A Variational Nodal Approach to 2D/1D Pin Resolved Neutron Transport for Pressurized Water Reactors. (4th May 2017)

• Record Type: Journal Article
• Authors: Zhang, Tengfei; Lewis, E. E.; Smith, M. A.; Yang, W. S.; Wu, Hongchun
• Is Part Of: Nuclear science and engineering. Volume 186:Number 2(2017)
• Page Start: 120
• Page End: 133
• Publication Date: 2017-05-04
• Subjects: 2D/1D variational nodal method -- eliminating the interface homogenization; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; Nuclear energy; Nuclear engineering; Periodicals; 539.705
• DOI: 10.1080/00295639.2016.1273023
• Languages: English
• ISSNs: 0029-5639

Abstract

Abstract: A two-dimensional/one-dimensional (2D/1D) variational nodal approach is presented for pressurized water reactor core calculations without fuel-moderator homogenization. A 2D/1D approximation to the within-group neutron transport equation is derived and converted to an even-parity form. The corresponding nodal functional is presented and discretized to obtain response matrix equations. Within the nodes, finite elements in the x-y plane and orthogonal functions in z are used to approximate the spatial flux distribution. On the radial interfaces, orthogonal polynomials are employed; on the axial interfaces, piecewise constants corresponding to the finite elements eliminate the interface homogenization that has been a challenge for method of characteristics (MOC)–based 2D/1D approximations. The angular discretization utilizes an even-parity integral method within the nodes, and low-order spherical harmonics (PN ) on the axial interfaces. The x-y surfaces are treated with high-order PN combined with quasi-reflected interface conditions. The method is applied to the C5G7 benchmark problems and compared to Monte Carlo reference calculations.