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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.
M. Coquerelle, C. T. Walker
Nuclear Technology | Volume 48 | Number 1 | April 1980 | Pages 43-53
Technical Paper | Fuel | doi.org/10.13182/NT80-A32446
Articles are hosted by Taylor and Francis Online.
Mixed carbide, carbonitride, and nitride fuels have been irradiated in DFR and Rapsodie to a maximum burnup of 7.8 at.% at a maximum linear power of 135 kW·m−1. At low burnup, xenon release from helium-bonded fuels was found to be dependent on the chemical composition of the fuel Release was greatest from carbide (75%) and least from nitride fuels (35%). At medium burnup, improved gap conductance led to a fall in the fuel centerline temperature and consequently a decrease in gas release. For nitride and carbonitride fuels, over 75% of the retained fission gas was contained in bubbles (<1 µm in diameter) and in the fuel matrix. For all three fuels, xenon release from the outer unrestructured region of the fuel was <15%, whereas release from the central porous region was 50% or more. In the restructured region, gas was released to the plenum by way of interconnected pores. Gas in pores contained proportionally more krypton than the bonded gas, and consequently, it is proposed that atomic diffusion is the principal mechanism of gas transport within the fuel.
