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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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What’s the most difficult question you’ve been asked as a maintenance instructor?
Blye Widmar
"Where are the prints?!"
This was the final question in an onslaught of verbal feedback, comments, and critiques I received from my students back in 2019. I had two years of instructor experience and was teaching a class that had been meticulously rehearsed in preparation for an accreditation visit. I knew the training material well and transferred that knowledge effectively enough for all the students to pass the class. As we wrapped up, I asked the students how they felt about my first big system-level class, and they did not hold back.
“Why was the exam from memory when we don’t work from memory in the plant?” “Why didn’t we refer to the vendor documents?” “Why didn’t we practice more on the mock-up?” And so on.
L. Sudderth, D. Perez-Nunez, D. Keiser, S. McDeavitt
Nuclear Technology | Volume 202 | Number 1 | April 2018 | Pages 81-93
Technical Paper | doi.org/10.1080/00295450.2017.1420336
Articles are hosted by Taylor and Francis Online.
A fluidized bed chemical vapor deposition (FB-CVD) system with an inverted reactor was used to develop barrier coatings of zirconium nitride on the surface of U 8 wt% Mo microspheres in order to examine the resulting coating structure and composition, as well as to evaluate the effects of certain process parameters on the coating properties. The process utilized the metal-organic precursor tetrakis(dimethylamino)zirconium heated to 51°C ± 2°C. Time-dependent studies analyzed the coating produced after 2 to 8 days of operation at 100 mL/min precursor carrier flow rate and 500 mL/min fluidization flow rate. Flow-rate–dependent studies produced coated samples using a total flow rate of 600 mL/min, with the precursor carrier flow rate ranging from 100 to 300 mL/min and the fluidization flow rate adjusted accordingly. Ultrahigh-purity argon was used for the precursor carrier and fluidization gas. The CVD reaction was carried out at 280°C ± 10°C with precursor transport tubes heated to 60°C to 75°C. The zirconium-based coatings were manufactured up to 2.2 ± 0.3 µm thick after 2 days of deposition. The estimated coating thickness was not significantly impacted by extending the duration of the deposition process or increasing the precursor carrier gas flow rate. Imaging of the microsphere cross sections provided evidence of uranium oxide, zirconium oxide, and zirconium nitride layers formed within the coating, with nitrogen content becoming more dominant farther from the bulk U-Mo surface. Certain modifications to the process would improve the results, including installing the system inside an inert atmosphere to limit oxygen contamination and higher resolution analyses to better determine coating structure, and finally, performance of a kinetic study of the coating process, particularly over the first 24 h in which the majority of the deposition was suspected to have occurred by enabling partial powder removal during FB-CVD operation to analyze samples from different points within a single experiment.