Analysis of Fission Matrix Databases using Temperature Profiles obtained from High-Fidelity Multiphysics Simulations

TL;DR

This paper investigates how the choice of temperature profiles in fission matrix databases affects simulation accuracy, demonstrating that profiles from high-fidelity simulations improve results for Molten Salt Fast reactors.

Contribution

It introduces an analysis of temperature profile selection in fission matrix database construction, highlighting the benefits of using high-fidelity simulation data.

Findings

Using realistic temperature profiles improves multiplication factor accuracy.

Fission source distribution is more accurate with high-fidelity temperature data.

Uniform temperature profiles lead to less accurate reactor modeling.

Abstract

The Fission Matrix method is used to perform fast and still accurate neutronics simulations. It relies on precalculated databases obtained through a Monte Carlo simulation. To represent every state of the reactor, multiple databases are required. The actual state of the reactor is obtained from those databases. In this paper, we analyze the effect of the temperature profiles selected to construct the databases. To do so, the Molten Salt Fast reactor is selected. Two sets of databases are studied: the first uses temperature profiles obtained from high-fidelity Multiphysics simulations with Cardinal, and the second uses uniform temperature profiles. Results showed improved multiplication factor and fission source distribution when the temperature profiles used to generate the databases were similar to those expected when solving the fission matrix.