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:
anges to Regulatory Guide 1.150," prepared by the Ad Hoc Committee of the Electric Utility Industry. Ultrasonic examination of reactor vessel welds should be performed according to the requirements of Section XI of the ASME B&PV Code, as referenced in the Safety Analysis Report (SAR) and its amendments, supplemented by the following: 1. INSPECTION SYSTEM PERFORMANCE CHECKS The conduct of a quality exami- nation requires that the performance characteristics of the inspection system used be well defined and documented. This is particularly true for situations which require comparisons of examination results generated during successive examinations on the same components. A system comprises: a. a transducer; b. a single channel instrument or each channel of a multi-channel instrument; and c. a given cable type and length. The checks described in paragraphs 1.1 and 1.2 should be made for any UT system used for inspection of reactor pressure vessel (RPV) welds. The field performance checks described in 1.2 (with the possible exception of 1.2.c.) should be conducted on a basic calibration block that represents the thickness range to be examined. 1.1 Pre-exam Performance Checks a. Frequency of checks These checks should be verified within six months before reactor pressure vessel examinations performed during one outage. Pulse shape and noise suppression controls should remain at the same settings during calibration and exa- mination. b. RF Waveform A record of the RF (radiofre- quency) pulse waveform from a reference reflector should be obtained for each search unit used in the examination in a manner which will provide 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. 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.