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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.
D. R. Alexander, M. S. Krick
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 627-635
Technical Paper | doi.org/10.13182/NSE77-A15206
Articles are hosted by Taylor and Francis Online.
The total delayed neutron yield from 235U was calculated as a function of the energy of the neutron inducing fission. The calculations (based on fission data and fission systematics) extend from thermal to 15-MeV neutron energies. The energy-dependent delayed neutron calculations are generally consistent with experimental results from thermal to 14-MeV neutron energies. Delayed neutron yields per 104 fissions of 168.7 ± 16.7, 178.2 ± 17.2, and 88.9 ± 10.0 were obtained at thermal, fission-spectrum, and 15-MeV neutron energies, respectively. The energy dependence of the odd-even effect in the fission charge distribution was found to partially account for the near constant yield observed below 5-MeV neutron energy, as well as the rapid decrease in yield observed at the second-chance fission threshold.
