Derivation and Comparison of the Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials’ Unrestricted Derived Release Limits 

Health Canada, in support to the Federal Provincial Territorial Radiation Protection Committee (FPTRPC), is currently updating the Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials (NORM).  The guidelines will support the various regulatory authorities across the provinces and territories and are intended to help harmonize protection of the public and workers within Canada. The updated guidelines will be comprised of 3 volumes: the first on radiation protection as it applies to NORM, the second on radon, and the third on NORM transportation.  The third volume has been recently published and is being updated based on feedback from users and the Canadian Nuclear Safety Commission (CNSC).   The two other volumes are being completed and will clarify the scope of the guidelines, as well as recommendations related to worker protection strategies and, in particular the Unrestricted Derived Release Limits (UDRLs). This presentation will cover the current methodology used for the determination of the UDRLs for diffuse solid, liquid, and airborne releases.  The UDRLs will be compared to the CNSC exemption and clearance levels, and the methodology will be compared to that used by the International Atomic Energy Agency (IAEA) in their recommendations for NORM release criteria.  We will compare the differences and possible implications of the implementation of each method. In addition, an overview of some of the proposed updates to the guidelines will be given.