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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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.
Pietro Mosca, Claude Mounier, Richard Sanchez, Gilles Arnaud
Nuclear Science and Engineering | Volume 167 | Number 1 | January 2011 | Pages 40-60
Technical Paper | doi.org/10.13182/NSE10-10
Articles are hosted by Taylor and Francis Online.
Users' demands for multigroup transport calculations are wide and diverse, encompassing routine, rough, and fast calculations as well as very precise simulations. For these reasons, the use of accurate and efficient multigroup cross-section libraries is needed. In this work, we present an adaptive energy mesh constructor (AEMC) that builds a multigroup mesh from predefined requisites of precision and calculation time. For a given self-shielding model and number of groups, AEMC looks for the optimal bounds of a multigroup mesh that minimizes the errors of the multigroup transport solutions for a predefined set of infinite homogeneous medium problems. We have applied this methodology to define two energy meshes for fast sodium reactor applications: a 600-group mesh associated with an extension of the Livolant-Jeanpierre self-shielding method and a 1200-group mesh based on subgroup self-shielding. Tests in homogeneous media prove that the multigroup solutions are almost equivalent to Monte Carlo simulations. Simplified one-dimensional transport calculations confirm the accuracy of the 1200-group mesh and show that this mesh provides a precision similar to that obtained with the well-validated 1968-group ECCO mesh. The same tests reveal that the 600-group mesh optimized for subgroup self-shielding offers a good compromise between simulation time and precision.