WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence...
Transcript of WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence...
![Page 1: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/1.jpg)
WG8 Biota modelling:
Further development of
transfer and exposure models
and application to scenarios
![Page 2: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/2.jpg)
Activities agreed Nov. 2012
• Modelling exposure in spatially heterogeneous
environments
• Simple whole-organism ellipsoid geometries v’s
Voxel phantoms
• Develop scenario for Fukushima marine
environment
• Collate biological half-life data for wildlife
• ‘Lessons learnt’ documentation
![Page 3: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/3.jpg)
Address the uncertainty in biota modelling
results (indicated in EMRAS), and build more
confidence in simple modelling approaches as
used for regulatory purposes
![Page 4: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/4.jpg)
Estimating soil
contamination in
home ranges of
different species
Modelling spatially
heterogeneous environments
• Typically simplistic
– Point of capture media
concentrations
– Average over likely home-
range
• Is that good enough?
![Page 5: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/5.jpg)
Progress• Review of approaches used in other fields
• Various data sets proposed – most not
suitable
• Swedish moose data presented June 2014
– Aim this week – to derive scenario and begin
modelling
• Norwegian reindeer scenario also
proposed
– Present and decide this weekPhoto: STUK
![Page 6: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/6.jpg)
Compared dose rates from:
• Ellipsoidal whole-body dose * organ
mass ratio
• Voxel approach:
-detailed organ geometries
-organs are both targets and
emission sources
Dosimetry
![Page 7: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/7.jpg)
• Results generally agree <x10 for a range of radionuclides.
• Ellipsoidal approach is
conservative when using
real-world marine fish data
(137Cs, 90Sr, and 239+240Pu),
more so for gamma emitters.
• When real-world fish GI tract is included (often a source of elevated activity concentrations), the increase in whole-body dose is minimal (<factor of 5)
• Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified models.
1e-05
1e-02
1e+01
brain esophagus eyes heart kidney liver muscle pc rectum sbladder skeleton spleen testes
organ
Do
se
Ra
te (
uG
y/h
r)
Calc. Methodology
Mass Ratio
Voxel Organ
![Page 8: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/8.jpg)
Progress
• One paper in-press:
– E Ruedig, NA Beresford, ME Gomez Fernandez KA Higley.
A Comparison of the Ellipsoidal and Voxelized Dosimetric
Methodologies for Internal, Heterogeneous Radionuclide
Sources. J. Environ. Radioact.
• One paper submitted:
– MP Johansen, E Ruedig, K Tagami, NA Beresford, S
Uchida, K Higley. Radiological dose rates to marine fish
from the Fukushima Daiichi accident: the first three years
across the North Pacific. Environ. Sci. Technol.
![Page 9: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/9.jpg)
Dynamic models
• Models assume equilibrium
–Is it conservative?
–Not suitable for modelling
pulsed releases?
![Page 10: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/10.jpg)
Fukushima scenario
• Water & sediment inputs supplied by
WG10 (predictions to end July 2011)
– Cs-137, Sr-90, I-131
• Results submitted by 7 modellers
– Including one set from ERICA (equilibrium)
for comparison
– Paper drafted and will form focus of
discussions this week
![Page 11: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/11.jpg)
Biological half-lives for wildlife
• Reviews of freshwater, marine and terrestrial
organisms approaching complete
• QC being completed
• Publish dataset with DOI and associated data
paper
– Actions, responsibilities and timetable to achieve
this to be defined this week
![Page 12: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/12.jpg)
‘Lessons learnt’ document
• Introduction (to set context) by mid-term
• Capabilities of openly available models
– Tabulated draft by mid-term
• How you ‘make’ model do what you need
• Parameter values
• Dosimetry
• Coping with heterogeneous media
distributions
• Radionuclide specific issues
![Page 13: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/13.jpg)
‘Lessons learnt’ document
• Introduction (to set context) by mid-term
• Capabilities of openly available models
– Tabulated draft by mid-term
• How you ‘make’ model do what you need
• Parameter values
• Dosimetry
• Coping with heterogeneous media
distributions
• Radionuclide specific issues
![Page 14: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/14.jpg)
Agenda
• Monday & Tuesday: Animal-environment
modelling
– Define scenario(s) and start modelling
• Wednesday: Fukushima marine scenario,
Biological half-life DB, voxels, H & C
modelling
• Thursday: ‘Lessons learned’ document
– drafting
![Page 15: WG8 Biota modelling: Further development of transfer and ... · • Results provide more confidence (to practitioners, regulators, public) when faced with questions about simplified](https://reader033.fdocuments.us/reader033/viewer/2022053019/5f25b5b37c2e7b5a02308bdb/html5/thumbnails/15.jpg)
Papers published