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2026 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
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Front-end nuclear fuel supply cooperation: Turning allied interdependence into strategic advantage
The global nuclear revival, which is fueled by unprecedented demand for firm, affordable, dispatchable power for artificial intelligence and data center build-out, energy security imperatives, and climate commitments, has exposed a structural reality of the Western fuel cycle: No single allied nation currently possesses the full suite of front-end capabilities. From mining through conversion, enrichment, fabrication, and the emerging deconversion and metallization steps required for reactor fuels, capability is distributed across Canada, France, Japan, the United Kingdom, and the United States (collectively, the “Sapporo Five”), as well as a small group of close partners.
K. D. Lathrop
Nuclear Science and Engineering | Volume 45 | Number 3 | September 1971 | Pages 255-268
Technical Paper | doi.org/10.13182/NSE45-03-255
Articles are hosted by Taylor and Francis Online.
Remedies are considered for the ray effect, a flux distortion producing defect of the discrete ordinates approximation to the transport equation. The partially effective remedies of increasing the number of directions, selecting quadrature sets invariant under discrete rotations, and introducing coupling terms into the representation of the transport divergence operator are considered. Numerical results are presented showing the effectiveness of these remedies in a standard test problem. Remedies that eliminate the ray effect are also considered. We show how to formulate multidimensional discrete ordinate equations equivalent to spherical harmonic equations and relate the order of the equivalent spherical harmonic equations to the degree of precision of the numerical quadrature. We give numerical results for this kind of remedy in three test problems, including one with material discontinuities. We show how the use of orthonormal polynomials permits the formulation of discrete ordinates approximations which have properties “like” those of the highest order spherical harmonic equations consistent with the number of directions in the discrete ordinates approximation. We find that these formulations also eliminate ray effects. We conclude that the partially effective remedy of using more, specially chosen, directions is the most practical remedy for most applications, but that for especially difficult situations or for reference calculations, the defect-eliminating spherical harmonic-like formulations should be available for use.