Modeling noise experiments performed at AKR-2 and CROCUS zero-power reactors
Journal article, 2023
CORTEX is a EU H2020 project (2017-2021) devoted to the analysis of ’reactor neutron noise’ in nuclear reactors, i.e. the small fluctuations occurring around the stationary state due to external or internal disturbances in the core. One important aspect of CORTEX is the development of neutron noise simulation codes capable of modeling the spatial variations of the noise distribution in a reactor. In this paper we illustrate the validation activities concerning the comparison of the simulation results obtained by several noise simulation codes with respect to experimental data produced at the zero-power reactors AKR-2 (operated at TUD, Germany) and CROCUS (operated at EPFL, Switzerland). Both research reactors are modeled in the time and frequency domains, using transport or diffusion theory. Overall, the noise simulators managed to capture the main features of the neutron noise behavior observed in the experimental campaigns carried out in CROCUS and AKR-2, even though computational biases exist close to the region where the noise-inducing mechanical vibration was located (the so-called ”noise source”). In some of the experiments, it was possible to observe the spatial variation of the relative neutron noise, even relatively far from the noise source. This was achieved through reduced uncertainties using long measurements, the installation of numerous, robust and efficient detectors at a variety of positions in the near vicinity or inside the core, as well as new post-processing methods. For the numerical simulation tools, modeling the spatial variations of the neutron noise behavior in zero-power research reactors is an extremely challenging problem, because of the small magnitude of the noise field; and because deviations from a point-kinetics behavior are most visible in portions of the core that are especially difficult to be precisely represented by simulation codes, such as experimental channels. Nonetheless the limitations of the simulation tools reported in the paper were not an issue for the CORTEX project, as most of the computational biases are found close to the noise source.
Validation
CORTEX
Noise simulators
Experimental data
Author
Mathieu Hursin
Paul Scherrer Institut
Swiss Federal Institute of Technology in Lausanne (EPFL)
Andrea Zoia
University Paris-Saclay
Amélie Rouchon
University Paris-Saclay
A. Brighenti
University Paris-Saclay
I. Zmijarevic
University Paris-Saclay
S. Santandrea
University Paris-Saclay
Paolo Vinai
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Antonios Mylonakis
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
Vincent Lamirand
Swiss Federal Institute of Technology in Lausanne (EPFL)
Paul Scherrer Institut
K. Ambrozic
Swiss Federal Institute of Technology in Lausanne (EPFL)
T. Yamamoto
Kyoto University
S. Hübner
Technische Universität Dresden
A. Knospe
Technische Universität Dresden
Carsten Lange
Technische Universität Dresden
S. Yum
Technical University of Munich
R. Macian
Technical University of Munich
A. Vidal
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. 194 110066Core monitoring techniques and experimental validation and demonstration (CORTEX)
European Commission (EC) (EC/H2020/754316), 2017-09-01 -- 2021-08-31.
Areas of Advance
Energy
Subject Categories
Other Physics Topics
DOI
10.1016/j.anucene.2023.110066