Export of high activity radioactive sources and high activity aggregations of sources in a single shipment
Regulation 9AD of the Customs (Prohibited Exports) Regulations 1958 requires written permission to export certain radionuclides with an activity above the prescribed threshold activities listed in Schedule 7A of the regulations (see High activity radioactive sources).
The high activity radioactive sources listed in Schedule 7A intentionally reflect those radionuclides and their threshold activities in the IAEA Code of Conduct on the Safety and Security of Radioactive Sources (Code of Conduct), Annex I Table 1.
The regulations require ARPANSA to give due consideration to Australia’s international obligations when processing an export permit application for a high activity radioactive source.
Aggregation of sources
A proposed shipment of a single Category 1 or 2 radioactive source from Australia requires an export permit issued by ARPANSA. However, the aggregated activity of multiple lower activity sources in a shipment may pose a risk similar to a single Category 1 or Category 2 source.
Annex I of the Code of Conduct recommends appropriate attention be given to aggregation of lower activity sources which may require management under the principles of the Code of Conduct and therefore also require export permission from ARPANSA.
The high activity status of multiple radioactive sources in a single shipment can be categorised by the summed activity of the radionuclide divided by the appropriate D value and the calculated ratio A/D compared with the ratios A/D given in Table 1 of the Code of Conduct. If sources with various radionuclides are aggregated, then the sum of the ratios A/D should be used in determining the category, in accordance with the formula set out in either the Categorization of Radioactive Sources (IAEA Safety Standards Series No. RS-G-1.9) at page 9, or ARPANSA Code of Practice (RPS 11), Schedule B at page 19.
Rationale for aggregation of sources in a single export shipment
The IAEA Categorization Safety Guide (Categorization of Radioactive Sources IAEA Safety Standards Series No. RS-G-1.9) provides a categorisation system for radioactive sources, particularly those used in industry, medicine, agriculture, research and education. The categorization of radioactive sources assists regulatory bodies establish regulatory requirements that ensure an appropriate level of control.
The IAEA Categorization Safety Guide is also intended to provide support for the international harmonisation of measures for the control of radiation sources and their security, in particular for the implementation of the Code of Conduct.
The IAEA import export guidance specifically refers to paragraph 3.5 of the IAEA Categorization Safety Guide for additional information on aggregation of sources. Paragraph 3.5 recognises that there will be situations in which radioactive sources are in close proximity to each other, such as in manufacturing processes (e.g. in the same room or building) or in storage facilities (e.g. in the same enclosure). In such or similar circumstances, the regulatory body may wish to aggregate the activity in the sources to determine a situation specific categorisation for the purposes of implementing regulatory control measures.
In the case of radioactive source exports, ARPANSA considers the use of a sea cargo container, or a Unit Load Device (in the case of air freight) for the export of multiple radioactive sources in a single shipment to create a sufficiently closely confined storage environment during transport to warrant consideration of the aggregated activity of multiple radioactive sources (Category 3 sources and above) in a single shipment.
The introduction of aggregation of radioactive source activity for the purpose of categorisation of radioactive source export shipments also serves to harmonise the export permit source categorisation requirements for a shipment with the separate domestic transport security requirements under RPS 11 which considers the aggregation of radioactive sources for determining source categorisation when preparing a domestic transport security plan.