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
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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.
Jeffrey A. Favorite, Ashley D. Thomas, Thomas E. Booth
Nuclear Science and Engineering | Volume 168 | Number 2 | June 2011 | Pages 115-127
Technical Paper | doi.org/10.13182/NSE09-72
Articles are hosted by Taylor and Francis Online.
Particle fluxes on surfaces are difficult to calculate with Monte Carlo codes because the score requires a division by the surface-crossing angle cosine, and grazing angles lead to inaccuracies. We revisit the standard practice of dividing by half of a cosine “cutoff” for particles whose surface-crossing cosines are below the cutoff. We concentrate on the flux crossing an external boundary, deriving the standard approach in a manner that explicitly points out three assumptions: (a) that the external boundary surface flux is isotropic or mostly isotropic, (b) that the cosine cutoff is small, and (c) that the minimum possible surface-crossing cosine is 0. We find that the requirement for accuracy of the standard surface flux estimate is more restrictive for external boundaries (a very isotropic surface flux) than for internal surfaces (an isotropic or linearly anisotropic surface flux). Numerical demonstrations involve analytic and semianalytic solutions for monoenergetic point sources irradiating surfaces with no scattering. We conclude with a discussion of potentially more robust approaches.