[en] Statistical evaluation of failures of conventional pressure vessels - done for appraising failure probabilities of nuclear pressure vessels - shows that lots of defects are caused by cracks not being detected in pre-service inspection. Therefore the inspection in fabrication should be done with utmost accuracy. In Germany three time independent ultrasonic testing has been performed to objectify the results of inspection. A further possibility is to mechanize the scanning procedure. Principles or possible constructions are shown, and the advantages and disadvantages of this testing method are discussed. A combination of mechanized and manual testing might be a possible solution of the problem of in-fabrication inspections. The mechanized test will give the survey. A further investigation of the findings will be done by extensive manual testing. Advanced NDT-techniques for flaw analysis might substitute the manual tests in the future