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 Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Bipartisan Fusion Energy Act pushes for regulatory clarity
Sen. Alex Padilla (D., Calif.) introduced the Fusion Energy Act (S. 4151) last month with a bipartisan group of cosponsors—John Cornyn (R., Texas), Cory Booker (D., N.J.), Todd Young (R., Ind.), and Patty Murray (D., Wash.). The legislation would codify the Nuclear Regulatory Commission’s regulatory authority over commercial fusion energy systems to streamline the creation of clear federal regulations that will support the development of commercial fusion power plants—and would require a report within one year on a study of risk- and performance-based, design-specific licensing frameworks for “mass-manufactured fusion machines.
“Congress must do everything in its power to ensure continued U.S. leadership in developing commercial fusion energy facilities,” said Padilla as he introduced the bill. “The Fusion Energy Act would provide regulatory certainty for investors as the NRC develops and streamlines frameworks for such facilities.”
Ching-Hor Lee, Shi-Ping Teng
Nuclear Technology | Volume 101 | Number 1 | January 1993 | Pages 67-78
Technical Paper | Waste Management Special / Radioactive Waste Disposal | doi.org/10.13182/NT93-A34768
Articles are hosted by Taylor and Francis Online.
An analytical solution covering the entire range of sorption properties of rock has been derived for the migration of radionuclides along a discrete fracture in a porous rock matrix. The analysis takes into account the advective transport in the fracture, longitudinal hydrodynamic dispersion in the fracture, molecular diffusion from the fracture into the rock matrix, adsorption within the matrix, and the radioactive decay. For adsorption of radionuclide within the matrix, the effects of no sorption, linear nonequilibrium sorption, and linear equilibrium sorption are integrated into a generic transient analytical solution. Based on certain assumptions, the problem can be formulated into two coupled one-dimensional transport equations: one for the fracture and another for the porous matrix in a direction perpendicular to the fracture axis. The general solution is of a single semi-infinite integral form that can be evaluated by Gaussian quadrature. The results indicate that the assumption of equilibrium sorption within the rock results in underestimation of the concentration profile along the fracture in the early stages of migration. It is worth noting that the concentration profile of the nonequilibrium sorption case is slightly smaller than that of the equilibrium sorption case after a certain time. However, the profiles eventually approach the same value. It is also confirmed that the porosity of rock strongly affects radionuclide transport in a fracture.