Derivation of activity limits for the disposal of radioactive waste

0,83
MB in near surface disposal facilities

150
stron

2493
ID International Atomic Energy Agency

2004
rok

CONTENTS

1. INTRODUCTION 1

1.1. Background . 1

1.2. Objective.. 2

1.3. Scope.. 2

1.4. Structure 3

2. ACTIVITY LIMITS AND DISPOSAL SYSTEM SAFETY . 3

3. RADIATION PROTECTION CRITERIA .. 5

3.1. General.. 5

3.2. Radiological protection during the operational period . 5

3.3. Radiological protection in the long term . 6

3.3.1. Objective. 6

3.3.2. Criteria . 7

3.4. Use of radiation protection criteria . 8

4. APPROACH TO DERIVING ACTIVITY LIMITS 8

4.1. General.. 8

4.2. Assessment context.. 10

4.3. Disposal system description. 12

4.4. Scenario development and justification. 12

4.5. Model formulation and implementation 13

4.6. Derivation of activity limits. 14

5. ILLUSTRATIVE APPLICATION OF THE APPROACH .. 15

5.1. Assessment context.. 15

5.1.1. Purpose . 15

5.1.2. Radiological protection criteria 16

5.1.3. Calculation end points .. 16

5.1.4. Assessment philosophy. 16

5.1.5. Time frames 16

5.2. Disposal system description. 16

5.2.1. Waste characteristics.. 16

5.2.2. Engineered barrier characteristics 17

5.2.3. Geosphere and biosphere characteristics . 20

5.3. Scenario and model development - Operational period. 21

5.3.1. Development of scenarios 21

5.3.2. Identification of scenarios 22

5.3.3. Selection of scenarios 25

5.3.4. Model formulation and implementation .. 26

5.4. Scenario and model development - Post-closure period 33

5.4.1. Development of scenarios 33

5.4.2. Identification of scenarios 33

5.4.3. Selection of scenarios 35

5.4.4. Model formulation and implementation .. 36

5.5. Derivation of illustrative activity limits. 43

5.5.1. Operational period .. 44

5.5.2. Post-closure period . 46

5.5.3. Combined operational and post-closure periods.. 63

5.6. Treatment of uncertainties arising from the assessment 67

6. GUIDANCE ON THE USE OF THE APPROACH AND THE DERIVED ILLUSTRATIVE ACTIVITY

LIMITS 70

APPENDIX I: DISPOSAL SYSTEM DATA.. 73

APPENDIX II: MATHEMATICAL MODELS.. 78

APPENDIX III: SOURCE TERM AND HUMAN EXPOSURE DATA 114

APPENDIX IV: RADIONUCLIDE AND ELEMENT DEPENDENT DATA 128

APPENDIX V: COMPUTATIONAL TOOLS USED.. 139

REFERENCES. 143

CONTRIBUTORS TO DRAFTING AND REVIEW 145