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2026 Annual Conference
May 31–June 3, 2026
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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.
Norman P. Baumann, Willard G. Winn
Nuclear Technology | Volume 72 | Number 3 | March 1986 | Pages 353-358
Technical Paper | Radiation Protection and Health Physics Practices and Experience in Operating Reactors Internationally / Analyse | doi.org/10.13182/NT86-A33774
Articles are hosted by Taylor and Francis Online.
A long-lived gamma source, containing 370 MBq of 232U (72 yr) and 110 MBq of 228Th (1.9 yr), was developed as a permanent replacement for neutron-activated 24Na (15-h) sources that have been used in a 2D(γ,n)1H tritiated water detector. The 228Th, which will build up to 340 MBq in 10 yr and then decay in equilibrium with 232U, emits copious 2614-keV gamma rays for the (γ, n) process. Competing (α, n) backgrounds are reduced by placing the uranium/thorium source in a gold matrix to provide threshold and coulomb barriers against the reaction. The detection limits (∼0.0l-ml D2O) for typical stainless steel pipes (∼2-cm diam) measured with the uranium/thorium source are almost as low as those for comparable 24Na sources, which do not produce (α,n) backgrounds. This minor sensitivity loss can be offset by longer counting times, if necessary. Lower personnel exposure is realized with the new source. Overall, the practical advantages of using a longer lived source strongly favor the use of 232U/228Th instead of 24Na.
