Environmental Modelling for Radiation Safety (EMRAS) — A Summary Report of the Results of the EMRAS Program

J. JURI AYUB; H. VELASCO; OTROS

INTERNATIONAL ATOMIC ENERGY AGENCY

Lugar: Viena; Año: 2012 p. 53

978-92-0-129810-2

The IAEA’s progamme on Environmental Modelling for Radiation Safety (EMRAS) was launched in September 2003 and ran until 2007. The programme focused on the development, comparison and testing of environmental assessment models for estimating radiation exposure of humans and radiological impacts on flora and fauna due to actual and potential releases of radionuclides to terrestrial and aquatic environments. Models are essential tools for use in the regulatory control of routine discharges to the environment and in planning measures to be taken in the event of accidental releases; they are also used for predicting the impact of releases which may occur far in the future, for example, from underground radioactive waste repositories. It is important to check, to the greatest extent possible, the reliability of the predictions of such models by comparison with measured values in the environment or by comparison with the predictions of other models. A special feature of the IAEA’s modelling programme in this area is the possibility of testing models using ‘real environmental data’. Whenever possible, priority has been given to this approach in order to support the development of validated and reliable assessment models. The EMRAS programme focused on three themes covering fields of specific interest in relation to public exposures and environmental impacts. Within this context, altogether seven working groups were active: under Theme 1, Radioactive Release Assessment, Working Group 1 dealt with the revision of the Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments (Technical Reports Series No. 364) Working Group 2 worked on the modelling of tritium and carbon-14 transfer to biota and humans; Working Group 3 reported on the Chernobyl I-131 release: model validation and assessment of the countermeasure effectiveness; and Working Group 4 investigated model validation for radionuclide transport in the aquatic system ‘Watershed–River’ and in estuaries. For Theme 2, Remediation of Sites with Radioactive Residues, Working Group 1 reported on the modelling of naturally occurring radioactive material (NORM) releases and the remediation benefits for sites contaminated by extractive industries (uranium/thorium mining and milling, oil and gas industry, phosphate industry, etc.), and Working Group 2 studied remediation assessment for urban areas contaminated with dispersed radionuclides. For Theme 3, Protection of the Environment, Working Group 1 reported on model validation for biota dose assessment. The IAEA has been organizing programmes concerning international model testing since the 1980s. The programmes have contributed to a general improvement in models, in transfer data and in the capabilities of modellers in Member States. Due to the organization of the programme with plenary and working group meetings, EMRAS provided a well-accepted international forum for scientists, regulators and operators to exchange knowledge and experience in the field of environmental modelling. This report summarizes the content and outcomes of the EMRAS programme. The detailed reports of all working groups are published as IAEA reports and are provided on the CD-ROM which accompanies this report.