An atomic energy firm responsible for a radioactive leak from a lorry has been fined £250,000.
The cargo was being transported to Sellafield in Cumbria
The vehicle, which travelled from Yorkshire to the Sellafield nuclear plant in Cumbria, leaked radiation for 130 miles, a court heard.
Leeds Crown Court was told it was "pure good fortune" no one was dangerously exposed to the radiation in March 2002.
AEA Technology admitted health and safety breaches and was ordered to pay £151,000 costs.
The Oxfordshire-based company was transporting part of a piece of cancer treatment equipment, which had been decommissioned at Cookridge Hospital in Leeds, to the Sellafield complex.
But a "plug" was left off a specially-built 2.5 tonne container.
Mark Harris, prosecuting for the Health and Safety Executive, said: "Through pure good fortune no-one involved in the removal, containment and transfer of the source may have been directly exposed to the radiation beam.
"The risk of such exposure was undoubtedly present - at Cookridge, during the journey and at Sellafield."
He said detected radiation at Sellafield was between 100 to 1,000 times above what would normally be considered a very high dose rate.
He added that the radiation leak took the form of a narrow "beam", which was fortunately directed vertically into the ground.
Mr Harris said the result would have been much worse if the beam had escaped horizontally.