Transport requirements in respect of nuclear fuel may be summarised as:

• Delivery of new fuel to power stations and return to BNFL if it fails to pass final inspection, e. g., due to damage during handling.

• Return of irradiated fuel for reprocessing at BNFL.

• Consignment of small quantities of irradiated fuel for post-irradiation examination (PIE) at labora­tories.

• Consignment of PIE debris from laboratories to the fuel reprocessing plant.

• Return of discharged fuel flasks to power stations for further use.

The new fuel, which is only slightly radioactive, is transported by road in strong industrial containers (magnox fuel) or in Type A containers (AGR fuel), being treated with care because uranium is a chemical­ly toxic material and because even slightly damaged fuel is unsuitable for reactor use and costly to replace.

In the case of new AGR fuel, the stringent require­ments of criticality control necessitate that the amount of uranium in each package, and the number of pack­ages per vehicle are restricted. The criticality aspects of the packaging are subject to competent authority approval.

Flasks being returned after the removal of their load of irradiated fuel cannot be described as empty as they retain some residual radioactivity, possibly above the Type A limits. They are therefore referred to as ‘discharged flasks’, and are moved as Type В packages with similar pre-despatch precautions as those applied to loaded flasks.