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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
Fusion Science and Technology
July 2025
Latest News
Hash Hashemian: Visionary leadership
As Dr. Hashem M. “Hash” Hashemian prepares to step into his term as President of the American Nuclear Society, he is clear that he wants to make the most of this unique moment.
A groundswell in public approval of nuclear is finding a home in growing governmental support that is backed by a tailwind of technological innovation. “Now is a good time to be in nuclear,” Hashemian said, as he explained the criticality of this moment and what he hoped to accomplish as president.
Genn Saji, Roy A. Axford
Nuclear Science and Engineering | Volume 35 | Number 3 | March 1969 | Pages 319-331
Technical Paper | doi.org/10.13182/NSE69-A20010
Articles are hosted by Taylor and Francis Online.
A new theoretical formalism of the space-time kinetics is developed for heterogeneous reactor models. The basic time-dependent diffusion equation, which contains terms representing localized absorption and fast-neutron production by fuel rods, has been analytically transformed into a convolution integral form. This enables computation of space- and time-dependent flux for heterogeneous reactors by considering the sizes and spacings of the fuel rods, their geometrical locations, and the nuclear properties of the material used. Although the basic idea and mathematical formalism developed in this paper can be applied for various other space-time kinetics problems, the final calculation is performed for the forced oscillation problem. Two computer codes, HERMITS-1 and HERMITS-2, are developed. By using these codes, it is shown that contour maps of the static flux, phase angles, and amplitudes of neutron waves around the fuel rods can be calculated in an extremely short amount of machine time.