[en] The present characteristics can be summarized in one word: expansion. Impelled by the CEA, but also by such organisations as the Electricite de France and the Merchant Marine, the French nuclear effort for the years 1957-1961 reaches about 600 thousand millions francs; over half this sum will be spent by chemical industry on research, pilot installations, construction of plants and delivery. The aim is to work efficiently, quickly and profitably. This is achieved through close collaboration between the big state organisations and private industry. It is chiefly along the following lines that this large scale effort is carried on: - thorough chemical treatment of increasing tonnages of ores from the French Union, with the aim of producing pure, plentiful and cheap uranium. - careful preparation of nuclear fuels, economical and perfectly adapted to the various types of reactor in operation or under construction. - Further treatment of irradiated fuels to extract the plutonium completely, as well as the uranium and certain fission products. industrial manufacture of material of nuclear purity or corrosion resistant required by the technology of energy producing or research reactors. - Supply to the many foreign or French users of isotopes and radioactive tracers required by medicine, industry and agriculture in ever-increasing numbers. - Meticulous chemical treatment of gaseous or liquid effluent in strictly controlled stations in order that reactors and their annexes will be perfectly safe to use. This account shows the great extent of the effort laid out by a young, energetic chemical industry in full swing. Having made sure of its techniques and set up numerous installations it is fully in a position to confront the French atomic programme. In addition it is able and anxious to associate with the developments of foreign atomic industry, especially EURATOM and Eurochemic. (author)

[en] One of the methods checking ores in the course of treatment is the rapid quantitative determination of thorium. This measurement is carried out by means of a scintillation instrument which shows the β and α coincidences of ThC and ThC'. The treatment of irradiated fuel is accompanied by a large number of radioactive checks relative to the performance of the fixation and elution operations of uranium in the ion exchangers, to the concentration of radioactivity of effluent sent from the plant into watercourses. The operations of fixation and elution of the uranium are checked automatically by an instrument which takes a sample of 5 cm³ of solution, evaporates it and measures its activity every 10 or 20 minutes. Plutonium concentrations are measured: - in the presence of strong β γ activities, by means of rotating cylinder detectors; - in the presence of weak β γ activities, by means of α detectors scanning a constant level liquid surface; - by means of fission chambers relatively insensitive to γ. Fission product concentrations are measured by chambers, counters or scintillators, according to the amount of γ activity present. Finally, the activity of effluent to be emptied into watercourses is checked by means of a scintillation instrument, which measures the α activity on the one hand, and on the other hand the β γ activity of residue from a 100 cm³ sample taken and evaporated in 20 minutes. (author)

[en] This document reports the results of tests aimed at determining an optimal chemical processing for wastewaters from a column of extraction by solvents of a uranium-thorianite plant, and measurement problems due to the chemical composition of the studied solutions. A first part reports the measurement of the alpha global activity by scintillation. The second part presents and comments the obtained results. It shows the role of the intermediate filtration, and reports the determination of the optimal pH

[en] The reader will find in this paper an economic study of the re-utilization of depleted uranium from nuclear reactors, whether its content be above or under natural proportions. Re-utilization is possible either through bringing the depleted product up to its initial content of ²³⁵U by mixture with a richer concentrate, or else by passing it through a gaseous diffusion plant. The economic area of such re-utilization depends on a number of considerations. We give a general study of it, with reference to some typical gaseous diffusion facilities. (author)

[en] This report deals chiefly with the treatment of binary alloys (UAI, UMo, UZr, UCr, USi) with a low concentration of the additional element (≤2 per cent). The investigation was pursued with a view to the continued utilisation, with a minimum of modification, of the existing plants for treatment of non-alloyed irradiated uranium. In the first part, the usual process for the treatment of irradiated uranium by solvent extraction is briefly recalled. The second part is devoted to a study of the selective dissolution of the canning around certain of these alloys. The third part gives the behaviour of these different alloys at various phases of the usual treatment: a) dissolution; b) extractions; c) final treatment of fission products; d) final purification of plutonium. To conclude, possible alloys are classed as a function of their repercussions on the normal treatment. (author)

[en] After a brief recapitulation of the problem and its difficulties, the chemical process and the apparatus used are described. The results obtained at the various stages of the separation are then given, as well as the performance by the apparatus. (author)

[en] The average cadmium ratio in natural uranium rods has been measured, using equal diameter natural uranium disks. These values correlated with independent measurements of the lattice buckling, enabled us to calculate values of the resonance escape probability for the G1 reactor with one or the other of two definitions. Measurements were performed on 26 mm and 32 mm rods, giving the following values for the resonance escape probability p: 0.8976 ± 0.005 and 0.912 ± 0.006 (d. 26 mm), 0.8627 ± 0.009 and 0.884 ± 0.01 (d. 32 mm). The influence of either definition on the lattice parameters is discussed, leading to values of the effective integral. Similar experiments have been performed with thorium rods. (author)

[en] India will require a substantial increase in the generation of electrical power to meet the demands of her developing economy. A survey of available resources has been made in the context of development envisaged under the country's five-year plans and it is felt that atomic energy will have to be used in increasing quantities to supplement conventional fuel resources in order to attain the anticipated power targets in the next two decades. It has, therefore, been decided that a small beginning will be made with the erection and commissioning of anatomic power station of 250 MW (electric) capacity by the end of 1964. The installation of a further 750 MW of nuclear power by the end of the third five-year plan period, i.e. by March 1966, is under consideration. Present Pattern and future demand of energy is discussed, as well as available resources and immediate needs. Concerning nuclear fuel cycle and cost estimates it is stated that India's uranium reserves are not large enough to sustain a very long-term programme of power generation, but the reserves for thorium are. Therefore India's nuclear power production will have to be based primarily on thorium with a rather complicated fuel cycles and first, second and third generation atomic power stations. The Atomic Energy Establishment Trombay is India's national centre for research in the peaceful uses of atomic energy. India's first reactor, Apsara, which is of the swimming pool type, has been in operation for more than three years now and two other research reactors are under construction. These are the Canada-India Reactor, which is being built under the Colombo Plan in collaboration with Canada, and Zerlina, which is being designed and built by Indian scientists and engineers. The Canada-India Reactor will be a versatile high flux research reactor and will have facilities in which various power reactor concepts can be tried out in the so-called loop experiments. In addition, it will produce considerable quantities of radioisotopes for use in agriculture, biology, industry and medicine. The third reactor, Zerlina, will be a zero energy reactor for lattice investigations in natural uranium fuelled, heavy water moderated systems. Studies and work have begun on the prototype of a natural uranium fuelled, heavy water moderated, organic cooled power reactor. A plant for the production of thorium from monazite sands has been working for a number of years, and a plant for the production of uranium metal of atomic purity has been in operation since the beginning of this year. A fuel element fabrication facility has been completed and prototype fuel elements for the research reactors have already been produced. Investigations on the setting up of a large mill for treating uranium ores in Bihar are under way. In the field of moderators, a heavy water plant with an annual capacity of over 14 tons is being built at Nangal, as part of large fertilizer complex. The possibility of producing heavy water at other fertilizer plants under construction in the country is also being considered. Besides, studies have been made for the production of nuclear graphite from indigenous raw materials, and a decision on a plant is likely to be taken soon

[en] In this paper the results obtained from four years operation of the pilot plant when using bars of increasing activity, are summarised and compared with the results of parallel studies carried out in the laboratory. As a conclusion to the article, the optimum conditions for the different phases of a process based on solvent extraction are given. (author)