What is decommissioning?

Answer:   decommissioning is “The administrative and technical actions taken to allow the removal of some or all of the regulatory controls from a nuclear facility”.

The two main objectives of decommissioning are to render the site permanently safe and to recover it, as far as practicable, for reuse. Decommissioning strategies should be elaborated taking in account the funds available.

 

Background

The definition of decommissioning is “The administrative and technical actions taken to allow the removal of some or all of the regulatory controls from a nuclear facility” (except for a repository or for certain nuclear facilities used for the disposal of residues from the mining and processing of radioactive material, which are ‘closed’ and not ‘decommissioned’).

Decommissioned facility is “an installation or location at which residual structures and equipment essential for its use have been removed or rendered inoperable so that it is not used to store and can no longer be used to handle, process or utilize nuclear material”.

The two main objectives of decommissioning are to render the site permanently safe and to recover it, as far as practicable, for reuse. The reasons for decommissioning can be uneconomical operation, technical obsolescence, conclusion of research program, safety considerations, change in Governmental Policy, Accident, etc.

Decommissioning strategies should be elaborated: ideally planning for decommissioning should be started at the facility design stage, cost/benefit evaluation should be used to determine the best strategy. The sooner the better: early planning will allow timely allocation of funding and infrastructure. The strategies are immediate dismantling, deferred dismantling (Safe Enclosure) and entombment.

Decommissioning creates lots of wastes which need to be controlled and stored safely in appropriate interim storages. It is necessary to decrease as much as possible the volumes of radioactive wastes created. Major obstacles can be lack of funding, lack of waste management and disposal facilities and social issues. Decontamination and dismantling, clearance and site release criteria can also be adverse factors. The processes of dismantling are well known now. The site remediation may still pose questions if the competent safety authority has not yet issued the criteria for release from regulatory control.