Implementation of neutron tomography around the Algerian Es-Salam research reactor: preliminary studies and first steps

Kharfi, Fayçal; Boukerdja, Layachi; Attari, A.; Abbaci, M.; Boucenna, A.

doi:10.1016/j.nima.2005.01.102

Cited by 10 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tritium activity concentrations are found to vary significantly between the various metal samples investigated (Table ). The highest activity concentrations were observed for irradiated aluminum, but high activity concentrations were also observed, unsurprisingly, for the middle B 4 C (boron carbide) layer of Boral. − For nonirradiated metals, the highest activity concentration was associated with stainless steel and the lowest with Cu. The relative activity concentrations for different metal samples depended on the specific metal, its ambient 3 H concentration, the neutron flux (for irradiated metals), and the duration of exposure.…”

Section: Resultsmentioning

confidence: 94%

Using Thermal Evolution Profiles to Infer Tritium Speciation in Nuclear Site Metals: An Aid to Decommissioning

2014

View full text Add to dashboard Cite

Understanding the association and retention of tritium in metals has significance in nuclear decommissioning programs and can lead to cost benefits through waste reduction and recycling of materials. To develop insights, a range of metals from two nuclear sites and one non-nuclear site were investigated which had different exposure histories. Tritium speciation in metals was inferred through incremental heating experiments over the range of 20-900 °C using a Raddec Pyrolyser instrument. Systematic differences in thermal desorption profiles were found for nonirradiated and irradiated metals. In nonirradiated metals (e.g., stainless steel and copper), it was found that significant tritium had become incorporated following prolonged exposure to tritiated water vapor (HTO) or tritium/hydrogen gas (HT) in nuclear facilities. This externally derived tritium enters metals by diffusion with a rate controlled by the metal composition and whether the surface of the metal had been sealed or coated prior to exposure. The tritium is normally trapped in hydrated oxides lying along grain boundaries. In irradiated metals, an additional type of tritium can form internally through neutron capture reactions. The amount formed depends on the concentration and distribution of trace lithium and boron in the metal as well as the integrated neutron flux. Liberating this kind of tritium typically requires temperatures above 800 °C. The pattern of tritium evolution derived from simple thermal desorption experiments allows reliable inferences to be drawn on the likely origin, location, and phases that trap tritium. Any weakly bound tritium liberated at temperatures of ~100 °C is indicative of mostly HTO interactions in the metal. Any strongly bound tritium liberated over the range of 600-900 °C is indicative of neutrogenic tritium formed via neutron capture by trace Li and B. Neutron capture by lithium is likely to be more significant than for boron based on lithium's higher trace element abundance and neutron cross section. The time required for efficient thermal desorption of tritium ultimately depends on the metal composition, its tritium exposure history, integrated neutron flux, sample size, sample geometry, heating rate, and final desorption temperature.

show abstract

Section: Resultsmentioning

confidence: 94%

Using Thermal Evolution Profiles to Infer Tritium Speciation in Nuclear Site Metals: An Aid to Decommissioning

2014

View full text Add to dashboard Cite

show abstract

“…According to the manufacturer specifications, this system has a maximum intrinsic spatial resolution of 200 µm (171.5 µm calculated). All necessary experiments were performed at the neutron radiography facility of the Es-Salam research reactor (Kharfi, et al, 2005). To achieve this task, a MatLab code was developed.…”

Section: Temporal and Spatial Resolution Limit Study Of A Radiographimentioning

confidence: 99%

Temporal and Spatial Resolution Limit Study of Radiation Imaging Systems: Notions and Elements of Super Resolution

Kharfi¹,

Denden²,

Ali³

2012

Digital Image Processing

View full text Add to dashboard Cite

“…It is a two-dimensional mxn array of non-negative integers (gray levels) [18]. The gray level value represents the relative linear attenuation coefficient of the object.…”

Section: Application To Neutron Radiography Imagesmentioning

confidence: 99%

A Novel Approach for Regularized Signal Deconvolution Based on Hybrid Swarm Intelligence: Application to Neutron Radiography

Saadi

Guessoum

Bettayeb

2012

2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops &Amp; PhD Forum

View full text Add to dashboard Cite

In this work, we introduce a new approach for the signal deconvolution problem, which is useful for the enhancement of neutron radiography projections. We attempt to restore original signals and get rid of noise present during acquisition or processing, due to gamma radiations or randomly distributed neutron flux. Signal deconvolution is an ill-posed inverse problem, so regularization techniques are used to smooth solutions by imposing constraints in the objective function. Various popular algorithms have been developed to solve such problem. This paper proposes a new approach to the nonlinear degraded signals restoration which is useful in many signal enhancement applications, based on a synergy of two swarm intelligence algorithms: particle swarm optimization (PSO) and bacterial foraging optimization (BFO) applied for total variation (TV) minimization, instead of the standard Tikhonov regularization method. We attempt to reconstruct or recover signals using some a priori knowledge of the degradation phenomenon. The truncated singular value decomposition and the wavelet filtering methods are also considered in this paper. A comparison between several powerful techniques is conducted.

show abstract

Implementation of neutron tomography around the Algerian Es-Salam research reactor: preliminary studies and first steps

Cited by 10 publications

References 2 publications

Using Thermal Evolution Profiles to Infer Tritium Speciation in Nuclear Site Metals: An Aid to Decommissioning

Using Thermal Evolution Profiles to Infer Tritium Speciation in Nuclear Site Metals: An Aid to Decommissioning

Temporal and Spatial Resolution Limit Study of Radiation Imaging Systems: Notions and Elements of Super Resolution

A Novel Approach for Regularized Signal Deconvolution Based on Hybrid Swarm Intelligence: Application to Neutron Radiography

Contact Info

Product

Resources

About