Uranium resources, scenarios, nuclear and energy dynamics

ISBN 978-1-49-51-6286-2International audienceA dynamic simulation of coupled supply and demand of energy, resources and nuclear reactors is done with the global model Prospective Outlook for Long Term Energy Supply (POLES) over this century. In this model, both electricity demand and uranium supply are not independent of the cost of all base load electricity suppliers. Uranium consuming Thermal Neutron Reactors and future generation, free from the uranium market once started, breeder reactors are only one part of the market and are in a global competition, not limited to the other nuclear generation. In this paper we present a new model of the impact of uranium scarcity on the development of nuclear reactors. Many scenarios rely on the subjective definition of ultimate uranium resources. We suggest that when uranium will mainly be extracted together with other resources, its cost should not be simply a function of cumulated uranium mined but also of mine yearly outputs. We describe the sensitivities of our model to breeder reactor physical performance indicators. Used fuels can be seen as a liability or as a source of usable material and a scarce resource limiting fast reactor startups in fast development in India or China. We present the impact of synergetic strategies where countries with opposite strategies share used fuels

Petrological and Geochronological Peculiarities of Novoukrainka Massif Rocks and Age Problem of Uranium Mineralization of the Kirovograd Megablock of the Ukrainian Shield

Basing on the new and published data of isotopic dating, the ages of the rock complexes of the Novoukrainka granite massif (the Ukrainian Shield) and uranium mineralization in albitites with the complexes of the host rocks were compared. A sequence of the geologic events in the Ingul megablock of the Ukrainian Shield is marked: formation of the Kirovograd (2025–2060 mln. y. ago) and Novoukrainka (2025–2040 mln. y. ago) magmatic complexes — formation of the uranium deposits (~ 1800 mln. y. ago, but the age should be precised) — Korsun-Novomyrgorod magmatic complex (1730–1760 mln. y. ago). The Novoukrainka massif is presented by differentiated magma of the magmatic melt originated from the upper crust material.На основі нових та узагальнених літературних даних про ізотопне датування проведено вікові порівняння породних комплексів Новоукраїнського гранітного масиву та уранового зруденіння в альбітитах з комплексами вмісних порід. Визначено таку послідовність геологічних подій в Інгульському мегаблоці Українського щита: становлення кіровоградського (2025–2060 млн рр. тому) та новоукраїнського (2025–2040 млн рр. тому) магматичних комплексів — формування уранових родовищ (~ 1800 млн рр. тому, вік потребує уточнення) — корсунь-новомиргородський магматичний комплекс (1730–1760 млн рр. тому). Зроблено припущення, що Новоукраїнський масив представлений диференціатами єдиного магматичного розплаву, що утворився за рахунок плавлення верхньокорового матеріалу.На основании новых и обобщенных литературных данных по изотопному датированию осуществлено возрастное сравнение породных комплексов Новоукраинского гранитного массива и уранового оруденения в альбититах с комплексами вмещающих пород. Установлена такая последовательность геологических событий в Ингульском мегаблоке Украинского щита: становление кировоградского (2025–2060 млн лет назад) и новоукраинского (2025–2040 млн лет назад) магматических комплексов — формирование урановых месторождений (~ 1800 млн лет назад, возраст должен быть уточнен) — корсунь-новомиргородский магматический комплекс (1730–1760 млн лет назад). Высказано предположение, что Новоукраинский массив представлен дифференциатами единого магматического расплава, образовавшегося вследствие плавления верхнекорового материала

Le magmatisme de la région de Kwyjibo, Province\ud du Grenville (Canada) : intérêt pour les\ud minéralisations de type fer-oxydes associées

The granitic plutons located north of the Kwyjibo property in Quebec’s Grenville Province are of\ud Mesoproterozoic age and belong to the granitic Canatiche Complex . The rocks in these plutons are calc-alkalic, K-rich,\ud and meta- to peraluminous. They belong to the magnetite series and their trace element characteristics link them to\ud intraplate granites. They were emplaced in an anorogenic, subvolcanic environment, but they subsequently underwent\ud significant ductile deformation. The magnetite, copper, and fluorite showings on the Kwyjibo property are polyphased\ud and premetamorphic; their formation began with the emplacement of hydraulic, magnetite-bearing breccias, followed by\ud impregnations and veins of chalcopyrite, pyrite, and fluorite, and ended with a late phase of mineralization, during\ud which uraninite, rare earths, and hematite were emplaced along brittle structures. The plutons belong to two families:\ud biotite-amphibole granites and leucogranites. The biotite-amphibole granites are rich in iron and represent a potential\ud heat and metal source for the first, iron oxide phase of mineralization. The leucogranites show a primary enrichment in\ud REE (rare-earth elements), F, and U, carried mainly in Y-, U-, and REE-bearing niobotitanates. They are metamict and\ud underwent a postmagmatic alteration that remobilized the uranium and the rare earths. The leucogranites could also be\ud a source of rare earths and uranium for the latest mineralizing events

Role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium deposits: insights from reactive-flow modeling

The role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium (URU) deposits in sedimentary basins during tectonically quiet periods is investigated. A number of reactive-flow modeling experiments at the deposit scale were carried out by assigning different dip angles and directions to a fault and various permeabilities to hydrostratigraphic units). The results show that the fault dip angle and direction, and permeability of the hydrostratigraphic units govern the convection pattern, temperature distribution, and uranium mineralization. Avertical fault results in uranium mineralization at the bottom of the fault within the basement, while a dipping fault leads to precipitation of uraninite below the unconformity either away from or along the plane of the fault, depending on the fault permeability. A more permeable fault causes uraninite precipitates along the fault plane,whereas a less permeable one gives rise to the precipitation of uraninite away from it. No economic ore mineralization can form when either very low or very high permeabilities are assigned to the sandstone or basement suggesting that these units seem to have an optimal window of permeability for the formation of uranium deposits. Physicochemical parameters also exert an additional control in both the location and grade of URU deposits. These results indicate that the difference in size and grade of different URU deposits may result from variation in fluid flow pattern and physicochemical conditions, caused by the change in structural features and hydraulic properties of the stratigraphic units involved

Origin of the extreme polymetallic enrichment (Cd, Cr, Mo, Ni, U, V, Zn) of the Late Cretaceous-Early Tertiary Belqa Group, central Jordan

International audienceThe sedimentary formations of the Late Cretaceous to Early Tertiary Belqa Group correspond to pure to slightly clayey limestones and minor black shales characterized by a remarkable enrichment in phosphorous and various redox sensitive elements (Cd, Cr, Mo, Ni, U, V, Zn). Phosphorous enrichment is related to the great phosphorite deposition event that has occurred at the southern margin of the Tethys Ocean during this period. The very low organic matter contents in the limestones, despite their strong enrichment in redox sensitive elements, is attributed to a deposition in anoxic water but under shallow water conditions permitting the bacterial degradation of a large part of the organic matter. Most of the elements constituting the Belqa Group sediments have been deposited from the sea water either directly by chemical precipitation (most Ca and redox sensitive elements) or indirectly through biogenic activity (P, part of Ca and U), except for the minor detritial contribution presents in some limestones and more significantly in the shales. Such an origin is also supported by the REE patterns of the limestones which are similar to that of the present sea water. The anomalously high concentrations of some redox sensitive trace metals (Cr, Ni and probably Cd) compared to worldwide black shales is explained by an exogenic metal flux, corresponding to the leaching of the huge amounts of ophiolites obducted during the collision between the African-Arabian and Eurasian plates at the same time as the deposition of the Belqa Group sediments. Uranium is substituted for calcium in biogenic apatite in the limestones, but was also directly precipitated from sea water in the black shales in relation with the suboxic environment with the periodic anoxia developed during their deposition in restricted deeper basins. The pyrometamorphism resulting from the burning of organic-rich levels in clayey limestones has created a further enrichment of redox sensitive elements in the resulting marbles by a volume loss resulting from decarbonatation reactions and the combustion of the organic matter

The multiple ways of recycling Archaean crust: A case study from the ca. 3.1 Ga granitoids from the Barberton Greenstone Belt, South Africa

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Multi-scale spatial distribution of K, Th and U in an Archaean potassic granite: a case study from the Heerenveen batholith, Barberton Granite-Greenstone Terrain, South Africa

International audienceAbstract We describe the multi-scale distribution of K, Th and U in the ca. 3.1 Ga Heerenveen batholith of the Barberton Granite-Greenstone Terrain. Data were obtained with a combination of tools, including a portable gamma-ray spectrometer from the scale of the whole batholith to the scale of outcrops, and autoradiography for the thin section scale. U is concentrated preferentially in minor phases in the border shear zones of the batholith and, within these shear zones, in late pegmatites as well as fractures. The processes responsible for the concentration of U in the Heerenveen batholith is discussed in terms of magmatism, hydrothermalism (redistribution of U in fissures associated with magmato-hydrothermal fluids), and supergene alteration. The statistical properties of K, Th and U concentrations are different. K shows spatial correlation over large distance, largely mirroring mappable rock types, with increased variability at larger scales. In contrast, U is dominated by small-scale variations (“nugget effect”) and its variability is, averaged and smoothed by large-scale integration. Spatial and statistical features thus offer useful and complementary insights on petrogenetic and metallogenic processes in granitoids in addition to standard approaches (petrography, geochemistry)