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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.
Greg Wojtowicz, James Paul Holloway
Nuclear Science and Engineering | Volume 121 | Number 1 | September 1995 | Pages 89-102
Technical Paper | doi.org/10.13182/NSE95-A24131
Articles are hosted by Taylor and Francis Online.
A variational coarse-mesh technique is developed for the solution of the multigroup neutron transport equation in one-dimensional reactor lattices. In contrast to conventional nodal lattice applications that discretize diffusion theory and use node homogenized cross sections, the methods used here retain the spatial dependence of the cross sections and instead employ an alternative flux representation, a slowly modulated pin cell flux, that allows the neutron transport equation to be cast into a form whose solution has a relatively slow spatial and angular variation and that can be accurately described with relatively few variables. This alternative flux representation and the stationary property of a variational principle define a class of coarse-mesh discretizations of transport theory that are capable of achieving order-of-magnitude reductions of eigenvalue and pointwise scalar flux errors compared with diffusion theory while retaining the relatively low cost of diffusion theory.