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Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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Nuclear moratoriums crumble around the world
The recent surge in positive sentiment about nuclear as the most viable answer to global energy needs and decarbonization goals has found governments around the world taking steps to reverse course on decades-old bans, moratoriums, and restrictions on new nuclear development.
Haruo Sato
Nuclear Technology | Volume 127 | Number 2 | August 1999 | Pages 199-211
Technical Paper | Radioactive Waste Management and Disposal | doi.org/10.13182/NT127-199
Articles are hosted by Taylor and Francis Online.
The diffusion of radionuclides into the pore spaces of a rock matrix and the pore properties in fractured crystalline rocks were studied. The work concentrated on the predominant water-conducting fracture system in the host granodiorite of the Kamaishi In Situ Test Site, which consists of fracture fillings and altered granodiorite. Through-diffusion experiments to obtain effective and apparent diffusion coefficients (De and Da, respectively) for Na+, Cs+, HTO, Cl-, and SeO32- as a function of ionic charge were conducted through the fracture fillings and altered and intact granodiorite. The total porosity , density, pore-size distribution, and specific surface area of the pores of the rocks were also determined by a water saturation method and Hg porosimetry. The average is, in the order from highest to lowest, as follows: fracture fillings (5.6%) greater than altered granodiorite (3.2%) greater than intact granodiorite (2.3%), and gradually it decreases into the matrix. The pore sizes of the intact and altered granodiorite range from 10 nm to 200 m, and the fracture fillings from 50 nm to 200 m, but almost all pores are found around 0.1 and 200 m in the fracture fillings. The De values for all species are in the following order: fracture fillings greater than altered granodiorite greater than intact granodiorite, as with the rock porosity. In addition, no effect of ionic charge on De is found. No significant dependence for Da values on the rock porosity is found. The formation factors FF and geometric factors G of the rocks were evaluated by normalizing the free water diffusion coefficient Do for each species. The FF decreased with decreasing rock porosity, and an empirical equation for the rock porosity was derived to be FF = 1.57±0.02. The G values showed a tendency to slightly decrease with decreasing rock porosity, but they were approximately constant (0.12 to 0.19) in this porosity range. This indicates that accessible pores decrease into the rock matrix from the fractures, and diffusion is also reduced into the rock matrix. Furthermore, it was concluded that a simplified model based on FF and Do values is approximately reasonable to predict De.
