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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.
David Bernard, Olivier Fabbris, Romain Gardet
Nuclear Science and Engineering | Volume 179 | Number 3 | March 2015 | Pages 302-312
Technical Paper | doi.org/10.13182/NSE13-104
Articles are hosted by Taylor and Francis Online.
Three similar experiments performed in the 8-MW(thermal) MELUSINE experimental power pool reactor aimed at analyzing 1 GWd/tonne HM spent fuel pellets doped with several actinides and fission products. The goal was to measure the energy-integrated neutron-induced capture cross section in three different neutron spectra (from pressurized water reactor–like to undermoderated ones). This paper summarizes the combined deterministic APOLLO2 and stochastic TRIPOLI4 analysis using the JEFF-3.1.1 European nuclear data library. Very good agreement is observed for most neutron-induced capture cross sections of actinides except for a clear underestimation of 241Am(n,γ). An accurate value of its associated isomeric branching ratio is also suggested. A resonant fluctuation (factor of 2.7 between the two available excited levels regarding the l = 0 total orbital momenta) is suggested for this isomeric branching capture ratio. Finally, a precise value (more accurate than the reported JEFF-3.1.1 one) of the decay branching ratio of 242gAm(β+/ε) is deduced: 0.171 ± 0.001.
