On the simulation of neutron noise induced by vibrations of fuel pins in a fuel assembly
Journal article, 2023

Vibrations of fuel assemblies are an important issue in the safe operation of nuclear reactors, because they can challenge the integrity of the fuel with potential for radioactive releases. Reactor neutron noise-based techniques for monitoring vibrations are valuable for core diagnostic since they are not intrusive and make use of ordinary neutron flux measurements from ex-core and in-core detectors. The application of these techniques involves the solution of inverse problems that require numerical simulations capable of estimating the reactor neutron noise, given a model of the vibrations. For this purpose, several novel reactor neutron noise solvers have been developed in the CORTEX project using either Monte Carlo or deterministic methods, such as the discrete ordinates method, the method of characteristics, and the diffusion approximation. In the current work, these solvers have been scrutinized by computing the neutron noise induced by vibrations of one or multiple fuel pins in a simplified UOX fuel assembly benchmark, via proper variations of macroscopic neutron cross sections. The comparison of these neutron noise solutions obtained from the different methods shows novel insights into the simulation of neutron noise induced by mechanical vibrations, such as the challenges posed by the Monte Carlo method, the impact of the angular discretization on the application of the discrete ordinates method, and the accuracy of the diffusion approximation assessed via the higher-order neutron transport methods.

Monte Carlo

Reactor neutron noise modelling

Deterministic transport methods

Diffusion

Author

Paolo Vinai

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Huaiqian Yi

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Christophe Demaziere

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Amélie Rouchon

University Paris-Saclay

Andrea Zoia

University Paris-Saclay

Antoni Vidal-Ferràndiz

Polytechnic University of Valencia (UPV)

Amanda Carreño

Polytechnic University of Valencia (UPV)

Damian Ginestar

Polytechnic University of Valencia (UPV)

Gumersindo Verdu

Polytechnic University of Valencia (UPV)

Annals of Nuclear Energy

0306-4549 (ISSN) 1873-2100 (eISSN)

Vol. 181 109521

Core monitoring techniques and experimental validation and demonstration (CORTEX)

European Commission (EC) (EC/H2020/754316), 2017-09-01 -- 2021-08-31.

Subject Categories

Energy Engineering

Other Physics Topics

Areas of Advance

Energy

DOI

10.1016/j.anucene.2022.109521

More information

Latest update

12/1/2022