MODARIA II WG4: Working Group 4 Transfer processes and data for - - PowerPoint PPT Presentation

▶
modaria ii
SMART_READER_LITE
LIVE PREVIEW

MODARIA II WG4: Working Group 4 Transfer processes and data for - - PowerPoint PPT Presentation

Apr 09, 2023 308 likes •556 views

MODARIA II WG4: Working Group 4 Transfer processes and data for radiological impact assessment WG4 report status First full draft available for the meeting Prioritising data gaps Kd soils, freshwater (marine) Transfer to

slide-1
SLIDE 1

MODARIA II

WG4:

Working Group 4 – Transfer processes and data for radiological impact assessment

slide-2
SLIDE 2

WG4 report status

  • First full draft available for the meeting

– Prioritising data gaps – Kd – soils, freshwater (marine) – Transfer to animal products – Transfer to wild game in Japan

  • Discuss key messages of each section
  • Critically evaluate text
slide-3
SLIDE 3

Assessing the radiological impact from radioactivity in the environment

We need to adequately quantify the key transfer processes and recognise their limitations in radiological assessments

  • improve understanding of key processes
  • explore limitations of the models and uncertainty in

model results. The transfer processes and related data will vary depending on the situation considered;

  • planned, existing and emergency exposure situations
  • characteristics of the environment (terrestrial,

freshwater, marine)

slide-4
SLIDE 4

Extended remit

  • MODARIA WG4 focus was on temperate climates

and conditions in developed countries.

  • Important to consider what differences there are

in the assessment methodology when considering tropical, semi‐tropical or arid environments.

slide-5
SLIDE 5

WG4: Objectives

  • To identify key transfer processes for radioactivity in the

environment, in the context of the situation under consideration, for use in radiological impact assessment and to provide analysis of key relevant data.

  • To consider the impact of the accidental release from the

Fukushima Dai‐ichi site in Japan in 2011 and the applicability of existing models and data to the Japanese situation.

  • To provide advice on the applicability of assessment

models to tropical, semi‐tropical and arid environments.

slide-6
SLIDE 6

Relevance to regulatory goals of IAEA

Human and environmental radiological protection in situations

  • f regular operational activities and in accidental scenarios.

WG4 is working toward:

  • Strengthening evaluation of the radiological impact by

improving the data underpinning the models developed for assessing the transfer of RNs in the environment and therefore the radiological impact

  • To more appropriately assess exposure levels of the public

and in the environment to ensure an appropriate level of protection from the effects of ionizing radiation, associated with radionuclide releases and from existing radionuclides in the environment

slide-7
SLIDE 7

Development of a (smart) database for sorption distribution coefficients, Kd (from MODARIA to MODARIA II)

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-8
SLIDE 8

Kd variability

It is obvious that:

  • for a given radionuclide, there is not a single Kd value
  • values may vary within 5‐6 orders of magnitude range for a

specific radionuclide!

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-9
SLIDE 9

Kd variability

Methodological approach

(e.g., sorption; desorption; in situ)

Characteristics of the solid and liquid phases

(factors governing sorption mechanisms and radionuclide speciation) (e.g., pH; Eh; texture; organic matter content; water column/soil solution composition; particle size)

  • The relative weight of each variability source is radionuclide‐dependent!

Kd variability

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-10
SLIDE 10

Refining Kd best estimates derived from datasets

Sensitivity analyses show that Kd values are one of the most important source

  • f uncertainty in some risk calculations:
  • Need to refine Kd best estimates to derive them on the basis of site‐specific

information based on mechanisms and factors governing radionuclide interaction

  • Need to describe Kd variability of a dataset (use of density functions,

PDF/CDF)

From a simple dataset to a smart database

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-11
SLIDE 11

Starting point: datasets for soils and freshwater systems

IAEA EMRAS Programme (Environmental Modelling for Radiation Safety; 2003‐2007): WG1 ‐ Revision of “Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments, TRS 364”.

TRS 472

Dataset Description Best estimates: GM (GSD; (Min‐ Max) PDF/CDF derived Factors to group Kd to derive best estimates based on site‐ specific information Responsible Soil 2900 records ‐ 67 elements Yes No Texture + organic matter; pH; soil solution cationic composition; radiocaesium interception potential; etc. Vidal et al. (UB; SCK‐CEN) Freshwater 2900 records – 15 elements (single values for additional 10 elements) Yes Yes Methodology; suspended matter concentration; contact time; pH; solid‐to‐liquid ratio; Eh Ciffroy et al. (EDF; CEREGE)

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-12
SLIDE 12
  • IAEA MODARIA Programme (Modelling and Data for Radiological Impact

Assessments; 2012‐2015): WG 4 ‐ Analysis of radioecological data in IAEA Technical Reports Series publications to identify key radionuclides and associated parameter values for human and wildlife assessment (led by B. Howard, CEH). TECDOC in progress.

  • Creation of critically reviewed Kd datasets of soil and aquatic systems:
  • Soil dataset (responsible: Vidal et al., UB)
  • Freshwater dataset (responsible: Boyer et al., IRSN)

Update of datasets: MODARIA programme

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-13
SLIDE 13
  • Agreed criteria to accept / reject data (environmental solid matrices;

experimental approaches related to short/long term assessments; requirements for data from stable isotopes; treatment of replicates; etc.).

  • > 12,000 Kd entries for more than 80 elements:
  • Soil dataset: > 5000 entries for > 80 elements (plus > 2000 entries for 75 elements

from other geological materials, such as subsoils, till and gyttja).

  • Freshwater dataset: > 5000 entries for > 40 elements

Main outputs from MODARIA programme

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-14
SLIDE 14
  • Developed examples to show how to derive Kd best estimates (and density

functions) for a given radionuclide from data grouped according to the values of key properties governing radionuclide interaction:

  • For a few radionuclides, Kd could be predicted from linear multivariate correlations

based on key properties

  • Various Kd best estimates for a given radionuclide depending on the available

quantitative information on key properties

  • PDF/CDF possible for datasets with enough entries
  • Percentile ranges remove extraordinarily low or high Kd

values to decrease variability (if required)

  • Developed path forward to filling data gaps (e.g., chemical and environmental solid

matrix analogues).

Main outputs from MODARIA programme

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-15
SLIDE 15

MODARIA programme: key messages

  • Work in progress.
  • Datasets updates have benefited from inputs by member states.
  • Only “informed” Kd are now accepted (excepting when no data is available).
  • Significant improvement possible in best estimates Kd values: site‐specific

data improve assessments!

  • Kd will be reported for each element: not overall summary in big tables for all

elements anymore

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

slide-16
SLIDE 16

Kd smart database: so what is it?

  • The smart database would calculate the related Kd best

estimate and variability (e.g., in terms of CDF and percentile ranges)

  • The end‐user may obtain a Kd best estimate (and associated variability

description) from the database by introducing as much site‐specific information as possible, especially dealing with factors governing radionuclide interaction:

  • Environmental scenario (terrestrial? freshwater? marine?)
  • Type of solid matrix (soil?; deposited sediment?; suspended sediment?)
  • Short‐term assessment? Long‐term assessment? (sorption, desorption or in

situ‐field data?)

  • Properties: pH? organic matter content? particle size? contact solution

composition?

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

  • It should include practical guidance to address variability and limitations of Kd

approach

slide-17
SLIDE 17

MODARIA II: Future challenges to create the smart database

  • Continue efforts to identifying key factors to group Kd data

for other radionuclides (on the basis of easy‐to‐obtain information!).

  • Fill data gaps for prioritized radionuclides and scenarios, and

develop procedures and make recommendations for missing data.

  • Include marine Kd data (IAEA’s MARiS) and complete critical review of marine

datasets.

  • Select the appropriate software for the smart database, and move towards a

common structure for soil/freshwater/marine systems and export soil/freshwater/marine datasets into the agreed database common structure.

MODARIA II Programme. First technical meeting. IAEA Headquarters, Vienna Oct‐Nov 2016

  • Welcome other participants and datasets
slide-18
SLIDE 18

WG4 sub‐group Collation of environmental transfer parameters after the Fukushima accident (Fukushima parameters)

Open data sources (Radiation monitoring data, food monitoring data, institute reports) and papers published in journals (peer review) will be used to provide parameters after the Fukushima accident

slide-19
SLIDE 19

Japanese data survey

⽇本語データの検索

  • Radioactivity measurement has been carried out since 2011.
  • Environmental monitoring has been conducted by Nuclear Regulation Authority with

collaboration of other ministries, agency (i.e., Ministry of Environment, Fisheries agency), Fukushima Prefecture, and TEPCO.

Available at http://radioactivity.nsr.go.jp/en/

  • Food monitoring has been carried out by Ministry of Health, Labor and Welfare with

collaboration of local governments in affected areas. (ca. 30,000 data per months).

Available at http://www.mhlw.go.jp/english/topics/2011eq/index_food_radioactive.html

  • Most monitoring data are written in Japanese & English, but ‘Japanese only’ data are

also updated.

  • Japanese scientists published their papers in English or in Japanese.

Need Japanese scientists’ collaborations to collect many data as possible.

slide-20
SLIDE 20

Sub‐group: Fukushima parameters

Rice (TF) Rice (TF) Agricultural crops Agricultural crops Game animals Game animals Forest Forest River River Marine Biota Marine Biota Fresh water Biota Fresh water Biota

WG 4 WG 4

Parameter database

  • Based on TRS 472
  • Data collation
  • Data analysis

Parameter database

  • Based on TRS 472
  • Data collation
  • Data analysis

Japan side research groups

Corresponding group leaders Agreed are, River: Mr. Seiji Hayashi (NIES) Marine Biota: Mr. Hyoe Takata (MERI) Rice: Mr. Hirofumi Tsukada (Fukushima Univ.) Forest: Mr. Shoji Hashimoto (FFPRI) Game (& farm) animals: Ms. Keiko Tagami (QST) Scientific contributors (world‐wide)

Need your support & cooperation!

Counterpart Supported by Universities and Institutes

slide-21
SLIDE 21

Large coverage is expected

  • River: Mr. Seiji Hayashi (National Institute of Environmental Sciences)

– Under the Ministry of Environment – Carrying out river water monitoring in Fukushima Prefecture

  • Marine Biota: Mr. Hyoe Takata (Marine Ecology Research Institute)

– Under the co‐supervision of the then Environment Agency, Ministry of Agriculture and Forestry and

Fisheries, and Ministry of Trade and Industry since 1975

– This institute has been carried out radioactivity monitoring in marine systems (biota, water, sediment) more than 40 years, and Mr. Takata started measurements after the Fukushima accident

  • Rice: Mr. Hirofumi Tsukada (Fukushima Univ.)
  • Forest: Mr. Shoji Hashimoto (Forestry and Forest Products Research Institute)

– Under the Forestry Agency, Ministry of Agriculture, Forestry and Fisheries – Studying forest modeling & Cs fate tree body

  • Game (& farm) animals: Ms. Keiko Tagami (QST‐NIRS)

Start discussing what parameters should be collated; parameters we need to consider are listed in TRS‐472

slide-22
SLIDE 22

Plan

  • Discuss activities suggested by MODARIA proposal
  • Identify areas of interest to participants
  • Form relevant sub groups for each topic area
  • Define an initial objective and workplan
  • MODARIA report – finalise key messages
slide-23
SLIDE 23

Liaise with:

– WG 3 addressing assessments of exposure and data for planned releases to the environment, – WG 5 considering assessment of exposure and effects to biota – WG 7 on Kd in marine systems