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.
Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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
Jan 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
February 2025
Nuclear Technology
January 2025
Fusion Science and Technology
Latest News
When your test capsule is the test: ORNL’s 3D-printed rabbit
Oak Ridge National Laboratory has, for the first time, designed, printed, and irradiated a specimen capsule—or rabbit capsule—for use in its High Flux Isotope Reactor (HFIR), the Department of Energy announced on January 15.
P. K. Job, K. Subba Rao, M. Srinivasan
Nuclear Science and Engineering | Volume 84 | Number 3 | July 1983 | Pages 293-298
Technical Note | doi.org/10.13182/NSE83-A17798
Articles are hosted by Taylor and Francis Online.
It was shown earlier that nonsolvated crystalline BeH2 could serve as an effective moderator in reducing nuclear critical masses below minima achievable in CH2-moderated systems on account of its (n, 2n) reactivity bonus and higher hydrogen number density. The 9Be cross sections used in these calculations were found to overestimate the (n, 2n) multiplication. The precise (n, 2n) contribution to system reactivity and critical mass in the light of the latest 9Be cross-section data are evaluated. The results show that in the case of BeH2-moderated and BeO-reflected systems, five additional neutrons are born in the reaction multiplication in beryllium per 100 fission neutrons released in the core, resulting in a reactivity gain of ∼4%. The corresponding reduction in critical mass is ∼16%. The critical masses calculated with corrected 9Be cross sections show that the crystalline BeH2-moderated and BeO-reflected systems apparently have the smallest possible theoretical critical masses, namely, 0.180, 0.137, and 0.105 kg for 235U, 233U, and 239Pu, respectively.