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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.
Roberto Orsi
Nuclear Science and Engineering | Volume 157 | Number 1 | September 2007 | Pages 110-116
Computer Code Abstract | doi.org/10.13182/NSE07-A2716
Articles are hosted by Taylor and Francis Online.
This paper aims to stimulate research and to focus the attention of deterministic radiation transport code developers and users on further methodologies in transport analysis that some recent additions to the code package BOT3P potentially make possible in structured Cartesian or cylindrical mesh grids simulating complex geometries. In particular, BOT3P Version 5.0 can compute the possible area/volume error of material zones due to the stair-cased geometrical representation and automatically correct material densities in order to conserve masses, as described in a previous BOT3P paper published in Volume 154, Number 2 of Nuclear Science and Engineering to which the present one is logically and strictly related. When calculating areas and volumes refinements or when reducing the problem sizes of a voxelized geometry, typical of medical applications, BOT3P generates binary files that store also a fine submesh grid for each coarse cell at material interfaces. These files were originally conceived only for density correction computation and plotting purposes. However, the availability of such cell data intuitively suggests multistep transport analysis approaches that may combine detailed solutions at material interfaces with acceptable problem sizes and computational times. Reaching this appealing target could let deterministic codes based on structured mesh grid successfully deal with any challenging geometry problem. That might be particularly useful in medical and reactor applications.