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Conference Spotlight
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.
R. T. Santoro, R. G. Alsmiller, Jr., J. M. Barnes, G. T. Chapman
Nuclear Science and Engineering | Volume 78 | Number 3 | July 1981 | Pages 259-272
Technical Paper | doi.org/10.13182/NSE81-A20303
Articles are hosted by Taylor and Francis Online.
Integral experiments that measure the transport of ∼14-MeV deuterium-tritium (D-T) neutrons through laminated slabs of proposed fusion reactor shield materials have been carried out at the Oak Ridge National Laboratory. Measured and calculated neutron and gamma-ray energy spectra are compared as a function of the thickness and composition of Type 304 stainless steel, borated polyethylene (BP), and Hevimet (a tungsten alloy), and as a function of detector position behind these materials. The measured data were obtained by means of an NE-213 liquid scintillator using pulse-shape discrimination methods to resolve neutron and gamma-ray pulse-height data and spectral unfolding methods to convert these data to energy spectra. The calculated data were obtained using two-dimensional discrete-ordinates radiation transport methods in a complex calculational network that takes into account the energy-angle dependence of the D-T neutrons and the nonphysical anomalies of the Sn method. The transport calculations incorporate ENDF/B-IV cross-section data from the VITAMIN C data library. The measured and calculated neutron energy spectra are in good agreement behind slab configurations of Type 304 stainless steel and BP (∼10% for all neutron energies >850 keV). When 5 cm of Hevimet are added to a 45-cm-thick Type 304 stainless steel plus BP slab assembly, the agreement is less favorable. The agreement among the measured and calculated gamma-ray spectra for energies >750 keV ranges from ∼25% to a factor of ∼5 depending on the slab composition.
