COMPETENT AUTHORITY APPROVED FISSILE EXCEPTIONS UK EXPERIENCE

The IAEA transport regulations contain criteria for excluding some shipments of uranium and/or plutonium from the requirements pertaining to fissile material. The new 2012 edition (SSR-6) has completely overhauled these criteria which have been developed since the IAEA regulations were first introduced. One provision in the revised fissile exception criteria is for a material to be certified by a Competent Authority as posing no criticality safety concern and consequently able safely to be transported as non fissile. Such an approval would be given only following the successful assessment of a safety case justifying that the material would remain subcritical under normal and accident conditions. At PATRAM 2010 the author presented a paper giving a view of the type of material that might be approved under this scheme, the criteria against which an application for approval may be assessed and the type of arguments that an applicant would be expected to present. It particular, however, this paper stressed the radical change in approach that needs to be adopted if benefit is to be gained from this new criterion. This paper follows on from the 2010 paper and describes the Technical Assessment Guide produced by the UK Office for Nuclear Regulation and the types of material that have been presented to the UK Competent Authority as possible candidates for fissile exception.