Document: 10 CFR Part 50
Document ID: cfc9c7b0-bbcd-4774-97ce-900cbc760408
Document Type: cfr
Title: Codes and standards.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.55a
Revision Date: 
Chapter: 
Section ID: 50.55a
CFR Part: 50
CFR Title: 10

Content:
zed weld overlay examination. Following initial inservice volumetric inspection for Inspection Items C-2 and F-2 of Table 1 of ASME Code Case N-770-7, for weld overlay examination volumes that show no indication of crack growth or new cracking, in lieu of sample population, 100 percent of these optimized weld overlayed welds shall be added to the ISI program in accordance with -2410 of ASME Code Case N-770-7 and shall be examined once each inspection interval. ( 9 ) Deferrals. ( i ) The initial inservice volumetric examination of optimized weld overlays, Inspection Item C-2, shall not be deferred. ( ii ) Volumetric inspection of peened dissimilar metal butt welds shall not be deferred. ( iii ) For Inspection Item M-2, N-1 and N-2 welds, the second required inservice volumetric examination shall not be deferred. ( 10 ) Examination technique. Note 14(b) of Table 1 and Note (b) of Figure 5(a) of ASME BPV Code Case N-770-5 may only be implemented if the requirements of Note 14(a) of Table 1 of ASME BPV Code Case N-770-5 cannot be met. ( 11 ) [Reserved] ( 12 ) Stress improvement inspection coverage. Under Paragraph I.5.1, for cast stainless steel items, the required examination volume shall be examined by Appendix VIII procedures to the maximum extent practical including 100 percent of the susceptible material volume. ( 13 ) Encoded ultrasonic examination. Ultrasonic examinations of non-mitigated or cracked mitigated dissimilar metal butt welds in the reactor coolant pressure boundary must be performed in accordance with the requirements of Table 1 for Inspection Item A-1, A-2, B-1, B-2, E, F-2, J, K, N-1, N-2 and O. Essentially 100 percent of the required inspection volume shall be examined using an encoded method. ( 14 ) Excavate and weld repair cold leg. For cold leg temperature M-2, N-1 and N-2 welds, initial volumetric inspection after application of an excavate and weld repair (EWR) shall be performed during the second refueling outage. ( 15 ) Cracked excavate and