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.
H. L. McMurry and G. J. Russell and R. M. Brugger
Nuclear Science and Engineering | Volume 25 | Number 3 | July 1966 | Pages 248-260
Technical Paper | doi.org/10.13182/NSE66-A17832
Articles are hosted by Taylor and Francis Online.
Experimental data on the slow-neutron ( < 0.1 eV) scattering of room-temperature water have been obtained using the velocity selector at the Materials Testing Reactor. The data agree with the results of Haywood obtained using a slow-neutron velocity selector, with the results of Kottwitz and Leonard obtained using a triple-axis spectrometer, and with the results of Kirouac obtained using a linear accelerator plus phased chopper. There are marked differences from the results of Sakamoto and co-workers, who used cold neutrons and a rotating crystal spectrometer. An extension of the Nelkin model has been devised that gives calculated results in good agreement with the MTR data, whereas the Nelkin model generally gives poor agreement. The new model treats water as a mixture of 10% of free molecules and 45% each of two aggregates in which the effective masses for H scattering are 75 and 150. Each aggregate has a set of vibrational modes with energies distributed in the range 0 < E ≤ 0.125 eV, and each H2O molecule exhibits the internal modes with characteristic energies of 0.2, 0.45, and 0.46 eV. The amplitudes of the low-energy vibrations are selected so the calculated scattering agrees with the Materials Testing Reactor data. Total cross sections calculated on the new model and the Nelkin model agree quite well with the data. The new model gives values of the average cosine of the scattering angle that are closer to the data than those calculated by the Nelkin model, but the calculated results are always higher than the data. At very low neutron energies, the present Nelkin model calculations give total cross sections that are lower than those reported by Koppel and Young using essentially the same model. The reason for this is not known.