ML18106A624
| ML18106A624 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 05/28/1998 |
| From: | Wichman K NRC (Affiliation Not Assigned) |
| To: | Capra R NRC (Affiliation Not Assigned) |
| References | |
| GL-92-01, GL-92-1, NUDOCS 9806020425 | |
| Download: ML18106A624 (3) | |
Text
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May 28, 1998 MEMORANDUM TO:
- Robert A. Capra, Director Project Directorate 1-2 Division of Reactor Projects I/II FROM:
Keith°R~ Wi16~hicr~.98~Pefby:
Section A Materials and Chemical Engineering Branch Division of Engineering
SUBJECT:
REVISED SALEM GENERATING STATION UNIT 1 AND UNIT 2 REACTOR VESSEL WELD CHEMISTRY VALUES The NRC issued Generic Letter (GL) 92-01, Revision 1, Supplement 1 (GL 92-01, Rev.1, Supp. 1 ), "Reactor Vessel Structural Integrity" in May 1995. The purpose of this GL was to request licensees to identify, collect, and report any new data pertinent to the analysis of the structural integrity of their RPVs and to assess the impact of those data on their RPV integrity analyses relative to the applicable requirements.
By letter dated August 14, 1995, the licensee committed to participate in a Combustion Engineering Owners Group (CEOG) Reactor Vessel Working Group (RVWG) task performing a comprehensive evaluation of best estimate copper and nickel values for CE fabricated reactor vessel welds.
- In July 1997 the CEOG issued the report that contains the results of this evaluation. In response to their commitment, the licensee submitted revised information on the Salem Unit 1 and Unit 2 reactor vessel weld chemistry values by letter dated February 17, 1998.
The staff requires further information to complete its assessment of the information submitted by the licensee. In the attached Request for Additional Information (RAI), the staff has provided the*
questions to which we require response to complete our review. The NRC staff requests that you provide a response to the attached request for additional information within 60 days of receipt of this letter.
Docket Nos.: 50-272, 50-311
Attachment:
As stated cc: P. Milano, PM CONTACT:
Matthew A. Mitchell, NRR (301) 415-3303 DISTRIBUTION:
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555--0001 May 28, 1998 MEMORANDUM TO:
Robert A. Capra, Director Project Directorate 1-2 FROM:
SUBJECT:
Division of Reactor Projects I/II Keith R. Wichman, Chief Section A Materials and Chemical Engi eering Branch Division of Engineering REVISED SALEM GENERATING STATION UNIT 1 AND UNIT 2 REACTOR VESSEL WELD CHEMISTRY VALUES The NRC issued Generic Letter (GL) 92-01, Revision 1, Supplement 1 (GL 92-01, Rev.1, Supp. 1), "Reactor Vessel Structural Integrity" in May 1995. The purpose of this GL was to request licensees to identify, collect, and report any new data pertinent to the analysis of the structural integrity of their RPVs and to assess the impact of those data on their RPV integrity analyses relative to the applicable requirements.
By letter dated August 14, 1995, the licensee committed to participate in a Combustion Engineering Owners Group (CEOG) Reactor Vessel Working Group (RVWG) task performing a comprehensive evaluation of best estimate copper and nickel values for CE fabricated reactor vessel welds. In July 1997 the CEOG issued the report that contains the results of this evaluation. In response to their commitment, the licensee submitted revised information on the Salem Unit 1 and Unit 2 reactor vessel weld chemistry values by letter dated February 17, 1998.
The staff requires further information to complete its assessment of the information submitted by the licensee. In the attached Request for Additional Information (RAI), the staff has provided the questions to which we require response to complete our review. The NRC staff requests that you provide a response within 60 days of receipt of this letter.
Docket Nos.: 50-272, 50-311
Attachment:
As stated cc: P. Milano, PM CONTACT:
Matthew A. Mitchell, NRR (301) 415-3303
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REQUEST FOR ADDITIONAL INFORMATION REGARDING STAFF FOLLOW-UP TO GENERIC LETTER 92-01, REVISION 1, SUPPLEMENT 1 COMMITMENTS After reviewing the information submitted by Public Service Electric and Gas Company in your February 18, 1998, the information contained in the staffs Reactor Vessel Integrity Database (RVID), and the information in CEOG Report NSPD-1039, Revision 2, the staff has the following questions.
(1)
For Salem Unit 1 axial welds 2-042, A, 8, and C, the staff notes our RVID indicates that these welds were fabricated as tandem welds made from weld wire heats 348009 and 398196. Confirm that this information is still valid. You have given values of 0.176 wt.
percent copper and 1.038 wt. percent nickel for these welds, however, no specific information is provided for this tandem wire combination in the CEOG report.
(a)
What is the basis for the chemistry values that were cited for these welds?
(b)
Is data available for this tandem wire weld combination? If chemistry samples were taken, provide the data and your analysis of it. If not, explain why a generic value plus one standard deviation for this class of welds (e.g. welds made with copper-coated electrodes and welds using a Ni-200 cold wire feed) should not be used per the guidance given in Regulatory Guide 1.99, Revision 2, Section 1.1.
(2)
For Salem Unit 2 axial welds 2-442, A, 8, and C, the staff notes our RVID indicates that these welds were fabricated as tandem welds made from weld wire heats 13253 and 20291. Confirm that this information is still valid. You have given values of 0.219 wt.
percent copper and 0.735 wt. percent nickel for these welds, however, no specific information is provided for this tandem wire combination in the CEOG report.
(a)
What is the basis for the chemistry values that were cited for these welds?
(b)
Is data available for this tandem wire weld combination? If chemistry samples were taken, provide the data and your analysis of it. If not, explain why a generic value plus one standard deviation for this class of welds (e.g. welds made with copper-coated electrodes) should not be used per the guidance given in Regulatory Guide 1.99, Revision 2, Section 1.1.
(3)
For Salem Unit 2 circumferential weld 9-442, the staff notes that our RVID indicates that this weld was manufactured as a single arc weld using weld wire heat 90099. Confirm that this information is still valid. You have cited a best-estimate nickel value for this weld of 0.06 wt. percent based apparently on a bare wire analysis.
(a)
Provide additional information on how the bare wire analysis is performed and how_
the quality of the chemical composition data compares between the bare wire analysis and the analysis of a chemistry sample for an actual weld. Detailed information was given in Appendix A to the CEOG NSPD-1039 report for those data
-points which were obtained from actual welds. Does similar information exist for the bare wire analysis? How many samples was this bare wire analysis value based on?
(b)
The staff notes that the nickel value determined from the bare wire analysis differs from the generic value for low nickel wire welds (0.094 wt. percent on average with a standard deviation of 0.04 wt percent). Explain why the best-estimate value should be based on the bare wire analysis in lieu of applying the generic value plus one standard deviation for this class of welds per the guidance given in Regulatory Guide 1.99, Revision 2, Section 1.1.
ATTACHMENT