Overview of the IAEA national technical cooperation projects on

Anuncio
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).
[3] KLEIMAN, L., Carpetas Técnicas - Exploración Uranífera, Comisión Nacional de Energía
Atómica reports, unpublished (2000 - 2001).
[4] LÓPEZ, L., "Informes de la Meta Institucional 741 - Prospección Geológico Minera",
Comisión Nacional de Energía Atómica reports, unpublished (2000 - 2009).
[5] CUNEY, M., GAGNY, C., "Uranium favorability in granites - Argentina", IAEA expert
mission reports, unpublished (1993 - 1995).
[6] SOLIS, R., MALLET, R., "Informe de la inspectoría técnica de la obra de prospección aérea
70 ex.", Comisión Nacional de Energía Atómica report, unpublished (1980).
[7] SOLIS, R., MALLET, R., "Informe de la inspectoría técnica de la obra de prospección aérea
01/81", Comisión Nacional de Energía Atómica report, unpublished (1983).
[8] GRASTY, R., "Back-calibration of spectrometry gamma-ray airborne surveys (Córdoba and
Patagonia, Argentina)", IAEA expert mission reports, unpublished (1993 - 1994).
[9] FORD, K., LÓPEZ, L., “Characterization of levelling problems of Patagonia Gamma-Ray
spectrometry survey, Chubut Province, Argentina”, X Congreso Latinoamericano de
Geología y VI Congreso Nacional de Geología, Simposio Geofísica Aérea y Geoquímica en
la Prospección Geológica – Minera, Proceedings 31:117-121 (1998).
[10] LÓPEZ, L., FORD K., GRANT, J., "Levelling problems of a reprocessed gamma-ray
spectrometry survey, Chubut province, Argentina", IAEA Technical Meeting
“Radioelement mapping and status of the global radioelement baseline and maps”, Golden,
CO, USA, 23-26 June 2003 (in press).
[11] GRASTY, R., "Calibration of a carborne gamma-ray spectrometry system in Argentina",
IAEA expert mission report, unpublished (2001).
[12] EXPLORANIUM LTD, GR660 and GR330 spectrometer systems, technical documents,
unpublished (2001).
[13] LÓPEZ, L., GRASTY, R., PEÑALVA, G., "Carborne gamma-ray spectrometry test survey
in Argentina", IAEA Technical Meeting “Radioelement mapping and status of the global
radioelement baseline and maps”, Golden, CO, USA, 23-26 June 2003 (in press).
[14] LÓPEZ, L., “IAEA Technical Cooperation Project on ISL in Argentina”, IAEA Technical
Meeting on “Uranium Exploration, Mining, Production and Mine Remediation and
Environmental Issues”. Mendoza (Argentina), 2-6 October 2006 (CD-ROM) (2006).
[15] LÓPEZ, L., SLEZAK, J., "Proyecto de innovación tecnológica sobre depósitos de uranio
tipo lixiviación in situ (ISL) en Argentina", IX Congreso Argentino de Geología
Económica, Catamarca, 23 - 25 September 2009 (in preparation).
[16] SALVARREDI, J., ROJAS, G., Informes de avance - Estudios en Cuenca Neuquina,
Comisión Nacional de Energía Atómica report, unpublished (2006 - 2008).
[17] BIANCHI, R., PÁEZ, M., "Tipificación y distribución de depósitos de uranio en la cuenca
del Golfo de San Jorge", La Plata (CD-ROM) (2005).
[18] GORUSTOVICH, S., LÓPEZ, L., GUIDI, F., "Metalogénesis del yacimiento de uranio Don
Otto (Salta, Argentina). Su viabilidad de explotación por lixiviación en bloques", IX
Congreso Argentino de Geología Económica, Catamarca, 23 - 25 September 2009 (in
preparation).
Descargar