ASN considers that management of the waste resulting from decommissioning operations is crucial for the smooth running of the decommissioning programmes (availability of disposal routes, management of waste streams). This subject is addressed with particular attention during the assessment of the decommissioning and waste management strategies established by CEA, EDF and Orano (see point 4 and the Cahiers de l’ASN magazine issue No. 4). 1.2 THE ASN DECOMMISSIONING DOCTRINE Many factors can influence the choice of one decommissioning strategy rather than another: national regulations, social and economic factors, financing of the operations, availability of waste disposal routes, decommissioning techniques and qualified personnel, knowledge of the operating history, exposure of the personnel and the public to ionising radiation resulting from the decommissioning operations, etc. 1.2.1 Immediate dismantling The principle of decommissioning “within the shortest time frame possible under economically acceptable conditions” appears in the regulations applicable to BNIs (Order of 7 February 2012 setting the general rules relative to BNIs). This principle, which ASN has affirmed since 2009 with regard to BNI decommissioning and delicensing, was enshrined in legislation by Act 2015-992 of 17 August 2015 relative to Energy Transition for Green Growth (TECV Act). This approach aims to avoid placing the technical and financial burden of decommissioning on future generations. It also provides the benefit of retaining the knowledge and skills of the personnel present during operation of the installation, which are vital during the first decommissioning operations. The strategy adopted in France aims to ensure that: ∙ The licensee prepares the decommissioning of its installation as of the design stage and updates this preparation throughout the life of the installation. ∙ The licensee anticipates decommissioning and sends ASN the decommissioning application file before it stops operating the installation. ∙ The licensee has the financial resources to finance decommissioning, covering its anticipated expenses by dedicated assets. ∙ The decommissioning operations are carried out in as short a time as possible after shutting down the installation, a time which can nevertheless vary from a few years to a few decades, depending on the type of installation and the decommissioning complexity. The decommissioning plan, which describes the operations the licensee intends to implement to decommission its facility, aims to ensure optimal preparation and forward planning for decommissioning. Since 2007, this document has been required as from commissioning of the facility, and is then updated regularly during its lifetime. It capitalises on Operating Experience Feedback (OEF) by identifying any impacts on the future decommissioning operations, and must enable the licensee to justify the chosen decommissioning strategy on the basis of technical and economic criteria. 1.2.2 Post operational clean-out and achieving the final state The decommissioning and Post Operational Clean-Out (POCO) operations of a nuclear facility must lead to the gradual removal of the radioactive or hazardous substances from the structures and soils, with a view to delicensing the facility and its subsequent withdrawal from the list of BNI. The radioactive substances can result from activation or deposition phenomena caused by the activities of the BNI or the incidents it has experienced. Hazardous chemical substances can also be present in the facility due to the use of certain processes or products (hydrocarbons, hydrofluoric acid, sodium, etc.). In some cases, the radioactive or hazardous substances migrate into the structures of the BNI buildings, or even into the soils of the site and its surroundings, in which case they must be cleaned out. POCO corresponds to the operations to reduce or eliminate radioactivity or any other hazardous substances remaining in the structures or soils alike. Known contamination Complete POCO Compatible with all uses Adapted POCO Incompatible with all uses Utilisation restriction Conservation of memory Diagnostic Contamination partially removed Contamination entirely removed Acceptable impact Unacceptable impact Impact assessment Simplified flowchart of ASN’s “contaminated sites and soils” doctrine ASN Report on the state of nuclear safety and radiation protection in France in 2023 347 • 14 • Decommissioning of Basic Nuclear Installations 14 05 15 08 11 04 06 07 13 AP 03 10 02 09 12 01
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