Conducting integrated environmental impact assessment and feasibility study for the environmental remediation of uranium legacy sites of Min-Kush and Shekaftar

Uranium production in Central Asian countries between 1944 and 1995 has left behind a huge legacy of uranium mining and processing wastes and abandoned conventional uranium mines. After 1995 most of the conventional uranium mines were closed. The European Commission first addressed the problem of legacy uranium mining in 1995, with a project that covered uranium mines and mills in Uzbekistan, Kyrgyzstan, Tajikistan, the Russian Federation and Ukraine, within the frame of the TACIS nuclear safety assistance programme. Other studies were eventually carried out, which focussed on specific sites or areas (i.e. a preliminary assessment of the uranium production legacy sites in Uzbekistan and other Central Asian countries carried out within the IAEA Regional Technical Cooperation Project RER/9/086 from 2005 to 2008, and other studies by United Nations Development Programme (UNDP) supported by the European Commission (EC), Organization for Security and Cooperation in Europe (OSCE), the World Bank (WB), the European Bank for Reconstruction and Development (EBRD) and the North Atlantic Treaty Organization (NATO). As a result of these studies, and based upon a preliminary qualitative risk assessment of the legacy sites it was possible to identify the priority sites requiring remediation. The legacy sites of Min-Kush and Shekaftar in the Kyrgyz Republic are among the identified priority sites of Central Asia.

The Min-Kush mining and milling site is located in mountainous terrain close to the town of Min-Kush, some 2100 m above sea level. The mine and mill site comprises four closed mines, four waste rock piles, and tailings facilities. The tailings are stored at four impoundment sites: Tuyuk-Suu, Taldy-Bulak, Kakk, and Dalnee. These sites were active between 1955 and 1960 when the mill was operational. They contain an estimated total of 1.9 million cubic meters of uranium tailings and cover an area of 19.65 ha. The mines are located within 11 km of the town of Min-Kush.

The Shekaftar site is located in Ala-Bukynsky District of Djalalabad Province, the site was worked from 1946 to 1957. The mining complex comprises of 3 closed mines and 8 mining waste disposal areas that contain about 700,000 cubic metres of low-radiation rock and low-grade ores. Houses with gardens are located in the vicinity and none of the dumps have been rehabilitated. Average exposure dose rate of gamma-radiation on the surface of the disposal areas is equal to 0.6 -1.5 μSv/h.

The objective of this project was to conduct an environmental impact assessment and feasibility study, for the safe management and remediation activities for the Min-kush and Shekaftar sites. The environmental impact assessment and the feasibility study will be the basis for subsequent decision making regarding remediation of the sites. The project consisted of an initial analysis of existing data, identification of data gaps, recommended site characterization activities to fill data gaps, proposed remediation concepts and alternatives, establishment of site-specific monitoring systems for initial characterizations and long-term surveillance as well as time schedule and cost estimates.

In order to achieve the set objectives, the following project activities had to be carried out:

• A detailed description and characterization of the current geological, physical, chemical and radiological status of both sites
• A thorough integrated analysis of alternative remediation activities of both sites, including a cost estimation and a safety analysis
• The determination of significant social, safety and environmental a) positive and negative impacts, b) direct and indirect impacts, and c) immediate, short and long-term impacts of the proposed remediation activities
• Management plan to mitigate the negative impacts of the remediation works
• Monitoring plan for both sites
• Assessment of further possible needs for technical assistance for successful implementation of the actual remediation projects
• The involvement of local authorities, the population and other organisations present at the sites
• The identification of policy and institutional needs for implementing the recommendations issued in the frame of the project

The project started on 16 March 2015 and was successfully completed on 15 March 2017. It was implemented by the consortium WISUTEC GmbH, Wismut GmbH, C&E GmbH and Facilia AB, led by WISUTEC. The Beneficiary was the Government of the Kyrgyz Republic, represented by the Ministry of Emergency Situations (MES) and by the Agency for Tailings Management Facilities (AOX).

The project implementation was divided into 11 tasks:

• Task 1 Preparations, Planning and Organisation of Kick-off Meeting
• Task 2 Identification national legislative and regulatory framework applicable to remediation of uranium mining and milling
• Task 3 Assessment of the current status of the Min-Kush and the Shekaftar sites
• Task 4 Assessment of the impacts and risks of each site
• Task 5 Definition and selection of remediation strategies
• Task 6 Remediation plans for the sites of Min-Kush and Shekaftar: Feasibility Study
• Task 7 Development of environmental monitoring and maintenance plans
• Task 8 Environmental Impact Assessment
• Task 9 Public consultation and participation. Involvement of relevant governmental agencies and local stakeholders
• Task 10 Identification of policy and institutional needs to implement environmental assessment recommendations
• Task 11 Final report. Dissemination of the results

For the Min-Kush site, a parallel project run by Rosatom and financed by the Community of Independent States (CIS) is addressing the remediation of tailings ponds. However, since the exact boundary of this project was not clear at the time the INSC project started, it was decided to proceed including the whole Min-Kush site in the tasks from 1 to 5 and complete tasks 6 to 11 only for those object of the Min-Kush site that were not included in the CIS project.

The project kick-off meeting was held in Bishkek 14 April 2015.

The technical part of the project started in March 2015 with Task 2, the analysis of the legal and regulatory framework in Kyrgyzstan. The Contractor analysed the Kyrgyz legal and regulatory framework under the aspects that concern the remediation of uranium production legacy sites, and compared it with accepted international regulations and standards. The outcomes included a thorough understanding of the legal and regulatory framework of the Kyrgyz Republic according to which the project deliverables had to be developed. Gaps and discrepancies with respect to international best practice were also identified but were relatively minor.

The next project phase (Tasks 3 and 4) included the assessment of the status of both sites by the use of engineering surveys, sampling and measuring, field inspections, review of existing documents, etc., with the aim of having a complete, sound description of the status of the sites and the risks resulting from the existing situation.

The data review and investigations carried out revealed a significant degradation of the local socio-economic and natural conditions as a consequence of previous uranium mining activities and remaining legacies.

In summary the current situations at Min-Kush and Shekaftar can be characterised as follows:

• Exceedances of radiological and/or non-radiological drinking water standards by some effluents and spring waters at Min-Kush and Shekaftar
• The exposure doses from staying at the waste dumps and other contaminated areas are below the selected reference level of 1 mSv/year.
• Exposure of members of the public from the use of water affected by the legacies may result in doses exceeding 0.1 mSv/a.
• Inorganic chemical quality parameters (metals) of water that is affected by the legacies exceed Kyrgyz standards for drinking water in some cases.
• Geotechnical instabilities with resulting community safety risks at several underground mine workings at Min-Kush and Shekaftar.
• Outdoor radon concentrations are in the order of 30 Bq/m³ at both sites
• There is no significant cultural heritage at either site that would need to be specifically protected during remediation works
• The local economies of Min-Kush and Shekaftar are characterised by small-scale or subsistence agriculture. A substantial contribution to the livelihoods depends on remittances of Kyrgyz citizens working abroad.
• Erosion risks of waste rock dumps and in particular of dump no. 3 of the Shekaftar site located on the banks of the Sumsar River in Shekaftar
• 6 waste rock dumps located within the village of Shekaftar
• Insufficient long-term geotechnical stability of the Tuyuk-Suu and Taldy-Bulak tailings facilities at Min-Kush, while geotechnical failure of the tailings facilities Kak and Dalnee is sufficiently improbable
• Indoor radon concentrations during summer time at Min-Kush exceeded the Kyrgyz standard of 200 Bq/m³ in some instances
• Some areas (Ak-Ulak, Rudny Sklad No. 6) show gamma radiation levels significantly exceeding the natural background
• No red-listed species were found.

The gathered information provided a sound basis for the execution of the next tasks of the project.

In result of the dedicated risk assessment a set of applicable technical rehabilitation measures were developed for different groups of objects (Task 5). At least 3 remediation options (including the 'do nothing' option) were examined for each object. Their costs and benefits were estimated and compared by a Multi-Attribute Utility Analysis (MAUA). This resulted in a proposal of best remediation measures, finally evaluated in Feasibility Studies for both sites that were agreed with and endorsed by the Uzbek Beneficiaries to have a sound basis for the following technical planning (Task 6) and the environmental impact assessment (EIA) (Task 8).

The following principal remediation measures were proposed:

Shekaftar

• Relocation of waste rock dumps located in the village of Shekaftar (waste rock dumps 1, 2, 5-7) and on the banks of the Sumsar River (waste rock dump no. 3) to waste rock dump no. 4 outside of Shekaftar
• Closure of open shafts with concrete slabs
• Installation of a pipeline to prevent use of water that is unsafe for human consumption
• Demolition of dilapidated buildings and on-site burial of the demolition rubble
• Prohibition of the use of contaminated waters by administrative decree and warning signs

Min-Kush

• Closure of open shafts with concrete slabs
• Closure of adits with brick walls and crushed rock
• Concrete plugs for sinkholes
• New water discharge installations for the prevention of erosion of wastes
• Demolition of dilapidated buildings and on-site burial of any contaminated demolition rubble
• Cover placement on contaminated soil areas
• Prohibition of the use of contaminated waters by administrative decree and warning signs

For the tailings facilities of Tuyuk-Suu, at Min-Kush, relocation to the Dalnee tailings site was proposed by the Contractor under Task 5. For Kak and Taldy-Bulak, in-situ stabilisation was considered the optimal solution in the Task 5 report. However, the tailings were then excluded from the following tasks of the project as it was clear at this point that the remediation of all 4 tailings will be included in the CIS project.
The general remediation strategy of Task 5 and the subsequent feasibility studies developed under Task 6 have been agreed with and endorsed by the Beneficiary and the EC, to have a sound basis for the following technical planning of remediation measures and the EIA.

The engineering design documents comprise the following:

• A detailed design including “Explanatory Notes” of the construction works with all detailed descriptions of planned activities,
• The “Technical Specifications” as basis for tender documents of the remediation works,
• A detailed cost estimate. Both reports were elaborated according to international standards and Kyrgyz regulations. The calculated net project costs (without value added tax) are 4.1 million EUR for the Min-Kush site and 3.5 million EUR for the Shekaftar site.

Monitoring programs for the remediation works and the post-remediation period have been developed under Task 7. Due to the limited scope of the proposed works, they are rather simple and should not cause major problems even under constraints of human and financial resources, if the recommendations listed below are followed. For none of the remediated objects there will be a need for extensive long-term environmental monitoring or aftercare. However, administrative measures to prevent people from using unsafe water should be continued in the future. Key elements of the post-remedial monitoring activities for the remediated sites are:

• Control of the stability of closure measures at shafts, adits and sinkholes
• Control of the integrity and functionality of technical structures (water diversion channels, water pipes, cover on contaminated areas), and maintenance measures as necessary
• Control of warning signs and implementation of a public risk awareness programme related to the use of water that is unsafe for human consumption
• Control of the quality of discharge water as a matter of precaution.

Necessary improvements of the monitoring capabilities in terms of equipment, human resources and training needs have also been identified. It is to be noted that the preparation of technical specifications for the purchase of the needed laboratory equipment is part of the activities included in INSC project REG4.01/10.

By integration of the outputs of the previous tasks, Environmental Impact Assessment (EIA) studies (Task 8) for remediation works at each of the sites of Min-Kush and Shekaftar were prepared in compliance with Kyrgyz and international standards and agreed with the Kyrgyz authorities.

In general, the environmental and social impacts of the proposed remediation works are negligible or minor due to the limited scope of works (simple civil engineering measures). Relocation of waste rock dumps in Shekaftar is the only activity that may have a major environmental impact, albeit for a limited period of time only. Effective mitigation measures have been developed that will keep the impacts to an acceptable level. No unacceptable environmental impacts of the remediation works are expected.

Effective doses to workers during the implementation of remediation works may reach 1 mSv/a at Shekaftar under conservative assumptions. Effective doses incurred by workers at Min-Kush will be well below 1 mSv/a.

Effective doses to members of the public will remain well below 1 mSv/a at all sites.

Public consultation and participation activities, involvement of relevant governmental agencies and local stakeholders (Task 9) have been continuously implemented during the project. Each individual project task was performed in close collaboration and agreement with the Beneficiary and other relevant Kyrgyz organisations. In particular, a successful stakeholder involvement and information program was implemented under Task 9 at both sites, in close collaboration with the Beneficiary and the local Aarhus Centres. Formal regulatory requirements were followed in the preparation and carrying out of the stakeholder consultation meetings. No objections to the proposed remediation program (Feasibility Study) and the findings of the EIA were raised by the local stakeholders.

The main results of the review the authority and capability of the institutions at local, regional and national levels to oversee the remediation works and the long term surveillance, inspection and monitoring plans (Task 10) are that generally more definite regulations regarding responsibilities for the monitoring during remedial works and for the long-term stability of remedial activities (surveillance, inspections, maintenance, long-term monitoring) should be developed by the government. Specific recommendations for improvements were prepared by the contractor for:

• Development of policy, legal/regulatory and guidance documents
• Stakeholder involvement and communication
• Training and professional development, human resources development

Sufficient financial resources, based cost estimates of the post-remediation activities (monitoring, surveillance, maintenance, and corrective action) should be available under the state budget.
The Final Meeting was successfully held on 29 March 2017, concluding the project activities.
Based on the continuous cooperation in all project phases of the Contractor with the Beneficiary, all deliverables (technical reports) have been endorsed by the Kyrgyz project counterpart.
All the project deliverables have been peer reviewed by a team of independent international experts set-up by IAEA.