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Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
Standards Program
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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Latest News
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
H. Guo, G. Martin, L. Buiron (CEA)
Proceedings | 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) | Charlotte, NC, April 8-11, 2018 | Pages 1231-1240
CEA is largely involved in the study of GEN-IV Sodium Fast Reactors (SFR). Some innovative reactivity control systems are proposed such as utilization of different absorbers or moderators materials, modification of absorber pin geometry, and application of burnable neutron poison. These designs possess potentials to improve its safety margin, economical performance or core characteristics while its complete analysis requires notably more accurate calculation of efficiency and evolution of isotopes’ concentrations under irradiation.
At the same time, the new determinist transport code APOLLO3® is under development at CEA and it will replace ERANOS code for fast reactors analysis. The scheme in APOLLO3® is constituted with two steps: sub-assembly calculation and core calculation with Multi-Parametric Output Library as connectors which enable the interpolation of cross-sections according to specific parameter. In this paper, each step and different cross-section scheme are detailed and validated by continuous energy Monte Carlo calculations. These results are also compared with determinist code system ERANOS.
Our works show high adaptability of TDT solver in APOLLO3® to complexes geometries and evolution of isotopes. With the ability of MINARET to treat unstructured mesh, the heterogeneous geometry, keeping absorber pins at core level calculation, improves significantly the calculation of control rods’ efficiency. APOLLO3® compute more accurately core’s reactivity variation with burn-up tabulated cross section scheme. Although variation of spatial self-shielding effect is very significant in absorber depletion, tabulated cross-sections scheme is able to bring this variation from sub-assembly calculation to core calculation. Hence, even homogeneous control rod description at core level shows accurate computation of reactivity variation.
Consequently, with development and validations, APOLLO3® shows improvement on SFR control rods neutronic simulation and analysis. With these new schemes presented in this paper, innovative reactivity control systems designs will be completely characterized and investigated in the near future.
