radionucleide uptake in pelagics

7/29/2019 Radionucleide Uptake in Pelagics

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RADIONUCLIDE UPTAKE AND TRANSFER INPELAGIC FOOD CHAINS OF THE BARENTS SEAAND RESULTING DOSES TO MAN AND BIOTA

A project funded by the Norwegian Transport and Effects Programme,supported by the Norwegian Department of Foreign Affairs and Norwegian

Department of the Environment


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PREFACE

This project was a collaboration between the Norwegian RadiationProtection Authority (NRPA), the Institute of Marine Research, theAgricultural University of Norway, the Institute for EnergyTechnology and SPA TYPHOON, Russia. The work was funded bythe Ministry of Foreign Affairs and the Ministry of Environmentand co-ordinated through the Norwegian Polar Institute incollaboration with the NRPA.


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CONTENT

1. Introduction 11.1 Present and potential sources of radionuclides 1

1.1.1 Global fallout 1

1.1.2 The Chernobyl accident 21.1.3 Western European Reprocessing plants 31.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment 4

1.2 Prevailing regional marine currents 51.3 Mobility and biological uptake of radionuclides 7

1.3.1 Mobility 71.3.2 Biological uptake 9

1.4 Traditional impact assessments 101.5 Project objectives 12

1. Introduction ................................................................................................................... 191.1 Present and potential sources of radionuclides ...............................................................19

1.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................211.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment ......................................................................................................................22

1.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................25

1.3.1 Mobility ....................................................................................................................25

1.3.2 Biological uptake .....................................................................................................271.4 Traditional impact assessments .......................................................................................281.5 Project objectives ............................................................................................................30

2. Methodology .................................................................................................................. 342.1 Field work Barents Sea expedition January-February 1999 ........................................342.2 Sampling and pre-treatment of samples Barents Sea expedition January-February 1999...............................................................................................................................................35

2.2.1 Sampling of biota and sediment ..............................................................................352.2.2 Pretreatment of sea water during field-work ............................................................352.2.3 Ultrafiltration of Pu isotopes ....................................................................................35

2.3 Laboratory studies ...........................................................................................................35

2.4 Analyses of field samples from Barents Sea 1999 expedition ........................................362.4.1 -emitting radionuclides ..........................................................................................362.4.2 -emitting radionuclides ..........................................................................................362.4.3 -emitting radionuclides ..........................................................................................36

2.5 Human and biota dosimetric models ...............................................................................373. Radionuclide activity concentrations in the environment ..............................................38

3.1 Collation of data .............................................................................................................383.2 Results from the Barents Sea expedition 1999 ...............................................................40

3.2.1 Radionuclides in seawater ........................................................................................403.2.2 Radionuclides in sediment .......................................................................................473.2.3 Radionuclides in biota ..............................................................................................49

3.3 Caesium-137 and technetium-99 in seaweed ..................................................................503.3.1 Materials and methods .............................................................................................51


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3.3.2 Results and discussion .............................................................................................514. Mobility and uptake of radionuclides in marine systems .............................................. 57

4.1 Introduction .....................................................................................................................574.1.1 Mobility and bioavailability of radionuclides ..........................................................57

4.2 Materials and methods ....................................................................................................58

4.2.1 Mobility of radionuclides .........................................................................................584.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................634.3.2 Bioavailability of radionuclides ...............................................................................66

Activity levels in biota bioconcentration factors ...........................................................66Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67

Table 4.4: Laboratory derived rate constants (Fig. 4.5) and BCFs for mussel soft parts (dryweight) when exposed to cationic tracers added to ultrafiltered seawater (Brretzen, 2001)................................................................................................................................................67

Ingestion and depuration of metals associated with particles ...........................................694.4 Conclusions .....................................................................................................................70

5. Radionuclide uptake and transfer in pelagic food chains of the Barents Sea................725.1 Introduction .....................................................................................................................725.2 Materials and methods ....................................................................................................745.3 Results and discussion ....................................................................................................75

Specie ................................................................................................................................775.4 Conclusion ......................................................................................................................78

References .......................................................................................................................... 786. Ecological dosimetry models ........................................................................................ 79

6.1 TYPHOON methodology ...............................................................................................79Under natural conditions, organisms are exposed to various sources of ionizing radiation.Absorbed dose to hydrobionts depends on a number of factors. Among them are type andenergy of emitters (photons, beta particles, alpha particles, protons, neutrons, etc.),radiation source geometry (point or extended), space distribution and time evolution ofradionuclide concentrations in components of aquatic ecosystems, ecological-

physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In thegeneral case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottom

sediments is considered, the sediments can be represented as an infinitely thick sourcewith a uniformly distributed activity. In these cases, the beta- and gamma-radiation dose


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rates nearby the surface of bottom sediments are equal to 0.5 P and 0.5 P,respectively. In the general case, as radionuclides are non-uniformly distributed in

bottom sediments, the external gamma-radiation dose rate from the sediments to theorganisms can be calculated with the formulas similar to Equation 6.16.........................846.1.3 Formalised algorithms ..............................................................................................85

6.2 NRPA methodology .......................................................................................................856.3 Biota doses derived from archived data .........................................................................876.3.1 TYPHOON study ....................................................................................................876.3.2 NRPA study .............................................................................................................876.3.3 Combined results .....................................................................................................89

6.4 Biota doses derived from the Barents Sea expedition 1999 - NRPA ..............................896.4.1 Input data ..................................................................................................................89

6.5 Biota doses derived from release scenarios TYPHOON .............................................906.5.1 Release scenario .......................................................................................................906.5.2 Results : Potential doses to marine biota in the Tsivolki Fjord (Realisation of theIASAP Scenario) ..............................................................................................................90

6.6 Interpretation of results in terms of dose-effects relationships.......................................917. Dose assessment for human populations ..................................................................... 94

7.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ........................................................................................................95One of the general assumptions for box modelling of the dispersion of radionuclides inmarine system relates to instantaneous mixing in each box which, in term, results in

practical calculations to an instantaneous mixing in the whole of oceanic space. A newapproach for box modelling, which includes dispersion of radionuclides during time, wastherefore created in order to provide a better and more realistic/physical approachcomparing to traditional box modelling. Calculations of concentrations of radionuclides inthe marine environment and doses for man for some scenarios indicate differences of up toorders of magnitude between the traditional and new approach for box modelling.............957.3 Human doses derived from archived data .......................................................................96

7.3.1 Individual doses .......................................................................................................967.3.2 Collective doses .......................................................................................................97

7.4 Human doses derived from release scenarios TYPHOON ..........................................977.4.1 Assessment of the long-term radiological consequences of RW dumping in theArctic Seas - TYPHOON ..................................................................................................977.4.2 Assessment of the long-term radiological consequences for various dischargescenarios - NRPA ..............................................................................................................98

8. Development of guidelines for vulnerability assessment ............................................ 100

8.1 Introduction ...................................................................................................................1008.2 Considerations for a radioecological sensitivity assessment ....................................... 1008.2.1 Abiotic ....................................................................................................................1018.2.2 Biotic ......................................................................................................................103

8.3 What can be practically included in a radioecological sensitivity assessment ? ...........1048.3.1 A scenario for the quantification of Radioecological Sensitivity .......................... 105

8.4 Calculation of Radioecological sensitivity ....................................................................1068.5 Recent developments made, with respect to radiecological sensitivity analysis, withinthe Effects Programme .................................................................................................... 1078.6 Recommendations for future monitoring programmes ................................................109

8.6.1 Monitoring areas .................................................................................................... 109

8.6.2 Sampling programmes ........................................................................................... 1101. Introduction ................................................................................................................... 19


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1.1 Present and potential sources of radionuclides ...............................................................191.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................211.1.4 Other actual and potential sources of radioactivity to the northern marine

environment ......................................................................................................................221.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................25

1.3.1 Mobility ....................................................................................................................251.3.2 Biological uptake .....................................................................................................27

1.4 Traditional impact assessments .......................................................................................281.5 Project objectives ............................................................................................................30



2.3 Laboratory studies ...........................................................................................................352.4 Analyses of field samples from Barents Sea 1999 expedition ........................................36

2.4.1 -emitting radionuclides ..........................................................................................362.4.2 -emitting radionuclides ..........................................................................................362.4.3 -emitting radionuclides ..........................................................................................36


3.1 Collation of data .............................................................................................................383.2 Results from the Barents Sea expedition 1999 ...............................................................403.2.1 Radionuclides in seawater ........................................................................................403.2.2 Radionuclides in sediment .......................................................................................473.2.3 Radionuclides in biota ..............................................................................................49

3.3 Caesium-137 and technetium-99 in seaweed ..................................................................503.3.1 Materials and methods .............................................................................................513.3.2 Results and discussion .............................................................................................51

4. Mobility and uptake of radionuclides in marine systems .............................................. 574.1 Introduction .....................................................................................................................57

4.1.1 Mobility and bioavailability of radionuclides ..........................................................57

4.2 Materials and methods ....................................................................................................584.2.1 Mobility of radionuclides .........................................................................................584.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................63

4.3.2 Bioavailability of radionuclides ...............................................................................66Activity levels in biota bioconcentration factors ...........................................................66


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Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67Table 4.4: Laboratory derived rate constants (Fig. 4.5) and BCFs for mussel soft parts (dryweight) when exposed to cationic tracers added to ultrafiltered seawater (Brretzen, 2001)................................................................................................................................................67

Ingestion and depuration of metals associated with particles ...........................................69

4.4 Conclusions .....................................................................................................................705. Radionuclide uptake and transfer in pelagic food chains of the Barents Sea................725.1 Introduction .....................................................................................................................725.2 Materials and methods ....................................................................................................745.3 Results and discussion ....................................................................................................75



6.1 TYPHOON methodology ...............................................................................................79Under natural conditions, organisms are exposed to various sources of ionizing radiation.

Absorbed dose to hydrobionts depends on a number of factors. Among them are type andenergy of emitters (photons, beta particles, alpha particles, protons, neutrons, etc.),radiation source geometry (point or extended), space distribution and time evolution ofradionuclide concentrations in components of aquatic ecosystems, ecological-

physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In thegeneral case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottomsediments is considered, the sediments can be represented as an infinitely thick sourcewith a uniformly distributed activity. In these cases, the beta- and gamma-radiation doserates nearby the surface of bottom sediments are equal to 0.5 P and 0.5 P,respectively. In the general case, as radionuclides are non-uniformly distributed in

bottom sediments, the external gamma-radiation dose rate from the sediments to theorganisms can be calculated with the formulas similar to Equation 6.16.........................84

6.1.3 Formalised algorithms ..............................................................................................856.2 NRPA methodology .......................................................................................................856.3 Biota doses derived from archived data .........................................................................87

6.3.1 TYPHOON study ....................................................................................................876.3.2 NRPA study .............................................................................................................876.3.3 Combined results .....................................................................................................89


6.5 Biota doses derived from release scenarios TYPHOON .............................................906.5.1 Release scenario .......................................................................................................906.5.2 Results : Potential doses to marine biota in the Tsivolki Fjord (Realisation of the

IASAP Scenario) ..............................................................................................................906.6 Interpretation of results in terms of dose-effects relationships.......................................91


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7. Dose assessment for human populations ..................................................................... 947.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ........................................................................................................95One of the general assumptions for box modelling of the dispersion of radionuclides inmarine system relates to instantaneous mixing in each box which, in term, results in



7.4 Human doses derived from release scenarios TYPHOON ..........................................977.4.1 Assessment of the long-term radiological consequences of RW dumping in the

Arctic Seas - TYPHOON ..................................................................................................977.4.2 Assessment of the long-term radiological consequences for various dischargescenarios - NRPA ..............................................................................................................98

8. Development of guidelines for vulnerability assessment ............................................ 1008.1 Introduction ...................................................................................................................1008.2 Considerations for a radioecological sensitivity assessment ....................................... 100

8.2.1 Abiotic ....................................................................................................................1018.2.2 Biotic ......................................................................................................................103



8.6.1 Monitoring areas .................................................................................................... 1098.6.2 Sampling programmes ........................................................................................... 110


1.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................21

1.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment ......................................................................................................................221.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................25



2. Methodology .................................................................................................................. 342.1 Field work Barents Sea expedition January-February 1999 ........................................342.2 Sampling and pre-treatment of samples Barents Sea expedition January-February 1999

...............................................................................................................................................352.2.1 Sampling of biota and sediment ..............................................................................35


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2.2.2 Pretreatment of sea water during field-work ............................................................352.2.3 Ultrafiltration of Pu isotopes ....................................................................................35


2.4.1 -emitting radionuclides ..........................................................................................36

2.4.2 -emitting radionuclides ..........................................................................................362.4.3 -emitting radionuclides ..........................................................................................36






4.1.1 Mobility and bioavailability of radionuclides ..........................................................574.2 Materials and methods ....................................................................................................58

4.2.1 Mobility of radionuclides .........................................................................................584.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60

Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................634.3.2 Bioavailability of radionuclides ...............................................................................66Activity levels in biota bioconcentration factors ...........................................................66Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67


Ingestion and depuration of metals associated with particles ...........................................694.4 Conclusions .....................................................................................................................705. Radionuclide uptake and transfer in pelagic food chains of the Barents Sea................72

5.1 Introduction .....................................................................................................................725.2 Materials and methods ....................................................................................................745.3 Results and discussion ....................................................................................................75



6.1 TYPHOON methodology ...............................................................................................79

Under natural conditions, organisms are exposed to various sources of ionizing radiation.Absorbed dose to hydrobionts depends on a number of factors. Among them are type and


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energy of emitters (photons, beta particles, alpha particles, protons, neutrons, etc.),radiation source geometry (point or extended), space distribution and time evolution ofradionuclide concentrations in components of aquatic ecosystems, ecological-

physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In the

general case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottomsediments is considered, the sediments can be represented as an infinitely thick sourcewith a uniformly distributed activity. In these cases, the beta- and gamma-radiation dose



6.2 NRPA methodology .......................................................................................................856.3 Biota doses derived from archived data .........................................................................87





7.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ........................................................................................................95One of the general assumptions for box modelling of the dispersion of radionuclides in

marine system relates to instantaneous mixing in each box which, in term, results inpractical calculations to an instantaneous mixing in the whole of oceanic space. A newapproach for box modelling, which includes dispersion of radionuclides during time, wastherefore created in order to provide a better and more realistic/physical approachcomparing to traditional box modelling. Calculations of concentrations of radionuclides inthe marine environment and doses for man for some scenarios indicate differences of up toorders of magnitude between the traditional and new approach for box modelling.............957.3 Human doses derived from archived data .......................................................................96


7.4 Human doses derived from release scenarios TYPHOON ..........................................97

7.4.1 Assessment of the long-term radiological consequences of RW dumping in theArctic Seas - TYPHOON ..................................................................................................97


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7.4.2 Assessment of the long-term radiological consequences for various dischargescenarios - NRPA ..............................................................................................................98


8.2.1 Abiotic ....................................................................................................................1018.2.2 Biotic ......................................................................................................................1038.3 What can be practically included in a radioecological sensitivity assessment ? ...........104

8.3.1 A scenario for the quantification of Radioecological Sensitivity .......................... 1058.4 Calculation of Radioecological sensitivity ....................................................................1068.5 Recent developments made, with respect to radiecological sensitivity analysis, withinthe Effects Programme .................................................................................................... 1078.6 Recommendations for future monitoring programmes ................................................109


1. Introduction ................................................................................................................... 19

1.1 Present and potential sources of radionuclides ...............................................................191.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................211.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment ......................................................................................................................22

1.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................25










3.3 Caesium-137 and technetium-99 in seaweed ..................................................................50

3.3.1 Materials and methods .............................................................................................513.3.2 Results and discussion .............................................................................................51


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4.2.1 Mobility of radionuclides .........................................................................................58

4.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................634.3.2 Bioavailability of radionuclides ...............................................................................66Activity levels in biota bioconcentration factors ...........................................................66

Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67Table 4.4: Laboratory derived rate constants (Fig. 4.5) and BCFs for mussel soft parts (dryweight) when exposed to cationic tracers added to ultrafiltered seawater (Brretzen, 2001)................................................................................................................................................67





6.1 TYPHOON methodology ...............................................................................................79Under natural conditions, organisms are exposed to various sources of ionizing radiation.Absorbed dose to hydrobionts depends on a number of factors. Among them are type andenergy of emitters (photons, beta particles, alpha particles, protons, neutrons, etc.),radiation source geometry (point or extended), space distribution and time evolution ofradionuclide concentrations in components of aquatic ecosystems, ecological-

physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;

Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In thegeneral case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottomsediments is considered, the sediments can be represented as an infinitely thick source

with a uniformly distributed activity. In these cases, the beta- and gamma-radiation doserates nearby the surface of bottom sediments are equal to 0.5 P and 0.5 P,


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respectively. In the general case, as radionuclides are non-uniformly distributed inbottom sediments, the external gamma-radiation dose rate from the sediments to theorganisms can be calculated with the formulas similar to Equation 6.16.........................846.1.3 Formalised algorithms ..............................................................................................85

6.2 NRPA methodology .......................................................................................................85

6.3 Biota doses derived from archived data .........................................................................876.3.1 TYPHOON study ....................................................................................................876.3.2 NRPA study .............................................................................................................876.3.3 Combined results .....................................................................................................89



6.6 Interpretation of results in terms of dose-effects relationships.......................................91

7. Dose assessment for human populations ..................................................................... 947.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ........................................................................................................95One of the general assumptions for box modelling of the dispersion of radionuclides inmarine system relates to instantaneous mixing in each box which, in term, results in



7.4 Human doses derived from release scenarios TYPHOON ..........................................977.4.1 Assessment of the long-term radiological consequences of RW dumping in theArctic Seas - TYPHOON ..................................................................................................977.4.2 Assessment of the long-term radiological consequences for various dischargescenarios - NRPA ..............................................................................................................98

8. Development of guidelines for vulnerability assessment ............................................ 1008.1 Introduction ...................................................................................................................100

8.2 Considerations for a radioecological sensitivity assessment ....................................... 1008.2.1 Abiotic ....................................................................................................................1018.2.2 Biotic ......................................................................................................................103






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1.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................211.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment ......................................................................................................................22

1.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................251.3.1 Mobility ....................................................................................................................251.3.2 Biological uptake .....................................................................................................27



2.2.1 Sampling of biota and sediment ..............................................................................35





3.1 Collation of data .............................................................................................................38

3.2 Results from the Barents Sea expedition 1999 ...............................................................403.2.1 Radionuclides in seawater ........................................................................................403.2.2 Radionuclides in sediment .......................................................................................473.2.3 Radionuclides in biota ..............................................................................................49




4.2.1 Mobility of radionuclides .........................................................................................584.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................634.3.2 Bioavailability of radionuclides ...............................................................................66

Activity levels in biota bioconcentration factors ...........................................................66Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67


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6.1 TYPHOON methodology ...............................................................................................79Under natural conditions, organisms are exposed to various sources of ionizing radiation.Absorbed dose to hydrobionts depends on a number of factors. Among them are type and


physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In thegeneral case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottomsediments is considered, the sediments can be represented as an infinitely thick sourcewith a uniformly distributed activity. In these cases, the beta- and gamma-radiation doserates nearby the surface of bottom sediments are equal to 0.5 P and 0.5 P,respectively. In the general case, as radionuclides are non-uniformly distributed in


6.2 NRPA methodology .......................................................................................................856.3 Biota doses derived from archived data .........................................................................876.3.1 TYPHOON study ....................................................................................................876.3.2 NRPA study .............................................................................................................876.3.3 Combined results .....................................................................................................89





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7.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ........................................................................................................95One of the general assumptions for box modelling of the dispersion of radionuclides inmarine system relates to instantaneous mixing in each box which, in term, results in

practical calculations to an instantaneous mixing in the whole of oceanic space. A new

approach for box modelling, which includes dispersion of radionuclides during time, wastherefore created in order to provide a better and more realistic/physical approachcomparing to traditional box modelling. Calculations of concentrations of radionuclides inthe marine environment and doses for man for some scenarios indicate differences of up toorders of magnitude between the traditional and new approach for box modelling.............957.3 Human doses derived from archived data .......................................................................96


7.4 Human doses derived from release scenarios TYPHOON ..........................................977.4.1 Assessment of the long-term radiological consequences of RW dumping in theArctic Seas - TYPHOON ..................................................................................................97

7.4.2 Assessment of the long-term radiological consequences for various dischargescenarios - NRPA ..............................................................................................................98


8.2.1 Abiotic ....................................................................................................................1018.2.2 Biotic ......................................................................................................................103





1.1.1 Global fallout ...........................................................................................................201.1.2 The Chernobyl accident ...........................................................................................201.1.3 Western European Reprocessing plants ...................................................................21

1.1.4 Other actual and potential sources of radioactivity to the northern marineenvironment ......................................................................................................................221.2 Prevailing regional marine currents ................................................................................231.3 Mobility and biological uptake of radionuclides ............................................................25



2. Methodology .................................................................................................................. 342.1 Field work Barents Sea expedition January-February 1999 ........................................342.2 Sampling and pre-treatment of samples Barents Sea expedition January-February 1999

...............................................................................................................................................352.2.1 Sampling of biota and sediment ..............................................................................35


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2.4.1 -emitting radionuclides ..........................................................................................36

2.4.2 -emitting radionuclides ..........................................................................................362.4.3 -emitting radionuclides ..........................................................................................36







4.2.1 Mobility of radionuclides .........................................................................................584.2.2 Biotest experiments with Mytilus edulis .................................................................60Sediment collection and characterisation ..........................................................................60Organism collection and handling ....................................................................................60Uptake experiments from tracers in ultrafiltered seawater ...............................................60

Uptake experiments of tracers associated with suspended sediments ..............................61Depuration experiments ....................................................................................................61Tracer measurements ........................................................................................................62

4.3 Results and discussion ....................................................................................................634.3.1 Mobility of radionuclides - Results from Barents Sea field data .............................634.3.2 Bioavailability of radionuclides ...............................................................................66Activity levels in biota bioconcentration factors ...........................................................66Laboratory experiments - Uptake and depuration from ultrafiltered seawater ................67


Ingestion and depuration of metals associated with particles ...........................................694.4 Conclusions .....................................................................................................................705. Radionuclide uptake and transfer in pelagic food chains of the Barents Sea................72

5.1 Introduction .....................................................................................................................725.2 Materials and methods ....................................................................................................745.3 Results and discussion ....................................................................................................75



6.1 TYPHOON methodology ...............................................................................................79

Under natural conditions, organisms are exposed to various sources of ionizing radiation.Absorbed dose to hydrobionts depends on a number of factors. Among them are type and


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physiological parameters and stage of ontogenesis of the organism (IAEA, 1976, 1979;Kryshev & Sazykina, 1986, 1990, 1995; Amiro, 1997; Sazykina et al., 1998). In the

general case, the assessment of doses to organisms is an intricate problem. For the sakeof simplicity, the dose rate assessments, as a rule, will be presented below for uniformdistribution of radionuclides throughout the volume of organisms (for incorporatedemitters) or environment (in calculations of external exposure)...................................... 796.1.1 Radiation dose from incorporated radionuclides .....................................................796.1.2 Radiation doses from external sources ....................................................................84The dose rates to aquatic organisms from alpha and beta emitters scattered in the waterdepth are calculated with the following formulas: ............................................................84In many cases, when exposure to aquatic organisms nearby the surface of bottomsediments is considered, the sediments can be represented as an infinitely thick sourcewith a uniformly distributed activity. In these cases, the beta- and gamma-radiation dose



6.2 NRPA methodology .......................................................................................................856.3 Biota doses derived from archived data .........................................................................87





7.1 TYPHOON methodology ...............................................................................................947.2 NRPA methodology ...........................

radionucleide uptake in pelagics

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