An increasing number of nuclear facilities are coming to the end of their useful lives and are being, or are going to be, decommissioned with a view to removing the sites from regulatory control. In many cases, decommissioning activities include the decontamination of land, buildings and other structures such as underground pipes and tanks, or ponds, at the site that became contaminated as a result of an authorized practice. The objective of this Safety Guide is to provide guidance to the regulatory body and operators for the release of sites, or parts of sites, from regulatory control after a practice has been terminated. Such release may include cleanup of contaminated sites, and this Safety Guide also aims to provide guidance in this area.