SECY-06-0078, Approval of Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors Extension Request
| ML063400177 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 12/13/2006 |
| From: | Fields M NRC/NRR/ADRO/DORL/LPLIV |
| To: | James M. Levine Arizona Public Service Co |
| Fields M, NRR/DORL/LP4, 415-3062 | |
| References | |
| BL-03-001, GL-04-002, SECY-06-0078, TAC MD3335 | |
| Download: ML063400177 (4) | |
Text
1 In a November 7, 2006, docketed e-mail (Agencywide Documents Access and Management System Accession No. ML063130267), the licensee reported that all known Fiberfax on Palo Verde, Unit 2, had been removed during the fall 2006 refueling outageapproximately 155 cubic feet.
December 13, 2006 Mr. James M. Levine Executive Vice President, Generation Arizona Public Service Company P.O. Box 52034 Phoenix, AZ 85072-2034
SUBJECT:
PALO VERDE NUCLEAR GENERATING STATION, UNIT 2 - APPROVAL OF GENERIC LETTER 2004-02 EXTENSION REQUEST (TAC NO. MD3335)
Dear Mr. Levine:
In an October 12, 2006, updated response to the Nuclear Regulatory Commission (NRC) Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors [PWR]," Arizona Public Service Company (APS or the licensee) provided information on its ongoing activities for resolution of the Generic Safety Issue 191 (GSI-191) containment sump clogging issue. In this letter, APS requested an extension of time to delay installation of the new containment sump strainers at Palo Verde Nuclear Generating Station (Palo Verde), Unit 2, until the refueling outage scheduled for April 2008. APS had committed, in its September 1, 2005, response to GL 2004-02, to install new containment sump strainers at Unit 2 during its fall 2006 refueling outage.
APS stated that its strainer designer and manufacturer, Control Components, Inc. (CCI), had informed APS of a strainer fabrication/delivery delay for the Palo Verde, Unit 2, strainer, which would result in the new strainers not being available for mockup testing (assembly) and installation during the fall 2006 Unit 2 refueling outage. APS reported that the delay was stated by CCI to be due to CCIs workload, which included supplying new containment sump strainers to other nuclear plants with fall 2006 refueling outages.
In accordance with SECY-06-0078 extension acceptability criteria, APS provided a plant-specific technical/experimental plan with milestones, stating that the new strainer confirmatory head-loss testing, capture ratio verification, and chemical effects margin validation are scheduled to be completed by March 31, 2007.
APS stated in its October 12, 2006, letter that the following mitigative measures have been or will be put in place in Unit 2 prior to December 31, 2007:
Compensatory operator actions in response to Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized Water Reactors, have been implemented; The licensee plans to remove Fiberfax insulation from Unit 2 during the fall 2006 refueling outage1; and
J. M. Levine
- Changes in programs and procedures to ensure and/or enhance the control of transportable debris (e.g., insulation, signs, and foreign materials) in containment will be implemented in Unit 2 during the fall 2006 refueling outage.
APS stated that the following favorable conditions exist at Palo Verde, Unit 2:
The existing two Palo Verde, Unit 2, sump screens of 210 square feet surface area each are relatively large compared to typical PWR screens prior to GL 2004-02 replacements; and Although Palo Verde uses trisodium phosphate as a containment sump pool pH buffer, no calcium silicate insulation material is used in containment that might react to form calcium phosphate precipitate.
The NRC has confidence that the licensee has a plan that will result in the installation of modifications that provide acceptable strainer function with an adequate margin for uncertainties. Further, the NRC has concluded that the licensee has put mitigation measures in place to reduce the risk for the requested short extension period (from December 31, 2007, to the April 2008 scheduled outage); therefore, it is acceptable to extend the completion date for the corrective actions for the issues discussed in GL 2004-02 until the completion of the Palo Verde spring 2008 refueling outage, currently scheduled to begin on March 29, 2008. Should the licensee elect to begin the Palo Verde, Unit 2, outage more than 30 days after March 29, 2008, the licensee will need to provide the NRC additional justification for further delay in completing corrective actions for GL 2004-02. A licensee with an approved GSI-191 extension into 2008 or beyond should send in an as complete as possible GL 2004-02 supplemental and/or request for additional information response by December 31, 2007. If any substantive GL corrective action analytical results or technical details change in 2008 (e.g., during an outage in which GL corrective action modifications are completed), a GL supplemental response should be submitted within 90 days of the change or outage completion.
Sincerely,
/RA/
Mel B. Fields, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-529 cc: See next page
J. M. Levine
- Changes in programs and procedures to ensure and/or enhance the control of transportable debris (e.g., insulation, signs, and foreign materials) in containment will be implemented in Unit 2 during the fall 2006 refueling outage.
APS stated that the following favorable conditions exist at Palo Verde, Unit 2:
The existing two Palo Verde, Unit 2, sump screens of 210 square feet surface area each are relatively large compared to typical PWR screens prior to GL 2004-02 replacements; and Although Palo Verde uses trisodium phosphate as a containment sump pool pH buffer, no calcium silicate insulation material is used in containment that might react to form calcium phosphate precipitate.
The NRC has confidence that the licensee has a plan that will result in the installation of modifications that provide acceptable strainer function with an adequate margin for uncertainties. Further, the NRC has concluded that the licensee has put mitigation measures in place to reduce the risk for the requested short extension period (from December 31, 2007, to the April 2008 scheduled outage); therefore, it is acceptable to extend the completion date for the corrective actions for the issues discussed in GL 2004-02 until the completion of the Palo Verde spring 2008 refueling outage, currently scheduled to begin on March 29, 2008. Should the licensee elect to begin the Palo Verde, Unit 2, outage more than 30 days after March 29, 2008, the licensee will need to provide the NRC additional justification for further delay in completing corrective actions for GL 2004-02. A licensee with an approved GSI-191 extension into 2008 or beyond should send in an as complete as possible GL 2004-02 supplemental and/or request for additional information response by December 31, 2007. If any substantive GL corrective action analytical results or technical details change in 2008 (e.g., during an outage in which GL corrective action modifications are completed), a GL supplemental response should be submitted within 90 days of the change or outage completion.
Sincerely,
/RA/
Mel B. Fields, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-529 cc: See next page DISTRIBUTION:
PUBLIC LPLIV r/f RidsAcrsAcnwMailCenter RidsNrrDorlLpl4 RidsNrrLAJBurkhardt RidsNrrPMMFields RidsRgn4MailCenter RidsOgcRp LWhitney, NRR ADAMS Accession No.: ML063400177 OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/SSIB/BC NRR/LPL4/BC NAME MFields LFeizollahi MScott DTerao DATE 12/13/06 12/12/06 11/14/06 12/13/06 OFFICIAL AGENCY RECORD
May 2006 Palo Verde Nuclear Generating Station cc:
Mr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street Phoenix, AZ 85007 Mr. Douglas Kent Porter Senior Counsel Southern California Edison Company Law Department, Generation Resources P.O. Box 800 Rosemead, CA 91770 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 40 Buckeye, AZ 85326 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Chairman Maricopa County Board of Supervisors 301 W. Jefferson, 10th Floor Phoenix, AZ 85003 Mr. Aubrey V. Godwin, Director Arizona Radiation Regulatory Agency 4814 South 40 Street Phoenix, AZ 85040 Mr. Craig K. Seaman, General Manager Regulatory Affairs and Performance Improvement Palo Verde Nuclear Generating Station Mail Station 7636 P.O. Box 52034 Phoenix, AZ 85072-2034 Mr. Matthew Benac Assistant Vice President Nuclear & Generation Services El Paso Electric Company 340 East Palm Lane, Suite 310 Phoenix, AZ 85004 Mr. John Taylor Public Service Company of New Mexico 2401 Aztec NE, MS Z110 Albuquerque, NM 87107-4224 Mr. Geoffrey M. Cook Southern California Edison Company 5000 Pacific Coast Hwy Bldg N50 San Clemente, CA 92672 Mr. Robert Henry Salt River Project 6504 East Thomas Road Scottsdale, AZ 85251 Mr. Jeffrey T. Weikert Assistant General Counsel El Paso Electric Company Mail Location 167 123 W. Mills El Paso, TX 79901 Mr. John Schumann Los Angeles Department of Water & Power Southern California Public Power Authority P.O. Box 51111, Room 1255-C Los Angeles, CA 90051-0100 Mr. Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, TX 78701-3326 Ms. Karen O'Regan Environmental Program Manager City of Phoenix Office of Environmental Programs 200 West Washington Street Phoenix AZ 85003