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On the installation of an in situ large-scale vertical sEALing (VsEAL) experiment on bentonite pellet-powder mixture

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2388-2401页

作者： Nadia Mokni Justo Cabrera Frédéric deleruyelle institut de radioprotection et de sûreténucléaire(IRsN) PSE-ENV/SEDRE/LETISFontenay-aux-Roses92260France

Recently,the institute for Radiological protection and nuclear safety(IRsN)has launched VsEAL(Vertical sEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems(Vss).The first VsEAL in situ test was emplaced in IRsN’s Underground Research Laboratory(URL)in Tournemire(France)in 2019 and was equipped with 76 wired and wireless sensors.The test is still in progress,but the collected set of data provides already valuable information of the hydro-mechanical behavior of Vss during hydration.The swelling core consists of a mixture of highdensity pellets and powder of MX80 bentonite in a ratio of 80/20(in dry mass).An innovative method was adopted to drill a 1-m diameter and w10-m deep shaft in order to minimize the rock perturbation at the sidewalls.Because a specific protocol was adopted to install the bentonite mixture together with a careful characterization of the core during construction,VsEAL 1 constitutes the unique in situ sealing test with a well-known initial structural distribution of the pellets and the powder.some heterogeneities occurred within the experiment during the installation process:a damaged zone developed around the shaft walls due to the interruption of the installation operations caused by COVID19 lockdown in France;a technological gap with a variable thickness between the last pellets layer and the top confining lid and a heterogeneous distribution of the bentonite powder at some layers inducing large inter pellets voids close to the bentonite-rock interface.Artificially injected water volume,relative humidity,water content and swelling pressure in both radial and axial directions were monitored.Comparison of the results showed that the presence of installation-induced heterogeneities led to the generation of preferential flow paths that influenced the swelling pressure evolution at radial and axial directions.

关键词： Bentonite pellet-powder mixture Heterogeneities Technological gap seals In situ test

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Ageing evaluation of cable insulations subjected to radiation ageing:Application of principal component analyses to Fourier Transform Infra-Red and dielectric spectroscopy

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High Voltage 2022年第4期7卷 652-665页

作者： simone Vincenzo suraci sandrine Amat Lea Hippolyte Astrid Malechaux Davide Fabiani Claire Le Gall Océane Juan Nathalie Dupuy LIMEs Department of ElectricalElectronic and Information EngineeringUniversity of BolognaBolognaItaly Aix Marseille University Avignon UniversitéCNRSMarseilleFrance institut de radioprotection et de sûreté nucléaire MarseilleFrance

The evolution of properties of crosslinked polyethylene(XLPE)-based insulating mate-rials under radio-chemical ageing conditions is presented and discussed.In total,seven different polymer compounds were tested,characterised by an increasing quantity of additives,for example,antioxidants(AOs)and fillers as flame retardants.samples were analysed using different testing techniques,that is,Fourier Transform Infra-Red and dielectric spectroscopy.This allowed a broad characterisation of the polymer,bringing to good correlations between the arising of new chemical groups caused by ageing and the modifications on the complex permittivity.Phenol-based AOs are found to be the most efficient in terms of protection against oxidation.On the contrary,flame retardants are concluded not to have any impact on the material ageing.Acquired data were then treated using the principal component analysis.The data treatment successfully distinguished the material composition(with and without additives)and the ageing environments.The results confirm the relevance of this analysis in understanding the impact of irradiation on the chemical and functional properties of the polymer materials studied.

关键词： component principal bringing

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Numerical modeling of bedload and suspended load contributions to morphological evolution of the seine Estuary(France)

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International Journal of sediment Research 2021年第6期36卷 723-735页

作者： Baptiste Mengual Pierre Le Hir Aurélie Rivier Matthieu Caillaud Florent Grasso IFREMER DYNECO/DHYSED Laboratory Centre de Bretagne UMR 7266 LIENss CNRS-La Rochelle University IRsN (institut de radioprotection et de s?reté nucléaire) PRP-ENV/SERIS/LRC Laboratory

This numerical modeling study(i) assesses the influence of the sediment erosion process on the sediment dynamics and subsequent morphological changes of a mixed-sediment environment, the macrotidal seine estuary, when non-cohesive particles are dominant within bed mixtures(non-cohesive regime), and(ii) investigates respective contributions of bedload and suspended load in these dynamics.A three dimensional(3 D) process-based morphodynamic model was set up and run under realistic forcings(including tide, waves, wind, and river discharge) during a 1-year period. Applying erosion homogeneously to bed sediment in the non-cohesive regime, i.e., average erosion parameters in the erosion law(especially the erodibility parameter, E0), leads to higher resuspension of fine sediment due to the presence of coarser fractions within mixtures, compared to the case of an independent treatment of erosion for each sediment class. This results in more pronounced horizontal sediment flux(two-fold increase for sand, +30% for mud) and erosion/deposition patterns(up to a two-fold increase in erosion over shoals, generally associated with some coarsening of bed sediment). Compared to observed bathymetric changes, more relevant erosion/deposition patterns are derived from the model when independent resuspension fluxes are considered in the non-cohesive regime. These results suggest that this kind of approach may be more relevant when local grain-size distributions become heterogeneous and multimodal for non-cohesive particles. Bedload transport appears to be a non-dominant but significant contributor to the sediment dynamics of the seine Estuary mouth. The residual bedload flux represents, on average, between 17 and 38% of the suspended sand flux, its contribution generally increasing when bed sediment becomes coarser(can become dominant at specific locations). The average orientation of residual fluxes and erosion/deposition patterns caused by bedload generally follow those resulting from suspended sediment dynamics. sediment mass budge

关键词： Non-cohesive sand-mud mixtures Erosion suspended sediment transport Bedload transport Morphodynamics seine Estuary

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Maintenance of radiation-induced intestinal fibrosis:Cellular and molecular features

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World Journal of Gastroenterology 2007年第19期13卷 2675-2683页

作者： Valérie Haydont Marie-Catherine Vozenin-Brotons UPREs EA 27-10 "Radiosensibilité des tumeurs et tissus sains" Institut de Radioprotection et de Sreté Nucléaire/Institut Gustave Roussy. Villejuif Laboratoire de Radiopathologie. sRBE/DRPH. institut de radioprotection et de sreté nucléaire Fontenay-aux-Roses France

Recent advances in cell and molecular radiobiology clearly showed that tissue response to radiation injury cannot be restricted to a simple cell-killing process, but depends upon continuous and integrated pathogenic processes, involving cell differentiation and crosstalk between the various cellular components of the tissue within the extracellular matrix. Thus, the prior concept of primary cell target in which a single-cell type (whatever it’s epithelial or endothelial cells) dictates the whole tissue response to radiation injury has to be replaced by the occurrence of coordinated multicellular response that may either lead to tissue recovery or to sequel development. In this context, the present review will focus on the maintenance of the radiation-induced wound healing and fi brogenic signals triggered by and through the microenvironment toward the mesenchymal cell compartment, and will highlight how sequential and sustained modifi cations in cell phenotypes will in cascade modify cell-to-cell interactions and tissue composition.

关键词：放射疗法辐射诱发小肠纤维性变细胞特征分子特征

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Tissue toxicity induced by ionizing radiation to the normal intestine:Understanding the pathophysiological mechanisms to improve the medical management

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World Journal of Gastroenterology 2007年第22期13卷 3031-3032页

作者： MC Vozenin-Brotons UPREs EA 27-10 "Radiosensibilité des tumeurs et tissus sains". institut de radioprotection et de sreté nucléaire/institut Gustave Roussy. Villejuif France Laboratoire de Radiopathologie. SRBE/ DRPH. Institut de Radioprotection et de Sreté Nucléaire. Fontenay-aux-Roses France

At the present time, more than one-half of all cancer patients are treated with radiation therapy. despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer ... 详细信息

关键词：组织毒性致电离辐射肠道病理生理学药物中毒

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Bayesian inference of biomass growth characteristics for sugi(C.japonica)and hinoki(C.obtusa)forests in self-thinned and managed stands

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Forest Ecosystems 2021年第4期8卷 1006-1023页

作者： Valerie Nicoulaud-Gouin Marc-Andre Gonze Pierre Hurtevent Phillippe Calmon institut de radioprotection et de surete nucleaire St Paul-Lez-DuranceFrance

Background:Forests are an important sink for atmospheric carbon and could release that carbon upon deforestation and degradation.Knowing stand biomass dynamic of evergreen forests has become necessary to improve current biomass production models.The different growth processes of managed forests compared to self-managed forests imply an adaptation of biomass prediction models.Methods:In this paper we model through three models the biomass growth of two tree species(Japanese cedar,Japanese cypress)at stand level whether they are managed or not(self-thinning).One of them is named self-thinned model which uses a specific self-thinning parameterαand adapted to self-managed forests and an other model is named thinned model adapted to managed forests.The latter is compared to a Mitscherlich model.The self-thinned model takes into account the light competition between trees relying on easily observable parameters(e.***.stand density).A Bayesian inference was carried out to determine parameters values according to a large database collected.Results:In managed forest,Bayesian inference results showed obviously a lack of identifiability of Mitscherlich model parameters and a strong evidence for the thinned model in comparison to Mitscherlich model.In self-thinning forest,the results of Bayesian inference are in accordance with the self-thinning 3/2 rule(α=1.4).structural dependence between stand density and stand yield in self-thinned model allows to qualifying the expression of biological time as a function of physical time and better qualify growth and mortality rate.Relative mortality rate is 2.5 times more important than relative growth rate after about 40 years old.stand density and stand yield can be expressed as function of biological time,showing that yield is independent of initial density.Conclusions:This paper addressed stand biomass dynamic models of evergreen forests in order to improve biomass growth dynamic assessment at regional scale relying on easily observable parameters.These models can be used to dynamica

关键词： Dynamic Biomass self-thinning sugi Hinoki Competition-density rule

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Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture

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Journal of Rock Mechanics and Geotechnical Engineering 2014年第2期6卷 126-132页

作者： simona saba Jean-Dominique Barnichon Yu-Jun Cui Anh Minh Tang Pierre delage Ecole des Ponts ParisTech Laboratoire Navier institut de radioprotection et de surete nucleaire(IRsN)

Pre-compacted elements （disks, tutus） of bentonite/sand mixture are candidate materials for sealing plugs of radioactive waste disposal. Choice of this material is mainly based on its swelling capacity allowing all gaps in the system to be sealed, and on its low permeability. When emplaced in the gallery, these elements will start to absorb water from the host rock and swell. Thereby, a swelling pressure will develop in the radial direction against the host rock and in the axial direction against the support structure. In this work, the swelling pressure of a small scale compacted disk of bentonite and sand was experimentally studied in both radial and axial directions. Different swelling kinetics were identified for different dry densities and along different directions. As a rule, the swelling pressure starts increasing quickly, reaches a peak value, decreases a little and finally stabilises. For some dry densities, higher peaks were observed in the radial direction than in the axial direction. The presence of peaks is related to the microstructure change and to the collapse of macro- pores. In parallel to the mechanical tests, microstructure investigation at the sample scale was conducted using microfocus X-ray computed tomography （BCT）. Image observation showed a denser structure in the centre and a looser one in the border, which was also confirmed by image analysis. This structure heterogeneity in the radial direction and the occurrence of macro-pores close to the radial boundary of the sample can explain the large peaks observed in the radial swelling pressure evolution. Another interesting result is the higher anisotropy found at lower bentonite dry densities, which was also analysed by means ofμCT observation of a sample at low bentonite dry density after the end of test. It was found that the macro-pores, especially those between sand grains, were not filled by swelled bentonite, which preserved the anisotropic microstructure caused by uniaxial compression due to the absence of microstructure collapse.

关键词： Bentonite/sand mixture nuclear waste disposal Anisotropy swelling pressure Microstructure Microfocus X-ray computed tomography（μCT）

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sIMULATING HYDRIde EMBRITTLEMENT ON COLD-WORKED sTREss-RELIEVED ZIRCALOY-4 WITH GURsON-TVERGAARD-NEEDLEMAN DAMAGE MOdeL

SIMULATING HYDRIDE EMBRITTLEMENT ON COLD-WORKED STRESS-RELIE...

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第十八届国际反应堆结构力学大会

作者： Jean desquines Vincent Busser Frédéric Perales institut de radioprotection et de sreté nucléaire institut de radioprotection et de sreté nucléaire institut de radioprotection et de sreté nucléaire

＜正＞ Many experiments on irradiated fuel rod claddings demonstrated that one of the limiting phenomenon to the fuel burnup increase is the hydride embrittlement of the cladding. Zirconium-hydrides precipitate in the cladding as a result of the cladding oxidation by the primary water. Zirconium-hydrides have a detrimental influence on the overall cladding ductility. strain-controlled void nucleation in hydride precipitates was evidenced in previous studies as a key process in hydride embrittlement. The stress-relieved Zircaloy-4 is commonly used in commercial PWR’s;there is thus a great interest to provide physical models describing hydride-embrittlement applicant to this particular heat treatment.

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development of a portable reference aerosol generator （PRAG） for calibration of particle mass concentration measurements

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Particuology 2018年第2期16卷 134-142页

作者： Francois Gaie-Levrel soleiman Bourrous Tatiana Macé Laboratoire national de metrologie et d'essais (LNE) Chemistry and Biology Division Gas and Aerosol Metrology Department I Rue Caston Boissier 75724 Paris Cedex 15 France institut de radioprotection et de sUreté nucleaire (LRsN) PSNRES SCA Gif-sur-Yvette 91192 France

The tapered element oscillating microbalance with filter dynamics measurement system （TEOM-FDMs） is an instrument commonly employed by the French air quality monitoring network. This instrument is currently calibrated with calibration weights traceable to sI but having value and mass differences between each of them that are not representative of real atmospheric particle mass measurements. Moreover, these calibration weights do not allow detection of any technical problems associated with either the TEOM-FDMs sampling system upstream of the mass measurement or the intrinsic TEOM-FDMs filtration system. Therefore, a calibration method was developed using a portable reference aerosol generator （PRAG） that produces known and stable particle mass concentrations over time. Here, we present the characterization of the PRAG system in terms of a reference range of particle masses between 30 - 10 and 3456 ± 83 μg at three sampling times. Its coupling with the TEOM-FDMs and a global comparison between the defined reference range of particle masses and the measured masses obtained with each TEOM-FDMs implicated in this study are also presented.

关键词： Aerosol Generator Mass concentration Particulate mass Calibration TEOM-FDMs

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Total Indicative Dose determination in Water from the North Riviera Well Field of sOdeCI in Abidjan, Cote d’Ivoire

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Journal of Environmental Protection 2023年第12期14卷 1006-1015页

作者： Epi Zita Tatiana Kocola Achi Bogbé Douo Louis Huberson Gogon N’Guessan Guy Léopold Oka Antonin Aka Koua Marie Chantal Kouassi Goffri Laboratoire des sciences de la Matiè re Environnement et de l’Energie Solaire (LASMES) Universit&eacute F&eacute lix Houphou&eumlt Boigny Abidjan C&ocircte d’Ivoire Autorité de Radioprotection de S&ucircret&eacute et de S&eacute curit&eacute Nucl&eacute aire Abidjan C&ocircte d’Ivoire institut de Recherche en Energies Renouvelables (IREN) Universit&eacute Nangui Abrogoua Abidjan C&ocircte d’Ivoire Acadé mie des Sciences des Arts des Cultures d’Afrique (ASCAD) Abidjan C&ocircte d’Ivoire

The Uranium-238 (238U), Thorium-232 (232Th) families and Potassium-40 (40K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also ... 详细信息

The Uranium-238 (sup>238sup>U), Thorium-232 (sup>232sup>Th) families and Potassium-40 (sup>40sup>K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (sOdeCI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of sup>238sup>U, sup>232sup>Th and sup>40sup>K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclidessup>238sup>U, sup>232sup>Th, and sup>40sup>K vary for the seven boreholes from 0.150 to 0.166 msv/yr with an average of 0.161 ± 0.034 msv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 msv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 msv/yr. But all remain below the UNsCEAR reference dose of 0.29 msv/yr.

关键词： North Rivera (NR) Well Field Borehole Water Natural Radioactivity Gamma spectrometry Total Indicative Dose Committed Annual Effective Dose

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