of the confirmatory walkdowns or the slope surveys.
- 2. Corrective Action Updates No updates or changes to previous corrective actions have been identified as a result of the confirmatory walkdowns or the slope surveys.
Conclusion STP has completed the evaluations of the accessible portions of the systems described in the GL and has concluded they are in compliance with the current licensing and design bases, applicable regulatory requirements and remain capable of performing their design function.
As committed to in Reference 5, the following items remain to be performed:
" STP will perform the remaining piping slope surveys of normally inaccessible piping in the STP Unit 1 containment during 1RE1 5, currently scheduled to begin in October 2009 and provide a report 90 days after completion of the outage.