With the spent fuel placed in the transport flasks and ready to be dispatched to Sellafield, the regulations governing the transport then come into play. There are a bewildering range of rules and regulations...
Standard Magnox fuel comes in the form of a rod measuring approximately 1 metre long, 5 centimetres in diameter and weighing between 10-12 kilogrammes. The fuel rod is contained in a casing fabricated from magnesium alloy, hence the name Magnox. Prior to dispatch to Sellafield, and with the 'fins' mechanically removed, the rods are transferred from the power station cooling pond to an open-top fuel skip which is then fitted into the transport flask.
Nuclear trains rumbling across UK is a fairly familiar sight these days, but the cream coloured transport 'cabins' hauled in the twighlight hours through towns, cities and countryside conceal the real nuclear cargo - the spent fuel flasks. Because the flasks are generally loaded into their transport cabins at the reactor site, there is seldom any chance to see the flasks themselves. The exception to this is the imported foreign fuel which, having been unloaded at Barrow docks, is transported by rail to Sellafield unprotected by any cabin...
Nuclear fuel is fabricated from natural uranium imported from overseas by BNFL who operate a fuel fabrication plant at Springfields near Preston and a uranium enrichment plant at Capenhurst in Cheshire. Natural uranium is composed largely of two elements Uranium 235 (U-235) and Uranium 238 (U-238). Whilst this is suitable for making fuel for Britain's ageing Magnox reactors, it has to be enriched before it can made into fuel for the newer advanced Gas-Cooled Reactors (AGRs).
Every 'package' containing radioactive material for transportation is subjected to a range of tests laid down by the IAEA. The aim of the tests is to ensure that the necessary safeguards are built into the design of the flask, and the conditions under which it is transported, so that it will withstand severe accident conditions without presenting a significant radiological hazard...
