Document: NRC Regulatory Guide
Document ID: c55ba6c5-aa2d-4ad6-aba2-2001e16524ab
Document Type: regulatory_guide
Title: Ultrasonic Testing of Reactor Vessel Welds During Preservice and Inservice Examinations (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A015.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.150
CFR Part: 
CFR Title: 

Content:
for examination by the NRC staff. If the size of an indication, as determined in regulatory positions 6.1 or 6.2, equals or exceeds the allowable limits of Section XI of the ASME Code, the indications should be reported as abnormal degradation of reactor pressure boundary in accordance with the recommendation of regulatory posi- tion 2.a(3) of Regulatory Guide 1.16. Along with the report of ultrasonic examination test results, the following information should also be included: a. The best estimate of the error band in sizing the flaws and the basis for this estimate should be given. b. The best estimate of the portion of the volume required to be examined by the ASME Code that has not been effectively examined such as volumes of material near each surface because of near-field or other effects, volumes near interfaces between cladding and parent metal, volumes shadowed by laminar material defects, volumes shadowed by part geometry, volumes inaccessible to the transducer, volumes affected by electronic gating, and volumes near the surface opposite the transducer.1 1- c. The material volume that has not been effectively examined by the use of the above procedures may be examined by alternative effective volumetric NDE techniques. If one of these alternative NDE techniques is a variation of UT, recommendations of regulatory positions 1 and 3 should apply. A description of the techniques used should be included in the report. If other volumetric techniques or variations of UT are used as indicated in regulatory posi- tion 5, the effectiveness of these techniques should be demonstrated and the procedures reported for review by the NRC staff. 8. ALTERNATIVE METHOD Appendix A contains an alternative method that is pre- sented in Chapter 3 of the document "Recommended Change' to Regulatory Guide 1.150," prepared by the Ad Hoc Committee of the Electric Utility Industry and pre- sented to the NRC in August 1982.12 The NRC staff has evaluated this method and has found it to be