ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
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!
Latest Magazine Issues
Dec 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
January 2026
Nuclear Technology
December 2025
Fusion Science and Technology
November 2025
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.
Hans Ludewig
Nuclear Science and Engineering | Volume 44 | Number 3 | June 1971 | Pages 398-405
Technical Paper | doi.org/10.13182/NSE71-A20170
Articles are hosted by Taylor and Francis Online.
An analysis of the BNL heterogeneity experiment is described in this paper. The nuclear data used are based on ENDF/B Versions I and II and the DSN method is used in the analysis. In addition to determining the intracell fine structure for 235U and 238U fission and Mn capture, the variation of absolute 235U/238U fission ratio as a function of cell size is investigated. From these results it can be concluded that the fission ratio calculations are particularly sensitive to the fission cross section of 235U and 238U, suggesting that measurements of this type could be useful in checking the accuracy of data. The overall agreement between computed and measured quantities was found to be good for all quantities that could be characterized as asymptotic. The non-asymptotic nature of some quantities is investigated using two-dimensional calculations.
