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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. L. Carter, N. J. McCormick
Nuclear Science and Engineering | Volume 39 | Number 3 | March 1970 | Pages 296-310
Technical Paper | doi.org/10.13182/NSE70-A19991
Articles are hosted by Taylor and Francis Online.
A scheme is devised which combines in a coupled manner the sampling from the transport equation and the adjoint transport equation to improve the sampling for a functional such as the space- and velocity-dependent neutron distribution due to a given source distribution. Specific use is made of sampling from the transport equation to construct a scheme for a near-optimal subsequent sampling from the adjoint equation, even when inelastic scattering is present. The energy-dependent reciprocity relation is utilized to relate the solution of the adjoint equation to that of the transport equation itself. This procedure may be expected to be advantageous when the phase-space volume contributing to the functional in the region of interest is smaller than that volume in the source region. Numerical results demonstrate that calculation times in two example problems can be significantly reduced with the coupled sampling approach.