The uranium resources of Ukraine basically consist of deposits of alkaline metasomatic types. At present, Ukraine is seeking to discover more viable uranium deposits with cost ranges <US$40/kgU.
There are virtually no uranium stocks in Ukraine. All the uranium concentrate is dispatched to Russia in exchange for nuclear fuel elements for power reactors. Existing production from state-owned centres still does not meet the nuclear fuel requirements of the nuclear power stations of Ukraine. The deficit for producing nuclear fuel elements is covered by buying uranium from Russia.
In such a situation, the Ukrainian geological enterprises have to intensify their exploration work, and existing production centres have, in a short space of time, to enlarge the production capacity of existing mines and begin to exploit new known uranium deposits, in order to provide Ukrainian nuclear power stations with domestically-produced natural uranium.
Uranium Exploration and Deposits in Ukraine
Exploration for commercial uranium deposits was started in Ukraine in 1944. As a result, the Pervomayskoye deposit was discovered in 1945 and the Zheltorechenskoye deposit was discovered in 1946. They were associated with alkaline metasomatism of the ferruginous rocks of the Krivoy Rog region.
The first commercial uranium deposit (Michurinskoye) was discovered in 1964. It was associated with alkaline metasomatism and crush zones in the granite-gneiss complex of the Ukrainian shield. Further exploration for this new type of deposit led to the discovery of the Kirovograd uranium-ore region. The uranium content in ores of these deposits does not exceed 0.2%. Special radiometric, general geophysical, radio-hydrogeological methods and drilling were used for uranium exploration.
As well as the now mined-out Pervomayskoye and Zheltorechenskoye deposits, the Krivoy Rog region contains the non-commercial Annovskoye and Kremenchugskoye deposits. In addition, the non-commercial Nikolo-Kozelskoye deposit in sandstones and conglomerates of the lower suite of the Krivorozhian series is known here.
The Kirovograd ore-bearing region contains the Severinskoye, Michurinskoye and Vatutinskoye deposits, as well as a number of ore shows. Apart from albitite-type deposits, several small ones associated with processes of potassium metasomatism and close in the age to the regional granitisation (Yuzhnoye, Kalinovskoye, Lozovatskoye) are known here.
As noted above, uranium exploration and development for mining in Ukraine are conducted by the state geological enterprise Kirovgeology, responsible to the State Committee of Ukraine for Geology and Utilisation of Mineral Resources. Uranium mining and processing are conducted by the state association Vostochny Integrated Mining and Concentrating Plant (VostGOK), under the Ministry of Energy of Ukraine, with its main office located in the town of Zheltye Vody, which is at the centre of the Krivoy Rog region, one of the largest mining areas of Ukraine. The VostGOK integrated ore-concentrating works, which processes uranium ores from both the Krivoy Rog and the adjacent Kirovograd regions, is also situated in Zheltye Vody.
At present the major uranium ore resources are concentrated in the Kirovograd region, which is a the source of raw material for the VostGOK ore-concentrating works. These deposits are associated with uranium-bearing albitite formation in zones of deep faults of the Ukrainian shield. Their origin is associated with sodium metasomatism superimposed on the granite-gneiss basement within an area of tectonomagmatic protoactivisation which occurred at the end of the Ukrainian shield orogenesis.
The uranium ore formation was 1.7 billion years ago, and followed regional potassium granitisation. Uranium minerals are presented by oxides (uraninite, nasturan), silicates (uranophane, boltwoodite, betauranotile, coffinite), and titanates (brannerite, davidite). Furthermore, albitite always contains hematite, magnetite, apatite, malacone and rutile. Besides uranium deposits in albitites, commercial uranium deposits confined to coal-sand sediments in sedimentary cover of the Ukrainian shield have been discovered.
VostGOK has also mined out two deposits (Deviadovskoye and Bratskoye) by the ISL method. Other similar deposits have not yet been exploited. Deposits of other types discovered in Ukraine so far are not economically viable taking into account market prices.
The total assessment of uranium resources of Ukraine (with costs up to US$130/kgU) has not changed recently. It comprises 366 000 tU in situ resources, including 81 000 tU of reasonably assured resources (RAR), 50 000 tU of estimated additional resources category I (EAR-I), 3900 tU of EAR-II, and 231 100 tU of speculative resources (SR). There are no resources with the costs lower than US$40/kgU in the total of 131 000 tU of RAR and EAR-I.
Of the RAR and EAR-I, 62 600 tU have costs lower than $80/kgU, concentrated in the albitite-type Vatutinskoye (25 500 tU) and Michurinskoye (27 000 tU) deposits, and in other small deposits (10 100 tU) within the sedimentary cover of the Ukrainian shield which can be mined by the ISL method. The remaining 68 400 tU of RAR and EAR-I are concentrated in the albitite-type Severinskoye deposit (50 000 tU), in the pegmatite-type Yuzhnoye, Kalinovskoye and Lozovatskoye deposits (15 000 tU) and in the Adamovskoye, Krasnooskolskoye and Berekskoye deposits (3 400 tU) in bitumens.
The area of alkali metasomatites developed between the Vatutinskoye deposit in the west and the Michurinskoye deposit in the east is the most promising to explore for new commercial albitite-type deposits. The north-west slope of the Ukrainian shield is very promising to discover high-grade uranium deposits (unconformity-related deposits). Also, the Zapadno-Inguletskaya tectonic zone located westerly from the Krivoy Rog iron-ore basin is promising to discover vein and vein-impregnated uranium deposits.
However, the development of these areas for further exploration is limited by insufficient and unstable funding of exploration activity.
Classification of uranium reserves and resources
The Ukrainian government has approved a national classification system for mineral reserves and resources, which embraces all kinds of minerals and is adapted for market principles of resource utilisation. The various groups and classes in this system are in harmony with the United Nations International Framework for Solid Fuel Mineral Reserve/Resource Classification (1997), and the IAEA Uranium Resources Classification. Clauses of the UN International Mineral Resources Classification (1979) were taken into account too.
The new classification has three basic definitions of mineral reserves/resources, dividing them in accordance with economic efficiency, the stage of feasibility study, and the degree of exploration. Market economy principles require the introduction of these definitions. The classification takes into account technical and economic feasibility studies, including studies of detailed mining, technical, geographical, economic, socio-economic and environmental aspects, as well as other assessments of mineability, the subsequent development of deposits, ore processing, and market conditions for the supply of the commodities to be mined.
Explored and detailed evaluated reserves which can be mined economically are classified as assured reserves (proved mineral reserves), while the balance explored and preliminarily explored reserves are preliminarily evaluated as belonging to the estimated reserves (probable mineral reserves). The use of the new classification for minerals is regulated by the instructions of the State Committee on Reserves (DKZ) of Ukraine.
A specific classification for uranium ore deposits has been elaborated and will be approved soon. This will classify uranium deposits according to their geological and industrial types, dividing the reserves according to their value and the uranium content in the ore, the complexity of the geological structure, their industrial importance, the stage of technical, economic and geological study, the level of their commercial knowledge, the reserves evaluation, and the ease of exploitation.
In particular, the classification of uranium deposits according to their geological-industrial types will be based on that introduced by the IAEA. In addition to dividing uranium reserves according to their industrial importance and size and quality of reserves, the classification will include production cost groups of up to US$40/kgU, up to US$80/kgU, up to US$130/kgU, and above US$130/kgU.
By approving this new classification system for mineral reserves and resources, and elaborating the classification for uranium deposits, Ukraine has taken an important step in developing a system of geological-economic assessment and state registration of raw materials consistent with internationally recognised schemes and market economy principles.
Environmental Protection at Uranium Sites
Zheltye Vody
From the start of mining in Zheltye Vody, two quarries (named Gabayevsky and Veseloivanovsky) existed on the territory of the site. In addition, three tailings facilities were built, known as "KBZh", "Sch" and "R".
The mining activity in the Novaya and Olkhovskaya mines has led to a large quantity of waste being deposited, with total volume of 550 000 m³. The affected territory, which covers an area of 968 hectares, consists of the following:
The Olkhovskaya mine was closed in 1980. The waste and below-grade rock from the Novaya mine are now directed into a depression.
The tails from the hydrometallurgical plant and iron ore enrichment plant are stored in the tailings facilities. The "KBZh" tailings facility is 3 km from the northern boundary of the town within the protective zone of the hydrometallurgical plant. A closed limonite quarry was used as a receptacle for the tailings. The water surface is 55 hectares. The quarry's volume was almost completely filled up with tails in 1987 and now after partial upgrading it is used as a reserve storage for emergency outflow from the hydrometallurgical plant . The tailings comprise leached uranium ore pulp, with uranium content of about 0.007%. The quantity of tailings is 19.34 million tonnes. Radon 222 emission from the surface of the tailings varies from 0.05 to 3.0 Bq/m²/s.
The "Sch" tailings facility is located 1.5 km to the south of the town within the boundary of the Scherbakovskaya gorge, and has been in use from 1977. The storage area is 250 hectares. The stored volume of tailings is 43.54 million tonnes. The leached uranium ore pulp has a uranium content of about 0.007%. Radon 222 emission from the tailings area varies from 0.5 to 2.0 Bq/m²/s. The stored tailings total activity is 1.8 x 1015 Bq.
The "R" tailings facility is located on the left side of valley of the River Zholtaya within the Razbery gorge. It has been in use from 1969 as storage for iron ore waste from the Novaya mine enrichment facility. The tailings area is 230 hectares.
The mine waters with radionuclide content are directed after treatment to the natural water system. The volume of effluents is 2.4 million cubic metres per year.
Ingulskoye Mine
The Radon 226 content of the repositories varies from 843 to 1389 Bq/kg. All radionuclides of the uranium family are present in the waste rocks. The rate of Rn 222 flow into the atmosphere from the repository surface is from 0.85 to 1.28 Bq/m²/s, with an average value of 1.07 Bq/m²/s. Mine waters are directed after treatment into a hydrographic net; the annual volume is 2.6 million cubic metres.
Smolino Mine
There is a waste rock repository on the site with basis area of 5.3 hectares. The volume of stored rock is 1.06 million cubic metres. Dosimetric surveys show the surface contamination with radionuclides is concentrated on the site and in the area of the solid waste repositories. The underground mine waters are directed to a mine water cleaning unit, and after treatment are discharged into the natural hydrosystem.
In-Situ Leaching Sites
The Deviadovskoye site is located in Dnepropetrovsk region, 30 km southeast from Zheltye Vody. The ISL methods were practised on an industrial scale from 1966 up to 1983. The chemicals used were sulphuric and nitric acids. The area of the site is 12 hectares, the ore body area is about 218 hectares, and the area for underground storage is 120 hectares. The deposit coincides with uranium bearing coal-and-clay Paleogen sands.
As a result of ISL mining, the underground water was contaminated at a depth of 80 m. The halo of residual solution was distributed a distance of 1.7 km along the underground water flow and for 0.35 km against the flow. The nearest settlement in the underground flow direction is 4 km distant.
The volume of residual solutions after the ISL mining of uranium in the Buchak aquifer is 7.09 million cubic metres. The volume of water in tailing ponds is 1 million cubic metres, and the volume of contaminated silt in ponds-collectors is about 40 000 m³. Because of leakage from pipelines, contamination of soils and ground occurred. The volume of contaminated soils is about 50 000 m³.
The Bratskoye ISL site is located in Nikolayev region, 200 km to the south from Zheltye Vody. The deposit of uranium is located in Paleogen sediments. The industrial mining of uranium took place there from 1971 to 1984. The orebody area is 95.5 hectares. Sulphuric acid and nitric acid were used as chemicals for working solution preparation.
At the end of the exploitation of the deposit, all the working solution present in the orebody was left in place. The volume is 5.2 million cubic metres. The halo of residual solutions was distributed for 3 km along the underground water flow and for 1.2 km against the flow, to a depth of 50 meters.
The Safonovka site is also located in Nikolayev region. The deposit of uranium relates to uranium-bearing coal-clay sands. The mining of uranium took place during the period from 1982 to 1993. The surface technological structure covered 5 hectares.
The PCHZ Site
Experience of Remediation of Affected Areas
From many projects proposed for the remediation of affected areas in Ukraine, the following have been carried out:
Rehabilitation of ISL Sites
The technique for rehabilitation consisted of replacement of the affected ground (between the rows of the working wells and where solution had been split) with clean earth and ploughing up to 50 cm from the surface with a trenching plough. After liming of the soils the site was handed over to an agricultural enterprise. For years afterwards, the site was used mainly for growing industrial and forage crops. The rehabilitation of the entire site was finished by the end of the 1980s.
The same technique was applied to the rehabilitation of the Bratskoye site. The whole territory of this site was re-cultivated by 1991. The entire site has been returned to agricultural operation, and is used for growing grain.
Restoration of Olkhovskaya Mine
The total amount of removed and utilised rocks was about 550 000 m³. The contaminated soil under the repositories was removed up to depth of one metre, and transported to the quarry. The total area of the restored territory was about 15 hectares. The equivalent gamma dose rate on the site was about 0.10 to 0.22 mSv/hour. The re-cultivated territory was used partially for the construction of garages, partially for a mechanical enterprise, and partly for gardening.
Restoration of the "KBZh" Tailings Facility
The project foresees the construction of a multilayer protective cover. The structure will consist of 0.4 m of loam, 0.4 m of waste rocks, 3.5 m of layer-by-layer compressed loam, and 0.3 m of black soils. It is planned to use the recovered territory after the rehabilitation as an agricultural pasture.
Rehabilitation at the Ingulskoye Mine
Results from a simulation showed the absence of underground water contamination with natural radionuclides during a period of 1000 years. Radon emission from the rehabilitated territory will not exceed the background levels for the territory. The restored territory is planned to be used for trees and bushes.
The Nuclear Fuel Cycle in Ukraine
At the disintegration and collapse of the former USSR, Ukraine had 15 nuclear power reactors in operation and five under construction. The Ukrainian nuclear industry consisted of VostGOK, which mines and processes uranium ore, and the Pridneprovsky Chemical Plant. Thus, the nuclear power plants of Ukraine found themselves without a scientific-research base in the nuclear fuel cycle, without a nuclear fuel fabrication enterprise, without an away-from-reactor (AFR) spent fuel store, and without organisations for spent fuel management, processing technology and safety.
Nevertheless, the nuclear energy industry of Ukraine, from the beginning of its existence as a separate entity to this day, has operated with stability and efficiency. This is confirmed by quantitative and qualitative indices. Thus, in spite of the general stagnation of industrial activity in Ukraine, the nuclear branch has increased electricity generation and its basic funds, keeping skilled engineers and trained workers.
Looking at different energy sources for electricity generation in Ukraine, the country is presently supplying electricity from the following sources:
According to the National Programme on Energy Development, after 2000 Ukraine is planning to supply 35.5% of total electricity generation from nuclear power, with the installed capacity of NPPs reaching 22.7% of the total.
Today the industrial capacity for nuclear fuel cycle operations in Ukraine only provides 10% of the resources required for the production of the fabricated fuel used in the country's reactors. This 10% comprises:
The remaining 90% of the resources for nuclear fuel are supplied today by the Russian Federation and Kazakhstan.
Taking into account of the importance of nuclear energy in the energy/electricity sector of the country, national security makes it necessary to create domestic nuclear fuel cycle facilities. Even during the creation of national nuclear fuel cycle facilities, Ukraine is planning to reduce permanently dependence on foreign sources.
Analysis of the nuclear fuel cycle shows that uranium enrichment is the most expensive stage of the nuclear fuel cycle (45% of the total). But for Ukraine, taking into account national conditions, the task of enriching uranium independently is not realistic. States which possess nuclear weapons (USA, Russia, UK, France, China) have enrichment plants which benefited from programmes of nuclear armament.
Therefore, it is only possible at present to reduce the foreign component of nuclear fuel in Ukraine to 45% of the total value. Only in the case of the possible implementation of heavy water cooled and moderated reactors (CANDUs) in Ukraine could nuclear fuel be entirely domestically produced.
The task of reducing the dependence on foreign nuclear suppliers from 90% to 45% is being carried out by Goskomatom and other government ministries and departments. The composite programme for the creation of a nuclear fuel cycle in Ukraine consists of five separate programmes:
The aim of the first programme, mining and processing of uranium ore, is to establish facilities to satisfy domestic reactor related requirements for natural uranium. This programme foresees:
Conclusion
Nuclear energy will continue to be developed in Ukraine. The potential of the country's uranium and zirconium resources are sufficient to provide the nuclear energy industry for a minimum of 100 years. Measures to strengthen the nuclear energy industry are backed by the programme to create a nuclear fuel cycle industry in the country.
Most of VostGOK's activities are concentrated on the various industrial sites at Zheltye Vody. These comprise mining and supporting enterprises, including the Olkhovskaya and Novaya mines, the uranium ore processing plant, the sulphuric acid plant, and some other facilities. The company's headquarters are also on the site.
The site of the Ingulskoye mine is located south of the city of Kirovograd. The deposit is operating with three shafts and is developed to a depth of 700 metres. The mined ore undergoes preliminary sorting into ore for processing, below-grade ore, and waste rock. The latter two types are directed to the waste rock repository. The total area of such repositories is 44.7 hectares. The volume of the stored rocks is about 2.4 million cubic metres.
The site of the Smolino mine is located in Kirovograd region, 3 km from the mining town of Smolino. The site allows the underground mining of the Vatutinskoye deposit at a depth of 500 m. It also has a facilities for crushing, sorting, inventory and shipping of the ores. The mine is operating with four shafts.
In-situ leaching (ISL) of uranium was carried out on the Deviadovskoye, Bratskoye and Safonovka deposits by VostGOK.
The Pridneprovsky Chemical Plant (PCHZ) is situated on the right bank of the River Dnepr in the region of Dneprodzerzhinsk city of Dnepropetrovsk region. The enterprise performs its activity on two sites: the site of the plant, and the site of the "S" tailings pond and reloading station, located 10 km to the southeast of the plant. Also southeast of the plant is the temporarily closed "D" tailings storage facility on the right beach of the River Dnepr, located 300 m from the plant site. All these sites were used for the storage of radioactive waste.
The very first site of in-situ leaching of uranium in the former Soviet Union was the Deviadovskoye site. The plot was used for the testing and improvement of ISL technology. The tests led to considerable surface contamination by acids as well as by radionuclides. In 1975 the most contaminated part of the site's territory was rehabilitated, the first time this had been done in former Soviet Union.
The restoration of the site around the Olkhovskaya mine was performed during the period from 1979 to 1982. The technique included the selective deconstruction of a pit heap, waste rock repositories and below-grade ores. Some of the rock was transported to the hydrometallurgical plant for processing, and some was used in tailings pond construction. The remainder (the largest part) was stored in a nearby quarry.
The rehabilitation works were started in 1991 and have been continued up to the present time. About 85% of the territory of the tailings facility has been covered with loam to a depth of 0.4 m, preventing dust escaping from the tails material. The tailings area is 55 hectares.
One of the possible ways to decrease the impact of uranium mining waste on the environment is to use it to fill up gorges and ravines. Such a scheme for filling ravines is being carried out near the Inguiskoye mining enterprise. The amount of mining waste to be stored in ravines is about 500 000 m³. The specific alpha activity of the rocks varies from 370 to 39 000 Bq/kg, which characterises them as a mixture of low activity radioactive rocks.