Nodal Green’s Function Method Singular Source Term and Burnable Poison Treatment in Hexagonal Geometry

Bingham, A.A. ; Ferrer, R.M. ; ougouag, A.M.

Idaho National Laboratory

关键词: Neutron Diffusion Model;    Diffusion;    Neutron Diffusion Equation;    Burnable Poisons;    Neutrons;   

DOI  :  10.2172/983357
RP-ID  :  INL/EXT-09-16773
RP-ID  :  DE-AC07-05ID14517
RP-ID  :  983357

美国|英语

来源: UNT Digital Library

【 摘 要 】

An accurate and computationally efficient two or three-dimensional neutron diffusion model will be necessary for the development, safety parameters computation, and fuel cycle analysis of a prismatic Very High Temperature Reactor (VHTR) design under Next Generation Nuclear Plant Project (NGNP). For this purpose, an analytical nodal Green’s function solution for the transverse integrated neutron diffusion equation is developed in two and three-dimensional hexagonal geometry. This scheme is incorporated into HEXPEDITE, a code first developed by Fitzpatrick and Ougouag. HEXPEDITE neglects non-physical discontinuity terms that arise in the transverse leakage due to the transverse integration procedure application to hexagonal geometry and cannot account for the effects of burnable poisons across nodal boundaries. The test code being developed for this document accounts for these terms by maintaining an inventory of neutrons by using the nodal balance equation as a constraint of the neutron flux equation. The method developed in this report is intended to restore neutron conservation and increase the accuracy of the code by adding these terms to the transverse integrated flux solution and applying the nodal Green’s function solution to the resulting equation to derive a semi-analytical solution.