Researchers looked at links between cancer and radiation
His study does show a link between workers who received higher doses of radiation and some forms of cancer, reports New Scientist magazine.
But Dr David McGeoghegan, who co-authored the study into workers at the Springfields fuel fabrication plant in Preston, said that it was likely these findings were generated by chance.
However a spokesman for the National Radiological Protection Board said that further research was needed, particularly as previous studies had shown a link between radiation exposure and lung cancer in uranium miners.
The study looked at the health records of 19,500 people employed at the plant between 1946 and 1995.
It found an association between lung cancer developing two decades later and radiation dose at the plant.
'No firm conclusions'
However, Dr McGeoghegan pointed out that when combined with other similar studies into cancer cases and radiation dose, no firm conclusions could be drawn.
He said: "It is impossible to take this study in isolation from other studies."
A spokesman for British Nuclear Fuels, which commissioned the study, said that the fact that Dr McGeoghegan had been unable to take account of smoking among workers as part of the study meant that the results for lung cancer were not entirely reliable.
He said: "The study also finds that the overall incidence of lung cancer amongst the Springfields workforce is actually significantly lower than one would expect compared to the general population, particularly so for radiation workers."
Dr Michael Clark, from the NRPB, an advisory body to both the nuclear industry and government, said: "Given the link between lung cancer and uranium mining, it would be sensible to investigate this finding further.
"It would also be useful to look at the internal dose of radiation received by workers."
Dr McGeoghegan plans to do exactly this as the study is extended over the coming years, using urine testing to determine the internal dose.