The scenario for each nuclear installation (immediate or deferred dismantling) is selected by the operator on a case by case basis, generally in the light of comparative studies. However, the operator is asked to justify that the strategy proposed is the best one in terms of safety and radiation protection. The operator is also asked to justify the dismantling end-state of the considered installation.
The Nuclear Safety Authority encourages complete dismantling either immediately or after slight deferral, for various reasons. At present all operators in charge of a current dismantling operation apply this policy.
The technical provisions applicable to installations to be decommissioned must obviously be in compliance with general safety and radiation protection rules, notably regarding worker external and internal exposure to ionising radiation, criticality, the production of radioactive waste, release to the environment of radioactive effluents or measures designed to limit accident hazards and mitigate their consequences.
Waste originating from dismantling work is managed in the same way as waste originating from installations in operation. Although Directive 96/29/Euratom so allows, French regulations have not adopted the notion of “clearance threshold”, i.e. the generic levels of radioactivity below which the effluents and waste from nuclear activity can be disposed of as current waste without specific radioactive supervision. In other words, there is no release of materials from nuclear zones which are not declassified from nuclear zones to conventional zones.