Secret journey to safeguard radioactive material
22 December 2010 Last updated at 19:27 GMT
An international project is underway to move radioactive substances into secure facilities and prevent them from ending up in the hands of terrorists.
A convoy of nuclear material has arrived at a secure facility in Russia after an extensive journey by road, rail and ship from Serbia.
The details of the shipment and the route had to be kept secret until the material reached its destination.
Gordon Corera reports.