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:
cceptable as a volumetric examination method. Otherwise, the use of high-intensity radiography or tandem-probe UT technique, among other techniques, should be considered. The above type of flaw is the most significant but the most difficult to detect. Because of this, the present recom- mendations are being made despite their potential impact on cost and radiation exposure. The potential impact may be as follows: a. Additional NRC staff time may be needed to evaluate the effectiveness of UT techniques on a generic basis to detect perpendicular planar flaws. After techniques are recognized to accomplish the above, NRC staff time that is being spent currently on evaluating problems on a plant-by- plant basis is expected to be considerably reduced. b. Reactor downtime may increase, depending on the examination time differentials between the conventional and refined techniques. This may, however, be offset by a reduction in the downtime currently needed for NRC experts to evaluate data that sometimes requires further clarification and reexamination.2'4 c. Additional cost might be incurred in changes needed to add transducers or data-gathering capability to existing automated equipment or to automate current manual examinations. Automation of current manual techniques is likely to reduce radiation exposure to personnel. 6. SIZING AND RECORDING OF INDICATIONS 6.1 Traveling Indications This position recommends the recording of traveling indications. If RPV welds do not have any travel indications 1"Probability of Detecting Planar Defects in Heavy Wall Welds by Ultrasonic Techniques According to Existing Codes," Dr. Ing. Hans- Jurgen Meyer, Quality Department of M.A.N., Nurnberg, D 8500 Nurnberg 115. 2 "Interim Technical Report on BWR Feedwater and Control Rod Drive Return Line 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,