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Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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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Survey says . . . Emotional intelligence important in nuclear industry
The American Nuclear Society’s Diversity and Inclusion in ANS (DIA) Committee hosted a workshop social at the 2024 Winter Conference & Expo in November that brought dozens of attendees together for an engaging—and educational—twist on the game show Family Feud.
Ivars Neretnieks
Nuclear Technology | Volume 71 | Number 2 | November 1985 | Pages 458-470
Technical Paper | Radioactive Waste Management | doi.org/10.13182/NT85-A33698
Articles are hosted by Taylor and Francis Online.
The diffusivities measured by various investigators of several species in compacted bentonite clay have been compiled and analyzed. Small anions diffuse slower than an uncharged molecule such as methane. Large anions move orders of magnitude slower still. The actinides thorium, uranium, plutonium, neptunium, and americium are considerably retarded by sorption effects. Their movement can be explained by pore diffusion with retardation. Cesium, strontium, and protactinium move considerably faster than can be explained by these effects. The faster mobility is probably due to surface migration. A simplified model is presented by which the importance of the backfill barrier in retarding the radionuclides can be assessed. It is based on the computation of the evolution of the concentration profile of the diffusing nuclide in the backfill. Using this model, the flow rate out from the backfill to the flowing water can be compared to the inflow into the backfill due to leaching. A second model treats nuclides with solubility limitations in a similar way. A diagram is presented where the maximum outflow or concentration of a nuclide from the backfill can be determined as a function of barrier thickness and nuclide diffusivity and decay constant. Using the experimentally obtained diffusivities, it is found that a 0.375-m-thick backfill will eventually let through practically all 129I, 99Tc, 226Ra, 231Pa, 234U, 235U, 238U, and 237Np. The maximum release rate for 137Cs, 90Sr, 239Pu, 240Pu, and 243Am will decrease by one to three orders of magnitude compared to the leach rate. Americium-241 will decay to insignificance in the backfill.