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2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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RIC session focuses on interagency collaboration
Attendees at last week’s 2026 Regulatory Information Conference, hosted by the Nuclear Regulatory Commission, saw extensive discussion of new reactor technologies, uprates, fusion, multiunit deployments, supply chain, and much more.
With the industry in a state of rapid evolution, there was much to discuss. Connected to all these topics was one central theme: the ongoing changes at the NRC. With massively shortened timelines, the ADVANCE Act and Executive Order 14300, and new interagency collaboration and authorization pathways in mind, speakers spent much of the RIC exploring what the road ahead looks like for the NRC.
Jeffrey A. Favorite
Nuclear Science and Engineering | Volume 175 | Number 1 | September 2013 | Pages 44-69
Technical Paper | doi.org/10.13182/NSE12-17
Articles are hosted by Taylor and Francis Online.
It is often desirable to solve radiation transport problems in one-dimensional spherical geometries even if the actual object being modeled is not spherical. It may be possible to use perturbation theory to account for the difference between the real multidimensional system and the spherical approximation. This idea is tested using uncollided as well as multigroup inhomogeneous transport problems with upscattering. Asymmetric and nonuniform perturbations are made to the shielding (not the source) of spherical geometries, including transformations from a sphere to a cube (the surface transformation function is derived), and Schwinger, Roussopolos, and combined perturbation estimates are applied. For uncollided fluxes, perturbation theory, particularly the Schwinger estimate, worked very well when the response of interest was the flux measured at a symmetric spherical 4 detector external to the geometry, but perturbation theory did not work well when the response of interest was the flux measured at a single external point (unless extra care was taken to account for geometric effects). For neutron-induced gamma-ray line fluxes, the Roussopolos estimate worked well when the response of interest was the flux measured at an external 4 detector or an external point detector.