2.1. Does the 2008 economic crisis impact uranium exploration?
Figs 4a and 4b illustrate, respectively, the number and cumulative number of deposits discoveries vs. time since the 1950’s, together with their corresponding (cumulative) tonnage (Fig. 4c and 4d). The figures come from the declared values in the UDEPO database. Major economical crises and nuclear accidents are superposed on the time diagram (Fig. 4a) and uranium prices for comparison. Details of Fig. 4b over the period 1950-2000 are reported in Figs 5a-d.
24 The figures in this table are liable to change as new data become available. The first uranium producer in the World is Kazakhstan with 23,127 t U in 2014, more than half produced by KazAtomprom, followed by Canada (9,134 t U), Australia (5,001 t U) and Niger (4,057 t U) (see at http://www.world-nuclear.org/information-library/facts-and-figures/uranium-production-figures.aspx ).
25 Given the many nuclear power programs in construction in several countries in the World, this figure is certainly overestimated as one can expected an increase in World uranium consumption in the next coming decades.
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(a) (b)
(c) (d)
Fig. 4. (a) Number of deposits discovered against time recorded in the UDEPO database since the 1950’s. Oil crisis and nuclear accidents seemed to have been a great impact. U prices remained to drive exploration before 2008. (b) Cumulated number of deposits. (c) U (in Mt U) tonnage discovered against time since the 1950’s (d) Cumulative tonnage.
As indicated in Fig. 4, the number of uranium deposits discovered has decreased after major nuclear accidents (Three Miles Island, Chernobyl, Fukushima), indicating that exploration activity was significantly reduced shortly after these incidents. On the contrary, every oil or energy crises were followed by a reassessment in exploration activity leading to the discovery of new oil deposits some years after (Fig. 5a). Uranium prices seem to have relatively less impact in uranium exploration activities in the past, but high uranium prices seem to have driven the exploration before the 2008 crisis and the Fukushima accident. However, recent studies on U price changes related to exploration delays show that exploration tends to increase during times of high uranium prices, but the time lag between exploration success and production of uranium plays a significant role in influencing price volatility [5, 6]. This is probably explained why the recent 2008 crisis had no impact on the number of uranium deposit discoveries (the highest numbers of discoveries were registered just after the crisis) probably due to the emergence of new exploration areas such as Asia. In conclusion, exploration was very active the past 10 years with major discoveries (or reported discoveries) in regions like Africa, Asia, Middle East, and South America (Fig. 6), but recently decreased following the Fukushima accident. Major turning points (in 1975, 1983, and 1992) can be observed on the cumulative curves (Fig. 5b, d), indicating significant discoveries in terms of numbers and tonnages (some of them due to new explored areas or discoveries such as Africa in 1975, Canada in 1982, and Asia in 1992).
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(a) (b)
(c) (d)
FIG. 5. Data for period before the 2000’s. (a) Number of deposits discovered against time recorded in the UDEPO database since the 1950’s. (b) The same as (a) but with cumulated number of deposits. (c) U (in Mt U) tonnage discovered against time over the same period (d) with cumulative tonnage.
(a) (b)
FIG. 6. (a) Quantity (in Mt) of uranium discovered compared to known resources vs. decades as recorded in the UDEPO database since the 1980’s. (b) The same as (a) but detailed per continent indicating the emergence of South America in the 1990’s, Asia in the 2000’s, and Middle East in the 2010’s.
What next? It is hard to say and be prognostic if the uranium prices will increase again or not in the next few years, but given the long term on-going nuclear programs in India and China there are signals that U spot prices will increase in the near term. More precisely, a recent study by [1] suggests that increase in use of civil atomic power in some emerging economies, such as South Korea and China, would question the availability in uranium resources and may lead to a supply shortage for the forthcoming decade, despite the fact that global uranium resources are
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more than sufficient to supply reactor-related demand for the rest of the century, especially if the super regenerators technology is started in operation.
2.2. Identifying new target areas
Geology plays a major role in identifying potential resources for natural commodities.
However, global multivariate indicators based on past discoveries can help in pointing out lacking or unexplored prospective areas. This approach is used in oil and gas exploration assessment for identifying geologically-permissive prospective areas [7] and in mineral exploration for locating undiscovered mineral resources in large tracts [8], [9]. Keeping this in mind, the amount of uranium per square kilometer (in U kg/km2) (referred as Exploration Index EI, Fig. 7) has been introduced. It has been calculated per continent in order to identify the exploration degree of a region. The ranking of continents in order of increasing EI is: Europe (EI = 920), North America (800), Africa (617), Australia (417), World (382), Middle East (176), South America (46), and Asia (43). In short, regardless of geological endowment (which is certainly wrong, if compared with other metals such as gold) but given their vast areas, the higher the EI is, the better the region is for exploration. Or, in geological context, the higher the EI, the better the chance a country has for successful exploration.
(a) (b)
FIG. 7. (a) Radar diagram of exploration index (values indicated) calculated per continent. (b) Continents are ranked in decreasing exploration index showing the best to the least explored area.
Regardless of geological context, it is indicated that there are more uranium deposits to be found in the Middle East, South America and Asia, given their vast areas compared to Europe, North America and Africa26.
2.3. Discussion
Several other approaches including geological indicators have been used in the past for estimating potential undiscovered mineral resources, country by country, such as the work by [10] for estimating potential uranium resources in the USA, including 700 areas and 1,022 files
26 Kazakhstan is included in Middle East.
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accounting for economical constraints on the uranium price, assuming log-normal distribution of grade and resources. More recently, based on a cumulative distribution curves approach (called endowment curves), Jaireth and Huston [11] discussed the spatial distribution of gold, uranium, and base metal (copper, lead and zinc) on mineralized regions of several cratonic terranes and districts in the world (including Canada, Australia, Chile, Poland, Uzbekistan, and Ghana). They concluded that mineral districts with a single giant or super-giant deposit represent areas with higher fertility but also highly focused or concentrated mineral system, reflecting more intense and duration of metal accumulation caused by larger systems of energy and mass flux. This index does not pretend to be a universal key to identify new deposits; it is only a global indicator (in the UNEP sense) to point out eventually unexplored areas. It must be cross-validated with some other geological and exploration indicators to best identify the most potential targets. Keeping in mind these limitations, it appears that Europe is the best explored (920) while significant potentiality seems to exist in Asia, which presents some similar geological contexts as the Europe (such as Hercynian complexes). Several types of such indices can be derived, such as the number of deposits per square kilometer. This approach is global and valid only on large areas containing a collection of different geological formations of different ages, so that the geological context is assumed to be significantly represented.
The global aspect is one of the weaknesses of the methodology. It is suited to uranium, which is very mobile in oxidizing contexts and precipitates in reducing conditions, unlike some other commodities, such as gold, that occurs in very specific geological settings. This explains the diversity of geological settings in which uranium deposits can occur, varying from phosphate, sedimentary, plutonic to volcanic-related deposit-types (see Fig. 8). In order to account for their geological setting, uranium deposits have been grouped according to the classification recommended by the IEAE, which comprises 15 main types. Then, a statistical study was carried out to try to build a grade-and-tonnage model.
FIG. 8. Classification of uranium deposits into 15 main types according to their geological cycle. The median graded and tonnages are indicated per deposit type (modified after [12, 13]).
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3. URANIUM DEPOSITS STATISTICS ACCOUNTING FOR THEIR GEOLOGICAL