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
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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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Latest News
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Wilfried Pfingsten
Nuclear Technology | Volume 140 | Number 1 | October 2002 | Pages 63-82
Technical Paper | Radioactive Waste Management and Disposal | doi.org/10.13182/NT02-A3324
Articles are hosted by Taylor and Francis Online.
In the vicinity of a cementitious nuclear waste repository, mineral reactions will change the hydraulic conditions and the parameters describing radionuclide transport with time during the cement degradation phase. Porosity changes due to mineral and cement reactions will influence permeability and diffusivity. Formation water rich in CO2 will lead to calcite precipitation in the water-conducting zones surrounding the cementitious waste repository. This will have an impact on the radionuclide release from the cementitious repository into the host rock environment. The sequentially coupled flow, transport, and chemical reaction code MCOTAC is used to include such processes in the modeling. A porosity-permeability relation and a porosity-diffusivity relation are used for describing cement degradation and related secondary mineral precipitation and their coupling to reactive transport modeling. Two-dimensional model calculations are used to predict the temporal evolution of transport parameters for radionuclides within a "small-scale" near field of a cementitious waste repository. Reduced solute transport is calculated in the repository near field due to porosity and permeability changes at the rock-repository interface. Within the small-scale porous medium approach, coupling of chemical reactions and hydrodynamic parameters indicates a self-sealing barrier at the host rock-repository interface for several scenarios. This barrier might persist for very long times and effectively contain radionuclides within the engineered repository system. Taking into account flow path and barrier-specific heterogeneity will be a further step to improve the understanding of coupled processes in the vicinity of a real cementitious near field.
