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
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
Meeting 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
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
July 2025
Fusion Science and Technology
Latest News
DOE extends Centrus’s HALEU production contract by one year
Centrus Energy has announced that it has secured a contract extension from the Department of Energy to continue—for one year—its ongoing high-assay low-enriched uranium (HALEU) production at the American Centrifuge Plant in Piketon, Ohio, at an annual rate of 900 kilograms of HALEU UF6. According to Centrus, the extension is valued at about $110 million through June 30, 2026.
P. Goldschmidt
Nuclear Science and Engineering | Volume 49 | Number 3 | November 1972 | Pages 263-273
Technical Paper | doi.org/10.13182/NSE72-A22541
Articles are hosted by Taylor and Francis Online.
Pontryagin’s Maximum Principle and Robbins’ Criterion allow us to find, in the general case of intermediate reactors, the distribution of fuel enrichment that minimizes the critical mass of a reactor of given power and subject to constraints on the maximum power density and on the enrichment. The two group diffusion model is used in slab geometry. The optimal sequence of control (enrichment) zones is made up of a central constant power density zone, a zone of maximum enrichment, a zone of variable enrichment (where the control is singular) and finally an external zone of minimum enrichment (or a reflector). In the particular case of fast reactors the optimal solution does not include the singular control zone.
