Uranium - Past and Future Challenges

Uranium has been mined in Namibia since the 1970s. The worldwide increasing need for energy in the early 2000s has triggered an increased interest in uranium exploration, often referred to as “the Namibian Uranium Rush”. All in all, five mining licenses have been granted by the Namibian Government, with currently two mines in operation, a third under construction undertaking trial mining, the fourth under care and maintenance after completing a large scale and successful trial period and the fifth in project finance negotiations. In addition, highly intensive prospecting activities at additional deposits are at an advanced stage. The finalization of the strategic environmental impact assessment (SEA) on uranium mining in 2010, the first of its kind and scale in the world, has enabled the Namibian government to assess this uranium rush and its tremendous legal, socioeconomic and environmental impacts and to prepare for different future scenarios, including both, a skyrocketing and a complete breakdown of demand scenario. The Fukushima disaster and plans of the Namibian government to significantly increase royalties and company taxes in 2011 have threatened the market situation, forcing investors to reevaluate Namibian uranium mining projects. However, with the tax and royalty increase initiative since withdrawn, most projects have soon been back on track with significant pace, when again low market prices hampered some of the projects or even completely put them on hold.

Rare earth elements (REE: La to Lu) are critical for high-technology applications. In Australia, undeveloped REE resources are associated with several deposit types including uranium ores. These include the Olympic Dam Cu–U–Au–Ag deposit and uranium mineralisations in the Yilgarn, Mount Painter, Olary and Mount Isa regions. At the Mary Kathleen uranium mine site, tailings are stored in a purpose-built tailings dam structure, with an estimated 7 Mt of mill tailings carrying approximately 3 wt% total REE oxides. This makes it one of the largest undeveloped REE resources in Australia.

Recognizing the environmental impacts of mining and associated industries and their minimization has become more important over the last two or three decades. The International Atomic Energy Agency (IAEA) supports good practice in uranium mining and milling worldwide. As well as its well-known safety standards for radiation protection and waste management, it has produced guidance and acted as a gatherer and provider of information on geological, technological, environmental and regulatory aspects of the uranium production cycle. It is involved in a number of Technical Cooperation projects on this and related topics throughout the world.

Experiences have shown that unregulated uranium mining practices have led to significant radiological risk to workers, public and the environment. Tanzania is about to start uranium mining in different parts of the country. Although the legislation and regulations to control doses to workers, public and the environment are in place, there are challenges to adequately address best practice requirements during and after the mining operations. This paper provides an overview of the challenges in addressing the regulatory compliance.

During WW2 oil was produced through pyrolysis of alum shale giving rise to waste that was deposited in the open pits and in a waste deposit. The waste deposit still today has significantly elevated temperatures (above 500 °C). Remaining pyrite in the waste material has also led to ARD with elevated trace metal concentrations. The waste deposit is no great environmental problem today but as soon as the waste pile cools off both the volumes of drainage and concentration of uranium will increase significantly.

An overall criterion for protecting freshwaters against uranium chemo-toxicity should encompass all the compartments of the freshwater environment at risk (water column, sediment, predators, and humans). According to the latest European recommendations, we revised the interim Environmental Quality Standard currently applicable in France, to introduce physico-chemical parameters affecting uranium bioavailability in water and therefore toxicity, by using chemical speciation modelling in aqueous phase including both mineral ligands and organic mat-ter. Additionally, we completed the poor available data set related to sediment toxicity by implementing dedicated standardized tests and we explored the question of secondary poisoning. Human health was also briefly considered, to fulfill the methodological requirements.

The Urgeiriça mine and milling facilities, Portugal, was in operation until 2001. Site remediation, including clean-up of milling plant facilities and terrains was implemented during 2006-8 and it was completed with the placement of a multilayer cap on milling tailings and construction of a drainage system for retrieval of mine water and waste piles seepage followed by neutralization in a mine water treatment plant. During this period the monitoring of environmental radioactivity was periodically carried out in the Urgeiriça area. Results of environmental surveys carried out during last 10 years on ambient radiation dose, radon in surface air, radionuclide concentrations in soils, agriculture products, and water from wells and from surface streams receiving mine effluents, are reviewed. Results of this environmental survey are presented and radiation exposure of the local population is discussed.

In this region the water supply of inhabitants with drinking water is carried out from the rivers and canals originating from mountain rivers and including the river Mailuu-Suu. Therefore, the contamination of the river Mailuu-Suu and streams in the uranium province may further influence in the region on such large rivers as the Kara-Darya and Syr-Darya. Insufficient hydro isolating the bottom of the tailings could make pollution subsoil waters with radionuclide. In any case water supply from well of subsoil water may be contaminated with radioactive and other chemical elements.

Modern uranium mining practices are designed to bring operations more in line with sustainable development goals, in particular with respect to environmental and socio-economic criteria. It is now widely recognised that a social license to operate is a key prerequisite for successfully establishing and running any mining project. This paper examines the use of indicators as a vehicle to convey stakeholder-relevant information about mine site development with a view to facilitate social licensing processes.

Recognising how fundamental the ‘social licence to operate’ is to any uranium mining project, in 2012 the IAEA initiated a series of training courses and workshops on stakeholder engagement and social licensing issues. While the social licence has different features in each country, and is negotiated in different ways, without one, a project’s chances of success are significantly compromised. This paper summarises the findings from a workshop held in Istanbul, Turkey, in February 2014, and offers some perspectives on likely future developments.

There are many low grade uranium ore deposits identified in different states of India. Mining and ore processing operations have been undertaken at several locations in the eastern province of Jharkhand since the past several decades. Mining and processing of ore also commenced recently at a site in the southern state of Andhra Pradesh. Other deposits are in different stages of exploration and development. Monitoring for natural radiation and radon has been an integral part of the environmental surveillance at the ore deposits and mining sites. To supplement departmental environmental monitoring, the baseline radiation surveys around the proposed mining sites are sometimes entrusted to educational and research institutions of excellence in the country during the past several years. This paper aims to give an overview of the radiation monitoring in the environment around the uranium ore deposits and mining sites. Gamma radiation levels and annual exposure rates in Jaduguda area and that in different states are summarized. An overview of the studies conducted for restoration of the tailings pile and role of vegetation and plants is also given. Public awareness program undertaken in the vicinity of mining sites for information of the local stakeholders is also highlighted.

Advanced geophysical methods including high-resolution seismic surveying and novel borehole logging techniques have been launched at Heathgate to better quantify both hydro(geo)logical and geochemical conditions that determine the feasibility of in situ recovery (ISR) from sedimentary-hosted uranium. This data is the input to hydrological and reactive transport modeling to optimize well-field design and performance with regard to ore-lixiviant contact and leaching chemistry. The redox puzzle is solved for specific deposit characteristics by a new, practicable kinetic leach model providing control criteria for optimized recovery.

The Pridneprovsky Chemical Plant was a largest uranium processing enterprises, producing a huge amount of uranium residues. The Zapadnoe tailings site contains the majority of these residues. We propose a theoretical framework based on Multi-Criteria Decision Analysis and fuzzy logic to analyse different remediation alternatives for the Zapadnoe tailings, in which potentially conflicting economic, radiological, social and environmental objectives are simultaneously taken into account. An objective hierarchy is built that includes all the relevant aspects. Fuzzy rather than precise values are proposed for use to evaluate remediation alternatives against the different criteria and to quantify preferences, such as the weights representing the relative importance of criteria identified in the objective hierarchy. Finally, it is proposed that remediation alternatives should be evaluated by means of a fuzzy additive multi-attribute utility function and ranked on the basis of the respective trapezoidal fuzzy number representing their overall utility.

Uranium (U) can be found in concentrations of 2-200 mg/kg U in phosphate fertilizers if the rock phosphate is of sedimentary origin. About 14,000 tons of U were applied by mineral phosphate fertilizers in Germany from 1951 to 2013. This equals a cumulative load of 1 kg/ha U to agricultural soils. Actually, about 114 to 228 tons of U is distributed by fertilization.

Total Dissolved Solids (ion composition), concentrations of some trace elements and pH-values determination results of vein-fractured water samples from the open pit of the Tulukuevskoe U-Mo deposit in acid volcanic rocks of Transbaikalia are presented. Rest upon obtained data it is possible to assume that in the southern part of the open pit a flat-lying ore-bearing untapped structure exists. An inverse relationship between the content of hydrocarbonate ions in veinfractured waters and concentration of uranium is presented.

In Kvarntorp, Sweden, 40 million m

3

of shale residues containing up to 150 ppm uranium is the result from some 30 years of oil extraction. This work focuses on the release of uranium from discarded unprocessed shale in contact with wood chips in 1 m

3

scale. After 15 months of incubation it was clear that shale mixed with wood chips generated leachates with a lower average content of uranium (14 μg L

−1

) then shale covered with wood chips (1,300 μg L

−1

). This indicates that natural forestation of the pile might increase the release of uranium.

From 1946 to 1978, extensive mining of U and Pb–Zn ores went on in the northern edges of the Fergana valley on the foothills of the Tien Shan Mountain Range. The mining and milling activities left behind large volumes of wastes in the lower section of the Sumsar-Say, which is a cross boundary river. The mill tailings of the Pb–Zn milling in Sumsar and the low-grade U ore heaps in Shekaftar need an urgent remedial action because the legacy sites became chronic sources of toxic and radioactive contaminants for the Sumsar-Say River. In the Sumsar Say valley, the river acts as a powerful transport agent of the released contaminants carrying them to the places of potential impact, which are the down-stream settlements in Kyrgyzstan and Uzbekistan. For the settlements along the river, Sumsar-Say is the main source of water and the population uses it indiscriminately. Thus, the exposure of the local population to the contaminants is via a multitude of pathways. The legacy sites requiring remediation most are (a) the tailings facility #1 in Sumsar that is chronically loosing tailings into the Sumsar-Say River and (b) the low-grade U ore heaps in Shekaftar, which are within the domain of the river, particularly ore heap no. 5, which is directly located in the river. The paper discusses possibilities of remediation and, regarding the risk and feasibility assessment, arrives at the conclusion that sustainability of remediation would be best achieved by taking out the sources of contaminants from the reach of the Sumsar Say River.

This study deals with concentrations of heavy metals and the main uranium series radionuclide in the Syr Darya surface waters (Kazakhstan). Large proportion of studied heavy metals were transported with suspended matter (> 0.45 μm), while large proportion of U (98–100 %) and Mo (81–100 %) were in dissolved forms and colloidal fraction (< 0.45 μm).

Based on 26 Soviet reports, a database was compiled for uranium exploration purposes, containing information about more than 1,100 anomalies of uranium and other radioactive components, and featuring some 300 zones that cover nearly all of Mongolia. The database is currently being reviewed from the perspective of relationships between recent tectonic movements, geological settings and genetic origin of anomalies. While the database was being compiled, the primary focus was on the geological properties of the reported anomalies and zones. The methods and the main results of this effort are presented in the paper.

The Northern Territory of Australia (NT) has a long association with mining, including the mining of uranium. Current activity includes all aspects of the uranium production cycle including many exploration projects, the Ranger Uranium Mine and a number of remediation sites. There are also a number of rare earth projects approaching the development phase and some NORM related projects which are equally approaching development status. The paper describes the current state of uranium exploration activities and progress on remediation works in the NT before providing an update on the ongoing development and remediation-related activities at the Ranger Uranium Mine. The paper will also provide an update on recent changes in the regulatory regime.

In this paper, investigation of mine water disasters was conducted, the current situation of mine water prevention and control was analyzed, the basic theories and practical technology for mine water control were summarized, and some science and technology countermeasures were developed to prevent and control mine water disasters, which can be briefly summarized as studying basic theories, developing key technology and equipment, constructing research and development platform, and strengthening safety management.

Triggered by observations that a disproportionally high number of leukaemia patients came from a particular area around the small town of Pofadder in the arid Northern Cape Province, a subsequently conducted research project established a geo-statistical link between naturally elevated U-levels in groundwater and haematological abnormalities. In this paper results from a follow-up study are presented indicating the water is indeed the most important pathway for U-exposure while consumption of contaminated sheep meat also contributes but to a lesser extent.

Large volumes of uraniferous gold tailings deposited over more than a century in densely populated metropolitan areas of South Africa (SA) pose potential health hazards to millions of residents of nearby settlements, including many vulnerable, impoverished populations. In order to inform the selection of suitable sampling populations for epidemiological studies a mapping methodology based on a Virtual Geographic Environment (VGE) combined with a Geographical Information System (GIS) was developed. The structure, architecture and database of the system are presented.

After more than a century deep level gold mining in and around Johannesburg stopped in 2008 resulting in the gradually flooding of the abandoned mine void. Triggered by extensive media reports on the risks associated with acidic mine water rising to the surface of the inner city ranging from collapse of high-rise buildings, sinkholes, water pollution and increased seismicity two major banks with headquarters in Johannesburg commissioned a desk top risk assessment from which selected results are discussed in this paper. Based on these findings low-cost, low energy alternatives to the currently adopted pump-and-treat approach are proposed.

In situ leach (ISL) has become one of the standard uranium production methods. Hydrogeology is important for all mining below the water table, but it is doubly important in ISL mining for efficient production of uranium. Prevention of unwanted groundwater contamination must be considered and controlled, and the final status of the target aquifer is also of high importance. Hydrogeological testing has been undertaken at a number of Australian ISL sites, some of which proceeded to production. Here we consider the associated hydro-geological testing undertaken for some of these projects, with case studies and les-sons learned.

The tunnels were sealed by rock walls with cut-out overflow and closed down after backfilled with clay soil or mixed soil. Ventilating shafts were backfilled with uranium waste and then closed down by backfilling clayed soil and revegetation. The waste rock piles were covered by clayed soil and revegetation. γ-rays radiation dose rate from waste rock piles reduced by 90 % after remediation. Radon fluxes were reduced to 0.5 Bq/m2 s from 1.66 Bq/m2 s after remediation. The uranium geological prospecting work in the Northeast China Region (NCR) was conducted from 1957, and has submitted numbers of uranium deposit to the country, contributing to the China nuclear industry. With the improvement of people’s environmental awareness, the decommissioning projects management was gradually conducted for the uranium exploration facilities starting from the early 1990s. The uranium exploration facility decommissioning projects management mentioned in this paper mainly refers to the exploration tunnels and mining debris in the NCR during the period of ‘Eleventh Five-Year (2006–2010) Plan’ of China.

Lynas Australia plans to re-use its mill tailings from its rare earth production in Malaysia for road construction purposes. As those tailings are large masses and rich in thorium, radiological doses would result from that use. Comparing the collective doses of this re-use with collective doses from nuclear energy production shows that a wind power plant constructed with rare earth magnets so poses doses in the lower range of nuclear power production as per GWa.

The study has shown that in a soil with a logKd of 4–5 for uranium between the aqueous and the solid phase only some 20 % of the soil inventory of uranium is mobilized. Five consecutive L/S 10 extractions with alkali released some 75 % of the uranium inventory but not the entire content of organic matter. The mobilization of uranium coincides with that of organic matter as evidenced by size exclusion chromatography and ICP-MS. The stationary uranium coelutes with to a high extent with humic and fulvic substances.

The aim of this paper is to give a new way of phosphate deposits prospection using in situ monazite dating. U-Th–Pb data for a single grain of monazite from locality Kamenne Doly Quarry were combined with previously obtained monazite ages from Pisek pegmatites and their GPS positions (

φ

,

λ

) were processed by a MATLAB script to define region of monazite or phosphate occurrence. At least 3 assumptions have to be made. Monazites are of similar ages, are products of an extensive geological event affecting a significant amount of rock bodies in a region and the shallow rock environment is the same at different depths.

One important factor which affects migration of U(VI) in the subsurface is the sorption at the solid/solution interface. Many factors control the sorption of U(VI) on mineral surfaces and one significant candidate among them is the distri-bution of aqueous species. In this study, column experiments were carried out to investigate the transport of uranium, arsenate and uranium-arsenate together (0.5:0.5 μM/l) in columns packed with SiO2, Al2O3, TiO2 and FeOOH at pH 6.5. Transport behavior of U(VI) and As(V) through SiO2 and TiO2 packed columns are identical in the inlet solutions containing either U(VI) or As(V) separately, or both together. In the presence of equimolar U(VI) and As(V), a substantial in-crease in As(V) mobility and a slight decrease in U(VI) transport through Al2O3 were observed. When Al2O3 is replaced with FeOOH, a significant change in the pattern of mobility was shown by As(V); whereas U(VI) showed only minor changes. The changes in transport behavior of both elements can be attributed to the competitive sorption between uranyl and arsenate species or due to the for-mation of uranyl-arsenate species. The immobilization of uranyl and arsenate with the aforementioned minerals are in the order FeOOH > TiO2 > Al2O3 > SiO2 under our experimental conditions. This study thus gives potential information about the transport behavior of uranyl and arsenate in natural systems, especially when both elements are present.

The operation of a phosphate fertilizer industry in Drapetsona, near Piraeus port (Greece), resulted in the deposition of 10 million tons of phosphogypsum (PG) into an old limestone quarry, in the period 1979-1989. The whole deposit has been recently remediated using geomembranes and thick soil cover with vegetation. The purpose of the present study was to characterize representative samples of that phosphogypsum, using diffraction (powder-XRD), microscopic (SEM-EDS), analytical (ICP-MS), and spectroscopic techniques (High-resolution γ-ray spectrometry and XRF). The material contains crystalline gypsum (CaSO4.2H2O) and Ca-Si-Al-S-F (chukhrovite-type/meniaylovite) phases. The natural radioactivity is mainly due to the 238U series and particularly 226Ra (average: 462 Bq/kg), which is relatively low compared to PG from the rest of the world. Furthermore, leaching experiments using local (Attica) rainwater, together with ICP-MS, were performed to assess the potential release of elements in the environment.

The company Lynas mills and refines the concentrated rare earth bearing ore from its Mt. Weld/Australia mine in its LAMP facility in Kuantan/Malaysia. The ore concentrate has high concentrations of thorium and small concentrations of uranium as by-products. Oeko-Institute was commissioned with an independent evaluation of the environmental aspects of the plant. Several aspects show serious deficiencies in applying emission standards. The largest radiological problem is that the operator plans to re-use its tailings as road-building material. Large collective doses would result from this practice.

Study of sorption of uranium onto mineral surfaces plays a key role in controlling its mobility in groundwater. This work focuses on sorption properties of granites of Nizhnekansk massif in order to find optimal conditions for restriction of uranium migration in the environment. Four different types of granites from Itatsky and Kamenny sites were involved in sorption experiments. Distribution coefficients were determined in different conditions and sorption kinetics was analyzed. The results of these experiments are considered to have practical application in searching for the optimal place for efficient geochemical isolation of spent nuclear fuel and high-level radioactive waste.

Fraxinus excelsior

,

Glyceria fluitans

and

Hypholoma subericaeum

were investigated as contemporary indicators for the impact of acid mine drainage (AMD) in the soil-water-biomass system. The study was carried out in a (former) U mining area with special emphasis on the elements Fe, Ni and U and the fractionation of Rare Earth Elements which can be found in higher contents in growth locations close to groundwater discharge from the underground mines.

F. excelsior

showed higher contents of these elements in sapwood, than in heartwood.

Uranium mining in the US spanned a period from the end of World War II into the 1980 s. The legacy of this mining was illness and death for thousands of workers along with thousands of abandoned mines. Compensation programs for former workers and their heirs as well as remediation efforts for the contaminated sites appear to have cost well over $5 billion US dollars, which may exceed the value of the uranium ore extracted. Most of the cost has been born by the taxpayers to date, although a recent settlement will require one of the private companies to pay about $1 billion US dollars for uranium site remediation. The history suggests that there are likely to also be externalized costs from present-day uranium mining, especially in developing countries where regulation is less stringent.

In water-rock interactions, microbes play an important role in mobilization and immobilization of metals, including radionuclides. Water of three wells from a rhyolite joint aquifer known for high Rn and Ra concentrations were investigated for their microbial communities and hydrochemistry. The saline waters of NaCl type were used to isolate strains of the native microbe population. Both Gram-negative, like

Pseudomonas grimontii,

and Gram-positive, e.g.

Mycobacterium hodleri,

were identified. These microbes can produce siderophores, necessary to supply the cells with iron. In addition to iron, such small molecules may complex other elements, including radionuclides. Thus, they can impact the mobility of radionuclides in the groundwater. The potential of microbial processes in radionuclide reactive transfer is further discussed with respect to other potential mechanisms.

The underground workings in the older parts of the Witwatersrand Gold Fields of South Africa have been abandoned and allowed to flood. Pyrite in the ore and host rock leads to the generation of acid mine drainage in the flooding underground workings as well as in surface residue deposits. The difference in topo-graphic elevation across these goldfields creates a driving hydrostatic head which has caused the discharge of acid mine drainage in the West Rand Gold Field and threatens to cause similar problems in the Central and East Rand. Laboratory simulations and simple models have been used to try to understand the hydraulic and chemical dynamics of the flooding mines with the aim of optimising solutions to this problem in the medium- to long-term.

The Wismut GmbH has the obligation to rehabilitate the damages at their legacies resulting from the former uranium ore mining. According to the legislations in Germany, the handling with radioactive material is subject to the regulatory control through licensing. As a result of the rehabilitation measures, the limit of 1 mSv per year on the effective doses for public exposure must not be exceeded. In this article, the success of rehabilitation from the supervisory authority’s perspective is debated.

Large volumes of uranium wastes are generated by nuclear- fuel pro-duction, nuclear power plants, and by facilities producing nuclear weapons. Uranium is present in various chemical forms such as elemental, oxide, sulfide, ionic, inorganic complex, organic complex, and co-precipitated with iron-, manganese- oxides, and carbonate. The mineralogical association and the oxidation states of uranium affect solubility, stability, bioavailability, and environmental mobility. Microorganisms affect the speciation of various chemical forms of uranium present in wastes and contaminated soils. The speciation of uranium affected by microbial action such as bioreduction, biosorption, biotransformation of uranium complexed with naturally occurring organic ligands, and solubility are reviewed.

Weathering of pyrite rich alum shale processing waste has led to metal pollution in Kvarntorp, Sweden. Here we use a fungal strain isolated from the site to monitor the excretion of uranium/metal stabilizing ligands under uranium induced stress. After 2 weeks 91 % was lost from a 10 mg L

−1

solution but 57 % already within 10 min. The formation of colloidal/particulate uranium is mainly controlled by organic exudates phosphorus excreted by the fungus. Most likely, the change in solution properties from metabolic processes resulted in the formation species through adsorption and precipitation.

The treatment of acid mine drainage in the uranium deposit Curilo, Bulgaria, was very efficient for a long period of time. However, the treatment of such waters containing high concentrations of iron, including a portion in the ferrous state, caused serious problem on the efficiency of the cleaning process. These problems were avoided by the pretreatment of these waters by a system for iron removal consisting of a unit for bacterial oxidation of the ferrous ions to the ferric state and a unit for precipitation of the ferric iron as a result of chemical neutralization.

Controlled Flooding of section I of the uranium leach operation at Königstein has been finished by January 2013 with about two third of mine volume being filled. The paper provides an extensive compilation of the general technological, hydraulical and geochemical findings of the flooding process. Further-more the permit application for final flooding up to the natural water level and the approval procedure regarding the final flooding step are been discussed.

Samples of saprotrophic (24 species) and ectomycorrhizal (26 species) macrofungi were collected from a U-polluted Norway spruce plantation and analyzed for the metals content. Concentrations of metals (Ag, Pb, Th and U) were also analyzed in ectomycorrhizal tips, non-mycorrhizal spruce fine roots and underlying soil. The concentration of U in macrofungi from the polluted area were circa 4x higher than those reported for macrofungi from pristine sites but generally did not exceed 3 mg/kg (dry weight).

Sulfate Reducing Bacteria (SRB) strain form and its sulfate-reducibility was identified after enrichment, separation and purification of SRB from some an-aerobic sludge of a uranium mine. The growth of SRB was stabilized 72 h after inoculation. The influence of inoculation quantity, pH, temperature, SO42- concentration on the growth of SRB was discussed. Sulfate treatment effect with 6.5 g/L SO42- concentration was 51.8 % in 15 days and 69.1 % in 30 days by SRB, respectively. Treatment effect of sulfate was 64 and 83 %, the one of uranium was 60 and 82.3 % from simulated wastewater by SRB and SRB + Fe0, respectively.

Since the discovery of gold in the Witwatersrand Goldfields in 1886, gold mines produced more than 270 tailings storage facilities (TSFs). In terms of their spatial dimensions tailings are by far the most important source of pollution associated with gold mining. In recent years there has been an increase in reclamation of tailings within the Central-, West, East and Klerksdorp, Orkney, Stilfontein and Hartbeesfontein (KOSH) goldfields. In a number of cases it has been identified that reclamation has been incomplete and without proper remediation. This article will highlight case studies of inappropriate reclamation activities within the Witwatersrand Goldfields and the associated environmental and social impacts.

Management of emerging water volumes and their chemical composition is an important part of the remediation of a former mill site with 2 tailings storage facilities. A vast number of constraints are to be considered resulting from available technical installations as well as requirements for environmental protection on the site but also catchment scale. Based on a case study lessons learned for similar remediation projects are presented which may allow to consider relevant aspects of water management already at an early stage of a mining legacy remediation planning.

For the past 13 years, the U.S. Department of Energy (DOE) has managed the Moab Uranium Mill Tailings Remedial Action (UMTRA) Project in Utah. As DOE designed and constructed tailings-removal and disposal systems, and now relocates the 14 million tonnes of uranium mill tailings away from the Colorado River, DOE has continued to place its highest priority on workplace safety. The project is ahead of the schedule and below the cost at completion, based on the approved lifecycle estimate.

Much remains to be done in terms of addressing the decommissioning of facilities and remediation of sites affected by past uranium mining and processing operations. The Constraints to Implementing Decommissioning and Environmental Remediation (CIDER) project was launched by the IAEA to contribute to improving the current levels of performance on Decommissioning and Environmental Remediation (D&ER) programmes through promoting greater cooperation amongst IAEA Member States and relevant international organizations. This paper analyses the major constraining factors that affect the implementation of D&ER programmes and how these impediments might be overcome.

A greenhouse pot experiment was conducted to evaluate the feasibility of using

Hieracium pilosella

and soil microorganisms for phytostabilization of uranium-containing shale residues. Conductivity of leachates significantly decreased and pH increased when plants were grown on the substratum.

H. pilosella

has ability to change the hydrochemical parameters and to decrease the mobilization of uranium. Moreover,

H

.

pilosella

is able to accumulate significant amounts of uranium in the shoots.

Successful implementation of mine remediation projects depends on a wide range of key aspects, one of the most critical is water management. Irrespective of both its importance regarding remedial success and its relevance to remediation cost, water management issues are frequently underestimated in the design and execution of remedial work. In this regard, the paper summarizes some of the most relevant findings from more than 20 years of implementing the WISMUT programme, one of the biggest mine reclamation projects worldwide.

The objective of the presented study is to assess the evolving mine water quality of uranium mines abandoned between 1958 and 1992 in the Czech Re-public. The sampling proved that actual uranium concentrations in mine waters did not in most cases exceed 0.45 mg/L. Uranium concentrations in the discharges from the adits abandoned more than 40 years ago were below MCL of US EPA for drinking water. Special attention is given to the most recently abandoned Mine Olší. Upon the geochemical modelling results using Geochemist’s Workbench, three time phases of mine water evolution can be defined at this deposit.

The selection of poor quality natural sand and gravel filter pack media for water supply wells leads to insufficient hydraulics, increased well clogging, higher electrical energy demand, reduced life-cycle, and increased Operations & Maintenance costs. Extensive comparative field and laboratory studies since 2008 proved, glass bead filter pack wells can achieve two figure savings for O & M at enhanced well performance and lifetime cycles.

This article provides an insight into the extent of remediation of residues of the uranium mining of the Wismut GmbH. Using the example of the waste rock dump Beerwalde in the Ronneburg region the layout of the measurement systems and the measurement technology used will be described. The results of the long-term measurements show the importance of this measurement campaigns for this remediation project in particular, and future remediation projects in general.

In December 2013, the Council of the European Union adopted new Basic Safety Standards (BSS) for radiation protection (RP) which Member States are required to transpose into national law by 6 February 2018. Given that the remediation of uranium mining legacy sites in Germany (WISMUT sites) will need to continue well beyond 2018, the questions arises whether the new standards will have implications for WISMUT in terms of practical radiation protection and radiological assessment of the remedial success. Therefore, the paper contrasts cur-rent radiation protection concepts with the BSS and comments to case examples.

The implementation of engineered solutions to U contamination in the subsurface results in reductive immobilization of uranium in the form of U(IV) precipitates, including mineral phases, i.e., uraninite (UO2), or non-crystalline biomass-associated U(IV) agglomerates. Crystalline uraninite is a preferable end product for U bioremediation due to its greater resistance to re-oxidation and re-mobilization processes in comparison to non-crystalline biomass-associated U(IV) species. Nevertheless, under field conditions, the latter species was reported to be predominant. According to our findings, the groundwater composition exerts significant control over the product of non-crystalline U(IV) species in the field

Residual waste dumps and tailings from previous U-mining activities in Mailuu-Suu represent a potential risk on local water resources. In 2006, a monitoring program has been initiated to determine the contamination status of local water resources, taken as a baseline to assess the impact of coming remediation activities. Field data supplemented by laboratory experiments shed light on uranium mobilization and transport path. The presented findings conclude into simple mitigation measures which have been introduced to local authorities and citizens.

It is well known that element transfer into plant shoots is highly variable and often very low in comparison with the accumulation in roots. On the other side, the role of Fe plaque on metalloid (P, As) and heavy metal stabilization on root surfaces has been widely researched on. In a reed dominated wetland along a flow gradient of seepage water plant and related water samples were taken to determine the relation between Fe plaque formation and U immobilization on the root surface of common reed (

Phragmites australis

TRIN. ex Steudt.). Fe plaques were observed in all sampling sites with a significant increase from near mine wa-ter inflow (Fe: 5449 mg·kg

-1

) to the near outlet (Fe: 16189 mg·kg

-1

), while an average of 87.1 % U was found fixed on root surfaces. The result indicated that an enhanced Fe plaque formation in the aeration zone of mine water inflow may inhibit more U from root inner ad- and absorption (accumulation) and/or competition with other elements (e.g. As). Both the increase of Fe plaque and the related root surface U coating is associated with a decreased redox potential in the surrounding interstitial water indicating that a reducing environment induced by organic matter decay (plant litter) could be an important factor. However, EDAX analysis showed that the U complex forming particles were not tightly adhered to the root surface but surround the root loosely. U is accumulated only to a small ex-tent within roots (rhizofiltration

in sensu strictu

). This is different to other metal-oids (like As) and heavy elements (ions) which fully bind to root surfaces and in-side the rhizodermis.

A uranium milling tailings impoundment is enclosed by 9 artificial dams and covers 1.7 km

2

. The impoundment cease to receive uranium tailings in 1994 and the dams are reinforced in 2008. The impoundment will be covered and stabilized in a few years. A large number of tailings’ water and seepage need to be treated and then discharged into the Xiangjiang river during covering. Pore water of 14 boreholes and seepage from 6 pump house were monitored to understand pore water and seepage quality. The water quality monitoring indicates that there is distinctly temporal and special variation of pore water and seepage qality in dif-ferent position and time. The detected primary constituents of pore water includes U,

226

Ra, Mn, SO

4

2

, Cl-, NO

3

-, NH

3

-N, F- and other heavy metal.

The main results of large-scale (1:25 000) neotectonics mapping within Dniprodzerzhynsk industrial site in the Dnipropetrovsk region of Ukraine are given. Neotectonic mapping was made on the basis of morphosructural (morphotectonic) methods. Neogeotectonic study allows to determine the influence of recent activity geostructures and their activation impact on rock properties (physical, mechanical, filtration and other) on which tallings are located. The location area safety of tailings facilities and uranium production waste of the Dneprodzerzhinsk industrial site by neotectonic criteria is evaluated.

Our laboratory has developed antibody-based sensors that provide on-site, near real-time information about uranium in environmental samples. The monoclonal antibody at the heart of this technology (clone 12F6) specifically recognizes U(VI) complexed to a chelator (2,-9-dicarboxyl-1-10-phenanthroline). Mutagenesis of a single amino acid in the 12F6 antibody light chain significantly increased its binding to chelated U(VI). Insertion of a gold-binding peptide sequence enhanced the antibody’s ability to complex with the gold nanoparticles, a process required for the development of simple lateral flow strips for uranium monitoring.

A permeable reactive barrier system, known as the Wall and Curtain, was installed at the Chalk River Laboratories, Chalk River, Ontario, in 1998, to intercept a

90

Sr plume. The system employs clinoptilolite, a zeolite, as a reactive material which adsorbs

90

Sr. Reactive transport simulations of the site were conducted using the numerical code HydroGeoSphere to provide longevity estimates for the system. The HydroGeoSphere simulations included three solutes, for which zoned distribution coefficients were specified. Longevity estimates derived from the simulation were between 70 and 100 years for the Wall and Curtain system.

Radon diffusion is generally affected by nature of medium and the exterior conditions (temperature, pression …).

Solubility constant data for radium and strontium (celestite) sulfate has been determined across the temperature range of 0 to 300°C based on the available literature data for these two phases as well as similar data for calcium (anhydrite) and barium (barite) sulfate for which solubility constant data is available across the same temperature range. The thermodynamic data for the phases have been determined by assuming that the solubility constants are a function of the inverse of absolute temperature with a constant, but non-zero, heat capacity change. The sol-ubility for all phases shows a peak with respect to temperature, with the temperature at which the peak occurs increasing as the alkaline earth metals become heavier. The heat capacity change is a function of the ionic radius of the alkaline earth metal ion whereas the enthalpy of reaction at 25°C is related to the peak at which the maximum solubility occurs. The entropy of reaction at 25°C is related to the solubility constant and the derived enthalpy of reaction at that temperature.

In South Africa’s Witwatersrand mining area, the issue of acid mine drainage has risen to great public prominence, with community-based activists playing an important role in raising awareness. Conventional water quality monitoring is costly and often requires complex procedures. However, simple water quality tests exist for a number of parameters which can be used to identify potential contamination related to mining. These have been applied as part of a high school science project, looking at the environmental impact of gold and uranium mining in the upper Wonderfonteinspruit. The results allow identification and characterisation of water pollution. This demonstrates the ability of volunteer monitoring programmes using simple technologies to complement the work done by regulators, operators and researchers in mining environments.

The aim of this work was to simulate the radionuclides dispersion in the surrounding area of a coal-fired power plant, operational during the last 25 years. The dispersion of natural radionuclides (

236

Ra,

232

Th and

40

K) was simulated by a Gaussian plume dispersion model with three different stability classes estimating the radionuclides concentration at ground level. Measurements of the environmental activity concentrations were carried out by γ-spectrometry and compared with results from the air dispersion and deposition model which showed that the stability class D causes the dispersion to longer distances up to 20 km from the stacks.

In this work, a study of the intrinsic behavior of U and Th isotopes in sedimentary rocks was performed by sequential extraction. The results for the phosphate layers and limestone interlayers of Oulad Abdoun Basin are compared to those obtained previously for Timahdit black Shale rocks. Characterization car-ried out by ICP-AES and SEM-EDX showed that apatite, calcite, dolomite, quartz and clays are the essential components of the inorganic matrix. The selective leached phases are treated radiochemically before measuring U and Th isotopes by alpha spectrometry. Among the results, it should be noted that the U isotopes were concentrated in an anaerobic environment. Humic acids that are the richest organic phase in U are responsible for the concentration of

234

U,

238

U in the carbonates and apatite. In the mineral phase,

232

Th, of terrigenous origin is partitioned between the silicate and pyrite minerals.

The hydro-geochemical behavior of radium in groundwater may be not trivial, but is well known since many decades. Anyway comparatively few publications can be found on this topic. The isotope ratios of radium sampled during pumping tests can give information on ground water flow regimes, regarding the mixing behavior of groundwater. Radium-226 is from the radiological point of view the most important isotope in the uranium decay chain. Designing high level nuclear waste repositories this must be taken into account.

The strong dependence of water treatment efficiency from pollutant speciation was demonstrated at the example of uranium removal from TMF seepage water by ion exchange. The pH dependence of carbonate equilibria was used to manipulate uranyl speciation in the investigated seepage water. Ion exchange experiments were carried out with TMF seepage feeds of the same origin but of different pH and thus of different uranyl speciation. Geochemical modeling and TRLFS measurements revealed calcium uranyl carbonate complexes to hamper sorption to ion exchange resins, whereas non-calcium uranyl carbonate complexes promote sorption. The manipulation of uranyl speciation by pH adjustment caused a rise in ion exchange efficiency from insignificant to technically feasible levels.

When Martin Heinrich Klaproth, born in Wernigerode, presented the discovery of “uranite”, he could not know which role this new element would play. In 1823, Alexander von Humboldt published the idea of the “Classic Geological Square Mile” later used for parts of the Northern Harz area because of their geodiversity. Between 1880 and 1920, the two physicists Julius Elster and Hans Friedrich Geitel worked in the Harz area—Geitel coined the term “atomic energy” in 1899. A cluster of industry and the Mining Academy Clausthal developed in this area because of the diversity of mineral deposits and mining. In the Nazi era, this cluster conducted military research and partly also worked on the possible use of uranium (U) for weapon production. The German U reserve was placed in Staßfurt. After WW II, Wismut carried out prospection work in the Harz region, but no U deposits were found worth mining. The U source of an anomaly in surface waters within the agricultural landscape Magdeburger Börde is probably to be found in the intensive and long-time use of mineral phosphate fertilisers.

According to the EU Water Framework Directive (EU-WFD), all Euro-pean water bodies should achieve the so called “good water status” by 2027 at the latest. In contrast, the German Wismut remediation project, focusing on the elimination of the consequences of a long-lasting uranium industry from the cold war era, will continue beyond that deadline. In spite of intensive and costly water management and treatment measures an impact on water bodies surrounding the sites under remediation cannot be totally avoided. The presentation focuses on the quality levels reached for selected water bodies in comparison to the benchmarks of the EU-WFD and on ways how to deal with the latter.

In the article research results of the impact of natural geological formations, obtained from opencast mines in Poland, on changes in water chemical and microbiological composition in filtration processes at lysimeters stands were presented. Deposits, applied in the studies, improved the quality of water, particularly in terms of reducing the manganese and iron and enriching in minerals, such as calcium and magnesium. The microbiological quality of the filtered water improved in relation to the raw water.

In the NW of Chihuahua City, Mexico, San Marcos range formation is located. San Marcos area includes two uranium mineral outcrops, a river and its dam, which are the main water supply for the nearest agricultural lands. Assessing fractionation and distribution of U and Th isotopes contained in colloidal and dis-solved fractions of surface water is the aim of this work. U and Th isotopes’ activities were obtained by alpha spectrometry. 238U and 232Th contents in colloids ranged from 5 to 16, and from 0.3 to 0.5 mBq·g

−1

, respectively, with activity ratio (AR, 238U/234U) of up 6. The U distribution coefficient (kdU) ranged from 1·10

3

to 7·10

3

L·g

−1

. The results have shown a possible lixiviation of uranium from geo-logical substrate into the surface water and an important fractionation of uranium and thorium.

This paper presents the assessment of radiation exposure due to inhalation of Rn-222 and its progeny for workers and clients of selected thermal water spas. The evaluation of the radon risk is based on the activity concentration of Rn-222 in the investigated thermal waters. For this purpose, a radon transfer coefficient which describes a fraction of radon transferred from swimming-pool water to the indoor swimming-pool air was calculated. The evaluated annual effective dos-es for the model clients and workers range in the intervals of 0.40 μSv to 194 μSv and 0.022 mSv to 10.8 mSv, respectively.

In the present investigation indoor radon (222Rn), thoron (220Rn) and their progeny concentrations have been measured in the wide range of dwellings from 12 different villages of Hamirpur district, Himachal Pradesh, India by using LR-115 type-II based Pin-hole Radon-Thoron discriminating twin cup dosimeters, direct radon and thoron progeny sensors (DRPS/DTPS). As inhalation doses are predominantly due to daughter products of radon and thoron and not due to gases, it is important to measure the decay products directly for health risk assessments. In the study region different types of houses were selected randomly according to methodologies described by Radiological Physics and Advisory Division (RPAD), Bhaba Atomic Research Centre (BARC), Mumbai. The indoor radon concentrations in these villages have been found vary from 36.1 to 272 Bq/m3, with average value of 125.54 Bq/m3 and for thoron vary from 38.5 to 331 Bq/m3, with average value of 140 Bq/m3. The progeny concentrations of radon and thoron are found within the limits of 10.5 to 106.9 Bq/m3 and 0.9 to 6 Bq/m3 respectively, with average values 43.7 Bq/m3 and 3.34 Bq/m3 respectively. The average concentration values observed in these dwellings have been found within the safe limits as recommended by International Commission on Radiological Protection (ICRP) and United Nation Scientific Committee on the Effect of Atomic Radiation (UNSCEAR).

The purpose of radio-hydro-ecological monitoring of the “Shelter” object includes: evaluation of soil and groundwater radioactive contamination level and migration or gradual penetration of radio-nuclides to the environment around the safety block. The research objects are: soils of aeration zone, groundwater and the sources of their contamination - surface and block waters.

The migration of radionuclides in the

238

U-series in soils and their up-take by plants is of interest in various contexts, including the geological disposal of radioactive waste and the remediation of former sites of uranium mining and milling. In order to investigate the likely patterns of behaviour of U-series radio-nuclides being transported upward through the soil column, a detailed soil-plant model originally developed for studying the behaviour of radionuclides in soil-plant systems has been adapted to make it applicable to the U-series. In this paper, a brief account is given of the mathematical basis of the adapted model and key parameters are identified and then estimated. Hydrological data appropriate to a situation in which upwelling groundwater interacts with meteoric water in the soil zone are also selected, using meteorological data from a former uranium mining site in Spain as a key input. On this basis, a reference calculation are defined and run for a unit input rate of either U or Ra at the base of the soil column and for a simulation period of 5,000 years. Results for this case are then used to comment on potential long-term patterns of behaviour of U-series radionuclides in soils and their uptake by plants.

Currently there are only very expensive and time-consuming analytical methods for the determination of uranium in water such as the ICP-MS, which is solely useable in laboratories. Novel measurement systems based on biochemical reactions, which are made visible with the help of gold nanoparticles by color changing or fluorescence, shall represent an alternative. Within a project founded by the German Federal Ministry of Economics and Technology the SARAD GmbH worked together with the Technical University Bergakademie Freiberg to develop such systems.

U series radioactive disequilibrium has been used to obtain time con-strains for geological and geochemical processes and to assess conditions under which disequilibrium formed. Recently developed DECSERVIS-2 simulation model offers an opportunity to study the behaviour of natural radioactive decay chains as a function of time under variable nuclide mass flows into and out of the system which greatly improves interpretation radioactive disequilibria and liable processes. In the present paper DECSERVIS-2 simulation model is introduced and its use as an interpretation tool demonstrated with selected simulation examples.

Increasing attention has been paid to radon in both Slovenia and Kazakhstan. The paper reviews their activities in radon measurements and dose estimates for radon exposure mitigation. Slovenia succeeded to accomplish the main goal of managing exposure to radon in homes and at workplaces at acceptably low levels, while in Kazakhstan there are still quite a number of dwellings with potential radon risk needing further monitoring and mitigation measures.

The in situ recovery operation of a perched uranium mineralization within a thick, permeable aquifer can become a sensitive issue. Indeed, density difference between the injected high-density acidic solutions and fresh groundwater are liable to trigger density-driven migration of solution towards the bottom of the aquifer. The goals of this study are (1) to represent with a reactive transport model, the hydrogeological behaviour of such an ISL operation for quantifying the lost part of uranium and acid linked to the density driven flow, (2) to suggest some possible solutions to optimize the production.

Besides P, the application of phosphate fertilizers also introduces U to agriculturally used land. Still today there are many unknowns regarding the behavior of U in the subsurface. Therefore, in this study two different sites of agriculturally used land in the federal state of Saxony, Germany, were studied in detail by soil and water sampling with subsequent analysis of the samples’ composition and properties in the laboratory. Additionally, long-term land use-, weather- and water and soil analytical data from state authorities was considered. It was shown that the fate of U is influenced by soil properties (cation-exchange capacity (CEC), humic and organic matter content, the fraction of cohesive material (clay and silt)), fertilization (type, amount and frequency), ploughing depth, precipitation, and the factor time.

One of the main aspects in the remediation of closed uranium mine sites is the treatment of mine water. In order to understand speciation and processes in uranium mine waters, hydrogeochemical modeling is carried out. The importance of modeling in mine water treatment is shown by the example of two case studies. The first deals with precipitation processes in a stripping column. In the second case uranium speciation of different mine waters is characterized. By means of modeling results, treatment technologies can be adjusted and improved.

3D reactive transport model is an efficient tool to simulate uranium ISR operation: indeed the whole process is based on reacting fluid circulation in porous media. The simulation can help quantify the processes at stake and optimize the ore dissolution rate and the use of reagents. This study details the application of a 3D reactive transport approach using the code HYTEC at operation scale in Kazakhstan.

Sedimentary rock phosphates contain up to several hundred mg/kg of uranium (U), which seems low when compared to the U concentration in typical mined U minerals, but is significant in terms of U masses. U in rock phosphate is easy to recover, and sufficiently high stock market prices for U provided, will supply nuclear fuel cycles as a secondary U source. The paper presents a circumstantial case study on the recovery, use and fate of U derived from phosphate min-ing in the Negev desert and supports evidence that Israel’s nuclear facility at Dimona might be fed by U derived from refining rock phosphates at the Rotem Amfert mine for food and fertilizers. Evidence for U enrichment provides an archived compound fertilizer which contains depleted U.

Permeable reactive barriers (PRB’s) are of particular importance for uranium mining due to a cost-effective and long-term protection standard unlike other pump-and-treat methods. As a common approach, PhreeqC models are used to determine behaviour, effectivity and dimensioning of PRB’s. However, calculations and simulation of PRB’s frequently fail as comprehensive and reasonable planning and prediction tool, because requirements on PhreeqC models differ between users and developer on the one hand and the mining industry on the other hand. This paper demonstrates how reasonable planning but easy to understand solutions of in situ PRB’s can be managed by a combined approach of PhreeqC and numerical groundwater flow modeling results.

From 14 Swedish boilers (grate fired as well as fluidized bed) 31 different ashes were collected and analysed for uranium. Uranium concentrations ranged from 0.32 to 22 mg/kg dw. Average uranium concentration in the bottom ash and fly ash was 1.3 and 2.7 mg/kg dw, respectively, indicating that uranium in the fuel is quite volatile during combustion. Highest concentration of uranium was found in a fly ash from a boiler burning peat indicating that peat is a natural source of uranium.

Sedimentary phosphate from Moroccan deposit and its corresponding phosphogypsum where characterized by several physic-chemical techniques as well as by nuclear method.

A radium production factory was operated in the Barracão village, near Guarda, Portugal, and from 1908 to 1941 produced radium-barium sulphate salts for use in radiotherapy. The factory site has been closed for decades and surveil-lance was kept by the uranium mining company. In the early 80s of past century, the site was monitored and partly cleaned up with transfer of ore remainders and waste heaps to a waste disposal mine site elsewhere. New clean-up operation took place in 2007 and the facilities were fenced. The radioactivity levels in and around the Factory were recently re assessed and results are reported herein. Concentrations of uranium series radionuclides were determined in agriculture soils nearby, in water from irrigation wells, in the surface stream that received waste water from the factory, and in water from a public fountain in the village. Vegetables from agriculture plots near the factory were analyzed also and the effective radiation dose to inhabitants through consumption of these products was assessed. Radiation exposure of members of the public and results of clean-up operation are discussed.

For the present study, 172 groundwater samples (collected from wells and natural springs in Serbia) were analyzed for different chemical parameters including uranium. For each groundwater sample, information was compiled about the basic parameters of its chemical composition. Most of the samples were found to be of the Na – HCO3 and Ca, Mg − HCO3 water types, while only a few were classified as the Ca, Mg – SO4 or Na − Cl type. HR–ICP–MS is an analytical technique used for uranium determinations. The measured concentrations of uranium were in the range from 0.0005 μg/L to 25.34 μg/L.

Excluder seed crops of wheat and pea down-regulate the uptake of heavy metals from excessively metalliferous soil to equip their seeds with essential trace metals in quantities that correspond with “normal plant concentrations” and ensure thus their vigorous and stress-free germination. Due to this uptake blockage, non-remediable soils can be used to grow food- and forage-quality seeds. Breeding and providing certified heavy-metal excluder (seed) crops should thus be given precedence to flopping soil phytoextraction measures.

This paper presents the conception to employ High Temperature Reactors (HTRs) to power a combined phosphate fertilizer/phosphogypsum (PG) processing plant that produces phosphate fertilizer by the wet acid process while treating the main associated waste product PG to sulfuric acid/Portland cement. The idea is based on a past plant design proposed by Consolidated Minerals Inc. (CMI) and promotes the usage of a lean greenhouse gas emission energy source instead of the previously suggested coal-fired plant.

The introduction of on-line X-ray fluorescence (XRF) analysis in mining and processing industry of uranium and thorium-bearing materials is discussed. Potential applicability of industrial XRF analyzer CON-X series is shown for continuous measurement of uranium (U) and thorium (Th) in various materials (rutile and zircon sands, phosphate rock and fertilizers, carbonatite and granite as unconventional U and Th resources, monazite concentrate as Th and U associated resources and etc.) at the wide range of U and Th concentrations (from less than 100 ppm to percents). U and Th detection limits (DL) are estimated as less than 50 ppm at concentrations below then 0.1 %.

Nanofiltration offers new perspectives for the treatment of mine drain-age from former uranium mines, e.g. in East Germany. In this study the performance of various commercial nanofiltration membranes for a real mine water sample was determined experimentally and modelled. Experimental data is key to membrane selection and is necessary to validate modelling results. Mathematical modelling offers deeper insights into the interaction of uranium species with solid surfaces which also has the potential to extrapolate to other research fields.

Geochemical investigations and modeling of groundwater chemistry was performed in Tanjero area, Sulaimani city, Kurdistan region, Iraq. Uranium in waters of the area shows low concentrations, however, uranium is positively cor-related with other trace elements which are typical indicators for man-made con-taminations. Two main point sources of contamination show higher level of urani-um and V, Cr, Zn and Fe: the municipality dumping site of Sulaimani city and industrial dumping sites. Comparing 235U with 238U reveals that the uranium source is neither depleted uranium (DU) nor enriched uranium. Thus it is very likely that scrap iron from hydrocarbon production and storage facilities dumped in the land fill is the source of the slightly elevated uranium concentrations. De-pending on the uranium and other trace elements three different classes of water can be distinguished: contaminated water, non-contaminated waters and mixed water. Dominance of U (VI) and As (V) with the positive correlation between U and nitrate indicate oxidizing environment.

Radon measurements are currently under way along newly discovered faults in the northern Upper Rhine Graben near Groß-Gerau. Measurements of radon activity in soil air should show if the disruptions are recently active. In the process, it is difficult to compare the measurements of soil types, with different permeability, without logging the actual air flow. It is intended therefore to develop a standardised method which combines the measurement of radon with the detection of CO

2

in soil air. Outcomes will be used for correlation with radon concentrations in the indoor air of buildings in the region of Darmstadt (Kuhn 2013), which is situated in the tectonically active northern Upper Rhine Graben, in order to evaluate geogenic radon in the area.

River sediments are archives for past water contaminations. This is shown for the catchment of the Mulde River draining major parts of the Erzgebirge, Saxony, Germany. Mining activities have been impacting this part of Germany for over 850 years. It started with silver, then changing to lead, cadmium, zinc, tin, tungsten and copper. Finally, after 1945 a big uranium boom took place in this ar-ea which was led by the Soviet Union and the company SAG Wismut /SDAG Wismut, respectively. Until 1990 this area and parts of Thuringia produced 231,400 t of uranium and for this time period made the GDR the third biggest uranium producer of the world. Field work in 2011 revealed that both water and sediments still contain significant concentrations of uranium, cadmium, zinc, arsenic and other mining-related elements. Factor and cluster analysis has been used to visualize the data. Certain areas such as the former Freiberg mining area are high in lead, arsenic and cadmium but low in uranium. On Contrary, those areas where uranium ore was mined still show high uranium concentration in both water and sediments.

Uranium mining activities of the former Soviet-German stock company SDAG Wismut in East Germany caused significant radiological environmental impact. At the Wismut sites in the Ore Mountains the radioactive noble gas radon is of significant relevance for the environmental impact. The paper quantifies the different contributions of the uranium mining legacies to elevated outdoor and in-door radon concentrations. This is exemplified by the local radon situation at the Wismut site of Schlema-Alberoda. The mitigation measures taken by Wismut GmbH to reduce the radon exposure of the general public are presented.

Uranium (U) is a natural but undesired heavy metal in rock phosphates and processed phosphorus fertilizers. Analytical methods employing the direct de-termination of U through α-spectroscopy or ICP mass spectrometry are tedious and expensive, require sophisticated laboratory equipment and skilled staff. This contribution describes an easy to perform test based on a low-cost gamma-ray spectroscopy system. The determination of U was carried out through its only gas-eous decay product Radon (

222

Rn). Seven straight and compound fertilizer samples with different U and K content were measured and the spectra compared to that of the U-containing mineral schrockingerite.

In this study, results have been presented on remediation processes of oxidation of various petroleum hydrocarbons by

Pseudomonas

bacteria cells and by specific types of mixture between seed of legumes and cereals. It has been found that the maximum remediation activity of complex plant- microorganisms was characterized for saturated hydrocarbons.

Sandstone permeability is a key factor to study Jurassic coal field hydrogeological conditions and it’s also an important factor to study sandstone uranium in situ leaching hydrogeological conditions. Sandstone whole stress-strain process permeability characteristics under different confining and osmotic pres-sure were studied through laboratory tests. Sandstone permeability characteristics along vertical direction were studied through field tests. Relationships between permeability with failure process, confining pressure, osmotic pressure, bulk strain and buried depth were obtained respectively.