ML082610507

Request for Additional Information on Relief Request for Structural Weld Overlays

ML082610507
Person / Time
Site:	Saint Lucie
Issue date:	09/18/2008
From:	Mozafari B L Plant Licensing Branch II
To:	Stall J A Florida Power & Light Co
Orf, Tracy J.; NRR/DORL 415-2788
References
TAC MD9256
Download: ML082610507 (6)

Text

September 18, 2008 Mr. J. A. Stall Senior Vice president, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 1400 Juno Beach, Florida 33408-0420

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - ST. LUCIE PLANT, UNIT 1 - RELIEF REQUEST FOR STRUCTURAL WELD OVERLAYS (TAC NO. MD9256)

Dear Mr. Stall:

By letter dated April 29, 2008, Florida Power & Light Company (FPL) submitted Relief Request Number 2 (RR-2), related to the fourth 10-year inservice inspection interval for the St. Lucie, Unit 1. In RR-2, FPL requested approval to install full structural weld overlays as an alternative method of repair on dissimilar metal butt welds. We have reviewed the submittal and have determined that we need additional information before we can complete our review. Enclosed is our request for additional information.

This request was discussed with Mr. Ken Frehafer of your staff on September 16, 2008. It was agreed that a final response would be provided by September 26, 2008. If you have any questions, please feel free to contact me at 301-415-2020.

Sincerely, /RA/ Brenda L. Mozafari, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-335

Enclosure:

Request for Additional Information cc: See next page

REQUEST FOR ADDITIONAL INFORMATION ST. LUCIE NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-335 By letter dated April 29, 2008, Florida Power & Light proposed an alternative Relief Request 2 (RR-2) to the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, for mitigating primary water stress corrosion cracking on dissimilar metal welds using full structural weld overlays at St. Lucie, Unit 1 (SL-1). Currently, the U.S. Nuclear Regulatory Commission (NRC) staff has approved the use of ASME Section XI Code Cases N-504-3, "Alternative Rules for Repair of Class 1, 2, and 3 Austenitic Stainless Steel Piping Section XI, Division 1,: and N-638-1, "Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique Section XI, Division 1." The NRC staff used the requirements of Code Cases N-504-3 and N-638-1 and NRC-approved criteria associated with similar full structural weld overlay (SWOL) applications to aid in the evaluation of the SL-1, RR-2, Attachment 2. To complete its review, the staff is requesting the following additional information: 1. Discuss whether the subject nozzles have been ultrasonically examined under the Inservice Inspection (ISI) program or Electric Power Research Institute report, MRP-139 in previous refueling outages. If so, discuss whether flaws have been detected in the subject nozzles. 2. In Section 1.1, page 1, the Examination Category for the subject welds is identified as R-A. This is a risk-informed ISI (RI-ISI) examination category. (A) Discuss whether after the weld overlay installation, will the ISI examinations be based on the RI-ISI program or the proposed Relief Request No. 2 (RR-2)? (B) Discuss whether the subject welds will be removed from the RI-ISI program after the weld overlay installation. 3. Paragraph 2(a) of Attachment 2 of RR-2 states that the size of all flaws detected or postulated in the original weldment shall be projected to the end of the expected life of the overlay. Provide/describe the expected life of the overlay. 4. Paragraphs g(2) and g(3) of American Society of Mechanical Engineers (ASME) Code Case N-504-3 require evaluations of residual stresses and flaw growth of the repaired weldments. Section 2 of Attachment 2 to RR-2 requires similar evaluations. Section 2(b)7 of Attachment 2 states that effects of any changes in applied loads, as a result of weld shrinkage from the entire structural weld overlay on other items in the piping system, shall be evaluated. (A) Confirm that the analysis will be performed to show that the requirements of Subarticles NB-3200 and NB-3600 of the ASME Code, Section Ill are satisfied. (B) Confirm that the analysis includes the crack-growth calculations to demonstrate that crack growth in the weld overlay or base metal is acceptable and residual stress distribution in the weld overlay and original weld demonstrate favorable stress distribution. (C) The staff requests that the licensee submit the preliminary results of the evaluations prior to entry into Mode 4 from the refueling outage and the final evaluations within 60 days of the plant restart.

5. Paragraph I-2.1(g)(2) of Mandatory Appendix I of Attachment 2 to RR-2 provides a means of determining an Adjustment Temperature for the welding procedure qualification. This Adjustment Temperature was not a part of Code Case N-638-1 and, therefore, has not been approved by the U.S. Nuclear Regulatory Commission (NRC) staff. Explain the technical basis of this requirement. 6. Section 5.2 of RR-2, states that a barrier layer of austenitic stainless steel filler metal across the austenitic stainless steel base metal will be used to reduce the risk of cracks.

(A) Discuss whether paragraph (e) of Code Case N-504-3 is applicable to the barrier layer if austenitic stainless steel filler metal is applied. Paragraph (e) requires existence of certain delta ferrite content in the welded metal when austenitic stainless steel weld metal is used. (B) Identify the austenitic stainless steel weld filler metal that will be used for the butter layer. (C) Confirm that the Certified Material Test Report (CMTR) for the austenitic stainless steel filler wire shows a minimum delta ferrite of a specified amount. Provide the maximum and minimum delta ferrite content for the heat of austenitic stainless steel filler wire to be used, as stated on the CMTR. 7. What are the beginning and end dates for the fourth 10-year ISI interval at SL-1? 8. The following typographical errors were identified in the proposed alternative and should be corrected: (A) On page 6, on the second line of the first full paragraph 2(b)(6) should be 2(b)(5), on the third line of the same paragraph 2(b)(7) should be 2(b)(6), on the eighth line of the paragraph 2(a)(2)(b) should be 2(a)(2)(a). (B) On page 25, Section 2(a)(2)(b) in the third line "(b) or (c) above" should be deleted. (C) On page 26, Section 2(b)(6) in the sixth line 2(b)(4), (5), or (6) should be 2(b)(3), (4), or (5). (D) On page 36, Section I-2.1(f) should be changed to I-2.1(f)(4). 9. Mandatory Appendix I to Attachment 2 of RR-2 Section I-3(e) lists a number of methods that can be used in the welding procedure to determine interpass temperature. The staff's position is that the temperature measurement in 1-3(e)(1) should be used. If 1-3(e)(1) cannot be performed, 1-3(e)(2) or 1-3(e)(3) may be used. Please describe the method that will be used at SL-1 and provide a discussion of its acceptability. 10. Section 3(c)2 of Attachment 2 of RR-2 states no credit can be given in any portion of the examination volume where the ultrasonic beam passes through the cast stainless steel material. (A) Provide the weld overlay thickness. (B) Provide reduction in ultrasonic testing (UT) volume coverage for the weld overlay locations that involve cast stainless steel safe-ends, including estimated total UT examination coverage for preservice and ISI per sections 3(b) and 3(c) of RR-2. Discuss why reduction in examination coverage is acceptable. (C) Discuss whether a phased-array UT technique will be used in the volumetric examination. 11. Attachment 2 of RR-2, page 23, first paragraph, states that, "All Section XI references are to the 2004 Edition with the 2006 Addenda . . . ." This statement is not applicable to SL-1 and should be eliminated because the code of record for the SL-1 fourth 10-year ISI interval in which RR-2 is applicable is the 2001 Edition through 2003 Addenda. In addition, Table 1 of Attachment 2 can be deleted since the additional code references do not apply. The staff notes that the NRC has not incorporated by reference the 2005 and 2006 Addenda of the ASME Code in Title 10, Code of Federal Regulations, Section 50.55a. 12. Section 2.0 of Attachment 2 of RR-2 states that the code of record for the current ISI 10-year interval is, "Section XI, 2001 Edition including Addenda through 2003 and 2001 with 2001 Addenda for Appendix VIII . . . ." Please clarify the ASME Code Edition and Addenda that will be used for performance demonstration initiative examination per the ASME Code,Section XI, Appendix VIII because the 2001 Addenda of the ASME Code do not exist.

September 18, 2008 Mr. J. A. Stall Senior Vice president, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 1400 Juno Beach, Florida 33408-0420

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - ST. LUCIE PLANT, UNIT 1 - RELIEF REQUEST FOR STRUCTURAL WELD OVERLAYS (TAC NO. MD9256)

Dear Mr. Stall:

By letter dated April 29, 2008, Florida Power & Light Company (FPL) submitted Relief Request Number 2 (RR-2), related to the fourth 10-year inservice inspection interval for the St. Lucie, Unit 1. In RR-2, FPL requested approval to install full structural weld overlays as an alternative method of repair on dissimilar metal butt welds. We have reviewed the submittal and have determined that we need additional information before we can complete our review. Enclosed is our request for additional information.

This request was discussed with Mr. Ken Frehafer of your staff on September 16, 2008, it was agreed that a final response would be provided by September 26, 2008. If you have any questions, please feel free to contact me at 301-415-2020.

Sincerely, /RA/

Brenda L. Mozafari, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket No. 50-335

Enclosure:

Request for Additional Information cc: See next page DISTRIBUTION

PUBLIC RidsOgcRp RidsNrrDorlDpr LPL2-2 R/F RidsAcrsAcnwMailCenter RidsNrrDciCpnb RidsNrrPMBMozafari RidsRgn2MailCenter K. Hoffman RidsNrrLABClayton (Hard Copy) RidsNrrDorlLpl2-2 T. Chan ADAMS Accession Number: ML082610507 NRR-088 OFFICE LPL2-2/PM LPL2-2/PM LPL2-2/LA DCI/CPNB LPL2-2/BC NAME TOrf BMozafari BClayton TChan By memo dated TBoyce (BMoroney for) DATE 9/18/08 9/18/08 9/18/08 9/18/08 9/18/08 OFFICIAL RECORD COPY Florida Power and Light Company ST. LUCIE PLANT cc:Mr. Mano Nazar Senior Vice President and Nuclear Chief Operating Officer Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408 Senior Resident Inspector St. Lucie Plant U.S. Nuclear Regulatory Commission P.O. Box 6090 Jensen Beach, Florida 34957 Craig Fugate, Director Division of Emergency Preparedness Department of Community Affairs 2740 Centerview Drive Tallahassee, Florida 32399-2100 M. S. Ross, Managing Attorney Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Marjan Mashhadi, Senior Attorney Florida Power & Light Company 801 Pennsylvania Avenue, NW. Suite 220 Washington, DC 20004 Mr. Douglas Anderson County Administrator St. Lucie County 2300 Virginia Avenue Fort Pierce, Florida 34982 Mr. William A. Passetti, Chief Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin #C21 Tallahassee, Florida 32399-1741 Mr. Gordon L. Johnston Site Vice President St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957-2000 Mr. Christopher R. Costanzo Plant General Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Mr. Terry Patterson Licensing Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957

Don E. Grissette Vice President, Nuclear Operations, South Region Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Abdy Khanpour Vice President - Engineering Support Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. J. Kammel Radiological Emergency Planning Administrator Department of Public Safety 6000 Southeast Tower Drive Stuart, Florida 34997

Mark E. Warner Vice President, Nuclear Plant support Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Peter Wells, Acting VP, Nuclear Training and Performance Improvement Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Michael Page Acting Operations Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957-2000