Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30127
Improved Neutron Leakage Treatment on Nodal Expansion Method for PWR Reactors

Authors: Antonio Carlos Marques Alvim, Fernando Carvalho da Silva, Aquilino Senra Martinez

Abstract:

For a quick and accurate calculation of spatial neutron distribution in nuclear power reactors 3D nodal codes are usually used aiming at solving the neutron diffusion equation for a given reactor core geometry and material composition. These codes use a second order polynomial to represent the transverse leakage term. In this work, a nodal method based on the well known nodal expansion method (NEM), developed at COPPE, making use of this polynomial expansion was modified to treat the transverse leakage term for the external surfaces of peripheral reflector nodes. The proposed method was implemented into a computational system which, besides solving the diffusion equation, also solves the burnup equations governing the gradual changes in material compositions of the core due to fuel depletion. Results confirm the effectiveness of this modified treatment of peripheral nodes for practical purposes in PWR reactors.

Keywords: Transverse leakage, nodal expansion method, power density, PWR reactors

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1079176

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1563

References:


[1] W. M. Stacey, Nuclear Reactor Physics, Wiley-VCH, Weinheim, Germany (2004)
[2] H. Finnemann, F. Benneritz and M. R. Wagner, "Interface current techniques for multidimensional reactor calculations" Atomkernenergie 30, 123 (1977)
[3] F. C. Silva, A. C. M. Alvim and A. S. Martinez, "An Alternative Solver for the Nodal Expansion Method Equations" PHYSOR 2010 - Advances in Reactor Physics to Power the Nuclear Renaissance, Pittsburgh, Pennsylvania, USA (2010)
[4] A. S. Martinez, V. Pereira and F. C. da Silva, "A system for the prediction and determination of subcritical multiplication condition" Kerntechinik 64, 230 (1999)
[5] M. R. Wagner, K. Koebke and H. J. Winter, "A nonlinear extension of the nodal expansion method" Proceedings of ANS/ENS International Topical Meeting, Munich, Germany, 2, 43 (1981)
[6] H. D. Fischer and H. Finnemann, "The Nodal Integration Method - A Diverse Solver for Neutron Diffusion problems" Atomkernenergie- Kerntechnik, 30, 229 (1981)
[7] H. K. Joo, C. H. Kim, J. M. Noh and S. Kim, "A Semi-Analytic Multigroup Nodal Method" Annals of Nuclear Energy, 26, 699 (1999)
[8] B. Christensen, "Three-dimensional static and dynamic reactor calculations by the nodal expansion method" RISO National Laboratory DK-4000, Roskild, Denmark (1985)
[9] A. C. M. Alvim, F. C. Silva and A. S. Martinez, "Depletion Calculation for a Nodal Reactor Physics Code" ICONE 18 - 18th International Conference on Nuclear Engineering, Xi'an, China (2010)