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:
n 6 and for reflectors that exceed the Code-allowable criteria. 1.1 Frequency of Checks As a minimum, these checks should be verified within 1 day before and within I day 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. 1.2 Screen Height Linearity Screen height linearity of the ultrasonic instrument should be determined according to the mandatory Appen- dix I to Article 4, Section V of the ASME Code, within the time limits specified in regulatory position 1.1. 1.3 Amplitude Control Linearity Amplitude control linearity should be determined according to the mandatory Appendix II of Article 4, Section V of the ASME Code, 1977 edition, within the time limits specified in regulatory position 1.1. 1.4 Frequency-Amplitude Curve A photographic record of the frequency-amplitude curve should be obtained. This record should be available for comparison at the inspection site for the next two successive inspections of the same volume. The reflector used in generating the frequency-amplitude curves as well as the electronic system (i.e., the basic ultrasonic instrument, gating, form of gated signal, and spectrum analysis equip- ment) and how it is used to capture the frequency-amplitude information should be documented. 1.5 Pulse Shape A photographic record of the unloaded initial pulse against a calibrated time base should be obtained. The time base and voltage values should be identified and recorded on the horizontal and vertical axis ofthe above photographic record of the initial pulse. The method used in obtaining the pulse shape photograph, including the test point at which it is obtained, should be documented. 2. CALIBRATION I System calibration should be checked to verify the DAC curve and the sweep range calibration per nonmandatory Appendix B, Article 4, Section V of the ASME Code, as a minimum, before