Solving For CASS: A 50 year Lesson in Attenuation
Tracks
TECHNICAL SESSIONS
Knowledge Level - NDT Level I/NDT Level II
Knowledge Level - NDT Level III
Presentation Topic Level - Advanced
Target Audience - Level III Managers
Target Audience - Research/Academics
Target Audience- NDT Engineers
Target Audience- Technicians/Inspectors
| Thursday, October 9, 2025 |
| 8:00 AM - 8:30 AM |
| Fiesta 6 |
Speaker
Mr Paul Hayes
President
Solving For CASS: A 50 year Lesson in Attenuation
Presentation Description
Abstract:
Solving For CASS: A 50-year Lesson in Attenuation
Nuclear power provides approximately 20% of the U.S. baseload electricity, with 12% to 14% of that relying on Cast Austenitic Stainless Steel (CASS) components. For over five decades, various stakeholders have attempted to develop reliable ultrasonic inspection techniques for CASS—largely without success. Its coarse-grained, highly attenuative nature remains a significant barrier to conventional ultrasonic testing.
To further complicate matters, thermal fatigue cracking is projected to begin after around 40 years of service—yet many plants have already exceeded that threshold by decades.
A hybrid Conventional UT/PAUT transducer, specifically designed for this challenge, has been developed alongside high-power UT equipment capable of driving it effectively. This paper introduces novel approaches for inspecting some of the most attenuative materials—not only for CASS, but also Inconel welds, dissimilar metal welds, aerospace composites, and components from additive manufacturing.
It revisits some older “brute force” techniques and explores how merging them with modern technology yields promising results in overcoming long-standing inspection limitations.
Solving For CASS: A 50-year Lesson in Attenuation
Nuclear power provides approximately 20% of the U.S. baseload electricity, with 12% to 14% of that relying on Cast Austenitic Stainless Steel (CASS) components. For over five decades, various stakeholders have attempted to develop reliable ultrasonic inspection techniques for CASS—largely without success. Its coarse-grained, highly attenuative nature remains a significant barrier to conventional ultrasonic testing.
To further complicate matters, thermal fatigue cracking is projected to begin after around 40 years of service—yet many plants have already exceeded that threshold by decades.
A hybrid Conventional UT/PAUT transducer, specifically designed for this challenge, has been developed alongside high-power UT equipment capable of driving it effectively. This paper introduces novel approaches for inspecting some of the most attenuative materials—not only for CASS, but also Inconel welds, dissimilar metal welds, aerospace composites, and components from additive manufacturing.
It revisits some older “brute force” techniques and explores how merging them with modern technology yields promising results in overcoming long-standing inspection limitations.
Short Course Description
Biography
Paul Hayes is a 30 year veteran of the NDT industry. Throughout this time he has been fortunate to gain a great variety of experiences, successes and mistakes.
For the past 5 years, he has been the President of Sinewave Solutions, LLC., and largely an army of one. He has always found great satisfaction in helping others and sharing what he knows. Besides scrapping for work, or working on problems he has found a home of like minded people while volunteering at the ASME Code meetings.
Ever the student of Ultrasonics, the coming future and technology advancements are as one.
