Characterization and Localization of Partial-Discharge-Induced Pulses in Fission Chambers Designed for Sodium-Cooled Fast Reactors

Giacomo Galli (1, 2, 3) , Hassen Hamrita (1) , C. Jammes (4) , Michael J Kirkpatrick (2) , E. Odic (2) , Philippe Dessante (2) , Philippe Molinié (2) , B. Cantonnet (5) , J.-C. Nappé (5)

1 LCAE - Laboratoire Capteurs et Architectures Electroniques
2 GeePs - Laboratoire Génie électrique et électronique de Paris
3 UPMC - Université Pierre et Marie Curie - Paris 6
4 LDCI - Laboratoire de Dosimétrie, de Contrôle-commande et Instrumentation
5 PHOTONIS France S.A.S, Nuclear Instrumentation

During the operation of the superphenix and phenix reactors, an aberrant electrical signal was detected from the fission chambers used for neutron flux monitoring. This signal, thought to be due to partial electrical discharge (PD) is similar to the signal resulting from neutron interactions, and is generated in fission chambers at temperatures above 400 °C. This paper reports work on the characterization and localization of the source of this electrical signal in a high-temperature fission chamber. The dependence of the shape of the PD or neutron signal on the various experimental parameters (nature and pressure of the chamber filling gas, electrode gap distance, and fission chamber geometry) are described. Next, experiments designed to identify the location within the chambers where the PD are being generated are presented in way to propose changes to the fission chamber in order to reduce or eliminate the PD signal.

Keywords: neutron detector; partial discharge (PD); sodium-cooled fast reactors; triple point effect; Fission chamber; high temperature; instrumentation; nuclear instrumentation; radioactivity; ionizing radiation; neutrons; Neutron-gamma discrimination; Signal processing; spectrum analysis

Domains: Instrumentation and Detectors [physics.ins-det]; Nuclear Experiment [nucl-ex]; Data Analysis, Statistics and Probability [physics.data-an]

Giacomo Galli, Hassen Hamrita, C. Jammes, Michael J Kirkpatrick, E. Odic, et al.. Characterization and Localization of Partial-Discharge-Induced Pulses in Fission Chambers Designed for Sodium-Cooled Fast Reactors. IEEE Transactions on Nuclear Science, 2018, 65 (9), pp.2412 - 2420. ⟨10.1109/TNS.2018.2861566⟩. ⟨cea-01916651⟩