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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.
A. Sanchez, A. dos Santos
Nuclear Science and Engineering | Volume 131 | Number 3 | March 1999 | Pages 387-400
Technical Paper | doi.org/10.13182/NSE99-A2041
Articles are hosted by Taylor and Francis Online.
A new methodology that is applicable to individual nuclides is developed for the determination of the intermediate resonance (IR) parameters in the multigroup formalism. The method keeps the main steps commonly used for the determination of these parameters and is compatible with the methods utilized for the generation of the multigroup libraries for thermal and epithermal reactors. The proposed method does not impose any restriction on the formalism used to describe the resonances. Use is made of the computational approach used by the GROUPR module of the NJOY system (flux calculator option). A numerical scheme is presented to determine the IR parameters by means of an iterative approach. Numerical results for the IR parameters in a heterogeneous system composed of UO2 (238U only) and hydrogen as an external moderator are reported as a function of the dilution 0, heterogeneity factor , and temperature T for several epithermal groups of the MUFT structure. The results are consistent, as shown by the consistency checks performed.
