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
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.
D. C. Hunt, Robert E. Rothe
Nuclear Science and Engineering | Volume 53 | Number 1 | January 1974 | Pages 79-92
Technical Paper | doi.org/10.13182/NSE74-A23331
Articles are hosted by Taylor and Francis Online.
In evaluating fissile-material recovery operations involving metal salvage immersed in a reagent, a criticality safety engineer must be able to identify systems of minimum critical mass. Further, he must know the effect on the reproduction factor caused by changes in process variables such as container size or the fissile concentration of the reagent. This paper reports no new experimental results but studies the criticality aspects of fissile-metal immersion by analyzing the most applicable of the existing measurements. The results are expressed in terms of the critical mass of the metal region (excluding the mass of fissile material in solution) as a function of the fissile concentration and dimensions of the liquid cylinder., The analysis indicates that the critical mass of practical combinations of uranium metal and uranium solution always exceeds that of an 18.7-g/cm3, 93.2% 235U-enriched uranium sphere centered in a 300-g/liter metal-water mixture. The corresponding conservative approximation for plutonium systems holds for a 19.7-g/cm3, 95% 239Pu sphere in a 200-g/liter metal-water mixture. The upper limit of applicability of these results is 500 g/liter for both plutonium and uranium systems. The calculational techniques described in this paper underestimate critical masses of uranium by ∼5%; the calculated masses of plutonium are sufficiently overestimated to be conservative in practical applications.
