A Hemispherical Fission Chamber for the Neutron-Flux Monitoring

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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Neutron Flux Monitoring Based on Blind Source Separation Algorithms in Moroccan TRIGA MARK II Reactor

Science and Technology of Nuclear Installations ◽

10.1155/2017/5369614 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Hanane Arahmane ◽

El-Mehdi Hamzaoui ◽

Rajaa Cherkaoui El Moursli

Keyword(s):

Data Processing ◽

Neutron Flux ◽

Blind Source Separation ◽

Source Separation ◽

Research Work ◽

Nonnegative Matrix ◽

Fission Chamber ◽

Flux Monitoring ◽

Scientific Fields ◽

Material Irradiation

We present an overview of fission chamber’s functioning modes, theoretical aspects of the nonnegative matrix factorization methods, and the opportunities that offer neutron data processing in order to achieve neutron flux monitoring tasks. Indeed, it is a part of research project that aimed at applying Blind Source Separation methods for in-core and ex-core neutron flux monitoring while analyzing the outputs of fission chamber. The latter could be used as a key issue for control, fuel management, safety concerns, and material irradiation experiments. The Blind Source Separation methods had been used in many scientific fields such as biomedical engineering and telecommunications. Recently, they were used for gamma spectrometry data processing. The originality of this research work is to apply these powerful methods to process the fission chamber output signals. We illustrated the effectiveness of this tool using simulated fission chamber signals.

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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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Algorithm for the Correction of the Power Reading for Neutron Flux Monitoring Channels

Ядерная физика и инжиниринг ◽

10.1134/s2079562913080071 ◽

2013 ◽

Vol 4 (8) ◽

pp. 758-764

Author(s):

A. A. Semenov ◽

A. A. Druzhaev ◽

I. A. Sergeev ◽

N. V. Shchukin ◽

V. I. Strikovskii

Keyword(s):

Neutron Flux ◽

Flux Monitoring

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Genetic algorithm based risk-cost analysis of Neutron Flux Monitoring System for Prototype Fast Breeder Reactor

2011 International Conference on Recent Trends in Information Technology (ICRTIT) ◽

10.1109/icrtit.2011.5972442 ◽

2011 ◽

Author(s):

Molly Mehra ◽

M. L. Jayalal ◽

R. Jehadeesan ◽

S. Rajeswari ◽

S. A. V. SatyaMurty

Keyword(s):

Genetic Algorithm ◽

Cost Analysis ◽

Neutron Flux ◽

Monitoring System ◽

Fast Breeder Reactor ◽

Flux Monitoring ◽

Risk Cost

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Nuclear Instrumentation Systems in Prototype Fast Breeder Reactor

12th International Conference on Nuclear Engineering, Volume 2 ◽

10.1115/icone12-49354 ◽

2004 ◽

Cited By ~ 1

Author(s):

P. M. Vijayakumaran ◽

C. P. Nagaraj ◽

C. Paramasivan Pillai ◽

R. Ramakrishnan ◽

M. Sivaramakrishna

Keyword(s):

Neutron Flux ◽

Early Warning System ◽

Warning System ◽

Radiation Monitoring ◽

Fast Breeder Reactor ◽

Delayed Neutrons ◽

The Core ◽

Flux Monitoring ◽

Nuclear Instrumentation ◽

Fission Chambers

The nuclear instrumentation systems of the Prototype Fast Breeder Reactor (PFBR) primarily comprise of global Neutron Flux Monitoring, Failed Fuel Detection & Location, Radiation Monitoring and Post-Accident Monitoring. High temperature fission chambers are provided at in-vessel locations for monitoring neutron flux. Failed fuel detection and location is by monitoring the cover gas for fission gases and primary sodium for delayed neutrons. Signals of the core monitoring detectors are used to initiate SCRAM to protect the reactor from various postulated initiating events. Radiation levels in all potentially radioactive areas are monitored to act as an early warning system to keep the release of radioactivity to the environment and exposure to personnel well below the permissible limits. Fission Chambers and Gamma Ionisation Chambers are located in the reactor vault concrete for monitoring the neutron flux and gamma radiation levels during and after an accident.

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