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September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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DOE issues new NEPA rule and procedures—and accelerates DOME reactor testing
Meeting a deadline set in President Trump’s May 23 executive order “Reforming Nuclear Reactor Testing at the Department of Energy,” the DOE on June 30 updated information on its National Environmental Policy Act (NEPA) rulemaking and implementation procedures and published on its website an interim final rule that rescinds existing regulations alongside new implementing procedures.
A. G. Buchan, C. C. Pain, M. D. Eaton, A. J. H. Goddard, R. P. Smedley-Stevenson
Nuclear Science and Engineering | Volume 159 | Number 2 | June 2008 | Pages 127-152
Technical Paper | doi.org/10.13182/NSE159-127
Articles are hosted by Taylor and Francis Online.
This paper presents two new methods for discretizing the angular dimension of the Boltzmann transport equation that describes the transport of neutral particles such as neutrons and photons. Our methods represent the direction of particle travel using linear and quadratic varying approximations over a quadrilateral partitioning of the unit sphere's surface (which is used to represent a particle's direction), which is similar to the approximations provided by a finite element expansion. However, our approximations are generated using a second generation spherical wavelet technique. This method generates hierarchical sets of compactly supported basis functions that are important properties for our future work in applying adaptive resolution in the transport equation's angular dimension. These new wavelet methods are applied to five monoenergetic transport problems to demonstrate their capabilities to efficiently represent the angular flux. Particular emphasis is placed on their ability to approximate particle transport in problems involving extreme material cross sections, namely, particle streaming through voids and their transport through highly scattering media. We are able to show that the methods work well against the common methods SN and PN when used within established radiation transport codes.