The convoy was the largest to have crossed Germany

The train consisted of 12 containers carrying 21 spent nuclear fuel rods.

Three containers were separated from the convoy at Amiens and were put aboard a ship destined for the Sellafield reprocessing plant in the UK.

The rods are from five plants across Germany, including Brunsbuettel in northern Schleswig-Holstein state and Stade in Lower Saxony.

Since Germany restarted shipments earlier this year trains have faced serious delays caused by hundreds of protesters chaining themselves to the tracks along the route.

On Tuesday, German police detained six protesters in Karlsruhe and removed 17 others who had sat down on the line in Hamburg.

The environmental group Greenpeace said that "rarely has so much radioactivity been put on the rails".

Nuclear-free future

Germany stopped transporting spent fuel in 1998 when containers were found to have leaked radiation.

The decision to restart the shipments angered many environmentalists, particularly as the Green party now forms part of the ruling coalition.

Germany does not have the capacity to reprocess spent fuel itself, but the waste is returned to Germany after processing abroad.

In June Chancellor Schroeder signed an agreement with the nuclear industry to decommission the country's nuclear plants over the next 20 years.