A New Precursor Integral Method for Solving Space-Dependent Kinetic Equations in Neutronic and Thermal-Hydraulic Coupling System

The accurate prediction of the neutronic and thermal-hydraulic coupling system transient behavior is important in nuclear reactor safety analysis, where a large-scale nonlinear coupling system with strong stiffness should be solved efficiently. In order to reduce the stiffness and huge computational...

Full description

Saved in:
Bibliographic Details
Published in:Science and technology of nuclear installations 2020, Vol.2020 (2020), p.1-15
Main Authors: Cui, Menglei, Niu, Jinlin, Li, Fu, Guo, Jiong, Zhang, Han, Liu, Baokun, Wu, Yingjie, Wang, Yizhen
Format: Article
Language:English
Subjects:
Approximation
Coupling
Error analysis
High temperature gas cooled reactors
Hydraulics
Integrals
Kinetic equations
Mathematical analysis
Model accuracy
Neutron flux
Nuclear engineering
Nuclear reactors
Nuclear safety
Ordinary differential equations
Partial differential equations
Precursors
Reactor safety
Simulation
Stiffness
Truncation errors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The accurate prediction of the neutronic and thermal-hydraulic coupling system transient behavior is important in nuclear reactor safety analysis, where a large-scale nonlinear coupling system with strong stiffness should be solved efficiently. In order to reduce the stiffness and huge computational cost in the coupling system, the high-performance numerical techniques for solving delayed neutron precursor equation are a key issue. In this work, a new precursor integral method with an exponential approximation is proposed and compared with widely used Taylor approximation-based precursor integral methods. The truncation errors of exponential approximation and Taylor approximation are analyzed and compared. Moreover, a time control technique is put forward which is based on flux exponential approximation. The procedure is tested in a 2D neutron kinetic benchmark and a simplified high-temperature gas-cooled reactor-pebble bed module (HTR-PM) multiphysics problem utilizing the efficient Jacobian-free Newton–Krylov method. Results show that selecting appropriate flux approximation in the precursor integral method can improve the efficiency and precision compared with the traditional method. The computation time is reduced to one-ninth in the HTR-PM model under the same accuracy when applying the exponential integral method with the time adaptive technique.
ISSN:1687-6075
1687-6083
DOI:10.1155/2020/8265146