Lawrence you are a genious, THANK YOU!!!
Found it in AISC A360 N5f - just as you said!
"Increase in Ultrasonic Testing Rate
For risk category II, where 10% of CJP groove welds loaded in transverse tension are tested, an increase in the rate of UT is required for individual welders who have failed to demonstrate a high level of skill, established as a failure rate of more than 5%, after a sufficient number of their welds have been tested. To implement this effectively, and not necessitate the retesting of welds previously deposited by a welder who has a high reject rate established after the 20 welds have been tested, it is suggested that at the start of the work, a higher rate of UT be performed on each welder’s completed welds."
We have no official identification of welders so as a first step we will mutiply the number of welders working by 20 and UT those to investigate the overall quality of all welds.
In parallel, the current structural and mechanical contractors are getting replaced and we are re-writting project specs and contract documents to ensure welders are qualified, consumables verified and all materials verified.
Once the repalcement contractors have been correctly vetted they will go back and repair the failed welds of the previous contractor.