Modelling the environmental transport of tritium in the vicinity

1,92
MB of long term atmospheric and sub-surface sources

284
stron

4682
ID International Atomic Energy Agency

2003
rok

CONTENTS

SUMMARY 1

GENERAL INTRODUCTION 9

REFERENCES 11

PART A: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES:

Model-model inter-comparison exercise based on Scenario 1

A1. BACKGROUND AND OBJECTIVES 15

A2. SCENARIO DESCRIPTION 15

A3. DESCRIPTION OF TRANSPORT PROCESSES AND MODELLING APPROACHES 16

A3.1. Transport of tritium in the atmosphere . 16

A3.2. Wet deposition of tritiated water. 18

A3.3. Buildup of tritium in soil and plants . 18

A4. RESULTS AND DISCUSSION. 20

A4.1. Tritium concentration in air humidity. 20

A4.2. Tritium concentration in soil and plants . 22

A5. CONCLUSIONS. 23

REFERENCES TO PART A . 27

PART B: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES: A test of chronic atmospheric release models using

Canadian data

B1. BACKGROUND AND OBJECTIVES 31

B2. SCENARIO DESCRIPTION 31

B3. OBSERVATIONS 32

B4. COMPARISON OF PREDICTIONS AND OBSERVATIONS 33

B4.1. Air concentrations . 34

B4.2. Rain concentrations. 36

B4.3. Soil concentrations 37

B4.4. Plant water concentrations 40

B4.5. OBT concentrations 44

B4.6. Soil and plant HTO concentrations at specific times 46

B5. CONCLUSIONS. 47

REFERENCES TO PART B 49

PART C: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN

THE VICINITY OF PERMANENT ATMOSPHERIC SOURCES:

A test of chronic atmospheric release models using Russian data

C1. BACKGROUND AND OBJECTIVES 53

C2. SCENARIO DESCRIPTION 53

C3. MONITORING TECHNIQUES. 55

C3.1. Tritium on-site sampling and analysis 55

C3.2. Sampling technique. 55

C3.3. Sample processing. 55

C3.4. Measuring tritium content. 55

C3.5. Meteorology 56

C4. MODELS AND PARTICPANTS. 56

C5. COMPARISON OF PREDICTIONS AND OBSERVATIONS 57

C5.1. Atmospheric humidity. 59

C5.2. TFWT concentration . 61

C5.3. Soil moisture . 62

C5.4. Snow water 64

C6. CONCLUSIONS. 66

REFERENCES TO PART C 74

PART D: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES: A test of chronic atmospheric release models using

French data

D1. BACKGROUND AND OBJECTIVES 77

D2. SCENARIO DESCRIPTION 77

D3. MEASUREMENTS 78

D4. COMPARISON OF PREDICTIONS WITH OBSERVATIONS. 79

D4.1. Tritium concentrations in air. 79

D4.2. Tritium concentrations in plant water . 81

D4.3. Ttriium concentrations in rain. 83

D4.4. OBT concentrations 85

D4.4.1. OBT concentrations in beech tree rings 85

D4.4.2. OBT concentrations in oak leaves 85

D4.4.3. Discussion. 86

D5. CONCLUSIONS. 86

PART E: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES: Model inter-comparison exercise on sub-surface

infiltration pathways following long term atmospheric releases

E1. BACKGROUND AND OBJECTIVES 99

E2. SCENARIO DESCRIPTION 99

E3. DESCRIPTION OF TRANSPORT PROCESSES AND

MODELLING APPROACHES 100

E3.1. Transport of tritium to the watertable . 100

E3.2. Transport and decay of tritium in groundwater. 101

E3.2.1. Numerical modelling approach 101

E3.2.2. Tentative analytical modelling approach 102

E4. RESULTS AND DISCUSSION. 104

E5. CONCLUSIONS. 106

REFERENCES TO PART E 107

PART F: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES: Model-model intercomparison exercise on predicting the

rise of tritium from contaminated groundwaters

F1. BACKGROUND AND OBJECTIVES 113

F2. SCENARIO DESCRIPTION 114

F2.1. Evolution of the scenario 114

F2.2. Soil data 114

F2.3. Evaporation and transpiration data . 115

F3. GENERIC NUMERICAL APPROACH 116

F4. TENTATIVE ANALYTICAL APPROACH 117

F5. INFLUENCE OF ELEMENTAL PROCESSES ON TRITIUM TRANSPORT 118

F6. RESULTS AND DISCUSSION. 120

F6.1. Profiles of soil water content 120

F6.2. Profiles of tritium concentration . 121

F6.3. Fluxes of tritium from soil to the atmosphere. 121

F7. CONCLUSIONS. 122

F7.1. Numerical aspects . 122

F7.2. Problems related to the modelling approach. 123

F7.3. Conclusions of the intercomparison exercise 123

REFERENCES TO PART F 124

PART G: MODELLING THE ENVIRONMENTAL TRANSPORT OF TRITIUM IN THE VICINITY OF

PERMANENT ATMOSPHERIC SOURCES: Field data for wet and dry deposition of tritium

G1. INTRODUCTION 133

G2. EXPERIMENTAL PROGRAM. 133

G2.1. Selection of sampling sites 133

G2.2. Collection of samples 134

G2.3. Sample treatment and analysis 135

G2.4. Meteorological information 135

G3. RESULTS . 136

G4. DISCUSSION. 137

G5. CONCLUSIONS. 139

GENERAL CONCLUSIONS 152

Atmospheric pathways . 152

HTO releases: Air moisture concentrations 153

HTO releases: Soil moisture concentrations. 154

HTO releases: Plant aqueous and organic phase concentrations 155

HT releases: Air moisture concentrations. 155

HT releases: Soil moisture concentrations 156

Sub-surface pathways. 156

GENERAL RECOMMENDATIONS 157

Modelling . 157

Data acquisition methods . 158

Future studies . 158

REFERENCES 159

ANNEX I: MODEL DESCRIPTIONS

I–A. MODELS FOR ATMOSPHERIC RELEASES . 163

I–A.1. Model used by JAERI, Japan 163

I–A.2. Model used by Commissariat à l’Énergie Atomique, France . 165

I–A.3. Model used by AECL, Canada . 169

I–A.4. Model used by Studsvik Eco & Safety AB, Sweden 172

I–A.5. Model used by NIPNE, Romania . 176

I–A.6. Model used by VNIIEF, Russian Federation 181

I–A.7. Model used by CEA, France. 185

I–A.8. Model used by BEAK, Canada. 189

I–A.9. Model used by ANDRA, France. 192

I–A.10. Model used by LLNL, USA 193

I–A.11. Model used by FZK, Germany . 196

I–A.12. Model used by ZSR, University of Hannover, Germany 199

I–B. SOIL AND GROUNDWATER MODELS 203

I–B.1. Models used by Commissariat à l’Énergie Atomique, France . 203

I–B.2. Models used by Studsvik Eco & Safety AB, Sweden 208

I–B.3. Model used by NIPNE, Romania . 210

I–B.4. Models used by VNIIEF, Russian Federation 213

I–B.5. Models used by CEA, France . 217

I–B.6. Models used by ANDRA, France . 219