ML020710804
| ML020710804 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/20/2002 |
| From: | Richard Laufer NRC/NRR/DLPM/LPD2 |
| To: | Mccollum W Duke Energy Corp |
| Olshan L N, NRR/DLPM, 415-1419 | |
| References | |
| TAC MB3679, TAC MB3680, TAC MB3681 | |
| Download: ML020710804 (5) | |
Text
March 20, 2002 Mr. William R. McCollum, Jr.
Vice President, Oconee Site Duke Energy Corporation P.O. Box 1439 Seneca, South Carolina 29679
SUBJECT:
REQUEST TO USE ALTERNATIVE MATERIALS PER CODE CASES FOR THE FABRICATION OF REPLACEMENT REACTOR VESSEL CLOSURE HEADS AT OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 (TAC NOS. MB3679, MB3680 AND MB3681)
By letter dated November 28, 2001, you requested approval of the proposed alternative to use Alloy 690 type welding filler materials (Alloy 52/152) per American Society of Mechanical Engineers, Boiler and Pressure Vessel Code, Code Cases 2142-1 and 2143-1. The alternative materials will be used for the fabrication of the replacement reactor vessel closure heads at Oconee Nuclear Station, Units 1, 2 and 3. The staff concludes that the use of the proposed alternative materials for the intended applications will provide an acceptable level of quality and safety. Pursuant to Part 50.55a(a)(3)(i) of Title 10 of the Code of Federal Regulations, the staff authorizes the use of the proposed alternative. Our Safety Evaluation is enclosed.
Sincerely,
/RA/
Richard J. Laufer, Acting Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos.: 50-269, 50-270 and 50-287
Enclosure:
As stated cc w/encl: See next page
Mr. William R. McCollum, Jr. March 20, 2002 Vice President, Oconee Site Duke Energy Corporation P.O. Box 1439 Seneca, South Carolina 29679
SUBJECT:
REQUEST TO USE ALTERNATIVE MATERIALS PER CODE CASES FOR THE FABRICATION OF REPLACEMENT REACTOR VESSEL CLOSURE HEADS AT OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 (TAC NOS. MB3679, MB3680 AND MB3681)
By letter dated November 28, 2001, you requested approval of the proposed alternative to use Alloy 690 type welding filler materials (Alloy 52/152) per American Society of Mechanical Engineers, Boiler and Pressure Vessel Code, Code Cases 2142-1 and 2143-1. The alternative materials will be used for the fabrication of the replacement reactor vessel closure heads at Oconee Nuclear Station, Units 1, 2 and 3. The staff concludes that the use of the proposed alternative materials for the intended applications will provide an acceptable level of quality and safety. Pursuant to Part 50.55a(a)(3)(i) of Title 10 of the Code of Federal Regulations, the staff authorizes the use of the proposed alternative. Our Safety Evaluation is enclosed.
Sincerely,
/RA/
Richard J. Laufer, Acting Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos.: 50-269, 50-270 and 50-287
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC CHawes ACRS PDII-1 R/F LOlshan SRosenberg HBerkow OGC LPlisco, RII RLaufer GHill (6)
Accession Number: ML020710804 *No major changes to SE OFC PDII-1/PM PDII-1/LA EMCB/DE* PDII-1/ASC OGC NAME LOlshan CHawes MMitchell RLaufer RHoefling DATE 3/14/02 3/13/02 02/27/02 3/20/02 3/19/02 Document Name: C:\Program Files\Adobe\Acrobat 4.0\PDF Output\OconeeRRMB3679.wpd OFFICIAL RECORD COPY
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST TO USE ALTERNATIVE MATERIALS PER CODE CASES FOR THE REPLACEMENT OF REACTOR VESSEL CLOSURE HEADS AT OCONEE UNITS 1, 2 AND 3 DUKE ENERGY CORPORATION DOCKET NOS. 50-269, 50-270 AND 50-287
1.0 INTRODUCTION
By letter dated November 28, 2001, Duke Energy Corporation (the licensee, DEC) requested approval under the provisions of Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(a)(3) to use Alloy 690 type welding filler materials (Alloy 52/152) per American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code, Code Case 2142-1, F1-Number Grouping for Ni-Cr-Fe, Classification UNS N06052 Filler Metal,Section XI, and Code Case 2143-1, F-Number Grouping for Ni-Cr-Fe, Classification UNSW86152 Welding Electrode,Section XI, for the fabrication of the replacement reactor vessel closure heads at Oconee Nuclear Station, Units 1, 2 and 3.
The current code of record at Oconee Units 1, 2 and 3 for in-service inspection is the ASME Boiler and Pressure Vessel Code,Section XI, 1989 Edition with no Addenda. The code of record allows use of Alloy 600 (Alloy 82/182) welding filler materials, but does not include Alloy 690 type welding filler materials (Alloy 52/152). Industry studies indicate that Alloy 690 type welding filler materials (Alloy 52/152) are less susceptible to stress corrosion cracking than the Alloy 82/182 materials.
The referenced code cases introduce and classify new nickel-based weld metals that closely match Alloy 690. Code Case 2142-1 establishes welding classifications and other requirements for a bare wire filler metal. Code Case 2143-1 establishes welding classifications and other requirements for a coated electrode. These two code cases have not been incorporated by reference into the regulations and, therefore, their use requires NRC approval.
2.0 DISCUSSION Alloy 600 type welds metals (Alloy 82/182) were widely used during the construction of nuclear power plants. Operating experience has shown that Alloy 182 is susceptible to primary water stress corrosion cracking in the primary water environment of pressurized water reactors (PWRs). The licensee plans to use Alloy 690 type welding filler materials (Alloy 52/152) per the referenced code cases in the fabrication of the replacement reactor vessel closure heads for
Oconee Units 1, 2 and 3. The results of laboratory testing have shown that Alloy 52/152 materials are resistant to stress corrosion cracking in simulated PWR environments.
The staff has approved the use of Alloy 52/152 in the replacement of steam generators and the repair of thermocouple and control rod drive mechanism (CRDM) nozzles for a number of PWRs. Likewise, the licensee proposed use of Alloy 690 type welding filler materials (Alloy 52/152), per the referenced Code Cases, for fabrication of the replacement reactor vessel closure heads is acceptable as it will provide an acceptable level of quality and safety.
The purposes of Code Cases 2142-1 and 2143-1 are the establishment of uniform chemical and material properties, and the classification of the weld metal with respect to its welding characteristics. This classification of welding characteristics is known as F-No. Welds metals with like characteristics are grouped together for welding and welder qualification purpose in order to eliminate unnecessary duplication.
Code Case 2142-1 lists American Welding Society (AWS) specification (AWS A5.14) and unified numbering system (UNS) designation (UNS N06052) conforming to Inco 52 (Alloy 52).
It establishes the F-No. of this weld metal as F-No. 43 for both procedure and performance qualification purposes. Code Case 2143-1 lists appropriate AWS and UNS specifications for a coated electrode matching Inco 152 (Alloy 152) and establishes F-No. 43 for this material for welding purposes. By this set of specifications and F-No. assignments, these materials are completely described for welding purposes as similar in their welding characteristics to many other Code nickel-based weld metals. Thus, these two weld metals (Alloy 52/152) are exempted from the requirements for specific procedure and performance qualifications for non-Code materials.
The staff finds that these two code cases appropriately specify and classify the necessary weld metal parameter, and are acceptable for use. The staff has previously approved the use of these two code cases in the replacement of steam generators and the repair of thermocouple and CRDM nozzles for a number of PWRs.
3.0 CONCLUSION
Based on the above evaluation, the staff concludes that the proposed alternative to use Alloy 690 type welding filler materials (Alloy 52/152) per Code Cases 2142-1 and 2143-1 for the fabrication of replacement reactor vessel closure heads at Oconee Units 1, 2 and 3 will provide an acceptable level of quality and safety. Pursuant to10 CFR 50.55.a(a)(3)(i), the staff authorizes the use of the proposed alternative.
Principal Contributor: W. Koo Date: March 20, 2002
Oconee Nuclear Station cc:
Ms. Lisa F. Vaughn Mr. L. E. Nicholson Legal Department (PBO5E) Compliance Manager Duke Energy Corporation Duke Energy Corporation 422 South Church Street Oconee Nuclear Site Charlotte, North Carolina 28201-1006 7800 Rochester Highway Seneca, South Carolina 29672 Anne W. Cottingham, Esquire Winston and Strawn Ms. Karen E. Long 1400 L Street, NW Assistant Attorney General Washington, DC 20005 North Carolina Department of Justice Manager, LIS P. O. Box 629 NUS Corporation Raleigh, North Carolina 27602 2650 McCormick Drive, 3rd Floor Clearwater, Florida 34619-1035 Mr. C. Jeffrey Thomas Manager - Nuclear Regulatory Senior Resident Inspector Licensing U. S. Nuclear Regulatory Duke Energy Corporation Commission 526 South Church Street 7812B Rochester Highway Charlotte, North Carolina 28201-1006 Seneca, South Carolina 29672 Mr. Richard M. Fry, Director Mr. Henry Porter, Director Division of Radiation Protection Division of Radioactive Waste Management North Carolina Department of Bureau of Land and Waste Management Environment, Health, and Department of Health and Environmental Natural Resources Control 3825 Barrett Drive 2600 Bull Street Raleigh, North Carolina 27609-7721 Columbia, South Carolina 29201-1708 Mr. Peter R. Harden, IV Mr. Michael A. Schoppman VP-Customer Relations and Sales Framatome ANP Westinghouse Electric Company 1911 North Ft. Myer Drive 6000 Fairview Road Suite 705 12th Floor Rosslyn, VA 22209 Charlotte, North Carolina 28210