CLEARANCE (see reference below)
2.12. While exemption is used as part of a process to determine the nature and extent of application of the system of regulatory control, clearance is intended to establish which material under regulatory control can be removed from this control. As with exemption, a clearance may be granted by the regulatory body for the release of material from a practice.
2.13. Clearance is defined as the removal of radioactive materials or radioactive objects within authorized practices from any further regulatory control by the regulatory body. Furthermore, the BSS state that clearance levels “shall take account of the exemption criteria specified in Schedule I and shall not be higher than the exemption levels specified in Schedule I or defined by the regulatory body” (Ref. , para. 2.19). A footnote indicates that “Clearance of bulk amounts of materials with activity concentrations lower than the guidance exemption levels specified in Table I-I of Schedule I may require further consideration by the regulatory body” (Ref. , footnote 8).
2.14. In summary, the BSS provide radiological criteria to serve as a basis for the derivation of clearance levels but provide no definitive quantitative guidance on clearance levels. The activity concentration values developed in the following section for use in making decisions on the exemption of bulk materials may find use by regulatory bodies as a basis for the clearance of such materials.
Application of the Concepts of Exclusion, Exemption and Clearance, SAFETY GUIDE, No. RS-G-1.7 https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1202_web.pdf