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

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.

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Rejection of partial-discharge-induced pulses in fission chambers designed for sodium-cooled fast reactors

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2016.11.055 ◽

2017 ◽

Vol 848 ◽

pp. 109-113 ◽

Cited By ~ 3

Author(s):

H. Hamrita ◽

C. Jammes ◽

G. Galli ◽

F. Laine

Keyword(s):

Partial Discharge ◽

Fast Reactors ◽

Fission Chambers

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Fast Neutron-Flux Monitoring Instrumentation for Lead Fast Reactors: A Preliminary Study on Fission Chamber Performances

Volume 6: Nuclear Education, Public Acceptance and Related Issues; Instrumentation and Controls (I&C); Fusion Engineering; Beyond Design Basis Events ◽

10.1115/icone22-31011 ◽

2014 ◽

Cited By ~ 1

Author(s):

Luigi Lepore ◽

Romolo Remetti ◽

Mauro Cappelli

Keyword(s):

Neutron Flux ◽

Fuel Cycle ◽

Fast Reactors ◽

Fission Chamber ◽

Enhanced Sensitivity ◽

Flux Monitoring ◽

Preliminary Study ◽

Fast Flux ◽

Absolute Measurements ◽

Fission Chambers

Although Sodium Fast Reactors (SFRs) are the most investigated solutions for the future fast-flux facilities so far, Lead Fast Reactors (LFRs) promise to be a very competitive alternative thanks to their peculiarity concerning coolant-safety, fuel cycle and waste management. Nevertheless, the development of LFRs presents today some drawbacks still to be solved. Due to the harder neutron flux, the current instrumentation developed for SFRs is likely to be extended to LFRs as a first attempt. Otherwise, new monitoring instrumentation could be developed in order to assure more tailored results. Different measurement technologies can be considered for fast flux monitoring and flux absolute measurements in order to provide a reliable and quick calibration of the overall reactor neutron instrumentation. The goal of this paper is to study the validity of typical fast reactor fission chamber designs (e.g. SuperPhénix fission chambers), indicating which are the limitations when used in a LFR environment. Afterwards, alternative detector solutions with enhanced sensitivity and response will be proposed.

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