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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. E. Slovacek, D. S. Cramer, E. B. Bean, J. R. Valentine, R. W. Hockenbury, R. C. Block
Nuclear Science and Engineering | Volume 62 | Number 3 | March 1977 | Pages 455-462
Technical Paper | doi.org/10.13182/NSE77-A26984
Articles are hosted by Taylor and Francis Online.
The 238U(n,f) cross section has been measured from 3 eV to ≃ 100 keV with the Rensselaer Intense Neutron Spectrometer, a 75-ton lead slowing down spectrometer at the Gaerttner Laboratory at Rensselaer Polytechnic Institute. Four fission ionization chambers containing a total of ≃ 0.8 g of 238U (4.1 ppm 235U) were used for the measurements. The fission widths of the 6.67-, 20.9-, and 36.8-eV resonances were measured as (10 ± 1), (58 ± 9), and (12 ±2) neV, respectively. By combining these fission results and published resonance parameters, the 238U thermal fission cross-section contribution from positive energy resonances was determined to be (2.7 ± 0.3) µb. The resonance fission integral from 0.4 eV to 100 keV was determined to be (1.30 ±0.15) mb.
