The Wismut Rehabilitation Project: Present State, Outlook and Lessons Learned

Transcription

1 IAEA-Workshop: Regional Training Course on Remedation Infrastructure Development at a Test Site, Chemnitz, Germany, 3 7 December 2012 The Wismut Rehabilitation Project: Present State, Outlook and Lessons Learned Dr.- Ing. Stefan Mann, Wismut GmbH, CEO, Wismut GmbH

2 Retrospect 1946 Start of uranium mining under supervision of Soviet military 1947 Establishment of the "State-ran non-ferrous metal company Wismut 1954 Establishment of the bi-national Soviet-German Stock company (SDAG) Wismut

3 3 Review - Uranium Production Until 1990 uranium ore mining and processing by SDAG Wismut 231,000 t cumulative production making Wismut the world s fourthlargest uranium producer

4 4 Situation at Termination of Uranium Mining by Wismut 1990/91 5 underground mines 1 open pit 3000 ha operational areas 48 waste rock dumps 310 million m 3 2 uranium mills w/ 75 ha operational area Tailings ponds 570 ha 160 million t

5 5 Radiological Situation at Termination of Uranium Mining by Wismut 1990/91 37 km² WISMUT mining district population density: Saxony 247 inhabitants/km², Thuringia 154 inhabitants/km² 311 M m³ waste rock dumps Bq/g (Ra-226) 30.6 M m³/a mine water 25 t/a uranium discharged into river and creek system Radioactive releases (discharges) by mine exhaust air e.g. Schlema/Alberoda mine 900 TBq Rn-222, 130 MBq long-lived alpha emitter 5.7 km² Tailings Management Areas (tailings ponds) Inventory: 1,800 TBq (Ra-226), 320 MBq (Ra-226)/m²

6 6 Sites of Wismut GmbH

7 7 State of Remediation by October 2012 Underground Achievement Abandonment of underground mines 2,821 km 99.5 % Backfilling of mine voids 6,566 Mm³ 99.6 % Flooding of underground mines 61,345 Mm³ 97.0 % Closure of mine tunnels 226,262 m 93.9 % Surface Achievement Demolition of structures 779,198 m³ 90.0 % Contouring / Profiling 337,928 Mm³ 93.0 % Covering of areas 2,551 Mm³ 72.9 % Reclaimed areas 2,067 ha 73.1 % Water treatment 387,189 Mm³ 51.5 %

8 8 Remediation Results exemplified by Reclamation of Mine Dump 366 in Bad Schlema, Aue Operations Office Mine dump 366 in Schlema 1991 Feeder road across reclaimed dump 366 in 2010 Mine dump volume: ca. 7.7 Mm³ Footprint: ca. 43 ha Excavated material: ca. 3.5 Mm³ Fill material: ca. 3.5 Mm³ Capping material: ca. 370,000 m³

9 9 Facility Deconstruction and Renaturation Plant Area of Crossen Processing Unit near Zwickau Plant Area 1991 Reclaimed Area 2011

10 10 Remedation of Tailings Management Facilities Culmitzsch Tailings Management Facility in 1991 Culmitzsch Tailings Management Facility in October 2011 Tailings surface: ca. 250 ha Tailings thicknees: max. 72 m Tailings volume: ca. 85 Mio.m³ Interim cover: ca. 3.2 Mm³ Drain drilling: ca. 2,550 km Contouring: ca.15.5 Mm³ Final cover: ca. 5.7 Mm³ Trail building: ca km

11 11 Sources of contaminated water Flow from flooded uranium mines Mill tailings pond seepage Waste dump seepage

12 12 Development and Selection of Water Treatment Strategies Selection of technique, construction and equipment have to be licensable and low-cost The plant must be able to cope with large flow variations and a wide range of constituent concentrations Generation of residues must be low

13 13 Water Treatment Plant Sites Schlema-Alberoda WTP Königstein WTP Helmsdorf WTP Pöhla WTP

14 14 Flow chart Seelingstädt water treatment plant Supernatant, pore and seepage water Mixer Flow chart of the new Seelingstädt WTP Filtration HCl Stripping Ca(OH) 2 Precipitation HCl Discharge BaCl 2 Ca(OH) 2 FeCl 3 FHM FAFF Air Solid / liquid separation FA: flocculation agent Cement Water Dewatering Thickening Immobilisation Disposal at Culmitzsch TMA, basin B

15 15 Limitation of Emissions Radon Discharges Decrease of radon discharges from ventilation shafts at the Königstein, Dresden-Gittersee, Schlema-Alberoda, Pöhla, and Ronneburg mines ( ) Rn-222 [TBq] Volume 2,25 Mio. m³ 2,100 Mio. m³ Radon TBq 98.6 TBq Königstein Dresden-Gittersee Schlema-Alberoda Pöhla Ronneburg

16 16 Safeguarding of Remedial Results and Long-Term Tasks Documentation, preservation of technological know-how and information management; Inspection, repair, care and maintenance of covers; Treatment of contaminated mine water and seepage; Safeguarding of mine workings to be maintained accessible over the long-term; Environmental monitoring; Repair of surface damages.

17 17 Long- Term Costs (Estimate) with Focus on Key Operations (2010 Remedation Programme) 3% 5% 4% 2% Post-closure maintenance 12% Mine dump and area reclamation Tailings ponds Surface subsidence repair Monitoring 74% Water treatment

18 18 Funding

19 19 Corporate Structural Adjustment Current Scenario Transition Scenario Target Scenario Administrative structure Location-based structure Transitional structure Functional structure Range of tasks Remediation Remediation Long-term Long-term Workforce Blue collar jobs White collar jobs ca. 956 ca. 839 ca. 590 ca. 608 ca. 498 ca. 236 Personnel structure Qualification, requirements, capabilities, role, responsibility,

20 20 Educational Policy Public Relations R & D Projects Information System Publications

21 21 Summary Overall remediation volume complete > 85 %; 5.6 billion Euro spent so far for this effort; Sustainable limitation of radioactive and other emissions in compliance with licences; Following land reclamation, some 1,100 ha sold or leased out of a total of ca. 3,700 ha appropriated land; Development of state-of-the-art remedial technologies for water treatment, remediation of tailings management facilities and of mine dumps; Important economic factor; Internationally recognized reference object; Core remediation tasks to be completed by ca. 2020; Long-term tasks dominated by water treatment, maintenance, and environmental monitoring.

22 Thank you very much for your kind attention. Glückauf Dr.-Ing. Stefan Mann, CEO Wismut GmbH