Saved in:
Bibliographic Details
Main Authors: Caprais, Mathis, Bergeron, André, Greiner, Nathan, Tomatis, Daniele
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2410.19476
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909365094580224
author Caprais, Mathis
Bergeron, André
Greiner, Nathan
Tomatis, Daniele
author_facet Caprais, Mathis
Bergeron, André
Greiner, Nathan
Tomatis, Daniele
contents In nuclear reactors, Delayed Neutron Precursors (DNPs) are important for reactor safety and operation. In liquid nuclear fuels, DNPs are transported by the flow, and an advection-reaction balance equation for their concentration must be solved in addition to the Neutron Balance Equation. This research paper applies the method of characteristics to solve the DNPs equation, using techniques previously developed in petroleum engineering and groundwater analysis. The calculation strategy incorporates a pathline generation algorithm covering all the mesh cells of the geometry for concentration calculations, and pathlines are reconstructed for both step and piecewise linear velocity fields. The analytical solutions are used on a Cartesian mesh to compute the DNPs concentrations assuming a step source of DNPs. The results obtained on the steady state phases of a benchmark problem illustrate this new method's capability to solve advection-dominated problems in liquid-fueled reactors. The method developed in this work is suited to smooth velocity fields (e.g., laminar or RANS flows) where pathlines can be tracked, and where DNP diffusivity is negligible.
format Preprint
id arxiv_https___arxiv_org_abs_2410_19476
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A new calculation method using pathlines for delayed neutron precursors in liquid nuclear fuels
Caprais, Mathis
Bergeron, André
Greiner, Nathan
Tomatis, Daniele
Computational Physics
In nuclear reactors, Delayed Neutron Precursors (DNPs) are important for reactor safety and operation. In liquid nuclear fuels, DNPs are transported by the flow, and an advection-reaction balance equation for their concentration must be solved in addition to the Neutron Balance Equation. This research paper applies the method of characteristics to solve the DNPs equation, using techniques previously developed in petroleum engineering and groundwater analysis. The calculation strategy incorporates a pathline generation algorithm covering all the mesh cells of the geometry for concentration calculations, and pathlines are reconstructed for both step and piecewise linear velocity fields. The analytical solutions are used on a Cartesian mesh to compute the DNPs concentrations assuming a step source of DNPs. The results obtained on the steady state phases of a benchmark problem illustrate this new method's capability to solve advection-dominated problems in liquid-fueled reactors. The method developed in this work is suited to smooth velocity fields (e.g., laminar or RANS flows) where pathlines can be tracked, and where DNP diffusivity is negligible.
title A new calculation method using pathlines for delayed neutron precursors in liquid nuclear fuels
topic Computational Physics
url https://arxiv.org/abs/2410.19476