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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.
Sara A. Pozzi, Imre Pázsit
Nuclear Science and Engineering | Volume 154 | Number 3 | November 2006 | Pages 367-373
Technical Paper | doi.org/10.13182/NSE06-A2639
Articles are hosted by Taylor and Francis Online.
In a recent paper, a simple analytical model to describe the statistics of the number of scattering collisions undergone by fast neutrons as they slow down until they are absorbed was presented. In that study, it was assumed that the moderator was infinite and homogeneous and accounted for scattering and absorption by a single nuclear species. In the present paper, that methodology is extended to the more realistic case of neutron slowing down in a homogeneous mixture. The formulas are derived and evaluated numerically, and the results are found to be in very good agreement with corresponding Monte Carlo simulations. The average value of the number of collisions that a neutron undergoes before being captured is computed. The results for a capture-gated detector composed of hydrogen, carbon, and boron are discussed.