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Conference Spotlight
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.
P. Romstedt, W. Werner
Nuclear Science and Engineering | Volume 92 | Number 1 | January 1986 | Pages 71-83
Technical Paper | doi.org/10.13182/NSE86-A17867
Articles are hosted by Taylor and Francis Online.
The numerical calculation of critical two-phase flow in a convergent-divergent nozzle is complicated by a singularity of the fluid flow equations at the unknown critical point. A method of calculating critical state and its location without any additional assumptions is described. The critical state is identified by its mathematical properties: characteristics and solvability of linear systems with a singular matrix. Because the numerically estimable mathematical properties are the only necessary conditions for the existence of critical flow, some physical “compatibility criteria” (flow velocity equals model-consistent two-phase sonic velocity; critical flow is independent of downstream flow state variations) are used as substitutes for mathematically sufficient conditions. Numerical results are shown for the critical flow through LOBI nozzles and for the Super Moby Dick experiment. The two-phase flow is described by a model with equal phase velocities and thermodynamic nonequilibrium.