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.
K. F. Hansen, B. V. Koen, W. W. Little, Jr.,
Nuclear Science and Engineering | Volume 22 | Number 1 | May 1965 | Pages 51-59
Technical Paper | doi.org/10.13182/NSE65-A19762
Articles are hosted by Taylor and Francis Online.
A numerical procedure for the integration of the reactor kinetics equation is developed. It has the property of being numerically unconditionally stable for all values of the reactivity or integration-step size. The basic assumption of the method is that the neutron and precursor densities behave exponentially with a frequency characteristic of the asymptotic frequency corresponding to the reactivity. As a consequence of the assumption, and the factoring of the kinetics equation, it is then shown that for constant reactivity the asymptotic numerical eigensolution is exactly the asymptotic eigensolution of the differential kinetics equations. Thus, for constant reactivity, the asymptotic numerical solution can be shown to differ from the asymptotic analytic solution by at most a constant factor, proportional to ht2, for all time.
