[en] The pit water from uranium mines is normally treated to eliminate the soluble radium and suspended solids. The radium is precipitated together with the barium sulphate. The latter results from the reaction of barium chloride with an excess of sulphate ions. The suspended solids are flocculated by aluminium salts (chloride, polychloride). If necessary, synthetic flocculants are also used. Certain grades of pit water contain, sometimes incidentally, a few milligrams of uranium per litre. These quantities always remain too low for any direct recovery (treatment by ion exchange resins). By applying certain measures, the preceding processes can also be used to eliminate uranium. The latter is carried away by aluminium hydroxide in a very narrow zone of pH (6 to 7,4) which corresponds to the minimum solubility of the hydroxide. Depending on the characteristic of the water (pH, salinity), use is made either of aluminium sulphate or of sodium aluminate, with an addition of a base in extreme cases. This article gives various examples of applications in the Haute-Vienne, Chardon in Vendee, the Commanderie mine in Vendee, at Cerilly in Allier and at Lodeve in Herault

[en] Salt deposits lend themselves a priori well to the burial of radioactive wastes which can have a harmful effect for very many years. This property has already been put to use in the USA and in West Germany. It must approached, however, with prudence because geological investigation on the real site have not been made yet

[en] The uranium deposits worked by the Compagnie Generale des Matieres Nucleaires on French metropolitan Territory are mainly to be found as being in granite. These consist of subvertical mineralised fractures of metric thickness on the average, sometimes even thickening out to 10 metres. The contours of the mineral in situ are very variable and the contents scattered. In certain deposits, the ore body is weak and falls easily, but the roof and floor remain relatively strong, whilst they are themselves affected by cracks which cut them up into benches or splinters. The necessity of productivity and selectivity at the face and when loading, in these underground mines, has led to special methods of work being developed by means of descending horizontal slices being got below an artificially made roof of reinforced concrete, anchored by dowels to the roof and floor (Limousin) or by a cemented stowing placed hydraulically (Forez)

[en] It is the offer of energy which will determine an energy consumption in the near future. The availability makes it foreseeable that there will be considerable reductions in the national production. More coal will have to be imported as well as gas, reducing on the other hand the importation of oil so as to diminish an national dependance on oil. Fortunately nuclear electricity and the renewable energy sources will be a compensation which nevertheless will not avoid the necessity for substantial economies of energy

[en] Statement presented to the ISF Energie Commission, the 27th April 1979, giving details about the repair works on the water pressurised reactor of the nuclear power plant at Harrisburg, Pennsylvania. The 28th March, at 4 o'clock in the morning a failure causing the stopping of the steam generator water feed, in connection with another deficiency (no standby feed), causes a lack of water in the secondary circuit. A series of events leads afterwards to the very serious reported accident

[en] The performance of equipment are limited by the materials employed, they are submitted to extreme conditions and safety criteria are very severe. Are more particularly studied: the choice and the fabrication of nickel alloys for steam generator tubes of water reactors, stainless steels used in superphenix and briefly the stainless steel Uranus S1N for reprocessing facilities because of its outstanding resistance to oxidizing media

[en] The Cellier mine processes inframarginal uranium ores by a slow dump leaching. Fragmentary information concerning the evolution of the chemical properties of the solutions (inflow-outflow) as a function of the time has been the object of an analysis of data. The latter, which was both descriptive and predictive, made it possible on the one hand to identify facts which have intervened at the time of leaching and on the other hand to pinpoint the influence of the time factor and of the associations of chemical elements (aluminium, phosphorus, etc.) on the passing into solution of the uranium. As this treatment gives only a global view of the problem, it was completed by a mineralogical analysis. The fine mineralogical analysis of the fractions, made soluble by sulphuric attack in a heap, shows that sulphated concretions isolate the uranium from the leaching liquor. A screen of sulphate is composed of a macroscopic web of gypsum (calcium sulphate) in which a microscopic web of hydrated magnesium sulphate is inserted. In the gypsum web are trapped phosphorus minerals and in the magnesium sulphate web manganese and aluminium minerals. As regards the uranium, it is either distributed in the form of fine inclusions of uranyl hydroxide, or associated to chlorinated forms, derived from the treatment aids

[en] After having analysed the coal crisis, the oil and nuclear policies of European countries, the author highlights the consequences of the shock of the two oil crisis and illustrates the picture of the energy future of Europe

[en] The Compagnie Generale des Matieres Nucleaires (Cogema) mines in the South of France near Lodeve a uranium deposit of particular originality. The uranium, mainly in reduced form, is situated in a schistose and carbonated formation of Permian age. The difficulties of treating the ore are due to the presence of carbonates, to the refractory nature of the uraniferous mineralization, to the organic matter, and to the presence of sulphides and molybdenum minerals which cannot be separated by flotation before the chemical attack. This article describes the research, carried out for the complex process which takes into account the properties of the ore and the restraining factors of the environment. The principal features are: an alkaline attack; a preneutralization by sulphuric acid and a precipitation in lime which gives a preconcentrate with 25-30% U; a calcination at 600⁰C to eliminate the organic matter; an acid re-treatment to pass the uranium again into solution; a treatment of the remaining gypsum to recover the uranium present in it; a precipitation of magnesium uranate; a separation of the molybdenum; a crystallization of the effluents to prevent any discharge of sulphates in the environment. The plant carried out its first tests in the spring of 1981. lts capacity is 60 t/h of ore and 1000 t of uranium per year in concentrates of magnesium uranate

[en] Short paper describing the recovery of uranium from gold mining tailings. Twenty seven mines are concerned and seventeen plants ensure the treatment. In 1979, 4797 tonnes of uranium mineral was recovered. Brief technical indications are given on the sorting installations