Electrochemical Boron-Doped Diamond Film Microcells Micromachined with Femtosecond Laser: Application to the Determination of Water Framework Directive Metals

Planar electrochemical microcells were micromachined in a microcrystalline boron-doped diamond (BDD) thin layer using a femtosecond laser (Photo 1). The electrochemical performances of the new laser-machined BDD microcell were assessed by differential pulse anodic stripping voltammetry (DPASV) determinations, at nM level, of the four heavy metal ions of the European Water Framework Directive (WFD): Cd(II), Ni(II), Pb(II), Hg(II). The results are compared with those of previously published BDD electrodes [1]. The calculated detection limits are 0.4 nM, 6.8 nM and 5.5 nm 2.3 nM, and the linearities go up to 35nM, 97nM, 48nM and 5nM for respectively Cd(II), Ni(II) Pb(II) and Hg(II). The detection limits meet with the environmental quality standard of the WFD for three of the four metals. It was shown that the four heavy metals could be detected simultaneously, in the concentration ratio usually measured in sewage or runoff waters

Non Destructive Evaluation of Containment Walls in Nuclear Power Plants

Two functions are regularly tested on the containment walls in order to anticipate a possible accident. The first is mechanical to resist at a possible internal over-pressure and the second is to prevent leakage. The reference accident LLOCA (Large Loss of Coolant Accident) is the rupture of a pipe in the primary circuit of a nuclear plant. In this case, the pressure and temperature can reach 5 bar and 180°C in 20 seconds. The national project ‘Non-destructive testing of the containment structures of nuclear plants’ aims at studying the non-destructive techniques capable to evaluate the concrete properties and its damaging or progression of cracks. This 4-year-project is segmented into two parts. The first consists in developing and selecting the most relevant NDEs (Non Destructive Evaluations) in the laboratory to reach these goals. These evaluations are developed in conditions representing the real conditions of the stresses generated during ten-yearly visits of the plants or those related to an accident. The second part consists in applying the selected techniques to two containment structures under pressure. The first (technique) is proposed by the ONERA (National Office for Aerospace Studies and Research of France) and the second is a mock-up of a containment wall on a 1/3 scale made by EDF (Electricity of France) within the VeRCoRs program. Communication bears on the part of the project that concerns the damaging and cracking follow-up. The tests are done in bending on 3 or 4 points in order to study the cracks’ generation, their propagation, as well as their opening and closing. The mostly ultrasonic techniques developed concern linear or non-linear acoustic: acoustic emission [1], LOCADIFF (Locating with diffuse ultrasound) [2], energy diffusion, surface waves velocity and attenuation, DAET (Dynamic Acousto-Elasticity Testing) [3]. The data contribute to providing the mapping of the parameters searched for, either in volume, in surface or globally. Image correlation is an important additional asset to validate the coherence of the data. The spatial normalization of the data allows proposing algorithms on the combination of the experimental data. The tests results are presented and they show the capacity and the limits of the evaluation of the volume, surface or global data. A data fusion procedure is associated with these results

Non Destructive Evaluation of containment nuclear plants structures

International audienc

Non Destructive Evaluation of containment nuclear plants structure

International audienceFrench Projects of Investment for the Future, called “Research for Nuclear Safety and RadiationProtection” have been initiated to further research on the causes, the management, the impact of theobserved nuclear accidents and to propose and validate solutions to limit the risk and the consequences.In this context the "Non Destructive Evaluation of nuclear plants containment” project” (ENDE) witheight partners (six research institutes and two industrials) supported by the “National Agency of Research”,proposes a methodology for the Non Destructive Evaluation of the containment capacity to fulfil its twomajor functions: strength and leak tightness. The NDE measurements will be performed underconditions representing the specific solicitations of a decennial inspection, and after or during areference accident.The project aims to develop NDEs, to combine them by data fusion and to select the most efficientcombinations with quantitative criteria.The work is based on:• Structuring the knowledge and developing an experimental plan.• Evaluating the material in representative conditions of accidental solicitations (water saturation,porosity, strength, elastic modulus, stress) and the diffuse thermal damage (micro cracks)• Monitoring the transition from diffuse to continuous damage (cracks) and monitoring a crack understress (opening and width).• Implementing ND Techniques on-site.The ND techniques retained after selection will be implemented on a containment mock-up on the 1/3scale. This mock-up developed by EDF (Electricité de France) will be available in 2016. It will becomparable to those of real size containment regarding pressure and temperature conditions. Themeasures deduced from the NDEs will be introduced in another project (Macena) that aims to simulatethe water and heat transfers as well as creep occurring in a reference accident. We will present themethodology and the results obtained during the first year and a half

Microcellules électrochimiques planaires intégrées réalisées par micro-usinage laser

Procédé de fabrication de microcellules électrochimiques planaires, comportant : - la fourniture d'un substrat, ce substrat s'étendant essentiellement dans un plan dit plan du substrat et comprenant : - une première couche d'un matériau électriquement isolant - une deuxième couche d'un matériau électriquement conducteur, cette deuxième couche étant directement déposée sur la première couche - la gravure de la deuxième couche, pour délimiter et isoler électriquement l'une de l'autre : - une électrode de travail - une contre-électrode - une électrode dite de référence. Selon l'invention, la gravure de la deuxième couche est réalisée au moyen d'une succession d'impulsions d'un rayonnement laser, la durée de chacune de ces impulsions étant inférieure à 100ps, ces impulsions étant répétées avec une fréquence de répétition supérieure ou égale à 1kHz

Antipodal Vivaldi antennas dedicated to in-situ broadband microwave permittivity measurements

In the context of the ESA's SMOS and the ESA's BIOMASS space mission, the data processing algorithms require precise permittivity models of the different wood species. To develop the models, in situ sensors that could be easily deployed on the site dedicated to calibration/validation studies would be truly relevant. Microwave volume analysis can be a very useful tool to monitor material properties. There are very few commercial equipment dedicated to in-situ measurements and none of them is developed in order to leave the instrument on site for automatic measurements with specific constraints such as communication, low power consumption, frequency broadband, non-invasive measurement and cheap price. The main objective of the study presented is to develop an equipment to meet these challenges. In this article we will present the study that we conducted to design the broadband antennas needed by the device to perform efficient in situ measurements. Preliminary results on a concrete structure demonstrate the possibility to perform quality B scan despite the strict imposed specifications