Management of Waste Containing Tritium and Carbon-14

0,74
MB

120
stron

2479
ID International Atomic Energy Agency

2004
rok

CONTENTS

1INTRODUCTION 1

1.1Background 1

1.2Objectives and scope 2

2ENVIRONMENTAL AND REGULATORY ISSUES 3

2.1Problems associated with 14C and tritium in waste 3

2.2Regulatory issues 4

2.2.1Argentina 6

2.2.2Canada 6

2.2.3France 7

2.2.4Russian Federation 7

2.2.5United Kingdom 8

2.2.6United States of America 8

3PRODUCTION AND EMISSION PATHWAYS 11

3.1Carbon-14 production and release 11

3.1.1Natural production in the atmosphere 11

3.1.2Production in nuclear explosions 11

3.1.3Production in and release from nuclear power reactors 11

3.1.3.1Light water reactors 14

3.1.3.2Heavy water reactors 18

3.1.3.3Magnox reactors and advanced gas cooled reactors 21

3.1.3.4High temperature gas cooled reactors 23

3.1.3.5Fast breeder reactors 24

3.1.3.6Summary of waste containing 14C produced by reactor operation 24

3.1.4Release during spent fuel reprocessing 25

3.2Tritium production and release 28

3.2.1Production and release in nuclear power reactors 29

3.2.1.1Light water reactors 31

3.2.1.2Heavy water reactors 31

3.2.1.3Other types of reactor 32

3.2.2Release during spent fuel reprocessing 33

3.3Categories of waste containing 14C and tritium 36

3.3.1Reactor operation and fuel cycle waste 36

3.3.2Other waste 37

4REDUCTION OF PRODUCTION AND RELEASE 37

4.1Reduction of 14C production and release 37

4.2Reduction of tritium production and release 39

5TECHNOLOGIES TO CAPTURE 14C AND TRITIUM FROM EMISSION STREAMS 41

5.1Removal of 14C from gas streams 41

5.1.1Single-step chemical reaction involving absorption in an alkaline earth hydroxide slurry or solid

42

5.1.1.1Alkaline slurry scrubber 42

5.1.1.2Alkaline packed bed column 43

5.1.2Two-step chemical reaction involving sodium hydroxide and lime slurry 44

5.1.2.1Double alkali process 45

5.1.3Physical absorption 45

5.1.3.1Gas absorption by wet scrubbing 45

5.1.3.2Ethanolamine scrubbing 46

5.1.3.3Absorption in a fluorocarbon solvent 46

5.1.4Physical adsorption on an active surface 47

5.1.5Other methods 47

5.2Removal of 14C from liquid waste 49

5.3Separation of tritium from spent fuel 51

5.3.1Voloxidation 51

5.3.2Pyrochemical processing 51

5.4Removal of tritium from gas streams 52

5.4.1Removal of HT 52

5.4.2Removal of HTO 52

5.4.2.1Molecular sieves 53

5.4.2.2Dehumidification 53

5.5Removal of tritium from liquid waste 53

5.5.1Tritium enrichment 54

5.5.2Other tritium removal technologies 58

6ANALYTICAL AND MONITORING METHODS 59

6.1Carbon-14 monitoring systems 60

6.1.1Carbon-14 sample collection 60

6.1.1.1Air samples 60

6.1.1.2Water samples 61

6.1.1.3Vegetation and soils 61

6.1.2Carbon-14 sample preparation 61

6.1.3Analytical methods for 14C 63

6.1.3.1Gas counting 63

6.1.3.2Liquid scintillation counting 63

6.1.3.3Accelerator mass spectrometry 63

6.1.4Carbon-14 monitoring methods 63

6.2Tritium monitoring systems 64

6.2.1Air samples 64

6.2.2Samples of liquids 66

6.2.3Tritium analytical methods and monitoring systems 67

6.2.3.1Ionization chambers 67

6.2.3.2Proportional counters 67

6.2.3.3Scintillation crystal detectors 68

6.2.3.4Mass spectrometers 68

6.2.3.5Liquid scintillation counters 68

6.2.3.6Portable room air monitors 69

6.2.3.7Fixed station room air monitors 69

6.2.3.8Glovebox atmosphere monitors 69

6.2.3.9Hood and exhaust duct air monitors 69

6.2.3.10Exhaust stack air monitors 70

6.2.4Specialized instrumentation 70

6.2.4.1Remote field tritium analysis system 70

6.2.4.2Surface activity monitor 70

6.2.4.3Breathalyser 71

7IMMOBILIZATION AND WASTE FORM EVALUATION 71

7.1Immobilization technologies for waste containing 14C 72

7.1.1Cementation 73

7.1.2Other methods 73

7.2Immobilization technologies for waste containing tritium 74

7.2.1Drying agents 75

7.2.2Hydraulic cements 75

7.2.3Organic agents 76

7.2.4Hydrides 76

7.3Assessment of immobilized waste form and quality control 77

7.3.1Waste form characterization 78

7.3.2Waste form testing 79

8STORAGE AND DISPOSAL 81

8.1Waste acceptance requirements 81

8.1.1France 83

8.1.2Japan 84

8.1.3Spain 85

8.1.4United Kingdom 86

8.1.5United States of America 86

8.2Storage and disposal options for waste containing 14C and tritium 87

8.2.1Storage options 87

8.2.1.1Storage of HTO waste 88

8.2.1.2Storage of tritium gas 89

8.2.1.3Storage in engineered structures 89

8.2.1.4Storage of irradiated graphite waste 90

8.2.2Disposal options 91

8.2.2.1Near surface disposal 91

8.2.2.2Liquid injection into geological formations 92

8.2.2.3Disposal in geological formations 93

8.2.3Other options 93

8.3Strategy for the management of waste containing 14C and tritium 94

9CONCLUSIONS 94

REFERENCES 97

CONTRIBUTORS TO DRAFTING AND REVIEW 109