ML23067A340
| ML23067A340 | |
| Person / Time | |
|---|---|
| Issue date: | 03/07/2023 |
| From: | Jeffrey Poehler NRC/RES/DE |
| To: | |
| References | |
| Download: ML23067A340 (1) | |
Text
N-853-1 Proposed Travis Olson, Framatome NRC/EPRI Technical Exchange Meeting Revision March 7, 2023
Typical Branch Connection Purpose of N-853 Configuration B&W and some CE NSSS primary piping contain branch connections Contained in both the hot and cold legs Some locations mitigated through piping replacement during SGRs Locations not replaced remained susceptible to PWSCC Rules were needed for repair and mitigation as well as NDE PWROG funded a project to design and analyze a repair and mitigation approach Project supported technical basis for N-853 for Branch Connection Weld Metal Buildup (BCWMB)
Typical Branch Connection Status of N-853 Repair Configuration N-853 was approved June 2016 Endorsed as Acceptable Code Case by RG 1.147 R19 N-853-1 was approved November, 2020 Not yet endorsed by RG 1.147 Incorporated reference to N-888 or IWA-4600 for procedure qualifications of temperbead welding Proposed N-853-2 Draft presented to ASME TG-TBW and WG-W&SRP August and November 2022 meetings Currently incorporating comments and feedback from meetings
Cut Nozzle Flush and Install Weld Metal Buildup Implementation Steps Existing Configuration Fabrication Examinations:
Surface exam prior to welding Surface exam and UT of BCWMB (prior to hole drilling)
Surface exam of bore & J-prep Progressive PT of new J-groove weld Drill Bore & J-Prep and Bare metal visual PSI Install New Nozzle
N-853 and N-853-1 Figure 6 Proposed Changes Technical Changes All technical changes are associated with UT volumetric examination requirements Section 3 - Fabrication Examination Figure 6 - Surface and Volumetric Acceptance Examination for BCWMB Prior to Nozzle Welding Intent of revision is to allow use of ASME Section XI acceptance criteria and bring N-853 into alignment with other ASME C&S Distinguish volumetric exam requirements for structural versus non-structural Brings into alignment with other ASME C&S:
Non-Mandatory Appendix Q N-740-3 (Draft)
N-894 (Draft)
Editorial Delete Mandatory Appendix I - should have been deleted as part of N-853-1 revision Minor editorial changes throughout Proposed N-853-2 Figure 6
N-853 and N-853-1 Figure 6 Proposed Changes Section 3 - Fabrication Examination UT Qualification and Acceptance Criteria Current revisions require qualification to Section V and acceptance criteria of NB-5330 Proposed revision would permit qualification to Section XI Mandatory App. VIII, Supplement 11, using IWB-3514 pre-service acceptance criteria Volumetric Examination Volume Current revisions require essentially 100% of the BCWMB to be volumetrically examined for planar flaws (volume A-H-J-K-C-B)
Proposed revision would require structural portion of BCWMB (volume B-J-L-K-C-D) to be examined for planar flaws. Non-structural portion (volumes A-B-D-E and H-J-L-M) would only be examined for laminar flaws for reduction in UT coverage (not to exceed 10%) of the structural portion of the BCWMB only Proposed N-853-2 Figure 6
Precedence and Moving Forward Precedence Oconee RR RA-20-0334 NRC SER ML21124A170 UT in lieu of RT CC N-831-1 Majority of Section XI design specific ambient temperature temperbead code cases utilize Section XI qualifications and acceptance criteria Moving Forward Incorporate comments to draft N-853-2 Present to May TG-TBW, WG-W&SRP, SG-RRA August/November - WG-PQ&VE, SG-NDE Support technical basis for N-888 revision ASME Record 22-954, Revise N-888 to allow Section XI acceptance criteria Establish position on subsequent UT monitoring of flaws