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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.
Chang-Ho Lee, Thomas J. Downar
Nuclear Science and Engineering | Volume 146 | Number 2 | February 2004 | Pages 176-187
Technical Paper | doi.org/10.13182/NSE04-A2401
Articles are hosted by Taylor and Francis Online.
A hybrid nodal diffusion/simplified P3 (SP3) method was implemented within the framework of a one-node coarse-mesh finite difference formulation. The one-node formulation enables the use of various combinations of space, energy, and angular approximations within the framework of the one-node global/local solution approach. Spatial approximations include advanced nodal methods and fine-mesh finite difference methods. Energy approximations involve conventional two-group and multiple energy groups. Angular approximations contain both the diffusion and SP3 methods. Partial-moment boundary conditions are used to solve the one-node problems since they simplify the formulation of consistent interface conditions for the various methods. All directional moments are determined simultaneously to stabilize convergence of the one-node global/local solution approach. Results for a light water reactor mixed-oxide benchmark problem indicate that the hybrid application of the one-node-based nodal SP3 method developed here can provide substantial reductions in the computational time without compromising the accuracy of the solution.