Limiting Activities and Activity Concentrations in the Transport of Radioactive Materials

Abstract

The activity limits for Type A packages are determined by a set of criteria and hypothetical exposure scenarios known as the Q system. This system was first used to calculate activity limits for Type A packages for inclusion in the 19.85 IAEA regulations and the methodology has been described in the explanatory material for the regulations, IAEA Safety Series No 7. The new IAEA Basic Safety Standards incorporate revised dose coefficients for intakes of radionuclides. For the latest IAEA Transport Regulations, the Q system has been updated to take into account these more recent dosimetric data, and more comprehensive nuclear data. The updated Q system is described and some of the consequent changes in activity limits for Type A packages are illustrated. Member States of the European Union are subject to a Basic Safety Standards Directive, which contains radionuclide specific Exemption Values. The derivation of these values together With their application to transport is discussed.