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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.
R. D. McKnight
Nuclear Science and Engineering | Volume 75 | Number 1 | July 1980 | Pages 111-125
Technical Note | doi.org/10.13182/NSE80-A20322
Articles are hosted by Taylor and Francis Online.
A detailed validation study of the SDX fast reactor cell homogenization code, Benoist anisotropic diffusion coefficients, and an associated three-dimensional to one-dimensional unit cell modeling procedure has been in progress. These earlier results have investigated the standard zero power reactor (ZPR) plate-type unit cell The present study represents a complimentary validation effort for the ZPR pin calandria-type unit cell. The unit cell loading selected for this work consisted of a 5.08- × 5.08- × 30.48-cm voided calandria loaded with a 4 × 4 array of 0.957-cm (diam) × 15.24-cm mixed-oxide rods (15% PuO2/UO2). This unit cell was used in the pin zone measurements of the ZPR gas-cooled fast reactor program and also in the sodium-voided pin zone measurements of ZPR-6 Assembly 7. The validation effort consists of direct comparison with results of VIM (continuous energy Monte Carlo) calculations. The SDX/Gelbard methods have been shown to adequately predict both nonleakage and leakage effects for the voided pin calandria unit cell.
