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Conference Spotlight
2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Standards Program
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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Latest News
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.
Daniel Westlén, Janne Wallenius
Nuclear Technology | Volume 154 | Number 1 | April 2006 | Pages 41-51
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT06-A3716
Articles are hosted by Taylor and Francis Online.
We have designed a gas-cooled accelerator-driven system dedicated to transmutation of minor actinides. Thanks to the excellent neutron economy of the uranium-free fuel employed, the pin pitch to diameter ratio (P/D) could be increased to 1.8. The increased coolant fraction allows for decay heat removal at ambient pressure. The large coolant fraction further results in a low pressure loss - 26 kPa over the core, 35 kPa in total. Thanks to the large P/D, the elevation of the heat exchanger necessary to remove decay heat by natural circulation is just more than 1 m. The absence of uranium in conjunction with the presence of 35% (heavy atom) americium in the fuel results in a low effective delayed neutron fraction and a vanishing Doppler feedback, making subcritical operation mandatory.
