ML101670369
| ML101670369 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/2011 |
| From: | NRC/RES/DE/CIB |
| To: | |
| Bayssie Mekonen/RES 251-7489 | |
| Shared Package | |
| ML101670354 | List: |
| References | |
| DG-1223 RG-1.034, Rev 1 | |
| Download: ML101670369 (2) | |
Text
Staff Responses to Public Comments on Draft Regulatory Guide DG-1223, Control of Electroslag Weld Properties dated June 2009 (Proposed Revision 1 of Regulatory Guide 1.34 dated December 1972)
- 1. James H. Riley, NEI (NEI) 2. J.A. Gresham, Westinghouse (W)
Public Comments NRC Response The notices requested comments on all of these draft regulatory Extension to October 1, 2009 granted per guides by August 31, 2009. NEI and EPRI are collecting and NRC 7590-01-P dated August 11, 2009 consolidating industry comments on these draft guides, but it has (ML092230530).
become apparent that it will not be possible to complete a comprehensive review of all of these documents in the time available, NEI-1 The information contained in these draft guides is important to the industry's work on primary system materials and it is important to carefully evaluate the changes proposed. NEI is therefore requesting a 30-day extension of the public comment period on these draft guides until October 1, 2009, to allow adequate time to complete and document our review.
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Public Comments NRC Response This DG and the existing RG do not specifically say that the The second sentence under Procedure electroslag welding being addressed applies to joining, not cladding. Qualifications of Section B of RG 1.34 is While some of the information in this RG implies that it could only changed as follows:
apply to joining (as understood by a welding or materials engineer),
this point may not be clearly understood by all. It is suggested that the Review of the requirements of the procedure second sentence under Procedure Qualification be changed and qualification stated in Section IX indicates that W-1 another sentence be inserted, as follows: "Review of the requirements supplementary requirements are desirable to of the procedure qualification stated in Section IX indicates that the provide assurance of adequate weld metal supplementary requirements are desirable to provide assurance of properties when the electroslag welding adequate weld metal properties when the electroslag welding process process is used for joining. The qualification is used for joining. The qualification of electroslag welding process for of electroslag welding process for purposes of purposes of cladding is not addressed." cladding is not addressed.
Regulatory Position 4 appears to have an error. It indicates that The staff disagrees with the commenter.
production welds need to comply with the variables specified on the Production welds need to comply with the "procedure qualification". The procedure qualification does not specify variables used in the procedure qualification process variables for production welding but records what was used because using welding variables outside the during the test. The limits for production process variables are listed variable values used for qualification may W-2 on the "welding procedure". The last two words should change result in a deep pool of molten weld metal, and "procedure qualification" to 'Welding procedure." therefore cracks may develop because of the weaker centerline bond dentrites. It is the intent that each weld configuration will require its own procedure qualification.
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Public Comments NRC Response Regulatory Position 5 specifies: "If properties obtained from tests Position 5 of Section C of RG 1.34 is changed identified in Regulatory Positions 3 and 4 above are not acceptable..." as follows:
However, Regulatory Position 4 does not have any tests, thus no properties would be obtained. If properties obtained from tests or limits or W-3 there is a specific reason to question the welders ability to make production welds that meet the approved procedure as identified in Regulatory Positions 3 and 4 above are not acceptable, then...
Regulatory Position 5 says that if the properties obtained during The staff disagrees with the commenter. The testing are not acceptable "... additional procedure qualifications quality of production welds is ensured by should be performed in accordance with Regulatory Position 1 above." following the recommendations described in This does not permit remedy of the production weld from which the Position 4 and verified by the testing described tests were obtained. Options to rectify the production weld should be in Position 3. Therefore, if the test results are allowed, such as re-heat treatment (in the case of failed CVN tests); unacceptable or the process variables have W-4 obviously, re-heat treatment will not change the angle of solidification. not been controlled properly, then the The DG does not list options applicable to welds that do not meet the production weld is unacceptable.
macro-etch requirements. Since the concern stated in the Procedure qualification section is that "...cracks may develop because of the weaker centerline bond between dendrites", then performing additional NDT capable of detecting these cracks, additional CVN tests, or other possible remedies should be prescribed.
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