SSM has recently established new regulations for clearance of materials, rooms, buildings and land (SSMFS 2011:2). The regulations specify that license holders for practices involving ionising radiation shall take measures after the cessation of the practice to achieve clearance of rooms, buildings and land. The regulations state nuclide specific clearance levels in becquerel per m2 for rooms and buildings, but give no information on levels to be used for the clearance of land. Instead, it is stated that SSM shall decide on clearance levels on a case by case basis and that the license holder shall develop a control program for the methods and procedures to be used in clearance monitoring.
In the coming years, SSM intends to develop regulations, and possibly also guidance, on clearance of land that may be contaminated due to practices involving radioactive substances, such as the operation of nuclear facilities. As a basis for this work, and to support the development of robust procedures for performing clearance measurements and showing compliance with clearance levels for land, SSM has initiated the study presented in this report. The study evaluates methods and approaches used in different countries to achieve clearance of land where nuclear activities have been carried out (also called site release). The different methods and approaches are analysed using a broad variety of attributes.
The study is focused on the issue of showing compliance with given clearance levels for site release (also called derived concentration guideline levels, DCGL:s). SSM intends to continue working on establishing such clearance levels in Sweden. As a starting point, SSM foresees that levels applied will depend on the features of the specific site and on the expected future use of the land, for example farming or industrial use (i.e. green or brown field, respectively). This does however not exclude that general clearance levels for guidance may also be included in regulations (new regulations or a revision of SSMFS 2011:2).