Neutron noise experiments in the AKR-2 and CROCUS reactors for the European project CORTEX
* V. Lamirand, A. Rais, O. Pakari, P. Frajtag, D. Godat, M. Hursin, A.Laureau, C. Fiorina, and A. Pautz are with the Laboratory for Reactor Physics and Systems behaviour (LRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland (*corresponding author: firstname.lastname@example.org)
S. Hübner and C. Lange are with the Institute of Power Engineering, Technische Universität Dresden, 01062 Dresden, Germany.
J. Pohlus and U. Paquee are with the Institut fur Sicherheitstechnologie GmbH (ISTec), 85748 Garching, Germany.
C. Pohl is with TÜV Rheinland Industrie Service GmbH (TUV), 51105 Cologne, Germany.
V. Lamirand, M. Hursin, G. Perret, and A. Pautz are with the Nuclear Energy and Safety Research Division (NES), Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland.
Published online: 20 January 2020
The present article gives an overview of the first experimental campaigns carried out in the AKR-2 and CROCUS reactors within the framework of the Horizon 2020 European project CORTEX. CORTEX aims at developing innovative core monitoring techniques that allow detecting anomalies in nuclear reactors, e.g. excessive vibrations of core internals. The technique will be mainly based on using the fluctuations in neutron flux, i.e. noise analysis. The project will result in a deepened understanding of the physical processes involved. This will allow utilities to detect operational problems at a very early stage, and to take proper actions before such problems have any adverse effect on plant safety and reliability. The purpose of the experimental campaigns in the AKR-2 and CROCUS reactors is to produce noise-specific experimental data for the validation of the neutron noise computational models developed within this framework. The first campaigns at both facilities consisted in measurements at reference static states, and with the addition of mechanical perturbations. In the AKR-2 reactor, perturbations were induced by two devices: a rotating absorber and a vibrating absorber, both sets in experimental channels close to the core. In CROCUS, the project benefited from the COLIBRI experimental program: 18 periphery fuel rods were oscillated at a maximum of ±2 mm around their central position in the Hz range. The present article documents the experimental setups and measurements for each facility and perturbation type.
Key words: Core monitoring and diagnostics / noise analysis / research reactor experiment / zero-power reactor
© The Authors, published by EDP Sciences, 2020
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