A freight train carrying a steel flask containing nuclear fuel has arrived at the nuclear re-processing site at Sellafield.
Earlier, the five ton shipment of mixed oxide fuel was lifted from the hold of the British Nuclear Fuels ship after arriving by sea from Japan.
As the ship entered the harbour this morning, anti-nuclear protesters aboard a flotilla of small boats staged a demonstration but did not try to block the vessel.
The 18,000-mile two-month sea journey has been dogged by controversy and environmental protests.
The Pacific Pintail freighter made its way up the Irish Sea overnight with its sister ship, the Pacific Teal, shadowing it for protection. The plutonium mixed oxide fuel, or MOX, is being returned to Sellafield after a British Nuclear Fuels client in Japan refused to take the material when it emerged that safety records had been falsified.
Greenpeace claims that the MOX fuel contains 255 kilograms of plutonium, which would be enough to make 50 nuclear bombs. BNFL insists that the fuel is not weapons-grade.