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NRC proposes changes to its rules on nuclear materials
In response to Executive Order 14300, “Ordering the Reform of the Nuclear Regulatory Commission,” the NRC is proposing sweeping changes to its rules governing the use of nuclear materials that are widely used in industry, medicine, and research. The changes would amend NRC regulations for the licensing of nuclear byproduct material, some source material, and some special nuclear material.
As published in the May 18 Federal Register, the NRC is seeking public comment on this proposed rule and draft interim guidance until July 2.
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.