Last update on March 2014
Improvment of dispersion forecast and impact assessment of radionuclides in the environment
The goal of the Amorad project, launched in January 2014, is to answer the central question, “How can the consequences of a release of radioactive substances on humans and the environment be more accurately assessed?” It will improve two types of models, those that forecast the dispersion of radionuclides in the environment and those that assess the impact of radionuclides on two compartments of the biosphere and their interfaces, i.e. the marine environment and land ecosystems and associated surface water.
The accident that affected the Fukushima Dai-ichi nuclear power plant in March 2011 led to significant releases of radioactive substances that were transfered in the atmosphere and the Pacific Ocean. The populations (human and non-human) of the nearby regions were exposed temporarily or permanently to the substances, either by external irradiation or by ingesting plants grown in local soil. Assessment of the radiological and dosimetric consequences of the accident, like that of Chernobyl, is based on two complementary approaches, taking radiological measurements of the environment and people and using calculations and modelling to assess the consequences or estimate parameters that are not always accessible through measurement.
Although it has provided much data, modelling developed after the Chernobyl accident is flawed and in need of improvement. For example, the lack of spatiotemporal resolution must be filled in to determine the concentration of radioactive substances in each environmental compartment (atmosphere and land, aquatic and marine ecosystems). It is also necessary to improve treatment of transfer of these substances at interfaces between compartments, as well as handling the variable weather conditions that may be encountered.
The aim of the Amorad project is to overcome these technical obstacles.
Project Execution and Research Areas
IRSN is the coordinator the Amorad project. With a six-year time frame, the project brings together partners from numerous disciplines (oceanography, chemistry, biology, radioecology, etc.): research organisations, universities in France and Japan, companies, etc. Because of its wide scope, the project has an overall vision of interactions between the sources of radionuclides and the various pathways that affect humans (external exposure in various living locations, internal contamination by ingestion of food products and particles).
The project combines experimentation and modelling: data will be gathered in the field, phenomena will be modelled empirically or mechanically and ecosystems (marine and land) will generally be observed directly.
The Amorad project will study the major biosphere compartments – sea, land and interfaces - in order to relevantly treat radionuclide flux between them. In addition, new “workshop areas” will be located in the regions contaminated after the Fukushima accident for realistic treatment of radionuclide transfer in land ecosystems and flux to the sea.
Research Area 1 (Marine)
Study of radionuclide transfer in sediments and food chains and vulnerability of coastlines to accident situations
The main objective of this research area is to improve methods for assessing the impact on the marine environment (water, sediments and organisms) from the release of radionuclides during an accident. The marine environment is often considered to be dispersive; however, “pockets” of concentrations may be significant in certain compartments: trapping of radionuclides in sediments, effects of powerful events (floods and storms) on resuspension of contaminated sediments, complexity of supply by rivers leaching contaminated basins, possible concentrations in biological chains, etc.
To reach this objective, knowledge at several levels must be improved:
processes in the continent-ocean interface and particle transport on various time and space scales,
transfer of radionuclides in food chains and the sensitivity and vulnerability of affected ecosystems.
Decision support methods will also be developed to increase the benefit of information during operations (to support emergency management).
Four “workshop areas” will be used for this research:
in Japan, the area subject to releases from the Fukushima Dai-ichi nuclear power plant;
in the Manche department in northwest France, the nuclear power plants on the coast and the spent fuel reprocessing plant in La Hague;
and the Bay of Biscay and the Gulf of Lion, which are supplied by rivers on which nuclear facilities are located.
Another goal of the marine research area is to create scenarios combining a nuclear accident with natural catastrophes such as storms and flooding and to optimise environmental monitoring in the event of an accident affecting the marine environment.
Research Area 2 (Continental)
Study of radionuclide transfers in continental environments
The goal of this research area is to better understand and quantify radionuclide transfer processes in various environments over various time scales, particularly those that most influence the dosimetric impact on human populations after an accident. This will result from improving modelling methods integrated in decision support systems in France. To meet these needs, research will combine:
new data acquisition by monitoring sites in Japan and elsewhere;
analysis and prioritisation of data obtained from Japanese, French and international authorities;
development of models using a multidisciplinary approach (hydrology, ecophysiology, biogeochemistry and soil sciences).
Research is in two major parts: tracing erosion in river basins and radionuclide biogeochemical cycles in forest ecosystems.
The research will contribute to the development of assessment tools and methods necessary to study the impact of radioactive releases from nuclear facilities during normal operation.
They will also improve management of emergency situations by authorities due to improved estimation during emergencies of radiological and dosimetric consequences of a radionuclide release into the environment.
Models and calculation software will be developed and verified to meet these needs. They will also handle transfer within land and aquatic ecosystems and marine dispersion. These tools and the knowledge gained will also be a source of data to assess transfers of non-radiological pollutants.