Méthode de dosage du Methylmercure dans la chair de poisson

The methyl mercury determination techniqu~ .used for .fish tissue in monitoring programmes is described. Chromatographie measurement with electron capture detector is performed on purified toluen extract .La méthode de dosage du méthylmercure dans la chair de poisson utilisée dans les programmes de "suivi" de la qualité du milieu et des produits est décrite dans le présent rapport. Elle est basée sur la mesure chromatographique par capture d'électrons du méthylmercure sur l'extrait toluènique purifié

Effect of the bainitic and martensitic microstructures on the hardening and embrittlement under neutron irradiation of a reactor pressure vessel steel

International audienceThe hardening and the embrittlement under neutron irradiation of a RPV steel considering three different coarse grained microstructures (bainite, bainite-martensite and martensite) have been investigated. Bainite and martensite have a comparable irradiation induced temperature transition shifts but hardening is smaller for martensite than for bainite. Bainite appears to be less sensitive to non-hardening embrittlement (NHE) than martensite. The onset of brittle intergranular fracture after irradiation for the martensitic microstructure is likely the origin of this difference of sensitivity to NHE. However, the bainitic-martensitic microstructure has the largest irradiation induced shift and is the most sensitive to NHE amongst all the tested microstructures. These results show that the microstructure is an important parameter to control the irradiation induced non hardening embrittlement and the enhancement of the brittle intergranular fracture in reactor pressure vessel steels

Evaluation des valeurs de fonds géochimiques dans l’eau de mer des 4 métaux de l’état chimique DCE. Cas des Départements d’Outre-Mer

The Water Framework Directive 2000/60/EC requires monitoring of the chemical status of waters, based on the comparison of measured concentrations of selected chemicals to environmental quality standards (EQS). However, for metal elements, background concentrations are not zero (geochemical background) and vary depending on the geological context. As these concentrations may sometimes reach high levels, the WFD permits their inclusion in the surface waters. In metropolitan France, many studies provide an extensive literature on the concentrations of trace metals in coastal marine environment, which even if they are not natural are very low compared with the concentrations of these EQS. However, there are no such data arising from the overseas departments except French Guyana. Evaluation of the geochemical background (also called the present day reference levels) in these generally volcanic regions potentially enriched in trace elements, needs therefore an exhaustive sampling, from which the acquired set of data will indicate whether the situation differs from the metropolitan situation.La Directive Cadre 2000/60/CE sur l’Eau requiert un contrôle de l’état chimique des eaux, basé sur la comparaison de niveaux mesurés de concentrations de substances chimiques sélectionnées à des normes de qualité environnementales (NQE). Or, pour les éléments métalliques, les concentrations naturelles ne sont pas nulles (« fond géochimique ») et varient en fonction de la nature géologique du milieu. Ces concentrations pouvant parfois atteindre des niveaux importants, la DCE autorise leur prise en compte dans les eaux de surface. En métropole, de nombreuses études fournissent une littérature abondante sur les concentrations des métaux traces en milieu marin côtier, qui même si elles ne sont pas des niveaux naturels sont très faibles comparées aux concentrations de ces NQE. En revanche, on ne dispose pas à part en Guyane de données sur les eaux côtières des départements d’outremer. L’évaluation des fonds géochimiques (que l’on peut appeler aussi concentrations de référence actuelle) dans ces régions généralement volcaniques, potentiellement enrichies en éléments traces, a donc pour préalable un échantillonnage exhaustif, à partir duquel les données acquises indiqueront si la situation est différente de la situation métropolitaine

The PROMETRA Program: Fuel Cladding Mechanical Behavior under High Strain Rate

International audienceAn assessment of the mechanical properties of the highly irradiated fuel claddings under high strain rate has been carried out in the framework of the PROMETRA program undertaken by the French Institut de Radioprotection et de Sûreté Nucléaire in collaboration with Electricité de France and Commissariat à l’Energie Atomique (CEA). Three types of tests, including burst tests, hoop and axial tensile tests, have been performed at CEA-Saclay hot laboratories to determine the cladding tensile properties to use in the SCANAIR code. The prototypicality of each test with regard to the reactivity-initiated accident loading conditions can be addressed and analyzed in terms of strain or stress ratio. The high-strain-rate ductile mechanical properties of irradiated ZIRLO and M5 alloys derived from the PROMETRA program and their comparison to the stress-relieved irradiated Zircaloy-4 are reported. Then, the clad brittle behavior, in particular for highly corroded or spalled Zircaloy-4 cladding, is investigated

Methyl mercury distributions in relation to the presence of nano- and picophytoplankton in an oceanic water column (Ligurian Sea, North-western Mediterranean)

International audienc

Ductility and Failure Behaviour of both Unirradiated and Irradiated Zircaloy-4 Cladding Using Plane Strain Tensile Specimens

International audienc