RADIONUCLIDE UPTAKE AND TRANSFER IN PELAGIC FOOD CHAINS

1,79

MB

OF THE BARENTS SEA AND RESULTING DOSES TO MAN AND BIOTA

97

stron

3536

ID

Norwegian Ministry of the Environment

2001

rok

CONTENT

1. Introduction 1

1.1 Present and potential sources of radionuclides 1

1.1.1 Global fallout 1

1.1.2 The Chernobyl accident 2

1.1.3 Western European Reprocessing plants 3

1.1.4 Other actual and potential sources of radioactivity to the northern marine environment 4

1.2 Prevailing regional marine currents 5

1.3 Mobility and biological uptake of radionuclides 7

1.3.1 Mobility 7

1.3.2 Biological uptake 9

1.4 Traditional impact assessments 10

1.5 Project objectives 12

2. Methodology 17

2.1 Field work – Barents Sea expedition January-February 1999 17

2.2 Sampling and pre-treatment of samples Barents Sea expedition January-February 1999 18

2.2.1 Sampling of biota and sediment 18

2.2.2 Pretreatment of sea water during field-work 18

2.2.3 Ultrafiltration of Pu isotopes 18

2.3 Laboratory studies 18

2.4 Analyses of field samples from Barents Sea 1999 expedition 19

2.4.1 g-emitting radionuclides 19

2.4.2 b-emitting radionuclides 19

2.4.3 a-emitting radionuclides 19

2.5 Human and biota dosimetric models 20

3. Radionuclide activity concentrations in the environment 21

3.1 Collation of data 21

3.2 Results from the Barents Sea expedition 1999 23

3.2.1 Radionuclides in seawater 23

3.2.2 Radionuclides in sediment 30

3.2.3 Radionuclides in biota 32

3.3 Caesium-137 and technetium-99 in seaweed 33

3.3.1 Materials and methods 34

3.3.2 Results and discussion 34

4. Mobility and uptake of radionuclides in marine systems 39

4.1 Introduction 39

4.1.1 Mobility and bioavailability of radionuclides 39

4.2 Materials and methods 40

4.2.1 Mobility of radionuclides 40

4.2.2 Biotest experiments with Mytilus edulis 42

4.3 Results and discussion 45

4.3.1 Mobility of radionuclides -Results from Barents Sea field data 45

4.3.2 Bioavailability of radionuclides 47

4.4 Conclusions 52

5. Radionuclide uptake and transfer in pelagic food chains of the Barents Sea. 55

5.1 Introduction 55

5.2 Materials and methods 57

5.3 Results and discussion 58

5.4 Conclusion 61

6. Ecological dosimetry models 63

6.1 TYPHOON methodology. 63

6.1.1 Radiation dose from incorporated radionuclides 63

6.1.2 Radiation doses from external sources 68

6.1.3 Formalised algorithms. 69

6.2 NRPA methodology 69

6.3 Biota doses derived from archived data . 71

6.3.1 TYPHOON study . 71

6.3.2 NRPA study. 71

6.3.3 Combined results. 73

6.4 Biota doses derived from the Barents Sea expedition 1999 - NRPA. 73

6.4.1 Input data. 73

6.5 Biota doses derived from release scenarios – TYPHOON 74

6.5.1 Release scenario 74

6.5.2 Results : Potential doses to marine biota in the Tsivolki Fjord (Realisation of the IASAP

Scenario) 74

6.6 Interpretation of results in terms of dose-effects relationships. . 75

7. Dose assessment for human populations 79

7.1 TYPHOON methodology. 79

7.2 NRPA methodology . 80

7.3 Human doses derived from archived data 81

7.3.1 Individual doses. 81

7.3.2 Collective doses. 82

7.4 Human doses derived from release scenarios – TYPHOON . 82

7.4.1 Assessment of the long-term radiological consequences of RW dumping in the Arctic Seas -

TYPHOON. 82

7.4.2 Assessment of the long-term radiological consequences for various discharge scenarios -

NRPA. 83

8. Development of guidelines for vulnerability assessment. 85

8.1 Introduction 85

8.2 Considerations for a radioecological sensitivity assessment 85

8.2.1 Abiotic. 86

8.2.2 Biotic . 88

8.3 What can be practically included in a radioecological sensitivity assessment ? 89

8.3.1 A scenario for the quantification of Radioecological Sensitivity 90

8.4 Calculation of Radioecological sensitivity. 91

8.5 Recent developments made, with respect to radiecological sensitivity analysis, within the

“Effects Programme” . 92

8.6 Recommendations for future monitoring programmes . 93

8.6.1 Monitoring areas . 94

8.6.2 Sampling programmes. 94