Presentation: Forest Scenario Gene (Jige) Shen EcoMetrix Inc. ON, - - PowerPoint PPT Presentation

Presentation: Forest Scenario

Gene (Jige) Shen EcoMetrix Inc. ON, Canada

5th Meeting of the EMRAS II Working Group 8 “Environmental Sensitivity” 27‐28 September 2011 SCK CEN Headquarters

• Av. Herrmann‐Debroux 40, 1160 Brussels, Belgium

Scenario Location

Scenario Setup

Considered Pathways 1

Considered Pathways 2

Scenario Assumptions

• Progenies: Y‐90;
• Background radiation levels are neglected;
• Source loading assumptions: soil in mass basis (Bq/kg) and water

in volume basis (Bq/L)

• Animal diet assumptions: all animals of interest are wild animals

(no human feeds) and live in the site all year around (no migration) and only consume local foods.

• Human diet assumption: local residents live in the site 100% of

time, plant and fish foods are from local produce, and 1/3 of adult intake meat and ¼ infant meat intake are from local meat sources.

Seasonal Variation

Animal dietary data are on annual average basis from CSA N288.1‐08. Annual averaged human dietary data are used:

• Look at human doses at the end of certain years;
• I‐131 approaches to 0 after 2 months. Cs‐137 and Sr‐90 have effective half life of about 2
• months. The human doses are hardly show difference due to the diet changes over seasons;
• The human diet assumptions are already much conservative. To apply the seasonal diet

variation doesn’t increase accuracy. The seasonal variation consideration: the baseline water flow on a monthly basis.

40 45 50 55 60 65 0.2 0.4 0.6 0.8 1 Flow rate (L/s) Time (year)

Baseline Water Inflow

Human Dose (mSv/a)

0.5 1 1.5 2 2.5 2 4 6 8 10 12 Dose (mSv/a) Time (year)

Total Dose after the fallout

Adult Infant_1y 0.01 0.1 1 10 2 4 6 8 10 12 Dose (mSv/a) Time (year)

Total Dose after the fallout (log scale)

Adult Infant_1y 0.2 0.4 0.6 0.8 1 1.2 Air (inhalation) Air (external) Water (ingestion) Water (external) Soil (ingestion) Soil (external) Sediment (ingestion) Sediment (external) Aquatic plants Aquatic animals Terrestrial plants Terrestrial animals Dose (mSv/a) Pathways

Adult Dose at 0 year

Cs‐137 I‐131 Sr‐90 Y‐90

0.005 0.01 0.015 0.02 0.025 0.03 Air (inhalation) Air (external) Water (ingestion) Water (external) Soil (ingestion) Soil (external) Sediment (ingestion) Sediment (external) Aquatic plants Aquatic animals Terrestrial plants Terrestrial animals Dose (mSv/a) Pathways

Adult Dose at 1 year

Cs‐137 I‐131 Sr‐90 Y‐90

Animal Concentrations

100 200 300 400 500 600 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Mallard Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

5000 10000 15000 20000 25000 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Beaver Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

1.0E‐01 1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Animal Cs‐137 Concentrations

Beaver Mallard Caribou Moose Grouse

• The whole body concentrations for

“Hare”, “Loon”, “Muskrat”, “Vole”, “Scaup”, “Lynx”, “Mink”, “Wolf” are available;

• Animal rad doses and risk quotients

can be calculated in the scenario.

Plant Concentrations

0.2 0.4 0.6 0.8 1 1.2 1.4 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Blueberry Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

0.2 0.4 0.6 0.8 1 1.2 1.4 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Labrador Tea Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

The plants have two sources: soil and air. The soil source is the dominating source.

Fish Concentration

500 1000 1500 2000 2500 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Fish Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

The fish concentration in fresh weight basis is in equilibrium condition with the water concentration assuming the water/fish reaches equilibrium instantly.

Soil Concentration

1 2 3 4 5 6 7 8 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Soil Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

• Assume the initial 1000Bq/m2

ground activity uniformly distributed over the top 10cm layer.

• The dry bulk density is 1.6kg/L
• The water content is 0.15

That is: The soil initial concentration is 7.35Bq/kg (dry weight basis). This value applies to Cs‐137, I‐131, Sr‐ 90 and Y‐90.

Water/Sediment Concentrations

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 2 4 6 8 10 12 Concentration (Bq/L) Time (year)

Water Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

50 100 150 200 250 300 2 4 6 8 10 12 Concentration (Bq/kg) Time (year)

Sediment Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

• Assume the pond water 1000Bq/m2 is applied to all water depth;
• The water depth is 1.5m;
• Assume the sediment has no initial activity at time 0 from the fallout event.

That is:

• The initial water concentration is 0.667Bq/L. This applies to Cs‐137, I‐131, Sr‐90 and Y‐90;
• The sediment initial concentration is 0.

Air Concentration

0.0E+00 2.0E‐08 4.0E‐08 6.0E‐08 8.0E‐08 1.0E‐07 1.2E‐07 1.4E‐07 2 4 6 8 10 12 Concentration (Bq/m3) Time (year)

Outdoor air Concentrations

Cs‐137 I‐131 Sr‐90 Y‐90

The air concentration is in equilibrium condition with the soil concentration by a soil re‐suspension process.