ML070790245

Revision to Commitment Dates Associated with NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors

ML070790245
Person / Time
Site:	Palo Verde
Issue date:	03/02/2007
From:	Mauldin D Arizona Public Service Co
To:	Document Control Desk, NRC/NRR/ADRO
References
102-05651- CDM/SAB/GAM, GL-04-002
Download: ML070790245 (7)

Text

NRC Generic Letter 2004-02 LAMN David Mauldin Mail Station 7605 Palo Verde Nuclear Vice President Tel: 623-393-5553 PO Box 52034 Generating Station Nuclear Engineering Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-05651-CDM/SAB/GAM March 02, 2007 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Units 1, 2 and 3 Docket Nos. STN 50-528, 50-529, and 50-530 Revision to Commitment Dates Associated with NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors" By letter dated January 4, 2007, the NRC notified pressurized water reactor (PWR)licensees that the response due date for the request for additional information (RAI)related to Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors," may be extended.

The NRC expectation is that "all PWR licensees will submit a complete supplemental response as soon in 2007 as the information and analysis results are available," and "no later than December 31, 2007." The NRC recognized that licensees are experiencing delays in the supporting evaluations as a result of ongoing testing and analyses to support the resolution of chemical effects issues.Arizona Public Service Company (APS) has been experiencing delays in the supporting GL 2004-02 evaluations for PVNGS similar to those recognized by the NRC in the January 4, 2007 letter. As a result, APS is revising the commitment dates associated with new sump strainer testing, downstream effects, and chemical effects. The revised commitment dates are consistent with the RAI response due dates established in the January 4, 2007 NRC letter. The list of PVNGS GL 2004-02 commitments and due dates is provided in the enclosed table.A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway 0 Comanche Peak

• Diablo Canyon

• Palo Verde 0 South Texas Project 0 Wolf Creek ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Revision to Commitment Dates Associated with NRC Generic Letter 2004-02 Page 2 Please note that the containment sump strainer modification installation schedules and fiberfrax insulation removal schedules are not being revised by this letter. The sump strainer modifications will be installed and the fiberfrax insulation removed in Units 1 and 3 during their 2007 refueling outages as previously committed.

The sump strainer modification will be installed in Unit 2 during the spring 2008 refueling outage as approved by the NRC in their letter dated December 13, 2006. The fiberfrax insulation was removed from Unit 2 in the fall 2006 refueling outage, as previously committed.

If you have any questions, please contact Thomas N. Weber at (623) 393-5764.Sincerely, CDM/SAB/GAM/

Enclosure:

As stated cc: B. S. Mallett NRC Region IV Regional Administrator M. B. Fields NRC NRR Project Manager M. T. Markley NRC NRR Project Manager G. G. Warnick NRC Senior Resident Inspector for PVNGS Enclosure List of Generic Letter 2004-02 Commitments and Due Dates GL 2004-02 REGULATORY COMMITMENT MOST NEW DUE (from APS letter no. 102-05560 RECENT DATE BY dated August 30, 2006) DUE DATE THIS LETTER 1. Evaluate the recommendations contained in the December 31, Completed Westinghouse downstream effects evaluation for 2005 PVNGS and establish an implementation schedule for appropriate recommendations.

2. Perform confirmatory head-loss testing of new March 31, As soon in strainer with plant specific debris to ensure an 2007 2007 as adequate design. achievable, and no later than December 31, 2007 3. Verify that a capture ratio of 97% or higher can be March 31, As soon in achieved in the final design of the new sump screen 2007 2007 as to ensure that the fuel evaluation contained in the achievable, Westinghouse downstream effects evaluation is and no later bounding.

than December 31, 2007 4. Perform sump strainer structural evaluation to October 31, Completed ensure seismic and operational integrity.

2006 5. Validate allocated margins for Chemical Effects in March 31, As soon in strainer head-loss to ensure an adequate design. 2007 2007 as achievable, and no later than December 31, 2007 6. Perform a confirmatory containment latent debris June 30, 2006 Completed walkdown of PVNGS Units 1 and 3.7. Perform a confirmatory containment unqualified June 30, 2006 Completed coating walkdown of PVNGS Units 1 and 3.1 Enclosure List of Generic Letter 2004-02 Commitments and Due Dates GL 2004-02 REGULATORY COMMITMENT MOST NEW DUE (from APS letter no. 102-05560 RECENT DATE BY dated August 30, 2006) DUE DATE THIS LETTER 8. Review the existing programmatic controls for November 30, Completed containment coatings identified in the response to 2006 GL 98-04, "Potential for Degradation of the Emergency Core Cooling System and the Containment Spray System after a Loss-of-Coolant Accident Because of Construction and Protective Coating Deficiencies and Foreign Material in Containment," for their adequacy.9. Review the existing programmatic and procedural November 30, Completed controls in place to prevent potentially transportable 2006 debris (insulation, signs and foreign material) in the containment building to ensure that the bounding assumptions in the design of the new strainers will be maintained.

10. Implement in Unit 1 changes to programs and 1R13 refueling No Change procedures to ensure and/or enhance the control of outage transportable debris in containment. (approx.May 31, 2007)11. Implement in Unit 2 changes to programs and 2R13 refueling Completed procedures to ensure and/or enhance the control of outage transportable debris in containment. (approx.Nov. 30, 2006)12. Implement in Unit 3 changes to programs and 3R13 refueling No Change procedures to ensure and/or enhance the control of outage transportable debris in containment. (approx.Dec. 31, 2007)13. Install larger sump strainers in PVNGS Unit 1. 1R13 refueling No Change outage (approx.May 31, 2007)14. Install larger sump strainers in PVNGS Unit 2. 2R14 refueling No Change outage (to begin no later than April 28, 2008)2 Enclosure List of Generic Letter 2004-02 Commitments and Due Dates GL 2004-02 REGULATORY COMMITMENT MOST NEW DUE (from APS letter no. 102-05560 RECENT DATE BY dated August 30, 2006) DUE DATE THIS LETTER 15. Install larger sump strainers in PVNGS Unit 3. 3R1 3 refueling No Change outage (approx.Dec. 31, 2007)16. Remove installed Fiberfrax insulation in PVNGS 1R13 refueling No Change Unit 1. outage (approx.May 31, 2007)17. Remove installed Fiberfrax insulation in PVNGS 2R13 refueling No Change Unit 2. outage (approx.Nov. 30, 2006)18. Remove installed Fiberfrax insulation in PVNGS 3R13 refueling No Change Unit 3. outage (approx.Dec. 31, 2007)19. After plant specific strainer testing has been March 31, To be completed and the Westinghouse downstream 2007 submitted effects evaluation for PVNGS has been evaluated, along with APS will submit an update to the NRC to report the the NRC RAI validation of the allocated margins for chemical response as effects and identify any recommendations from the soon in 2007 Westinghouse evaluation to be implemented.

as the results are available, and no later than December 31, 2007 3 Enclosure List of Generic Letter 2004-02 Commitments and Due Dates References Arizona Public Service Company Letters 1. Letter no. 102-05221, March 4, 2005, 90-Day Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 2. Letter no. 102-05304, July 9, 2005, Response to NRC Request for Additional Information Related to Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 3. Letter no. 102-05336, September 1, 2005, Response to Request No. 2 in NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 4. Letter no. 102-05449, March 20, 2006, Revision to Commitment Dates Associated with NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 5. Letter no. 102-05523, June 29, 2006, Revision to Commitment Dates Associated with NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 6. Letter no. 102-05560, August 30, 2006, Revision to Commitment Date Associated with NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 7. Letter no. 102-05584, October 12, 2006, Unit 2 -Request for Extension to Delay Implementation of Containment Sump Strainer Changes Associated with NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 4 Enclosure List of Generic Letter 2004-02 Commitments and Due Dates References (continued)

NRC Letters to APS 1. Generic Letter 2004-02, dated September 13, 2004, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 2. Letter dated June 2, 2005, Request for Additional Information (RAI) Related To Generic Letter 2004-02, "Potential Impact Of Debris Blockage On Emergency Sump Recirculation At Pressurized-Water Reactors." 3. Letter dated February 9, 2006, Request For Additional Information Re: Response To Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors." 4. Letter dated March 28, 2006, Alternative Approach for Responding to the Nuclear Regulatory Commission Request for Additional Information Letter Re: Generic Letter 2004-02.5. Letter dated December 13, 2006, Unit 2 -Approval of Generic Letter 2004-02 Extension Request.6. Letter dated January 4, 2007, Alternative Approach for Responding to the Nuclear Regulatory Commission Request for Additional Information Letter Regarding Generic Letter 2004-02.5