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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.
L. P. Geraldo, L. A. Vinhas, M. T. F. Cesar
Nuclear Science and Engineering | Volume 89 | Number 2 | February 1985 | Pages 150-158
Technical Paper | doi.org/10.13182/NSE85-A18189
Articles are hosted by Taylor and Francis Online.
The photodisintegration of 237Np has been studied using monochromatic photons produced by thermal neutron capture in several materials. The partial cross sections σγ, f and σγ, n were measured in the energy interval from 5.43 to 10.83 MeV. Analyzing the photofission data according to the liquid drop model, the height (Ef) and the curvature (ℏω) of the simple fission barrier were determined: Ef = (5.9 ± 0.2) MeV and ℏ;ω = (0.8 ± 0.4) MeV. For the competition between photoneutron emission and fission (Γn/Γf), a constant value was found (1.28 ± 0.15) in the 6.73- to 10.83-MeV energy range. From this result the following nuclear temperatures for 237Np were extracted on bases of some models of level density: T = 0.84 ± 0.06 MeV (Fujimoto-Yamaguchi model) and T = 0.60 ± 0.04 MeV (constant nuclear temperature model).