JAZBEC MINING TAILINGS DISPOSAL FACILITY
The Jazbec mine tailings repository is an environmentally remediated and closed facility with disposed naturally occurring radioactive material in higher quantities.
The disposal of radioactive waste is the final phase of its management. Even after a repository is closed, the facility must continue to be monitored and the maintained in the state achieved by environmental remediation to ensure the integrity and stability of the repository and provide permanent protection of the environment and the population against the consequences of past uranium ore mining.
During the extraction and processing of uranium in the Žirovski Vrh Uranium Mine and during the closure of the mine and the ore processing plant, radioactively contaminated material was created, which is deposited in two landfills in the area of Žirovski Vrh. The Boršt hydrometallurgical tailings landfill is in the final phase of closure, which is being carried out by the public company RŽV d.o.o. The Jazbec mine tailings repository is an environmentally rehabilitated closed facility and has the status of a state infrastructure facility. Its management, long-term control and maintenance is carried out by ARAO as part of the mandatory state economic public service.
Odlagališče rudarske jalovine Jazbec is situated at the site of the former Žirovski Vrh uranium mine in the Poljanska Dolina valley, approximately 3 km south-east of the village of Gorenja Vas.
During the years of operation of the Žirovski Vrh Uranium Mine, poor ore, mining tailings and red sediment from the uranium ore processing plant were deposited at the Jazbec landfill, and during the closure of the mine after 1990, also uranium-contaminated construction material, soil, parts of contaminated technological equipment and material, obtained by decontamination of surfaces. The concentration of uranium and elements of its decay chain, which are otherwise found in nature, is slightly higher in this material.
The Jazbec mining tailings repository is now an environmentally rehabilitated closed facility and has the status of a state infrastructure facility. The status of the radiation facility was terminated with a closure permit issued by the Slovenian Nuclear Safety Administration at the end of 2014.
Elemental facts about Jazbec mining tailings disposal:
- the area measures 7.4 ha,
- the height difference between the lowest and the highest point is 82.5 m, the slope of the banks does not exceed 20%,
- the thickness of the protective covering is 1.95 m,
- the mass of the deposited material is 1,910,425 t,
- average concentration U3O8 je 69 g/t,
- the total activity of the deposited material is 21.7 TBq.
The repository is surrounded by a protective fence and overgrown with grass. Backwater, surface and storm water is discharged by a system of surface ditches and canals and a culvert under the repository.. The collected water flows through the common channel into the Brebovščica stream.
Environmental impact of the repository
After the closing and environmental remediation were completed, the release of radioactive substances from the Jazbec repository dropped significantly. In the direction towards Gorenja Vas, the impacts combine with the impacts of the Boršt repository, and with measurements along the confluence of Todračica and Brebovščica, it is not possible to distinguish between their impacts.
Based on the results of radioactivity monitoring, the total exposure of the population in the area maximum permissible would be 0.3 mSv/year. Actual estimated values do not exceed 0.1 mSv/year.
Repository maintenance
The Jazbec closed repository is a state infrastructure facility, managed and maintained by ARAO under the authority of the state. The main purpose of maintenance is to preserve the condition achieved through environmental remediation. This continues to ensure the protection of the environment and human health.
Regular maintenance includes mowing and fertilizing the grass, removing undergrowth on the inside and outside of the fence, and maintaining the fence around the repository. From time to time, additional maintenance work is required on the surface of the landfill, access roads, surface water drainage systems and technical monitoring facilities (piezometers, geodetic network points, inclinometers...).
At least once a year, and more often in the event of major weather problems or an earthquake, the condition of the repository is carefully inspected and maintenance work is determined. The drainage shaft and culvert under the Jazbec repository are also inspected from time to time. The last inspection showed that the culvert, the drainage shaft and the inlets of the drainage systems are still in good condition.
In addition to the annual inspection, data obtained through monitoring is also important when deciding on the necessary maintenance work. Changes in stability, water balance or discharges from the repository can mean that the condition of the repository has changed and that remediation is necessary to restore the previous condition.
