DIAMO, state enterprise, branch Těžba a úprava Uranu in Stráž pod Ralskem

In 1962 the area of activity of the current branch TÚU at Stráž pod Ralskem was investigated with discovery and subsequent confirmation of several rich uranium deposits. Therefore the origins of mining activity in this area date back to 1966, when as of 1 March the purpose-built organisation called Hamr Uranium Mines was established to – besides other things – construct a mine and a chemical treatment plant, including their trial operation.

The current branch TÚU at Stráž pod Ralskem was established in 1991 as part of the Czechoslovak Uranium Industry state enterprise, which in the same year moved its seat from Příbram to Stráž pod Ralskem and in 1992 changed its name to DIAMO, state enterprise.

In 1993 deep uranium mining was terminated and in 1996 chemical extraction of uranium was ended in the Česká Lípa region.

The basic aim of the activities of the TÚU branch is to eliminate the consequences of underground mining and in situ leaching of uranium, certainly one of the most extensive environmental burdens in the Czech Republic. Uranium mining in this area significantly affected the landscape by the established mines and plants for mining and processing of uranium ore, causing extensive contamination of ground waters.

Especially as a consequence of in situ leaching the contaminated ground water, not naturally stabilised underground, represents a cardinal and unacceptable risk of contamination of drinking water sources and threatening of the water-related ecosystems of the upper Ploučnice river and its tributaries. Considering these risks, active remediation works must be implemented including, in particular:

• Surfacing of the contaminated solutions by their pumping,
• Their treatment by decontamination technologies,
• Their release to rivers or return to the underground.

A major part of the plan of elimination of consequences of deep mining has been completed already. The underground of the mines and their surface objects are demolished, the tailings ponds are used in the context of clearance of residues of chemical extraction and landscaping on the surface of the former mines is implemented in harmony with the individual rehabilitation projects.

The in situ leaching consequence elimination includes cleaning of the rock environment and liquidation of abandoned and unneeded wells.

The TÚU branch operates a complex of unique treatment technologies for removal of contaminants from the pumped solutions.

Pumping of residual technological solutions from the individual wells must secure that the contamination will not spread in the direction of natural ground water flows outside the existing network of drills and the rehabilitation progress will be optimised.

Together with the rock environment cleaning in situ leaching extraction of uranium, restoration of the mine surface is addressed simultaneously.

Successful elimination of consequences of uranium mining is conditioned by detailed and periodic monitoring of all components of the environment, evaluation of the monitoring and continuous assessment of the risks connected with spread of the individual contaminants, both chemical and radionuclide.

In the context of its activities the TÚU branch emphasizes environment protection, radiation protection and nuclear safety, especially through:

• Preparation and management of the remediation and liquidation activities with minimised environmental burden;
• Monitoring of all components of the environment, its continuous evaluation and implementation of measures in reaction to the obtained results;
• Assessment of the effect of rehabilitation technologies, clearing and elimination activities on the environment in compliance with the generally binding legislation.

The staff of the TÚU branch annually monitors over 380 wells, 84 outlets and pumping points in the area of interest, with taking of nearly 30 earth samples and countless technological samples. Monitoring of this scope is an important source of information for evaluation and control of the progress of the rock environment remediation, optimisation of the contamination elimination technologies and follow-up of the effects of the performed activities in the surrounding environment with observance of the limits defined by the administrative authorities.