Nuclear Reactor Core Modeling Sparse Eigensystem Convergence
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Solution Overview
Problem
Current methods for modeling nuclear reactor cores face challenges in achieving accurate and efficient neutron flux calculations due to slow convergence and high computational efforts, particularly with Coarse Mesh Rebalancing procedures that depend on the proximity of the coarse mesh level to the full-core diffusion level.
Innovation Solution
A computer-implemented method for modeling nuclear reactor cores that partitions the core into cubes for grid-based calculations, using an iterative eigensystem solving procedure that conditions the system into a sparse eigensystem focusing on neutron incurrents or outcurrents, with operators defined to couple currents and fluxes, allowing for improved convergence accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Coarse Mesh Rebalancing procedures are used to accelerate eigensystem solving, then computational efficiency is improved, but convergence accuracy deteriorates and may lead to convergence stagnation
Solution Approach 1:
The invention transforms the original eigensystem into a spare eigensystem by changing the mathematical parameters and structure of the system. This transformation modifies the eigenvalue problem to eliminate the fundamental wavelength component, allowing for better convergence properties while maintaining computational efficiency through the altered system parameters
2Measurement precision
If iterative solving procedure is used for neutron flux calculation, then measurement precision is improved, but loss of time increases due to slow convergence
Solution Approach 1:
The invention extracts and eliminates the fundamental wavelength part of the eigenspectrum from the iterative solving process. By removing this problematic component that causes slow convergence, the remaining system can be solved iteratively with much faster convergence rates, reducing computational time while preserving the accuracy needed for neutron flux calculations
Data Source
AI summary
A computer implemented method for modelizing a nuclear reactor core, includes the steps of: partitioning the core in cubes to constitute nodes of a grid for computer implemented calculation, calculating neutron flux by using an iterative solving procedure of at least one eigensystem, the components of an iterant of the eigensystem corresponding either to a neutron flux, to a neutron outcurrent or to a neutron incurrent, for a respective cube to be calculated.The eigensystem iterative solving procedure includes a substep of conditioning the eigensystem into a spare eigensystem wherein the components of an iterant of the spare eigensystem correspond only either to neutron incurrents coming into the cubes or to neutron outcurrents coming from the cubes.