The IAEA has published a revision to Specific Safety Requirements No. SSR-6 Regulations for the Safe Transport of Radioactive Material. These are international model regulations that will eventually be adopted into UK legislation covering all aspects of radiological safety in transport, whether it be by road, rail, sea, inland waterway or air. Current legislation is based on the previous version issued in 2012.
There are a number of detailed changes in the revised issue but two in particular will be significant for the future management of radioactive wastes.
New material category - SCO-III
The transport regulations specify different packaging criteria depending upon the form of the material proposed for transport. One such category is Surface Contaminated Objects (SCO) - a solid object that is not itself radioactive but which has radioactive material distributed on its surface. The SCO provisions have been extended to include a new category SCO-III. In addition to meeting the general requirements for SCO designation, SCO-III objects are defined in para 413(c) as a large solid object that is too large to be transported in the type of package described in SSR-6. The section describes detailed criteria to be met regarding sealing of openings, inside being as dry as practicable and limits on contamination levels on external and inaccessible areas. This categorisation might be applicable to transport of large objects such as power station heat-exchangers, or other reactor components which arise as waste during decommissioning operations and which need to be transported e.g. to a processing plant or disposal facility.
Shipment after a period of storage
It is not uncommon for radioactive wastes to be conditioned and packaged into containers that provide both transport and disposal functions. The half-height freight container used for packaging of low level waste for disposal to the Low Level Waste Repository (LLWR) is an example. A similar approach has also been used for some intermediate level wastes but without a disposal route, such wastes have to be stored pending the provision of a GDF. The fact that transport packages may be manufactured and then stored prior to transport is now explicitly recognised within SSR-6 with the provision of additional requirements detailed in para 503(e):
For packages intended to be used for shipment after storage, it shall be ensured that all packaging components and radioactive contents have been maintained during storage in a manner such that all the requirements specified in the relevant provisions of these Regulations and in the applicable certificates of approval have been fulfilled.