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:
e Nozzle Cracking,"NUREG-0312, July 1977, p. 3. 3 "Analysis of the Ultrasonic Examinations of PVRC Weld Speci- mens 155, 202, and 203," R.A. Buchanan, Pressure Vessel Research Committee (PVRC) Report, August 1976. 4 "Summary of the Detection and Evaluation of Ultrasonic Indica- tions - Edwin Hatch Unit 1 Reactor Pressure Vessel," January 1972, Georgia Power Company. on the screen larger than the indication on the screen from the calibration holes (1/2-inch hole for a 12-inch weld thickness, 3/8-inch hole for an 8-inch thickness), this recommendation will not result in any more recording of indications. If the RPV welds being examined have several indications with travel in excess of the calibration hole diameter, the examination and recording time will be increased for the investigation of these flaws, depending on the number of these indications. Slag inclusions in welds are generally long cylindrical defects and do not have much depth unless they are associated with shrinkage or service- induced cracks. These slag inclusions are not expected to increase the number of indications that will be recorded. Increase in examination time will depend on the number, size, and complexity of geometry of through-thickness indications. For RPV girth or nozzle welds where examination is performed by automated equipment and data are recorded on tape, this position will mean no increase in examination time or radiation exposure; but interpretation, analysis, and reporting time for these depth indications will increase. The extra burden in terms of dollar cost will depend on the number, size, and complexity of flaws, and there are no rational bases or data available at this time to estimate the increase in the cost of examination. For RPV welds, mostly nozzle welds, where examination is performed manually and data are not recorded on tape, this position will mean extra examination time and increased radiation exposure to the examiners. Increase in dollar cost and radiation exposure