ANNEX: EXAMPLES OF KEY INFORMATION FILES

These criteria led to a "multi-layer" covering system based on the alternation of layers of various characteristics in terms of permeability. It is made of a synthetic material called geomembrane*, chosen for its elasticity and its capacity to adapt to ground movements. This material was soaked in bitumen to make it tight, then emplaced between several layers of sand and earth.

Laying a geomembrane strip. The strips are welded to each other along an axis parallel to the north-south axis.

Source: Andra.

The planned final configuration

The configuration of the repository as of 2017 allows for close monitoring by Andra but requires maintenance. It is not the planned final configuration, where no maintenance is required.

In the final configuration:

•The network of underground galleries that collects any infiltration water will be backfilled, as will the associated technical building, in order to stabilise these works.

•The repository will be in a passive (no human intervention required) configuration; monitoring as performed at present will be stopped; effluent management will be adapted.

Section 4. The disposed waste

The waste in the Manche repository contains substances that are harmful due to their radioactivity and/or their chemical nature. An inventory of these substances is proposed in this chapter. Despite the natural decay of radioactivity over time, the disposal centre site cannot be trivialised at the end of the monitoring period, due in particular to the presence of alpha* waste.