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.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
May 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
Fusion Science and Technology
Latest News
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.
Y. Namito, S. Ban, H. Hirayama
Nuclear Science and Engineering | Volume 120 | Number 3 | July 1995 | Pages 199-210
Technical Paper | doi.org/10.13182/NSE95-A24119
Articles are hosted by Taylor and Francis Online.
The effects of including linear polarization and Doppler broadening of the Compton-scattered photon energy, i.e., the Compton profile, in a calculation of the exposure buildup factors for plane normal gamma-ray sources are investigated by using an improved electron gamma shower Monte Carlo code, EGS4, for water, iron, and lead in the 40- to 250-keV range for penetration depths of up to 16 mean free paths (mfp). The effects of including the bound Compton total cross section (&sigmabC) and the bound Compton-scattered photon angular distribution by using the incoherent-scattering function [S(x, Z)] were also evaluated. The “pseudo” exposure buildup factors were calculated to determine these effects combined with the effects of Rayleigh and/or Compton scattering. The pseudo exposure buildup factor increases at points farther than a few mfp’s and decreases in the neighborhood of the source upon including linear polarization. It decreases upon including Doppler broadening. The degree of each effect varies with the atomic number of the material. The effect of linear polarization is large for materials of small atomic number; that of the Doppler broadening is large for materials of medium and large atomic number.