Overview of the IAEA national technical cooperation projects on uranium exploration in Argentina L. López, R. Ferreyra National Atomic Energy Commission (CNEA), City, Argentina E-mail address of main author: [email protected] Abstract. Since 1993, three IAEA National Technical Cooperation Projects have been developed in Argentina. Their objectives have been to improve the capability of the country to strategically plan and efficiently carry out its uranium exploration program 1. Introduction The uranium mining cycle activities in Argentina began in the 1950s. Then, the systematic exploration led to the discovery of several uranium deposits and, consequently, seven mining centers were in operation in the country and produced a historical total of 2 500 tonnes of U. In 1992, for economic reasons Argentina began to import uranium, a situation that progressively led to the closing of national production in 1998. In spite of that, the CNEA has continued to be active in several uranium projects that have progressed to different degrees of development. Furthermore, since 1993 three National Technical Cooperation Projects have been developed through the IAEA’s technological transfer devoted to uranium favorability and exploration, gamma-ray spectrometry surveys and ISL, respectively. 2. Technical Cooperation Project ARG 3/007 “Uranium favorability and exploration in Argentina” (1993 - 1996) In the context of this TC project, new skills were developed to carry out the assessment of the uranium favorability of the country. This program consists of the regional assessment of the country’s overall uranium potential, following the method applied by the National Uranium Resource Evaluation (NURE) from the United States. For these studies the national territory is divided into 57 research units where the speculative resources, taking into account the presence of existing uranium deposits in the area or in a similar geological environment, are determined. At present, this program is 55% completed [1][2][3][4]. This project has contributed to providing new guidelines for the exploration of volcanic and caldera related, sandstone and granitic geological types of uranium deposits. Main cooperation activities were developed in the San Rafael (Lower Permian) and San Jorge Basins (Cretaceous) and the Pampean Ranges (Lower Paleozoic). These areas represent some of the more important regions for uranium exploration in the country [5]. In addition, 140 000 km2 of airborne gamma ray spectrometry data from Patagonia and Pampean Ranges [6][7], were reprocessed and back-calibrated [8]. These surveys were originally conducted for detecting potential uranium mineralisation, an objective that was clearly reached, but the production of a new digital archive enhanced the application of this information in the fields of geological mapping and environmental issues [9][10] . 3. Technical Cooperation Project ARG 3/008 “Prospection of uranium and other elements using gamma-ray spectrometry surveys” (2001 - 2004) In the framework of this TC project, new capacities for the detection, processing and interpretation of airborne, carborne and ground gamma ray spectrometry data were developed. A carborne gamma–ray spectrometer system was successfully installed and calibrated, so that the gamma-ray count rates could be converted to ground concentrations of potassium, uranium and thorium [11]. This carborne system has a 4.2 l NaI detector mounted on the roof of a truck and can record up to 512 channels of gamma-ray spectral data [12]. This new gamma-ray spectrometer system increased the national capability for uranium exploration. Moreover, it enhances CNEA´s ability to conduct ground-based surveys to support mineral exploration and environmental studies [13]. 4. Technical Cooperation Project ARG 3/012-14 "Geology favorability, production feasibility and environmental impact assessment of uranium deposits exploitable by the in situ leaching (ISL) technology" (2007 - up to date) This is an ongoing project that is linked to the IAEA Regional Technical Cooperation Proect named “Upgrading of Uranium Exploration, Exploitation and Yellowcake Production Techniques taking Environmental Problems into Account (RLA 3006)” and considers the study of different areas of interest within the uranium mining cycle of ISL [14][15]. At the favorability stage, some Tertiary sandstone units of the Neuquina Basin are being investigated through the compilation of previous information, field reconnaissance, the gathering of logging and sampling data from oil wells, petrophysical determinations and petrological studies [16]. Also, in the Cretaceous San Jorge Basin based on airborne gamma ray spectrometry surveys, field geological reconnaissance and underground information, some targets with ISL possibilities were defined. In some locations, inferred and prognosticated uranium resources have been defined and a drilling program has been set up to be carried out this year [17]. Finally, the TC project includes pilot tests in order to determine the production feasibility of the remaining resources, evaluated in 216 t U, by block leaching mining in the Don Otto deposit [1]. This deposit was exploited from 1963 to 1980 by underground mining, obtaining a total of 275 tonnes of U [18]. According to the present knowledge, ISL should be considered as a sustainable alternative for uranium production in the future of our country. 5. Final considerations The advancements in the nuclear field reached by Argentina have been historically supported by the existence of uranium mineral resources in the country. The existence of favorable environments and advanced exploration programs, configure promising conditions to develop new uranium resources that would allow Argentina to increase the participation of the nuclear technology in the energy generation of the country. In this general framework, the role of the IAEA Technical Cooperation Projects is highly relevant for improving the capability of Argentina to strategically plan and efficiently carry out a variety of uranium projects. ACKNOWLEDGEMENTS These projects were conducted with funding from both the International Atomic Energy Agency and the National Atomic Energy Commission (Argentina). The authors are grateful to the Geological Survey of Canada, United States Geological Survey, CREGU (France), Australia Geosciences, University of Prague, WNU School of Uranium Production - DIAMO (Czech Republic), NAC Kazatomprom (Kazakhstan), AREVA (France) and Geological Survey of Argentina for the for their valuable support during the development of the projects. A very special thanks goes out to Kenneth Ford (Geological Survey of Canada) for his constructive suggestions and revising of the manuscript. REFERENCES [1] VALDIVIEZO, A., "Estudio de la favorabilidad geológico uranífera del territorio nacional”, Comisión Nacional de Energía Atómica report, unpublished (1995). [2] BLASÓN, R., QUER, J., ALDANA, V., "Discriminación en categoría de costos de los recursos uraníferos potenciales de yacimientos con control sedimentario e intragraníticos". Comisión Nacional de Energía Atómica reports, unpublishied (2003 - 2008). 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