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Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
Sicong Xiao, Kangyu Ren, Dean Wang
Nuclear Science and Engineering | Volume 189 | Number 3 | March 2018 | Pages 272-281
Technical Paper | doi.org/10.1080/00295639.2017.1394088
Articles are hosted by Taylor and Francis Online.
In order to improve the effectiveness and stability of the coarse-mesh finite difference method (CMFD), we developed a new nonlinear diffusion acceleration scheme for solving neutron transport equations. This scheme, called LR-NDA, employs a local refinement approach on the framework of CMFD by solving a local boundary value problem of the scalar flux on the coarse-mesh structure to replace the piecewise constant scalar flux obtained by CMFD. The refined flux is then used to update the scalar flux in the neutron transport source iteration. In this paper, a detailed convergence study of LR-NDA is carried out based on a two-dimensional fixed-source problem, and it shows that LR-NDA is much more effective and stable than CMFD for a wide range of optical thicknesses. In addition, we demonstrate that LR-NDA is a local adaptive method. LR-NDA does not necessarily require local refinement for all the coarse-mesh cells on the problem domain, i.e., it can be used only for relatively optically thick regions where the standard CMFD scheme would encounter the convergence problem.