The long term stabilization of uranium mill tailings

7,31
MB

309
stron

2495
ID International Atomic Energy Agency

2004
rok

CONTENTS

1. INTRODUCTION 1

1.1. Background 1

1.2. Objectives .. 2

1.2.1. Overall objective. 2

1.2.2. Scientific research objectives 3

1.3. The focus of the CRP 4

1.4. The structure of the CRP 5

2. HISTORICAL PRACTICES .. 6

2.1. The 'ages' of uranium production . 6

2.2. Age, number, geographic and climatic distribution of uranium mill tailings piles.. 8

2.3. Relationship of tailings piles to mine and mill facilities . 11

2.4. Historical approaches to tailings placements. 12

2.4.1. No effective containment. 12

2.4.2. Low embankments.. 13

2.4.3. Topographic depressions . 13

2.4.4. Valley fill . 13

2.4.5. Ring dyke or turkey nest dam 13

2.4.6. Mined out pit.. 13

2.4.7. Underground mine back-fill 14

2.4.8. Deep lake or river 14

2.5. Classification of uranium mill tailings . 14

2.6. Inappropriate uses of uranium mill tailings 15

3. ENVIRONMENTAL IMPACTS ..16

3.1. Events that have led to environmental impacts 16

3.2. Impacts on human health. 19

3.3. Potential radiological impacts upon the natural environment .. 21

3.4. Toxic and hazardous compounds in tailings and their potential impacts 23

4. REMEDIATION PROGRAMMES TO REDUCE HAZARDS FROM HISTORICAL URANIUM MILL

TAILINGS .. 24

4.1. Driving forces for remedial work 24

4.2. Remedial work undertaken. 25

4.3. Examples from the USA.. 26

4.4. Examples from France.. 26

4.5. Examples from Germany. 26

4.6. Examples form the Czech Republic .. 26

4.7. Examples from Australia . 27

4.8. Evaluation of the remedial works at historic tailings piles. 27

5. PRESENT DAY PRACTICES 28

5.1. Objectives 28

5.2. Standards for radiological and environmental protection 29

5.3. Member States' regulations, standards and guidelines. 30

5.4. Current approaches to tailings containment .. 32

5.4.1. Less-favoured options 32

5.4.2. Above ground disposal . 33

5.4.3. Below ground containment. 36

5.4.4. Deep lake . 39

5.4.5. Purpose-built containment .. 39

5.5. Current approaches to stabilise and isolate uranium mill tailings .. 40

5.5.1. Design objectives. 40

5.5.2. Containment preparation.. 40

5.5.3. Tailings preparation 41

5.5.4. Tailings discharge and deposition 43

5.5.5. Tailings consolidation 44

5.5.6. Tailings surface treatment 46

5.5.7. Decant water treatment . 47

5.5.8. Seepage control. 47

5.5.9. Covers 48

6. OUTSTANDING ISSUES 53

6.1. Overview .53

6.2. Issues relating to the physical properties of tailings.. 53

6.3. Issues relating to containment .. 56

6.4. Issues relating to tailings chemistry 57

6.5. Passive systems.58

7. NEW APPROACHES AND RESEARCH 59

7.1. Overview .59

7.2. Design and siting of containments.. 60

7.3. Physical stabilization . 60

7.3.1. Consolidation . 61

7.3.2. Paste technology .. 62

7.3.3. Grouting 63

7.4. Chemical stabilization ..63

7.4.1. Overview.. 63

7.4.2. Geochemical impacts. 64

7.4.3. Fixation technologies. 65

7.5. Encapsulation and covers 67

7.6. Effluent containment and treatment .. 68

7.7. Management systems. 69

7.8. Long term research priorities. 70

8. PERFORMANCE ASSESSMENT OF IMPOUNDMENTS.. 70

8.1. Purpose of performance assessment .. 70

8.2. Conceptual approaches .70

8.3. Performance assessment approaches . 71

8.4. Baseline data and regional characterization .. 72

8.5. Monitoring..72

8.6. Radiological impact73

8.6.1. Concept of critical groups 73

8.6.2. Scenarios.. 73

8.7. Non-radiological impacts 75

9.1. Historical practices . 75

9.2. Environmental impacts . 76

9.3. Remediation programmes 77

9.4. Present day practices . 78

9.5. Outstanding issues .. 79

9.6. New approaches 79

9.7. Performance assessment .. 80

10. CONCLUSIONS 81

REFERENCES 83

GLOSSARY. 99

ANNEX I. BRAZIL: A CASE STUDY ON THE URANIUM TAILINGS DAM OF POÇOS DE CALDAS

URANIUM MINING AND MILLING SITE 101

ANNEX II. CANADA: CAMECO RABBIT LAKE IN-PIT TAILINGS MANAGEMENT FACILITY -

TAILINGS INJECTION TRIAL PROGRAMME 121

ANNEX III. CHINA: STUDIES OF BENTONITE AND RED SOILS AS CAPPING OF THE URANIUM

MILL TAILING IMPOUNDMENTS 145

ANNEX IV. CZECH REPUBLIC: PREDICTING THE LONG TERM STABILIZATION OF URANIUM

MILL TAILINGS . 161

ANNEX V. FRANCE: METHODOLOGY TO ASSESS THE RADIOLOGICAL IMPACT OF DISPOSALS

OF URANIUM MILL TAILINGS AFTER REMEDIATION (SHORT TERM IMPACT).. 181

ANNEX VI. GERMANY: DEVELOPMENT OF TECHNOLOGIES FOR IN SITU REMEDIATION OF

CONTAMINATED SITES BY DIRECTED FORMATION OF NATURALLY OCCURRING SLIGHTLY

SOLUBLE MINERALS 195

ANNEX VII. KAZAKHSTAN: DEVELOPMENT OF METHOD OF COVERING RAISING DUST

BEACHES OF RADIOACTIVE WASTES STORAGE OUT OF OPERATION. 209

ANNEX VIII. REPUBLIC OF KOREA: REMEDIATION OF URANIUM MILL TAILINGS USING

NATURAL AND ORGANO-CLAYS .. 223

ANNEX IX. POLAND I: IMPROVEMENT OF SOIL PROPERTIES APPLIED TO CAPPING AND

MULTI-LAYER BARRIERS 233

ANNEX X. POLAND II: ROOM TEMPERATURE CERAMICS, THE BREAKTHROUGH MATERIAL

FOR LONG TERM STABILIZATION AND ISOLATION OF LOW-LEVEL URANIUM RESIDUES? .

249

ANNEX XI. RUSSIAN FEDERATION: POLYMERIC COATS FOR THE STABILIZATION OF

CONTAMINATED SURFACES.. 265

ANNEX XII. UKRAINE: RESEARCH AND DEVELOPMENT OF MEASURES TO BE TAKEN FOR

LONG TERM STABILIZATION AND ISOLATION OF URANIUM MILL TAILINGS . 281

ANNEX XIII. UNITED STATES OF AMERICA: RESEARCH AND DEVELOPMENT OF MEASURES

TO BE TAKEN FOR LONG TERM STABILIZATION AND ISOLATION OF URANIUM MILL

TAILINGS.. 297

LIST OF PARTICIPANTS. 311