Characterization and localization of partial-discharge-induced pulses in fission chambers designed for sodium-cooled fast reactors

Giacomo Galli (1) , Hassen Hamrita (1) , Christian Jammes (2) , Michael J Kirkpatrick (3) , Emmanuel Odic (3) , Philippe Dessante (3) , Philippe Molinié (3) , Bernard Cantonnet (4) , Jean-Christophe Nappé (4)

1 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)
2 LDCI - Laboratoire de Dosimétrie, de Contrôle-commande et Instrumentation
3 GeePs - Laboratoire Génie électrique et électronique de Paris
4 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 (HTFC). The relation between the shape of the PD signal and various parameters (nature and pressure of the chamber filling gas, electrode gap distance, and fission chamber geometry) are first described. Next, experiments designed to identify the location within the chambers where the PD are being generated are presented. After verification and refinement of the results of these localization studies, it should be possible to propose changes to the fission chamber in order to reduce or eliminate the PD signal.

Mots clés: Partial discharge; Neutron detector; High temperature; Triple point effect; Fission chamber; Sodium-cooled fast reactors; Instrumentation; Nuclear instrumentation; Electronic architecture; Neutron-gamma discrimination; Neutrons; Signal processing

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Instrumentations et Détecteurs [physics.ins-det]; Traitement du signal et de l'image [eess.SP]

Giacomo Galli, Hassen Hamrita, Christian Jammes, Michael J Kirkpatrick, Emmanuel Odic, et al.. Characterization and localization of partial-discharge-induced pulses in fission chambers designed for sodium-cooled fast reactors. ANIMMA 2017 – Advancements in Nuclear Instrumentation Measurement Methods and their Applications, Jun 2017, Liège, Belgium. 6 p., ⟨10.1051/epjconf/201817003002⟩. ⟨hal-01767704⟩