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.
Takashi Kiguchi, Shigehiro An, Akira Oyama
Nuclear Science and Engineering | Volume 43 | Number 3 | March 1971 | Pages 328-340
Technical Paper | doi.org/10.13182/NSE71-A19979
Articles are hosted by Taylor and Francis Online.
The energy modal synthesis method is applied to the computation of the neutron-multiplication factor, the sodium-void coefficient, and the spatial-power distribution of an idealized fast reactor configuration. The method is formulated by means of the variational principle and the error estimator is introduced by the expansion technique of the trial functions in the eigenfunction series. In the space-independent case, the sodium-void coefficient and its error are obtained very accurately by the linear combination of two modes, and the optimal two modes are chosen by the physical consideration. In the one-dimensional case, the continuous-type and the discontinuous-type energy modal synthesis method are formulated. In both cases the infinite-medium spectra and some supplementary modes are used as the trial energy modes. The results of a few-mode synthesis give a good estimate of the reactor parameters, and the error can be evaluated successfully by the error estimator.