Managing radioactively contaminated land: implications for habitat diversity

Vegetation cover and long-term conservation of radioactive waste packages: the case study of the CSM waste disposal facility (Manche District, France)

The CSM is the first French waste disposal facility for radioactive waste. Waste material is buried several meters deep and protected by a multi-layer cover, and equipped with a drainage system. On the surface, the plant cover is a grassland vegetation type. A scientific assessment has been carried out by the Géophen laboratory, University of Caen, in order to better characterize the plant cover (ecological groups and associated soils) and to observe its medium and long term evolution. Field assessments made on 10 plots were complemented by laboratory analyses carried out over a period of 1 year. The results indicate scenarios and alternative solutions which could arise, in order to passively ensure the long-term safety of the waste disposal system. Several proposals for a blanket solution are currently being studied and discussed, under the auspices of international research institutions in order to determine the most appropriate materials for the storage conditions. One proposal is an increased thickness of these materials associated with a geotechnical barrier since it is well adapted to the forest plants which are likely to colonize the site. The current experiments that are carried out will allow to select the best option and could provide feedback for other waste disposal facility sites already being operated in France (CSFMA waste disposal facility, Aube district) or in other countries.

The effect on ecological systems of remediation to protect human health

Environmental remediation of contaminated eco-systems reduces stresses to these ecosystems, including stresses caused by the production, use, and storage of weapons of mass destruction. The effects of these various stressors on humans can be reduced by remediation or by blocking the exposure of humans, but blocking the exposure of resident biota is almost impossible. Remediation may involve trade-offs between reducing a minor risk to public health and increasing risks to workers and ecosystems. Remediation practices such as soil removal disrupt ecosystems, which take decades to recover. Without further human disturbances, and with low levels of exposure to stress-ors, ecosystems can recover from physical disruptions and spills. Remediation to remove negligible risk to humans can destroy delicate ecosystems for very little gain in public health.