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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.
Byung-Ho Lee, Yang-Hyun Koo, Dong-Seong Sohn
Nuclear Technology | Volume 127 | Number 2 | August 1999 | Pages 151-159
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT99-A2991
Articles are hosted by Taylor and Francis Online.
A model for rim porosity that takes into account the effect of overpressurization on rim pores is proposed for high-burnup UO2 fuel. It is based on the assumption that all the fission gases produced are retained in rim pores, and the threshold pellet average burnup required for the formation of the rim region is 40 MWd/kg U. In addition, a thermal conductivity correlation is proposed that uses the rim porosity model developed. This correlation for the rim region considers both degradation of thermal conductivity with burnup across the fuel pellet and additional degradation at the pellet rim due to very high porosity. To calculate the temperature profile across the fuel pellet where the rim region is formed, the present correlation for the rim region is combined with the HALDEN, MATPRO, and SIMFUEL correlations for thermal conductivity for the fuel interior region where the rim feature does not exist. Application of the present correlation to the measured HALDEN fuel centerline temperature (Nuclear Energy Agency public database IFA-562) shows that good agreement between the calculated and measured fuel centerline temperature is obtained when the present correlation is combined with HALDEN thermal conductivity. On the other hand, when it is combined with SIMFUEL thermal conductivity, which does not consider the effect on thermal conductivity of fission gases and other volatile fission products, lower centerline temperature is obtained due to the characteristics of the SIMFUEL.
