A Linear Discontinuous Finite Difference Formulation for Synthetic Coarse-Mesh Few-Group Diffusion Calculations

The Analytic Coarse-Mesh Finite Difference Method for Multigroup and Multidimensional Diffusion Calculations

“…We also applied them in the mid-1980s as the basis of our synthetic lineardiscontinuous coarse-mesh finite difference method. 13,14 More recently, Chao introduced the general ACMFD method 1 and reviewed it in comparison with other previous approximations. 15 The decoupled modal space approach by a similarity transformation has also been extensively developed and successfully applied by Noh and Cho 16 ; Cho, Kim, and Park 17 ; and Woo, Cho, and Noh 18 in their analytic function expansion nodal method for multigroup and multidimensional reactor diffusion analysis.…”

“…Comparisons were made between the results obtained with the 2-D fine-mesh transport-corrected diffusion COBAYA code, 14 where the reflector is explicitly taken into account, and those obtained with the 2-D nodal SIMULA2D code, where the response matrices are used to obtain the boundary conditions in the core surroundings. Errors in power distributions due to the model implementation for the first cycle of the Ascó-II NPP are shown in Table V.…”

Methods and Results for the MSLB NEA Benchmark Using SIMTRAN and RELAP-5

“…It solves the neutron diffusion equations, in one or two groups, on coarse-mesh nodes~quarters of fuel assemblies! using a linear-discontinuous finite-difference scheme, 6 where the interface net currents are given in terms of the actual node average and the corrected interface averaged fluxes, using synthetic interface flux discontinuity factors for each group and node interface. SIMULA uses these synthetic coarse-mesh discontinuity factors, in the XY directions, precalculated by twodimensional~2-D!…”

“…1 through 5). It was developed as a single code merge, with data sharing through standard Fortran commons, of our 3-D neutronkinetics (NK) nodal code 6 SIMULA and the multichannel, with cross flows, thermal-hydraulics (TH) code 7 COBRA-*E-mail: arago@din.upm.es IIIC/MIT-2. Both codes solve the 3-D NK and TH fields with maximum implicitness, using direct and iterative methods for the inversion of the linearized systems.…”

Generación de librerías optimizadas con cuantificación de incertidumbres para cálculos realistas (BEPU) de reactores nucleares de agua ligera

“…Aragonés y C. Ahnert, ha venido desarrollando durante las últimas décadas una labor de investigación dirigida a desarrollar códigos de cálculo destinados al análisis y diseño de núcleos de agua ligera [1,5]. Esta larga experiencia investigadora está reflejada en el Sistema Español de Análisis de Núcleos de Agua a Presión (SEANAP) [2,3,29,18] implantado en varias centrales nucleares de España (Ascó I y II y Vandellós II).…”