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Hungary: glasnost reaches uranium mines

Nuclear Monitor Issue: 
#340
19/10/1990
Article

(October 19, 1990) On 4 October 1990 the Hungarian uranium mining company MEV for the first time allowed a visit of its uranium mining and milling facilities at Pecs in Southern Hungary by local and western ecologists. The company offered a visit of all facilities of interest and presented data on the environmental survey of the facilities.

(340.3404) WISE Amsterdam - The Hungarian uranium deposit at the foot of the Mecsek mountains is located in Permian sandstone. The ore has an average grade of 0.07% and has been mined since the early 1960s in depths down to 1000 meters. Five shafts exist, of which three are still active. High grade ores are transported by trucks over a distance of two kilometers on public roads to the milling site, where the ore is milled and leached using an acid leach process. Low grade ores (with grades below 0.01%) are piled up on special leaching piles where they are leached using a carbonate leaching process. This uranium-bearing leaching liquid is then concentrated, using ion exchangers, and introduced into the mill's extraction process. The uranium mill tailings are neutralized and pumped into two large tailings ponds. Annual production of yellow cake is 600 tonnes per year. It is delivered to the Soviet Union where it is purified and enriched for reactor use. Half of the amount of enriched uranium gained is then delivered back to Hungary for use in the Paks nuclear power plants. As production costs are not competitive on the world market, the Soviet Union won't continue to purchase the Hungarian uranium after subsidies by the Hungarian government are stopped. To increase production effectiveness, jobs will be reduced from the present number of 5700 to 2500 by the end of 1990. The Irish company Glencar Explorations is negotiating purchasing a majority share of MEV and continuing operations with a significantly reduced staff. The future of the mines is still uncertain.

But there Is no doubt that environmental problems resulting from the operations will remain for a very long time. The main problems are the two tailings ponds, which cover an area of one square kilometer each and contain a total of 15 million tonnes of tailings solids and nine million tonnes of liquids. The ponds were constructed in a plain using ring dike structures. The ground under the ponds consists of layers of clay and sand and was thought to be impervious until contamination resulting from the ponds was found in nearby observation wells early this year. The company is now studying how to stop seepage of contaminated liquids from the ponds.

At the surface of the ponds, the bare tailings material is exposed and thus subject to wind erosion and responsible for enormous radon emanations. Nevertheless, there still exist no concepts for reclamation of these tailings ponds. Because of the seepage problems, it might become necessary to move the tailings to better places - a very expensive task. After placing the material on impermeable layers, it should be covered with different layers to avoid intrusion of precipitation, prevent radon emanation and stop wind erosion for the long periods of time these materials present a hazard.

Another matter of concern for the long term are the now 15 leaching piles which contain a total of 2-3 million tonnes of low grade ore. They have been erected on a double plastic layer of 0.8 millimeters thickness each to prevent seepage of the leaching liquid, but plastic layers are known to be impermeable for a rather short period of time only. The reclamation concepts for these piles propose a reclamation in place by covering the piles with a layer of 30-50 centimeters of clay and revegetation. This seems to be not at all sufficient to meet the requirements of a long term reclamation.

In the short term (during continuation of mining), other environmental problems pose additional concerns, as there are: radon exhaust from the shafts, wind erosion from the leaching piles to adjacent residential areas, ore dust lost by the trucks on the road (elevated levels of radiation were found there by environmentalists) and others.

With all these unresolved problems, the legacy of uranium mining poses a huge challenge to the young democracy of Hungary.

Source and contact: Peter Diehl, Schulstr.13, W-7881 Herrischried, FRG, tel & fax: +49-7764-1034.