[en] Airborne survey for radioactive minerals started around 1945. The limited sensitivity of the tools used, the difficulties found for the topographic and training effect corrections, made difficult the evaluation of the results. The technical progresses realized in the recent past years in electronic and computer sciences allowed to overcome these difficulties and gave to the method all its potentialities. With the aerial spectrometric survey, a new step was made, because this method can be used for other topics than radioactive prospection such as geological survey and mining prospection for metallic and industrial minerals. The spectrometric method is based on the possibility to measure photopeak energies (gamma radiation) emitted by radioactive minerals and discriminate between them those emitted by U238, TI 208 and K40 respectively daughter products of uranium, thorium and potassium. For airborne survey, one consider that measuring instruments will allow to pick-up 80% of the radioactive emission concerning the first 15 to 30 centimetres of ground (1 metre maximum). The use of this method for geological and mineral exploration is based on the assumption that different rock types or ore bearing rock types are composed of certain amounts of rock forming minerals which comprise specific quantities of radioactive elements such as potassium, uranium and thorium (cf: Gabelman 77). To be able to evaluate the results of the spectrometric survey it will be necessary to know roughly the behaviour of the different radioactive elements through a complete geological cycle. (author)

[en] A report of the environmental assessment panel on Rabbit Lake, Saskatchewan. A review of the proposed development of the uranium mining facility at Rabbit Lake with respect to the environmental, health, safety, and socioeconomic impacts

[en] Uranium deposits which are located in Streltsov of Russia, Dornod of Mongolia and Xiangshan of China respectively are considered to be the largest volcanic uranium deposits in Meso-Cenozoic basin in the world. Their geologic setting, mineralization characteristic and ore-controlling factors have been summarized and multi-information comprehensive prospecting model for searching for large and super-large scale uranium field have been established. Based on the established model, uranium metallogenic prospect in Meso-Cenozoic volcanic basins located in Nanling districts of Fujian, Jiangxi and Guangdong provinces, China, has been evaluated. According to structures in depth, volcanic and post-volcanic phase structure characteristics and regional geochemistry field analysis, above districts are considered not to be favourable for forming large and super-large scale uranium field. But large or medium and small scale volcanic uranium deposits can be found in local favourable districts. In the light of above-mentioned, further reconnaissance should lay emphasis on Changpu basin and Renju basin

[en] On the basis of comprehensive analysis on various sedimentary environmental criteria, the authors establish a depositional facies model of wet fan formed by alluvial fan's fast pouring into lake for the ore-bearing rocks, and point out favourable horizons and facies for the formation of uranium mineralizations. Deep researches are also done to uranium mineralization characteristics in interlayer oxidation zone, zonation features of ore bodies and spatial distribution regularities of uranium mineralizations. Three sets of data on ore-formation ages (19 Ma, 12 Ma, 1.0 Ma) are obtained with U-Pb isotope method. Various ore-controlling factors of the sandstone-type uranium mineralizations are expounded in detail. Ore-formation mechanism and metallogenic model of sandstone-type uranium deposit in the basin are summarized. Finally, the authors propose some detailed suggestions for the delimitation of prospective areas and future work in the basin, and emphasize that the southwest margin of the basin, especially the area between deposit No.511 and deposit No.512 should be a key prospecting area in the future. (4 refs., 6 figs., 3 tabs.)

[en] Over the past fifty years the uranium industry has moved from a labor-intensive industry to a 'high-tech' and capital intensive industry. Organization of knowledge, manpower and material had to change to meet the demands of several stakeholders inherent to any project and to constantly adapt to technological innovations. Today, the mission of a uranium operation is not only to make a profit while selling yellow cake to electrical power stations but also to address issues regarding safety, health, environment and demands of the regulators and the public and assure the sustainability of the operations. Good mining practice begins with the proper planning and forecasting from the discovery of a deposit to decommissioning of a mine. This report describes and defines what is considered as good practice in the various activities of a mining operation and provides an overview of the management of a single operation. As technologies are progressing rapidly in the mining industry, and as this industry is transitional, this report emphasizes the importance of training employees at all levels of the organization. The statement on good practices for the various activities of a mining operation will be useful for organizations which are planning to open new mines or intend to modernize ongoing operations. Practical examples are given in the case of histories for four different countries. The objective of this publication is not to provide strict rules on the application of good practice but to give general guidelines that can be consulted and used in many different countries

[en] The major functions and duties of the Geological Survey Department include: To map the country geologically in a systematic manner at appropriate scales and publish such maps and geological reports for public use; to search for minerals in a systematic way and make available such information through reports, maps, and essay results; to provide up-to-date information on the mineral potential of Zambia to the Government; to provide the facilities and to act as the national repository for all information on geology, minerals, and mining. Growing interest in atomic energy and in uranium led in 1976 to the enactment of the Prescribed Minerals and Materials Commission Act, and to the establishment of a Commission to formulate policies and draw guidelines for work connected with uranium and other naturally, occurring radioactive minerals and compounds. The Act defines prescribed minerals as uranium, thorium, or other naturally, occurring radioactive metal ores, and includes plutonium and other artificial elements with their respective compounds. The functions of the Commission are wide and are concerned with the search for, exploitation of and usage of radioactive minerals and materials and for the production of energy. The paper describes the legal and fiscal environment established in Zambia to attract and regulate the foreign mining companies working in uranium exploration. The conditions established have proved to be highly successful in attracting foreign interests and investments and can be recommended to other developing countries interested in attracting such investment

[en] Studies were carried out on the radiological consequences of releases of uranium and thorium decay series radionuclides to the air and water from the Rabbit Lake, Cluff Lake and Key Lake mines in northern Saskatchewan. Sources of radionuclides were discharge from the water treatment systems, and releases in the form of radon gas and particulate radionuclides from the mining and milling operations. The concentrations of incremental radionuclides in the water, fish, moose, caribou, berries and other foods consumed by the local population were calculated. The analysis showed that about 70 percent of the dose was derived from radon release and subsequent inhalation of radon and its daughters. The second highest dose, about 20 percent, was derived from ingestion of caribou that had consumed lichens containing radon decay products. The high dilution involved in the aquatic pathway and the long hydraulic residence time in the lakes resulted in a very small fraction of the total dose coming from this pathway. Radon is the radioisotope released in the largest quantity by uranium mining and milling operations, calculated in this study to be 500 TBq/a for a large mine and mill complex such as Key Lake. Background radon releases for ordinary soils are on the order of 10,000 TBq/a within the 80 km radius modeled around each mine site. Thus the radionuclides released from the mines very rapidly become difficult to separate from background levels. The incremental radiological doses received by individuals in the region are calculated to be a small percentage of natural background. Regional overlap of operations with respect to their radiological dose consequences need only be investigated in detail when facilities are within about 50 km of each other or discharge into watersheds with low dilution potential or short hydraulic transport times

[en] There is excess uranium available on the market and prices go down. A programme of reduced uranium mining has been adopted in Czechoslovakia. Uranium mines are being closed gradually. The Hamr mine, where uranium is extracted by leaching, contributes 60% to Czechoslovak uranium production. Uranium supplies to the USSR were terminated. The Czechoslovak uranium industry is entering the world market while the entire fuel cycle of the Czechoslovak nuclear industry opens up to the world. (M.D.). 2 figs

[en] Xiangshan Fossil hydrothermal system is located within a volcanic basin of south-eastern China. The fact that most metal mineralizations were found in the discharge areas of the fossil hydrothermal system shows that the discharge areas were special geochemical fields. This paper discusses some important water-rock interactions in the discharge areas of Xiangshan fossil hydrothermal system. When the fluids circulating in the deep section of the hydrothermal system went upward to the discharge area, the physico-chemical conditions under which the fluids were saturated changed so considerably that the original physico-chemical equilibria were broken. Consequently, the fluids tended to move to new equilibrium by means of regulating their chemical compositions. Temperature and pressures of the fluids could be declined greatly in discharge area; the difference of temperature and pressure are determined to be 100--150 C and 1--2 x 10⁷ Pa. As a result, a large amount of CO₂ in solution escaped from the fluids in the discharge area, and UO₂(CO₃)_n^2(1-n), stable in CO₂-rich solutions, could be decomposed into UUO₂²⁺, which could be easily reduced into pitchblende associated by calcite and hematite. The pH values for the fluids tended to increase with the CO₂ escaping, however, the interactions between the hydrothermal fluids and the wall rocks (dominantly aluminosilicate) served as the buffers for the pH, and regulated the pH value around neutral point. The buffer effect was of great importance to uranium mineralization. In addition, isotope exchangements between the fluids and rocks took place extensively

[en] The 1998 edition of the mines and quarries guidebook provides: a comprehensive overview of mining activities in France and French-speaking countries relative to coal, uranium, non-ferrous ores and metals, industrial minerals, lime, limestone, silica, cermet and saline minerals; a list of recycling companies; a list of quarries and building material exploitations (organisational structure of main companies, granulates, cement industry, gypsum, plaster, tiles, bricks, stones..); a list and coordinates by department of more than 1400 quarries with the material exploited; an inventory of mining exploitations of Belgium, Switzerland and French speaking countries of Africa, a listing and organisational structure of research and engineering centres and administrations; an alphabetical and analytical repertory of more than 700 supplying companies of the mineral industry; and the status, organization and members of the mineral industry society. (J.S.)