Free measurement

In nuclear technology, the term " clearance measurement " is understood to mean the metrological proof that certain residues , especially those arising from the dismantling or demolition of a nuclear facility, such as construction rubble, metal parts, etc., have so little radioactive activity that they no longer need to be monitored. The decision to release the material from nuclear supervision is referred to as " release ". The clearance measurement is a preliminary stage of the release; the measurements themselves are referred to as " decision measurements" since they are used to decide on a release .

Only a small fraction of the total material in a nuclear facility has ever come into contact with radioactivity . Most of this can be freed from adhering radionuclides by decontamination measures . Material whose activity is demonstrably below a certain level can be released based on an official decision. After that, the material is no longer a radioactive substance in terms of nuclear law. When a nuclear power plant is demolished, about 97% of the total mass can ultimately be released.

literature

• The decommissioning of nuclear facilities, Federal Ministry for the Environment, Nature Conservation and Nuclear Safety , September 2001