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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
Yuchuan Guo, Guanbo Wang, Dazhi Qian, Heng Yu, Bo Hu, Xiangmiao Mi, Simao Guo
Nuclear Technology | Volume 204 | Number 1 | October 2018 | Pages 15-24
Technical Paper | doi.org/10.1080/00295450.2018.1469345
Articles are hosted by Taylor and Francis Online.
A flow blockage analysis model of a single channel is established using the best-estimate code RELAP5/MOD3.4. The reactor core is divided into seven hot channels, one average channel, one bypass channel, and corresponding fuel plates to take into account the interaction between the obstructed channel and adjacent channels. The coolant system is also modeled in detail to perform a better estimation. As a typical pool-type research reactor, JRR-3M is chosen for the analysis. The results indicate that the model can effectively simulate a single-channel blockage accident using the RELAP5/MOD3.4 code. Also, the thermal-hydraulic parameters in the blocked channel would be significantly affected if bubbles are generated as the blockage ratio continues to increase, which may damage the integrity of the fuel plate. Meanwhile, as for flow blockage of a single channel, the effect on adjacent channels is limited, even under high-blockage-ratio conditions.
