'Ultrasonic examination of austenitic welds at reactor pressure vessels'

摘要

Austenitic welds play an important role in reactor pressure vessels (RPV) both of pressurized water reactors (PWRs) and boiling water reactors (BWRs). These pressure retaining joints still pose problems for ultrasonic examination. During the lastyears quite some progress has been achieved. The state of the art of the practical application is described in "The Handbook on Ultrasonic Examination of Austenitic Welds" of the International Institute of Welding which was issued in 1986. This documenthas been prepared by an international working group under the chairmanship of X. Edelmann.Sulzer Brothers Limited, Winterthur Switzerland as manufacturer of both BWR and PWR RPVs has a long experience with ultrasonic examination of austenitic welds. In General Electric BWR RPVs the main recirculation line, the feedwater line and additionallines are connected to nozzles of the RPV with dissimilar metal welds joining stainless steel to carbon steel. The control rod drive housings are attached to the RPV with complex weld joints. Framatome and Westinghouse RPVs also are provided with weldsbetween the vessel and the main coolant line. Examples of ultrasonic approaches and examination results are presented. Aspects of fabrication, preservice and inservice inspections are covered.Complex weld joint designs both from the point of material and geometry make ultrasonic examination sometimes extremely difficult but based on case by case investigations reliable solutions can often be realized.