WG 4 - Nucleus · temperate values, but mean values are 4 to 5 times higher than the temperate...
Transcript of WG 4 - Nucleus · temperate values, but mean values are 4 to 5 times higher than the temperate...
MODARIA II
WG 4 :
Working Group 4 – Transfer processes and data for radiological impact
assessment
Kd sub group: Development of Global Kd database prototype
• MS Access database, based primarily on commonalties between current structure for Freshwater and Soil Kd datasets.
Freshwater Data Structure Soil Data Structure
Vidal et. al. Boyer et. al.
Tables
• Solid Parameters • Liquid Parameters
• Kd Parameters • Elements • Reference • Isotopes • Location
Development of Global Kd database prototype
Kd sub group
• Interim meeting May/June, tbd • IAEA Monaco
WG4 sub-group Collation of environmental transfer parameters after
the Fukushima accident (Fukushima parameters)
1st Interim meeting @ University of Tsukuba, 10-12 July, 2017
Catchment
Marine River
Forest
Agricultural product
Rice paddy field
Game
Food processing
- Agree ecosystems/areas for which datasets will be compiled - Updated data for forest, marine, catchments and food processing - Discussed radiocaesium fate in Japanese forest ecosystems and
parameters to be reported (e.g. translocation in tree and transfer to mushrooms)
- Discussed dataset compilation and application - plan to provide dataset in excel files, kept by each institutes or
maybe IAEA can hold completed version - may ask other organisations to supply additional data – will
distribute template(s). - Discussed table formats to be included to Subgroup document
from datasets - Consult Japanese topic leaders - try to follow the previous TRS
format. - Need to fill the gap between current status and data in TRS 422 &
472.
Forest data —Data compilation ongoing
• Concentration and Inventory data of – Trees (each organ, e.g. leaf, wood …) – Organic layers (litter layers) – Mineral soils – Mushrooms – Small wild animals (e.g. earthworms, insects
etc., NOT large mammals)
Journal papers Reports by governments On the Web
DATABASE
~9000 records
Information on time, location, and forest characteristics etc.
Forest data Compiled data showing dynamics of radiocesium in Fukushima forests
137Cs decreasing trends for Sugi needle leaf
Geographical distributions of data point
137Cs decreasing trends for litter in Sugi forests
Concentrations in each component normalized - dividing by 137Cs deposition (airborne monitoring)
Bare land Cultivated (gentle)
Catchment Soil Erosion Plots Grassland Cultivated (Steep)
Pasture A Forest (young ceder)
Marine apparent Kd(a)
1991-2010
95% = 1740 GM= 481 5%= 133
28 sites data, each year
In situ Kd(a) data after the Fukushima Daiichi accident increased 10 fold
Global fallout After FDNPP
vs. TRS 422 (2004) Parameters RI or
stable (S) 422 Marine
Kd, L/kg
CF
RI+S
RI+S
Sediment-water distribution coefficients
Concentration factors for biological materials
For Fish (no classification), Crustaceans, Molluscs, Macroalgae, Plankton, Cephalopods, Mesopelagic fish, Mammals
Fukushima Kd(a), L/kg
CR
Teff, t
RI
RI
RI
In-situ sediment-water distribution coefficients, before and after the accident
Concentration ratio, water-biota
Different fish species, Before and after the accident
Effective half-lives of marine sediment, water? Or other method to describe changes?
Agreed
vs. TRS 472 (2010) Parameters RI / stable
472 Terrestrial & Freshwater
a, m2/kg Ftr, - Ks, m-1 Kd, L/kg Fv, - Fm, Ff, d/kg or d/L Tag, m2/kg Teff, t CR Fr
RI RI RI RI RI RI+S RI RI RI RI
Interception coefficient Translocation ratio Resuspension factor Distribution coefficient in soil Concentration ratio from soil to plant Feed transfer coefficient, animal products Aggregated transfer factor, semi-natural ecosystem Effective half-lives (limited) Concentration ratio, water-biota Food processing retention factor
Fukushima Kd(a), L/kg Fv,, Teff
Tag, m2/kg Teff, t CR Fr
a, Fm, Ff, Ks,
RI RI RI RI RI RI, Stable RI
Agricultural soil and River Rice and other Crops Wild animals, plants, mushrooms River (water, sediment, biota), Forest (tree, soil, litter), Typhoon (heavy rain/storm) event Water-Freshwater biota Wild edible plants, etc. …Maybe some data available
Agreed
Next subgroup interim meeting @ Institute of Environmental Radioactivity, Fukushima University, with QST-NIRS support
• Planning to have a three-day meeting in May-June, including one day visiting tour to affected area.
• Prof. Hirofumi Tsukada (Corresponding) and Keiko Tagami (QST-NIRS: co-corresponding)
Tokyo
Fukushima
Fukushima Univ.
Fukushima Daiichi NPP
One day visiting tour area
MODARIA II
WG4 Sub-group “Transfer Parameters
in Non-temperate Systems”
Comparison of Cs-137 Transfer Factor Values Generated in India (Tropical Climate) with IAEA TECDOC -1616 (Temperate Climate ) Values
Range of CR values for India are narrower than that of temperate values, but mean values are 4 to 5 times higher than the temperate values.
Higher transfer factor values for soil to grass and rice may be correlated to higher bio-availability elements and high biomass growth in tropical climate.
Low dietary intake, body mass and milk yield of Indian
cows may be reason for higher grass to milk transfer factor (Fm) in comparison to temperate Fm values.
Need for revising the recommended / value for screening calculation to ensure adequate conservatism.
Data from India Mr Rout
Maize (Zea mays, L.) Cabbage (Brassica oleracea, L.)
137 Cs and 60Co TF o for reference crops and tropical soil were more than one order of magnitude higher than temperate areas. - soils did not have clay mineral 2:1 type - may explain lack of ageing effect after 17 years for 137Cs in these soils.
90Sr TF were similar or lower than temperate areas - some loss from top soil to deeper layer in the first 3 years of contamination due to high mobility of Sr. The data will be compared with data present at TRS 479 - and also transfer factor for stable elements will be produced.
Soil to Plant Transfer Factor for Brazilian Soils
0.00
0.01
0.10
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10.00
Ferralsol Goiânia Ferralsol-Al Acrisol Nitisol subtropical IUR
13
7C
s T
F MaizeCabbage
Resuspension rates and doses likely higher in arid environments yet dose potential in arid sites poorly
understood
Slide 18
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q PE
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DOWNWIND DISTANCE (M)
CS-137 desert grass/shrub woodland forest
Resuspension rates and doses likely higher in arid environments after environmental disturbance
Slide 19
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entr
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n %
Years
Arid Environment- Pu-239
With disturbance
Without disturbance
Non-temperate sub group
• Interim meeting? • Explore relevant activities in IAEA
and potential interaction/use of outputs