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
Decommissioning & Environmental Sciences
The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
J. J. Mcinerney
Nuclear Science and Engineering | Volume 17 | Number 3 | November 1963 | Pages 392-397
Technical Paper | doi.org/10.13182/NSE63-A17387
Articles are hosted by Taylor and Francis Online.
Some aspects of the relation between the energy dependence of the scattering cross section and the spatial distribution of neutrons slowing down in a hydrogeneous moderator are discussed. The neutron population in an infinite medium is analyzed using the mean square slowing down distance, , as a measure of its spatial extent. It is shown that, contrary to what is perhaps expected, the neutron population in many cases is distributed closer to its source with decreasing energy. In the analysis of this behavior it is found that diffusion theory may in some cases be expected to give good results close to the spatial position of the source. A correction term is also found for the “first flight” transport kernel often used in practical calculations.