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:
er a moving transducer mounted on the mechanism that will be used for examination of the component or a mechanism that duplicates the critical factors (e.g., transducer mounting, weight, pivot points, couplant) present in the scanning mechanism. b. Calibration speed should be at or higher than the scanning speed, except when correction factors established in 2.2.d. are used. c. The direction of transducer movement (forward or backward) during calibration to establish the DAC curve should be the same direction during scanning unless it can be shown that'a change in scanning direction does not reduce flaw detection capability. d. One of the following alternative guidelines should be followed to establish correction factors if static calibration is used. (1) Correction factors between dynamic and static response should be established using the basic calibration block or, (2) Correction factors should be established using models and taking -scaling factors into consideration (assumed scaling relationship should be verified) or, (3) Correction factors should be established using full scale mockups. 2.3 Calibration Confirmation Calibration confirmation per- formed as mid-shift or interim confirmation between on-site calibrations should comply with stability requirements in T-433, Article 4, Section V of the ASME Code. When an electronic simulator is used for on-site calibration confirmation after a Code-required block calibration performed off- site, the following should also apply: a. Complete system performance should be maintained stable prior to off-site calibrations and on-site calibration confirmation by use of target reflectors. The target reflectors should be mounted with identical physical displacement in both the off-site calibration facilities and the on-site mecha- nized equipment. Each on-site periodic calibration should be preceded by complete system per- formance verification using a minimum of two (2) target reflec- tors separated by a distance repre-