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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.
F. E. LeVert, M. A. Schultz
Nuclear Science and Engineering | Volume 49 | Number 2 | October 1972 | Pages 188-201
Technical Paper | doi.org/10.13182/NSE72-A35506
Articles are hosted by Taylor and Francis Online.
Local measurements of the inherent fluctuations in the gamma-ray density at specific locations in the core of the Pennsylvania State Triga Reactor have been conducted using two externally located detectors. Local power was determined for positions up to the center of the core from a distance of approximately 200 cm by measuring the zero-time cross correlation function in small intervals. Voids introduced by the removal of single fuel elements were readily located and mapped. Single collimator dc scans along diagonal rows in the core were successful in resolving the individual rows of fuel in the core. A comparison between the neutron distribution predicted by two dimensional multi-group diffusion theory and a single collimator measurement showed very good agreement in their respective shapes. Cospectral densities were obtained for the two cases where the collimators focused on and off a volume of fuel in the core. The frequency response data indicated, when interpreted in terms of an analytical model, that the observed output fluctuations were caused by temperature and coolant flow input fluctuations.