Transport of low-level NORM – a case for consistency and practicality

In 1996 the IAEA adopted a system for exemption of low-level radioactive material from transport regulations based on the principle that exemption values should be commensurate with the radiological risk posed by the material as estimated in terms of radiation dose (TS-R-1, 1996, Rev. 2005). For many naturally occurring radionuclides the dose-based, radionuclide-specific exemption concentrations tabulated in TS-R-1 were substantially lower than the previous radionuclide-independent definition of radioactive material (70 Bq g-1) due to the stringent dose criterion applied. It was recognized that this would bring huge quantities of previously unregulated natural materials handled in industry into the scope of the transport regulations. To minimize the economic impact of the dose-based values, a special provision in TS-R-1 provides for a 10-fold increase in exemption values for radionuclides in natural material provided the material is not intended to be processed for recovery of its radionuclides (Paragraph 107(e)). This provision reflects the IAEA concept that a dose criterion may be relaxed within cautious bounds to achieve a balance between practical issues and radiological concerns. For example, in a recent extension of the concepts underlying the IAEA Basic Safety Standards to bulk material (RS-G-1.7, 2004), the dose criterion for exposure to naturally occurringmore » radionuclides is, in effect, 100-fold greater than that for artificial radionuclides on the basis of practical considerations. However, the intended use aspect of Paragraph 107(e) is inconsistent with the basic principle underlying the Transport Regulations in that there is no dose basis for assigning different exemption values to identical materials on the basis of their anticipated use. In fact, under this provision the same material can move in and out of the scope of regulatory control as its anticipated use changes. The technical justification for safety requirements, or exemption from those requirements, for potentially hazardous material should be based on measurable properties of the material and not on intentions. To improve the practicality as well as the consistency of the Transport Regulations as applied to NORM, Paragraph 107(e) should be revised to apply to all natural materials, regardless of their intended use.« less