MODARIA MODARIA WG4 Analysis of radioecological data in IAEA TRS - - PowerPoint PPT Presentation

Analysis of radioecological data in IAEA TRS to identify key radionuclides and associated parameter values for human and wildlife assessment

MODARIA

MODARIA WG4

IAEA Parameter value compilations

Objectives

Using the recent data compilations:

• Identify data gaps which matter
• Provide guidance on need for further data for

different source terms

• Explore ways to make TRS data more usable

by modelling community

• Consider both human and wildlife

Meeting issues

• New info on parameter values, analysis of transfer

values and current sampling

• Isotopes in Source terms
• Collate list of relevant isotopes
• Which are important / unimportant re dose
• What is quality and quantity of available data in TRS / site
• Derivation of Screening values
• Focus on SRS19 update, soil-plant, plant-animal
• Revised TRS plant-animal DB
• Derivation of missing values
• A common Kd database for terrestrial, freshwater,

marine

• Document use of Kd in assessments for different source

terms

• Common DB structure
• Updates DB (ongoing)

New info / sampling

Japan USA Amchitka

• S. Korea

0.0001 0.001 0.01 0.1 1 10 100 Wild boar Asian black bear Sika deer Japanese pheasant

CRwo-soil Animals

Red: Range and GM (TRS479)

Norway

Source term information

• U mining
• Weapons testing sites
• Regulated releases
• Reprocessing
• power plants
• Land disposal
• arsenals

GRNC: Groupe Radioécologie Nord Cotentin

U mining - 238U-series rads

Wildlife organism doses

• 226Ra and 210Po most important
• Most important exposure pathway is internal
• Lower soil EMCLs in desert compared with tropical climate

Public doses

• animal-based - Po-210 (93%)
• plant-based - Po-210 (45%), Pb-210 (36%), Ra-226 (16%)
• Po-210 (88%) – overall diet

Test sites - wildlife

Screening assessments

• TRS 472 where possible
• 75 percentile, if n≥10

Soil-plant

• Crops – Grain, Potato, Rice; Forage - Grasses
• “all” soils TRS 472 category
• > 50 values - Am, Cd, Ce, Cm, Co, Cs, Ni, Np, Pb, Pm, Pu,

Ra, Ru, Sb, Sr, Th, U, Zn

• Analogue approach and using stable isotopes as support

for expert judgments of ratios between elements

• Comparison between NCRP 123 and TRS 472 max values

where < 10

Cow milk – revised TRS database Fm and CR vs Fa

R² = 0.6422 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 0.00 0.20 0.40 0.60 0.80 1.00

Fm cow milk Fractional absorption

R² = 0.8264 0.0E+0 5.0E-2 1.0E-1 1.5E-1 2.0E-1 2.5E-1 3.0E-1 3.5E-1 4.0E-1 0.2 0.4 0.6 0.8 1 1.2

CR cow milk Fractional absorption Supported by TREE project of RATE – funded by NERC, RWM and EA in UK

Plant – animal, SRS vs update

Kd activities

• Kd data and analysis reported by participants

Impact of simplification of processes

• Discussed database template

Kd Issues

• High uncertainty (several orders)
• Concerns several transfer pathways
• Conservatisms are not obvious
• Many gaps (data and reference values)

11/19/2014 MODARIA – WG4 - Kd 14

Needs

• Fill gaps
• Reduce uncertainty
• Recommendation for using Kd

Objectives

• Update soils and freshwater Kd databases
• Define a generic structure of Kd databases
• Develop uniforms databases for soils, freshwater and marine environments
• Perform cross analysis (media, elements, components, co-factors)
• Specify Kd impact on different transfer models

MODARIA – WG4 - Kd

11/19/2014 MODARIA – WG4 - Kd 15

Isotope Sorption Protocol Value & Statistics Sample Solution Solid Reference Kd Reference Experimental Approach Definition & Model Use

Global Generic Structure

For each item: define a generic list of relevant parameters for Kd in soils, freshwater and marine

MODARIA report

• What is Kd and how it is used in different source terms & models
• Technical document presenting a generic structure for Kd databases
• Examples of updated soils and freshwater Kd compilation CDFs
• Template of Excel file to enable contributors to input Kd data

11/19/2014 MODARIA – WG4 - Kd 16

Proposals for next « MODARIA »

• Development of soils, freshwater and marine databases (Access

Software)

• Transfer of existing compilations into these databases
• Update and complete reference values
• Cross analysis (multi-media, multi-elements, multi-components, co-

factors) to fill some gaps

• Specified Kd impacts on transfer models and consider application

GM min max 5th 95th Global data set 1135 6 650000 35 40700 Sand group 350 6 65400 15 7100 Clay group 6700 565 375000 560 81200 GM min max 5th 95th Global data set 1135 6 650000 35 40700 RIP/Kss < 100 80 10 715 11 470 RIP/Kss > 10000 9700 220 375000 1050 89100

GM values and data variability (range of values) may vary significantly according to the factors used to group the data,

• “intelligent” database should be able to provide parameter values (e.g., GM;

ranges of values according to percentiles) according to pre-established filters better accommodate end-user requirements decrease data variability. Filters could be applied in parallel or sequentially, if adequate data available.

Example: Kd (Cs) in soils

2015 Interim meetings

• Key dose formers for different source terms

and screening assessment parameter values

– With MODARIA WG8 – Vienna April

• Kd

– IAEA Monaco weeks of 13th April – Involving WG4 participants and some

• rganisations who have Kd databases or who

utilise them