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
Education, Training & Workforce Development
The Education, Training & Workforce Development Division provides communication among the academic, industrial, and governmental communities through the exchange of views and information on matters related to education, training and workforce development in nuclear and radiological science, engineering, and technology. Industry leaders, education and training professionals, and interested students work together through Society-sponsored meetings and publications, to enrich their professional development, to educate the general public, and to advance nuclear and radiological science and engineering.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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!
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Nuclear Science and Engineering
May 2025
Nuclear Technology
Fusion Science and Technology
Latest News
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
Richard A. Wolfe
Nuclear Technology | Volume 9 | Number 2 | August 1970 | Pages 218-228
Reactor Siting | Symposium on Theoretical Models for Predicting In-Reactor Performance of Fuel and Cladding Material | doi.org/10.13182/NT70-A28810
Articles are hosted by Taylor and Francis Online.
Calculations show that a 10% isotopic abundance of 238 Pu in a bare spherical 239 Pu-H2O system increases the minimum critical mass by ∼48%, thereafter the increase continues exponentially. These results, in addition to several subcritical neutron multiplication experiments with 238 Pu in both solution and dioxide form, confirm that 238 Pu behaves as a neutron poison in a well-moderated medium. Neutron multiplication experiments were conducted with four SNAP-19B (IRHS) heat sources with ∼1 kg 238 Pu per source. The results indicated that a neutron multiplication <1.2 existed when the heat sources were assembled in different array configurations. The criticality unit value for 238 Pu in either solution or dioxide form has been conservatively established at 2.0 kg. Thermocouples installed on process vessels have proven to be a new criticality control technique for determining gradual 238 Pu sludge buildup. Heterogeneous water-filled storage vaults provide the safest method for storing large quantities of PuO2 containing at least 76% 238Pu.
