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
Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
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.