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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
L. M. Gomes, P. N. Stevens
Nuclear Science and Engineering | Volume 114 | Number 3 | July 1993 | Pages 228-237
Technical Paper | doi.org/10.13182/NSE93-A24036
Articles are hosted by Taylor and Francis Online.
Ray effects, an inherent problem in the formulation of the discrete ordinates approximation to the transport equation, are studied. In particular, the effectiveness of using Monte Carlo procedures to generate a first or second collision source is investigated. Monte Carlo procedures provide a general methodology that can be applied to the discrete ordinates solution of complex problems in either two-dimensional or three-dimensional geometries for which ray effects are likely to occur. The Monte Carlo method, which is intrinsically free of ray effects, performs the transport of the source particle to the first collision sites, at which estimates for the uncollided fluxes are made. The uncollided fluxes are then used to compute the first collided fluxes. The uncollided, collided, or first collided fluxes are calculated as first or second collision scattering sources in a format suitable for input into the DORT two-dimensional and TORT three-dimensional discrete ordinates codes. The computational time and precision requirements of the Monte Carlo calculation are analyzed. The results show that significant improvements are achieved in the solution of test problems when using the estimated first collision source and that ray effects are virtually eliminated when using the estimated second collision source.