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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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
Woong Heo, Yonghee Kim
Nuclear Science and Engineering | Volume 189 | Number 1 | January 2018 | Pages 41-55
Technical Paper | doi.org/10.1080/00295639.2017.1373516
Articles are hosted by Taylor and Francis Online.
Thermomechanical effects, irradiation, and structural restrictions result in very tangled behavior of assemblies in sodium-cooled fast reactors (SFRs). Reactivity feedback caused by the assembly behavior (deformation or distortion) is one of the key parameters in the inherent safety analysis of fast reactor systems. However, to date there has been no accurate and efficient deterministic way to compute directly the reactivity changes by actual local perturbation. This paper evaluates the feasibility of applying the Galerkin finite element method (GFEM) based on linear shape functions to estimate reactivity changes due to local core deformations in SFRs. Assessment of reactivity changes is conducted for six types of deformation scenarios of the two-dimensional prototype Gen-IV SFR. Uniform expansions and local deformations are included in the scenarios. The results from the multigroup diffusion equation based on the GFEM are compared with references calculated by MCNP5. The study shows that diffusion analysis based on the GFEM with linear shape functions can properly estimate reactivity changes by core deformation in the fast reactor with ~13% relative error of Δρ.
