ML050770105
| ML050770105 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/08/2005 |
| From: | Jordan T South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-04-002, NOC-AE-05001862, STI: 31850630 | |
| Download: ML050770105 (7) | |
Text
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£ &2J9 JfSm,> barbs March 8, 2005 NOC-AE-05001862 STI: 31850630 1 OCFR50.54(f)
U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 90-Day Response to Generic Letter 2004-02: Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors
Reference:
Letter, Thomas J. Jordan to NRC Document Control Desk, "Request for Additional Information Bulletin 2003-01, "Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized Water Reactors," dated November 11, 2004 (NOC-AE-04001793) provides the South Texas Project's (STP) 90-day response to Generic Letter 2004-02. Additionally, Attachment 2 provides the status of STP's candidate operator action review detailed in Table 2 of the referenced letter.
The only commitments in this letter are summarized in Attachment 3.
If there are any questions regarding this response, please contact Scott Head at (361) 972-7136 or me at (361) 972-7902.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on Msrck. 8 200<a ordan Vice President, Engineering kjtl Attachments
- 1. 90-Day Response to Generic Letter 2004-02
- 2. Status of Candidate Operator Actions
- 3. List of Commitments
NOC-AE-05001 862 Page 2 of 2 cc:
(paper copy)
(electronic copy)
Bruce S. Mallett Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Richard A. Ratliff Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756-3189 Jeffrey Cruz U. S. Nuclear Regulatory Commission P.O. Box 289, Mail Code: MN16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP David H. Jaffe U. S. Nuclear Regulatory Commission R. L. Balcom Texas Genco, LP C. A. Johnson AEP Texas Central Company C. Kirksey City of Austin Jon C. Wood Cox Smith Matthews J. J. Nesrsta R. K. Temple E. Alarcon City Public Service
NOC-AE-05001862 Attachment I Page 1 of 2 90-Day Response to Generic Letter 2004-02: Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors NRC Requested Information 1 Within 90 days of the date of the safety evaluation report providing the guidance for performing the requested evaluation, addressees are requested to provide information regarding their planned actions and schedule to complete the requested evaluation. The information should include the following:
NRC Requested Information 1(a):
[Provide] A description of the methodology that is used or will be used to analyze the susceptibility of the ECCS and CSS recirculation functions for your reactor to the adverse effects identified in this generic letter of post-accident debris blockage and operation with debris-laden fluids identified in this generic letter. Provide the completion date of the analysis that will be performed.
STP Response 1(a):
STP plans to analyze the susceptibility of the emergency core cooling system (ECCS) and containment spray system (CSS) recirculation functions to the adverse effects of post-accident debris blockage and operation with debris-laden fluids identified in Generic Letter 2004-02. The methodology used will conform to the intent of NEI 04-07, "Pressurized Water Reactor Sump Performance Evaluation Methodology." The methodology will be supplemented with plant specific licensing basis information and contractor specific proprietary information as appropriate with the current state of knowledge. This analysis is scheduled to be completed no later than September 1, 2005.
Additionally, the current licensing basis for STP, as well as plant-specific features, may identify exceptions and/or refinements to be taken to the guidance given in NEI 04-07 prior to the September 1, 2005 submittal. If any exceptions or refinements to the guidance are identified during the performance of the analyses, supplementary letters to this response will be submitted to the NRC as soon as practical.
NOC-AE-05001 862 Page 2 of 2 NRC Requested Information 1(b):
[Provide] A statement of whether you plan to perform a containment walkdown surveillance in support of the analysis of the susceptibility of the ECCS and CSS recirculation functions to the adverse effects of debris blockage identified in this generic letter. Provide justification if no containment walkdown surveillance will be performed. If a containment walkdown surveillance will be performed, state the planned methodology to be used and the planned completion date.
STP Response 1(b):
Containment walkdowns have been completed at STP to support the analysis of debris blockage as identified in the Generic Letter. The walkdowns were performed by STP personnel using the guidelines provided in NEI 02-01, "Condition Assessment Guidelines, Debris Sources inside Containment,"
Revision 1.
Additional containment walkdowns to support the analysis of sump performance as identified in the generic letter will be performed during the 1 RE12 refueling outage scheduled during the Spring of 2005. The walkdown guidelines provided in NEI 02-01 Revision I will be utilized.
NOC-AE-05001 862 Page 1 of 2 Status of Candidate Operator Actions (COA) Under Consideration COA #
TITLE Evaluation Al a Candidate Operator After verifying containment conditions, actions to secure Action to Secure One Containment Spray (CS) Pumps are already under Spray Pump consideration per the existing STP Loss of Emergency Coolant Recirculation procedure. COA # Al a, would stop the containment spray pump prior to transfer to recirculation from the sump.
STATUS:
The STP design has three trains of containment spray pumps. STP is currently evaluating actions to remove CS pumps from service earlier in an event. This is being done as part of the final design evaluation and not being considered as an interim compensatory action.
Al b Operator Action to See response above. Additionally, COA # Al b would secure all Secure Both Spray CS pumps prior to recirculation conditions.
Pumps STATUS:
With verification of containment cooling, the action to remove all CS pumps from service is taken during recirculation by the existing STP EOP.
A6 Inject More Than One This action is already incorporated by the existing EOP RWST Volume From procedure.
a Refilled RWST or by Bypassing the RWST STATUS:
STP is evaluating additional methods of RWST makeup and evaluating containment flooding concerns associated with this action.
NOC-AE-05001 862 Page 2 of 2 Status of Candidate Operator Actions (COA) Under Consideration COA #
TITLE Evaluation A8 Provide Guidance on STP is currently training operators on symptoms of containment Symptoms and sump blockage and evaluating additional instrumentation Identification of needed to provide positive indication of sump blockage.
Containment Sump Blockage STATUS:
Training is ongoing. Evaluation of additional instrumentation needed to provide positive indication of sump blockage is ongoing for the final sump modification. No new instrumentation for the interim is being considered.
A9 Develop Contingency Contingency actions would be based on the completion of the Actions in Response evaluations for COA A8. If additional instrumentation were to: Containment Sump installed, then the STP EOP would be modified to include this Blockage, Loss of indication for evaluation of sump conditions. Until the extent of Suction, and plant modifications is established, operators will continue to be Cavitation trained for response to the existing plant configuration indication for sump conditions.
STATUS:
Training based on the existing configuration is ongoing. No additional contingency actions are contemplated for the interim.
NOC-AE-05001 862 Page 1 of 1 List of Commitments The following table identifies those actions committed to by the STP Nuclear Operating Company in this document. Any statements in this submittal with the exception of those in the table below are provided for information purposes and are not considered commitments. Please direct questions regarding these commitments to Joe Loya at (361) 972-7922.
Commitment Due Date Condition Report
- 1. STP plans to analyze the susceptibility of the emergency core 09/01/05 04-12498-2 cooling system (ECCS) and containment spray system (CSS) recirculation functions to the adverse effects of post-accident debris blockage and operation with debris-laden fluids identified in the Generic Letter 2004-02. The methodology used will conform to the intent of NEI 04-07, 'Pressurized Water Reactor Sump Performance Evaluation Methodology." The methodology will be supplemented with plant specific licensing basis information and contractor specific proprietary information as appropriate with the current state of knowledge. This analysis is scheduled to be completed no later than September 1, 2005.
Additionally, the current licensing basis for STP, as well as plant-specific features, may identify exceptions and/or refinements to be taken to the guidance given in NEI 04-07 prior to the September 1,
- 2005 submittal. If any exceptions or refinements to the guidance are identified during the performance of the analyses, supplementary letters to this response will be submitted to the NRC as soon as practical.