ML072820132
| ML072820132 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 10/31/2007 |
| From: | Feintuch K NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Richard Anderson Duane Arnold |
| Feintuch K, NRR/DORL/LPL3-1, 415-3079 | |
| References | |
| TAC MD5669 | |
| Download: ML072820132 (7) | |
Text
October 31, 2007 Mr. Richard L. Anderson Vice President Duane Arnold Energy Center 3277 DAEC Road Palo, Iowa 52324-9785
SUBJECT:
DUANE ARNOLD ENERGY CENTER - REQUEST FOR ADDITIONAL INFORMATION RE: RELIEF REQUEST FROM AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) BOILER AND PRESSURE VESSEL CODE, SECTION XI, RULES FOR INSERVICE INSPECTION OF NUCLEAR POWER COMPONENTS, 1998 EDITION, SUBSECTION IWB, SUBARTICLE IWB-2500, EXAMINATION AND PRESSURE TEST REQUIREMENTS, AND SUBSECTION 1WC, SUBARTICLE IWC-2500, EXAMINATION AND PRESSURE TEST REQUIREMENTS, TO ALLOW PERFORMANCE OF LIMITED EXAMINATIONS OF VARIOUS WELDS (TAC NO. MD5669)
Dear Mr. Anderson:
In a letter to the Nuclear Regulatory Commission (NRC) dated May 18, 2007, you requested relief from the American Society of Mechanical Engineers (ASME) Code,Section XI, Subarticles IWB-2500 and IWC-2500, to allow performance of limited examinations of various welds for the Third 10-Year Interval of the Inservice Inspection Program for the Duane Arnold Energy Center (DAEC), which ended on October 31, 2006.
The NRC staff is reviewing the information associated with the relief request and finds that additional information is needed, as shown in the enclosed request for additional information (RAI).
A telephone call between the NRC and members of your staff was held on September 25, 2007, to discuss a draft of the RAI. The draft RAI was subsequently revised on September 28, 2007, and on October 1, 2007. The version of October 1, 2007, is enclosed with this letter. On October 2, 2007, I spoke with Tony Browning of your organization, and he agreed to respond to this RAI by October 31, 2007. On October 22, 2007, I spoke with Thomas Byrne of your organization, who requested that the date for the expected response to this RAI be changed to November 7, 2007. On October 23, 2007, I notified Mr. Byrne that the date for the expected response is changed to November 7, 2007.
Regarding the date you requested for approval of this relief request, I spoke with Tony Browning on May 24, 2007, to clarify the needed date for the NRCs response to your relief request. It was agreed that the NRC would respond to your request for relief prior to the end of May, 2008. In your response to this letter containing the enclosed RAI, please confirm that a response from the NRC, prior to the end of May, 2008, meets your needs.
R. Anderson Please contact me at (301) 415-3079 if you have questions.
Sincerely,
/RA/
Karl D. Feintuch, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
RAI cc w/encl: See next page
R. Anderson Please contact me at (301) 415-3079 if you have questions.
Sincerely,
/RA/
Karl D. Feintuch, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
RAI cc w/encl: See next page DISTRIBUTION:
PUBLIC LPL3-1 R/F RidsNrrPMKFeintuch RidsNrrLATHarris RidsNrrDorlLpl3-1 RidsOgcRp RidsAcrsAcnwMailCenter RidsRgn3MailCenter RidsNrrDci TMcLellan RidsNrrDorlDpr ADAMS Accession Number: ML072820132 OFFICE NRR/LPL3-1/PM NRR/LPL3-1/LA NRR/CVIB/BC NRR/LPL3-1/(A)BC NAME KFeintuch THarris MMitchell CMunson DATE 10/26/07 10/26/07 10/30/07 10/31/07 OFFICIAL RECORD COPY
REQUEST FOR ADDITIONAL INFORMATION ON THIRD 10-YEAR INSERVICE INSPECTION PROGRAM REQUEST FOR RELIEF FOR DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331 (TAC NO. MD5669)
- 1.
SCOPE By letter dated May 18, 2007, the licensee, FPL Energy Duane Arnold, LLC, submitted a request for relief from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (ASME Code),Section XI, for Duane Arnold Energy Center (DAEC).
The request for relief is for the third 10-year inservice inspection (ISI) interval, in which DAEC adopted the 1989 Edition, no Addenda, of ASME Code Section Xl as the Code of record.
Title 10 of the Code of Federal Regulations (10 CFR) Part 50.55a(g)(5)(iii) does not have provisions to allow subsequent relief based on impracticality for previously authorized alternatives to the ASME Code. Authorized alternatives, such as ASME Code Cases, must be implemented in their entirety. Therefore, the current relief request for ASME Code,Section XI, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels must be evaluated under 10 CFR 50.55a(g)(6)(i), which requires additional information from the licensee.
- 2.
REQUEST FOR ADDITIONAL INFORMATION 2.1 Request for Relief, Examination Category B-D, Item B3.90, Full Penetration Welded Nozzles in Vessels The licensee previously proposed an alternative, which was approved by Safety Evaluation Report (SER) dated October 6, 2004 (ADAMS Accession No. ML042380089),
to use ASME Code Case N-613-1, which limits the examination volume of Examination Category B-D welds to the weld and 1/2-inch of adjacent base material on each side, in lieu of the ASME Code-required examination volume of the weld and 1/2-T of adjacent base material, where T is the vessel thickness. The current request for relief indicates that achieving greater than 90 percent (of the volume approved by the October 6, 2004, SER), could not be accomplished for the subject reactor pressure vessel (RPV) nozzle-to-vessel welds.
2.1.1 Please re-calculate and report the volumetric coverage(s) obtained for the subject Examination Category B-D nozzle-to-vessel welds with respect to ASME Code requirements, i.e., calculate the coverage when the volume required is the weld and 1/2-T of adjacent base material, where T is the vessel wall thickness.
2.1.2 The licensee stated that the subject nozzle-to-vessel welds are accessible from the vessel side of the RPV, but examinations cannot be performed from the nozzle side due to forging curvature. It is also stated that certain nozzle-to-vessel weld examinations are additionally limited by RPV design obstructions. However, these statements do not provide adequate descriptive information and technical discussion to support a determination of impracticality and that the required examinations have been performed to the maximum extent possible at DAEC.
- a.
Provide a detailed description of examination limitations including access requirements for automated or manual ultrasonic techniques employed, and a description of each component geometry that restricts or limits examinations.
The technical bases should include cross-sectional sketches of the weld indicating ultrasonic coverage(s) for each technique employed and details of the weld and base metal materials.
- b.
In addition, the licensee should submit argument(s) as to why the use of other inspection methods (such as phased array ultrasonic testing) would not reasonably increase the examination coverage(s).
2.1.3 State the total number of Examination Category B-D welds at DAEC, and provide a listing of the volumetric coverage(s) completed for each of these welds. Report any unacceptable flaws detected during the examination of the welds.
2.2 Request for Relief, Examination Category B-D, Item B3.100, Inner Radius Sections of Full Penetration Welded Nozzles in Vessels
- 1.
The licensee stated that the proximity of the RPV skirt weld obstructed access for performing the inner radius section examination on Standby Liquid Control Nozzle LCA-D001. However, this statement does not provide adequate descriptive information and technical discussion to support a determination of impracticality and that the required examination was performed to the maximum extent possible at DAEC.
- a.
Provide a detailed description of examination limitations including access requirements for automated or manual ultrasonic techniques employed, and a description of the component geometry that restricts or limits the examination.
The technical basis should include cross-sectional sketches of the inner radius section indicating ultrasonic coverage for each technique employed.
- b.
In addition, the licensee should submit an argument as to why the use of other inspection methods (such as phased array ultrasonic testing) would not reasonably increase the examination coverage.
2.3 Request for Relief, Examination Category B-J, Item B9.11, Pressure Retaining Welds in Piping 2.3.1 The licensee stated that Weld RBB-J001 is a branch connection of the recirculation bypass line to the recirculation discharge line, and that the weldolet side is not accessible for scanning due to geometry. However, this statement does not provide adequate descriptive information and technical discussion to support a determination of impracticality and that the required examination was performed to the maximum extent possible at DAEC.
- a.
Provide a detailed description of examination limitations including access requirements for automated or manual ultrasonic techniques employed, and a description of the component geometry that restricts or limits the examination.
The technical basis should include cross-sectional sketches of the weld indicating ultrasonic coverage for each technique employed.
- b.
State the size, thickness and materials of construction of the subject weld.
2.3.2 The licensee listed this weld as Examination Category B-J, Item B9.11, which is for circumferential butt welds, NPS 4-inch and larger. However, the licensee stated that Weld RBB-J001 is a branch connection. Discuss why this weld is not listed as ASME Code Item B9.31 or B9.32.
2.3.3 State the total population of ASME Code Examination Category B-J welds of similar pipe diameter and wall thickness examined on the same recirculation loop at DAEC, and discuss the volumetric coverage(s) obtained for each of these welds.
2.4 Request for Relief, Examination Category C-A, Item C1.20, Pressure Retaining Welds in Vessels 2.4.1 The license stated that heat exchanger tie-down brackets obstruct access to the subject head-to-shell weld, limiting examination coverage. However, this statement does not provide adequate descriptive information and technical discussion to support a determination of impracticality and that the required examination was performed to the maximum extent possible at DAEC.
- a.
Provide further text and/or a cross-sectional sketch describing the basis for impracticality and showing volumetric coverage for Weld HEA-CA-05. In addition, state or show the material, thicknesses, and outside diameters for the subject component. Discuss why the tie-down brackets cannot be removed to allow greater access.
- b. State whether the volumetric examination was performed with procedures and personnel that have been qualified in accordance with ASME Code,Section XI, Appendix VIII.
- 1.
State the total population of ASME Code Examination Category C-A welds at DAEC, and discuss the volumetric coverage(s) obtained for each of these welds.
Duane Arnold Energy Center cc:
Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Mr. M. S. Ross Managing Attorney Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Ms. Marjan Mashhadi Senior Attorney Florida Power & Light Company 801 Pennsylvania Avenue, NW Suite 220 Washington, DC 20004 Don E. Grissette Vice President, Nuclear Training and Performance Improvement Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408 John Bjorseth Site Director Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 Steven R. Catron Manager, Regulatory Affairs Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 U. S. Nuclear Regulatory Commission Resident Inspector=s Office Rural Route #1 Palo, IA 52324 Mr. M. Warner Vice President, Nuclear Operations, North Region Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408 Mr. D. A. Curtland Plant Manager Duane Arnold Energy Center 3277 DAEC Rd.
Palo, IA 52324-9785 Mr. R. S. Kundalkar Vice President, Nuclear Technical Svcs.
Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408 Daniel K. McGhee Iowa Department of Public Health Bureau of Radiological Health 321 East 12th Street Lucas State Office Building, 5th Floor Des Moines, IA 50319-0075 Chairman, Linn County Board of Supervisors 930 1st Street SW Cedar Rapids, IA 52404 October 19, 2007