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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.
H. Märten, D. Richter, D. Seeliger, W. D. Fromm, R. Böttger, H. Klein
Nuclear Science and Engineering | Volume 106 | Number 3 | November 1990 | Pages 353-366
Technical Paper | doi.org/10.13182/NSE90-A29063
Articles are hosted by Taylor and Francis Online.
The 252Cf neutron spectrum is measured at high energies with a miniature ionization chamber and two different NE-213 neutron detectors. The gamma-ray background and the main cosmic background caused by muons were suppressed by applying efficient pulse-shape discrimination. On the basis of two-dimensional spectroscopy of the neutron time-of-flight and scintillation pulse height, the sliding bias method is used to minimize experimental uncertainties. The experimental data, corrected for several systematic influences, confirm earlier results that show negative deviations from a reference Maxwellian distribution with a 1.42-MeV spectrum “temperature” for neutron energies above 6 MeV. Experimental results of this work are compared with various statistical model approaches to the 252Cf(sf) neutron spectrum.