Validation of axial void profile measured by neutron noise techniques in crocus
Paper in proceeding, 2020

Recently a joint project has been carried out between the Paul Scherrer Institut, the Ecole Polytechnique Federale de Lausanne and swissnuclear, an industrial partner, in order to determine the axial void distribution in a channel installed in the reflector of the zero power research reactor CROCUS, using neutron noise techniques. The main objective of the present paper is to report on the validation of the results against an alternative measurement technique using gamma-ray attenuation and simulations with the TRACE code. For the gamma-ray attenuation experiments, the channel used in CROCUS is installed out of the core in a Plexiglass water tank. The source and detector are fixed and the channel is moved axially to keep the geometry of the source/detector arrangement untouched. This is key to measure the void effect by gamma attenuation due to the low contrast of this technique. The paper compares the experimental results obtained with both techniques, with the outcomes of simulations carried out with the TRACE code. Even though the quantitative void fraction estimations are not consistent, the trends obtained with the simulation and experimental techniques are the same. The discrepancies between the various experimental techniques and the simulation outcomes are related to the heterogeneous distribution of the water-air mixture in the radial sections of the channel.

Void measurements

Two-phase flow

Attenuation measurements

Author

Mathieu Hursin

Paul Scherrer Institut

Swiss Federal Institute of Technology in Lausanne (EPFL)

Oskari Pakari

Swiss Federal Institute of Technology in Lausanne (EPFL)

Gregory Perret

Paul Scherrer Institut

Pavel Frajtag

Swiss Federal Institute of Technology in Lausanne (EPFL)

Vincent Lamirand

Paul Scherrer Institut

Swiss Federal Institute of Technology in Lausanne (EPFL)

Imre Pazsit

Chalmers, Physics, Subatomic and Plasma Physics

Victor Dykin

Chalmers, Physics, Subatomic and Plasma Physics

Gábor Pór

Budapest University of Technology and Economics

Henrik Nylén

Ringhals AB

Andreas Pautz

Paul Scherrer Institut

Swiss Federal Institute of Technology in Lausanne (EPFL)

International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020

Vol. 2020-March 1586-1593

2020 International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020
Cambridge, United Kingdom,

Subject Categories

Accelerator Physics and Instrumentation

Fluid Mechanics and Acoustics

Signal Processing

DOI

10.1051/epjconf/202124708004

More information

Latest update

1/3/2024 9