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:
oned for display. The reflector used in generating the RF return signal as well as the electronic system (i.e., the basic ultrasonic instrument, gating, and form of gated signal) should be documented. These records should be used for comparison with previous and future records. 1.2 Field Performance Checks a. Frequency of Checks As a minimum, these checks should be verified on-site before and after examining all the welds that need to be examined in a reactor pressure vessel during one outage. Pulse shape and noise suppression controls should remain at the same setting during examination and calibration. 4 1.150-10 b. Instrument Sensitivity during Linearity Checks The initial instrument sen- sitivity during the performance of 1.2.e. should be such that it falls at the calibration sensitivity or at some point between the calibration sensitivity and the scanning sensitivity. c. RF Waveform A record of the RF (radiofrequency) pulse waveform from a reference reflector should be obtained and recorded in a manner that will permit extraction of frequency amplitude information. At the highest amplitude portion of the beam, the RF return signal should be recorded before it has been rectified or conditioned for display. This should be determined on the same reflector as that used in 1.1.b. above. This record should be retained for future reference. d. Screen Height Linearity Screen height linearity of the ultrasonic instrument should be .determined according to the manda- tory Appendix I to Article 4, Section V of the ASME Code or Appendix I to Section XI of the ASME Code. e. Amplitude Control Linearity Amplitude control should be determined according to the man- datory Appendix II of Article 4, Section V of the ASME Code or Appendix I to Section XI of the ASME Code. f. Angle Beam Profile Characterization The vertical beam profile should be determined for each search unit used during the examination by a procedure similar to that outlined in nonmandatory Appendix B-60,