The aim of the project is to define a method for classifying territories by their sensitivity to a radioactive pollution, on the basis of their environmental and social characteristics, i.e. those characteristics associated with the human use of the environment. For example, the sensitivity of an urban environment will depend on the population density, the area covered, the urban services and their response to the contamination. The sensitivity of an agricultural area will be determined by the food chain and the way in which it is affected by contamination of the soil, crops or livestock. The end result of the SENSIB project will be a standardised tool capable of representing and comparing the sensitivity of an area to radioactive pollution using a single measurement scale. This standardized measurement of the environmental and population characteristics will be useful in risk assessment and management, and in all the operational stages of a nuclear installation including commissioning, normal operation, accident and post-accident situations, and during decommissioning. The project will provide mappings of the sensitivity to a range of concrete scenarios, and of the vulnerability of each area once the probability of pollution occurring has been taken into account. The concept of sensitivity is shared by other fields besides radioecology and can be used to assess vulnerability to chemical pollution, climate change, or population pressures. The results obtained from the SENSIB project will be applicable to other fields, especially that of chemical pollution, though a range of collaborations and partnerships.
The stages in the project
The SENSIB project is divided into five stages. These are:
Identification of sensitivity factors, i.e. all the characteristics of a territory likely to make the environment sensitive to a given type of pollution.
Characterization of their ranges of values.
Conversion of each range of values into a range of scores.
Allocation of a weighting to be applied to each sensitivity factor when calculating the overall sensitivity.
Calculation of an overall score with the aim of defining a single radiological sensitivity scale.
A prerequisite for these stages is the gathering together of all the available radioecological data (field data, modelling, and experimental results) and the processing of this data using a single approach. Two types of studies will be carried out during the period 2005-2008 (when the programme is jointly financed by the ADEME). These are ‘thematic’ and ‘applicative’ studies.
The thematic studies will be used to characterise the sensitivity factors according to the type of environment or theme. These include the atmosphere, the soil, riverbanks, agricultural land, and the human food chain (see diagram). In the case of the atmosphere, for example, one of the sensitivity factors to be studied is the type of precipitation. Each type of precipitation washes out the contaminants present in a cloud to a different degree, and this washout potential is a determinant factor in the size of the resulting deposits. The results of these studies will provide the building blocks needed to establish a method for classifying an environment according to its sensitivity to radioactive pollution.
The applicative studies are aimed at the development of innovative data analysis tool and their application to two distinct scenarios; the management of the consequences of discharges following a nuclear accident, and the sensitivity of the surrounding environments to chronic discharges from nuclear plants. The main focus of these studies will be the atmosphere, the soil, agricultural production and rivers. Other scenarios and environments may be studied after 2008.
The CLARA2 and PRIME research projects, which were chosen for funding by French research calls (see the news), are included in the SENSIB project. The results of the IRSN EXTREME programme will also be used by SENSIB.