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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!
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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.
Hiroshi Takahashi
Nuclear Science and Engineering | Volume 37 | Number 2 | August 1969 | Pages 198-215
Technical Paper | doi.org/10.13182/NSE69-A20679
Articles are hosted by Taylor and Francis Online.
The coherent neutron scattering from polycrystalline graphite is calculated using a sampling method with the Yoshimori-Kitano model and the Young-Koppel force constants. The calculations are compared with experimental results obtained by Carvalho, Eremeev et al., and Whittemore and it is shown that the agreement between the calculations and the experimental results is very good. For Carvalho's experiment, which corrects for multiple scattering, the agreement is good for the range of small momentum transfer (α) while for the experiments of Eremeev et al. the agreement is best for the range of intermediate α. A comparison of the dispersion relation, polarization vector and the dynamical structure factor for the Yoshimori-Kitano model and the Young-Koppel model indicates that the difference in the scattering laws is mainly due to the difference in the dispersion relations. A code called “ONE-PHONON” which uses a sampling method to calculate the scattering law is described. It is suggested that the measurement of the scattering law for each mode in pyrolitic graphite will give valuable information about the lattice dynamics of graphite.