Radioecology Models

Page under development 

In radioecology, models are used for a wide variety of applications; examples include the prediction of dose rates and activity concentrations and the associated risk from ionizing radiation. Models are used for a variety of purposes, theses include: calculating stability diagrams, equilibrium states, for transport of multiple components, mixed equilibrium or kinetic biogeochemical reactions, both, in surface ecosystems or associated groundwater flow systems. In radioecology the focus of the models is on human and biota impact assessments. 

Commonly used and freely available models developed by ALLIANCE partners: 

The ERICA Tool

The ERICA Tool is a software system that has a structure based upon the tiered ERICA Integrated Approach to assessing the radiological risk to terrestrial, freshwater and marine biota. More information is available here

Radon dose calculator

Models such as the ERICA Tool and RESRAD-BIOTA do not consider dose rates to wildlife from Rn-222 and short-lived daughter products (Po-218, At-218, Pb-214 and Bi-214). Vives i Batlle et al. (2008;2012) developed an approach to estimate dose rates from Rn-222 and short-lived daughter products using an allometric method to scale parameters for the respiratory system and consequently wholebody of wild animals.The resultant spreadsheet model has been made freely available from this website. The radon dose calculator was initially developed funding from the England and Wales Environment Agency.

Radon dose calculator (Version 15/4/20) Vives i Batlle et al 2017

Radon dose calculator (Version 7/12/11) Vives i Batlle et al 2012

References
J Vives i Batlle, D Copplestone, SR Jones. 2012. Allometric methodology for the assessment of radon exposures to wildlife. Sci Tot Environ., 427-428, 50-59. http://dx.doi.org/10.1016/j.scitotenv.2012.03.088

J Vives i Batlle, D Copplestone, SR Jones. 2012. Corrigendum to “Allometric methodology for the assessment of radon exposures to terrestrial wildlife” [Sci Total Environ 427–428 (2012) 50–59]  http://dx.doi.org/10.1016/j.scitotenv.2012.08.001

J Vives i Batlle, A Ulanovsky, D Copplestone. 2017. A method for assessing exposure of terrestrial wildlife to environmental radon (222Rn) and thoron (220Rn), Science of The Total Environment,
605–606, 569-577. https://doi.org/10.1016/j.scitotenv.2017.06.154

An example of the application of the Radon dose calculator can be found in:

NA Beresford, CL Barnett, J Vives i Batlle, ED Potter, Z-F Ibrahimi, TS Barlow, C Schieb, DG Jones, D Copplestone. 2012. Exposure of burrowing mammals to 222Rn. Sci Tot Environ., 431, 252-261. http://dx.doi.org/10.1016/j.scitotenv.2012.05.023

Ar - Kr - Xe dose calculator

After the last official release by the EA in 2002, and the arrival of the ERICA assessment tool, the EA R&D 128 methodology has been gradually superseded by ERICA. However, there is one aspect in which the R&D 128 version 1.2 has remained in use, namely, the calculation of does to biota arising from external exposure to Ar-41 and Kr-85, which fall outside the current ERICA tool's capabilities. However, a limitation exists in that the R&D 128 version 1.2 tool does not have the ability to calculate doses from Kr-88, Xe-131m and Xe-133, which can be significant in discharges from nuclear reactors. An additional problem is that the tool can only calculate doses for the R&D 128-defined biota, but not for ERICA reference organisms, which are based on the more modern ICRP reference animals and plants (RAPs). 

To rectify this, the Belgian Nuclear Research Centre has prepared a variant to the R&D 128 tool (version 2). This now includes the ability to calculate doses for all the environmentally relevant Ar, Kr and Xe isotopes, and covers not only the original R&D 128 organisms but also the ICRP reference animals and plants that the ERICA tool considers. This is no longer a release from the EA, but an adaptation to convey the additional features until this approach can be incorporated in a future release of the ERICA tool.

Calculation guide

Ar - Kr - Xe dose calculator  - Note: please be advised that this Excel spreadsheet does not work on French computers (encryption incompatibility)).

References
Vives i Batlle, J., Jones, S.R. and Copplestone, D. (2015). A methodology for Ar-41, Kr-85,88 and Xe-131m,133 wildlife dose assessment. Journal of Environmental Radioactivity 144, 152-161. https://doi.org/10.1016/j.jenvrad.2015.03.004

CROM

CROM is a tool for the integrated assessments of effective doses for humans and absorbed doses for biota. More information is available here

D-DAT - Dynamic Model for Ecosystem Risk Assessment 

A dynamic tool for the assessment of radiation doses to marine biota. A generic approach has been developed by WSC (funded by the Nuclear Decommissiong Authority) to simulate dynamically the uptake and turnover of a number of radionuclides by marine biota. The approach incorporates a three-compartment biokinetic model based on first order linear kinetics, with interchange rates between the organism and its surrounding environment. Model rate constants are deduced as a function of known parameters: biological half-lives of elimination, concentration factors and a sample point of the retention curve, allowing for the representation of multicomponent release. Radionuclides considered are 99Tc, I-isotopes, Cs-isotopes and 241Am. The new methodology has been tested and compared to non-dynamic assessment models developed for regulatory purposes. The approach has also compares well against research dynamic models developed to represent the uptake of technetium and radioiodine by lobsters and winkles. Assessments conducted on two realistic test scenarios demonstrated the importance of simulating time-dependency for ecosystems in which environmental levels of radionuclides are not in equilibrium.

References
Vives i Batlle, J., Wilson, R.C., Watts, S.J., Jones, S.R., McDonald, P. and Vives-Lynch, S (2008) Dynamic model for the assessment of radiological exposure to marine biota. Journal of Environmental Radioactivity 99 (11), 1711-1730. https://doi.org/10.1016/j.jenvrad.2007.11.002

Disclaimer
This demonstration version of the assessment tool is supplied "as seen", for evaluation purposes only. A fully tested release version of the tool is currently under development. It is not intended that this demonstration version be relied upon for decision making in "real" assessments and is for evaluation purposes only. (Contact Jordi Vives i Batlle for further information).

D-DAT dynamic Tool (Version 2.1) 

D-DAT Instructions 

Other models available:

The RESRAD family of codes

The RESRAD family of codes is developed at Argonne National Laboratory to analyze potential human and biota radiation exposures from the environmental contamination of RESidual RADioactive materials. 

PC CREAM 

PC-CREAM comprises a suite of models and data which can be used to perform the radiological impact assessments of routine, continuous discharges from virtually any type of installation and for performing prospective assessments as a key input to discharge authorisations and waste management decisions.