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[en] Nuclear industry is the 3. industrial sector in France, it generates a global sales revenue of 47.5 billion euros and involves about 3000 firms employing more than 220.000 qualified people. This infographic shows that all the stages of the nuclear chain are present in France from uranium processing to waste management via enrichment or recycling or reactor construction. It is also shown that nuclear activities (research centers, nuclear power plants, fuel fabrication plants, waste storages sites, and engineering activities) are spread all over the country except in Brittany and Corsica. (A.C.)
[en] Modern probabilistic seismic hazard assessment (PSHA) focuses on the separation and different treatment of epistemic and aleatory uncertainties. Recent site-specific PSHA studies have pointed out that, if the site response and its epistemic uncertainties can be appropriately considered by adjustments to median estimates from ground motion prediction equations (GMPEs), the aleatory variability (sigma) of the GMPEs can be replaced by the single-station sigma thus partially relaxing the ergodic assumption employed in the PSHA. The site-specific partially nonergodic approach, correctly applied, provides a more accurate representation of the seismic hazard at a specific site and a more rigorous treatment of uncertainties. This paper presents the strategy followed to apply this relatively recent approach to a critical infrastructure in Southern France located on hard-rock site conditions (Vs30 ∼ 2000 m/s). The target site conditions are defined in terms of shear-wave velocity (Vs) profiles and high-frequency attenuation (j0) based on the results of site investigations and on the exploitation of earthquake records at seismic stations in the target site area. The host-to-target Vs-j0 adjustment of median estimates for the selected GMPEs is performed by using the inverse random vibration theory approach (Al Atik et al. in Bull. Seismol. Soc. Am. 104:336-346, 2014) considering epistemic uncertainties in target Vs profile and j0. The single-station sigma model is developed based on Rodriguez-Marek et al. (Bull Seismol Soc Am 104:1601-1619, 2013) due to the lack of local data. The results of the site-specific partially nonergodic PSHA are discussed by means of a sensitivity analysis and are compared to the results from standard ergodic PSHA. We found that, for the considered site, the site-specific approach provides a substantial reduction (up to 50%) of the uniform hazard spectra at 10,000-year return period compared to the ergodic approach. (authors)
[en] French nuclear industry has launched a program for renewing itself while improving industrial quality, competencies and management of big projects. The challenge is all the more complex as the industrial partners are numerous and very diverse either in size or industrial strategies. The 6 points are summarized as follows: digesting the recent feedback experience on reactor construction to be ready to propose a renewed nuclear industry in 2021, drawing a precise mapping of nuclear industry in terms of industrialists, policy makers, craft unions, administrations and so on, improving communication and information exchanges between all the players, acknowledging that nuclear energy contributes strongly to energy independence, acknowledging that nuclear energy is reliable: despite the covid crisis the electricity supply has been assured, and acknowledging that the nuclear industry grows in France while all the other industrial sectors are declining. (A.C.)
[en] To investigate the comprehensive remediating effects of plant residues on biological and chemical properties and the long-term dynamics of these effects, litter from Caragana korshinskii (caragana) or Ziziphus jujuba var. spinosa (jujube) was mixed with three types of soil that were contaminated with 12.49, 27.54, and 45.37 g kg−1 of petroleum. The mixtures were incubated at 20–25 °C with consistent soil moisture for 360 days. Subsequently, the litter impacts on the soil microbial population, the activities of 12 types of soil hydrolytic, and redox enzymes related to the cycling of C, N, and P, and the available N, P, and K contents were determined during the incubation. The results indicated that both types of litter significantly accelerated the reproduction of soil microbes and significantly increased the activities of most of the hydrolytic enzymes and the available nutrient contents after the short-term treatments, while the litters usually simultaneously depressed the activities of polyphenol oxidase and peroxidase in the slightly and moderately contaminated soils. However, the comprehensive remediating effects of the litters on the lightly contaminated soil significantly decreased over time while it recovered to some extent at the end of the experiment. The remediating effects on the seriously contaminated soil exhibited the opposite trend, and their remediating effects on the moderately contaminated soil exhibited continuous weakening. Generally, the remediating effects of the caragana litter were more noticeable than those of the jujube litter, except for the effect on the slightly contaminated soil after 180 days of treatment.
[en] The mapping of the French nuclear industry was performed in 2019, it will give visibility to all its players whatever they are: firms, policy makers, craft unions, training bodies or administrations. The mapping was made through a questionnaire survey similar to the previous one made in 2014 but completed with international and digital transformation issues. It appears that 220.000 people are employed in nuclear industry compared to 218.000 in 2014 and they worked in more than 3000 enterprises and their qualification level is higher than the average in other industrial sectors. EDF and Framatome have certified more than 600 suppliers of equipment and services at the level 'nuclear standards'. More than half of the 3000 enterprises have export activities which is far more than in other industrial sectors. Nuclear industry handles all the activity fields that are necessary to its proper working, for instance the share of work for French firms in the construction of an EPR can reach 80% while in wind energy this share was only 40% in 2015. (A.C.)
[en] This analysis of the frequency, intensity, and duration of thermal inversions is based on daily minimum (tn) and maximum (tx) temperatures recorded over 3 years at 16 pairs of data loggers located under forest cover in the Jura Mountains of France. Each pair consists of a logger located at the bottom of a depression and another located higher up either nearby (local site) or more than 40 km away (regional site). The daily frequency of inversions is maximum at local sites for tn (50%) and minimum for tx at regional sites (4%). The maximum intensity of the inversions reaches 15.1 °C for tn and 16.2 °C for tx. The average intensity is about 2 °C: 1.5 °C for tx at local sites and 2.4 °C at regional sites. The duration of inversions is generally short: 60% of them last less than a day. Of the inversions that last for more than 1 day, 15% exceed 3 days and the maximum duration observed is 22 days. The relationship between the diurnal amplitude of temperature and the frequency, intensity, and duration of inversions indicates that mesoscale atmospheric conditions directly influence inversions.
[en] The south-eastern region of France is the first industrial region of the country with more than 500.000 jobs, 43.000 of which are in the nuclear industry. This industrial tissue is composed of sites of big companies like Framatome or Orano and of a variety of intermediate- or small-size enterprises like Filtration SA, Sileane or Curium. Filtration SA produces among others some filters of the primary and secondary cooling systems of reactors. Sileane develops intelligent robots that can face random situations. The KAMIDO robot can recover unknown objects one by one from a loose bulk and has been adapted to repackage radioactive wastes. Curium is specialized in the management of pollutions and contaminations in facilities. (A.C.)
[en] Seismic analysis in the context of nuclear safety in France is currently guided by a pure deterministic approach based on Basic Safety Rule (Regle Fondamentale de Surete) RFS 2001-01 for seismic hazard assessment, and on the ASN/2/01 Guide that provides design rules for nuclear civil engineering structures. After the 2011 Tohohu earthquake, nuclear operators worldwide were asked to estimate the ability of their facilities to sustain extreme seismic loads. The French licensees then defined the 'hard core seismic levels', which are higher than those considered for design or re-assessment of the safety of a facility. These were initially established on a deterministic basis, and they have been finally justified through state-of-the-art probabilistic seismic hazard assessments. The appreciation and propagation of uncertainties when assessing seismic hazard in France have changed considerably over the past 15 years. This evolution provided the motivation for the present article, the objectives of which are threefold: (1) to provide a description of the current practices in France to assess seismic hazard in terms of nuclear safety; (2) to discuss and highlight the sources of uncertainties and their treatment; and (3) to use a specific case study to illustrate how extended source modeling can help to constrain the key assumptions or parameters that impact upon seismic hazard assessment. This article discusses in particular seismic source characterization, strong ground motion prediction, and maximal magnitude constraints, according to the practice of the French Atomic Energy Commission. Due to increases in strong motion databases in terms of the number and quality of the records in their metadata and the uncertainty characterization, several recently published empirical ground motion prediction models are eligible for seismic hazard assessment in France. We show that propagation of epistemic and aleatory uncertainties is feasible in a deterministic approach, as in a probabilistic way. Assessment of seismic hazard in France in the framework of the safety of nuclear facilities should consider these recent advances. In this sense, the opening of discussions with all of the stakeholders in France to update the reference documents (i.e., RFS 2001-01; ASN/2/01 Guide) appears appropriate in the short term. (authors)
[en] After half a century of nuclear industry in France, the CEA and EDF are forced, for security reasons, to put some of their basic nuclear installations (nearly ten) to the final shutdown. The problem then arises of their future. Dismantle today or wait until tomorrow? The choice, unless it is made for reasons of safety and politics, is an economic choice. Being able to estimate, at their fair value, the costs of dismantling operations while respecting the established legal framework, is a new challenge that operators must take up. CEA is a pioneer in the dismantling field with eight major projects underway. This paper is devoted to the administrative aspects of dismantling (regulations, budget...): a first part is devoted to the environment in which the dismantling is located; the second deals with its costs, and a method to identify and quantify dismantling costs is proposed.
[fr]Apres un demi-siecle d'industrie nucleaire en France, le groupe C.E.A. ainsi que E.D.F, sont contraints, pour des raisons de securite, de mettre certaines de leurs installations nucleaires de base a l'arret definitif. Se pose alors le probleme de leur devenir. Demanteler aujourd'hui ou attendre demain? Le choix, a moins qu'il soit fait pour des raisons de surete et de politique, est un choix economique. Etre capable d'estimer, a leur juste valeur, les couts des operations de demantelement en respectant le cadre juridique etabli, est un nouveau defi que les exploitants (C.E.A., E.D.F.) se doivent de relever. Dans ce nouveau secteur industriel qu'est le demantelement, le C.E.A. est un pionnier en la matiere avec huit grands chantiers en cours. Les choix technologiques mis en oeuvre, d'ailleurs largement mediatises, ne seront pas abordes dans le cadre de ce memoire. Seul l'aspect administratif tel que reglementation et partie budgetaire sera developpe. Ainsi, cette etude se presentera en deux parties: la premiere consacree a l'environnement dans lequel se situe le demantelement; la deuxieme traitera de ses couts. Au constat de notre inexperience dans l'evaluation des depenses imputables au demantelement, une methode pour cerner et quantifier les couts de demantelement sera proposee. Cette analyse est d'autant plus importante que pres d'une dizaine d'installations nucleaires du Commissariat a l'Energie Atomique seront definitivement mises a l'arret avant la fin du siecle. (auteur)
[en] About 220.000 people are working in French nuclear industry which makes this industry sensitive to issues like recruitment and training. This industry has a poor image among the young generation and faces difficulties to enlist. The main difficulty is to convince young graduates that nuclear industry is an industry for the future despite the fact that only one reactor is being built in France and the shutdown of Fessenheim. In order to overcome this difficulty the government has launched the EDEC plan. The EDEC plan will allow actions for preserving jobs, increasing attractiveness of the nuclear sector and supporting graduating curriculum in nuclear engineering. (A.C.)