THERE are concerns that a train may have spilled uranium when it detrailed at a flooded NT river. 

The train was carrying 1500 tonnes of copper concentrate from OZ Minerals' Prominent Hill copper mine in South Australia when it derailed in bad weather caused by ex-tropical cyclone Grant on December 27.

Up to 1200 tonnes of the substance spilled into the nearby Edith River, Oz Minerals said in a statement to the Australian Securities Exchange (ASX) on December 28.

The copper concentrate from Oz Minerals' mine contains less than 0.008 per cent of uranium, according to the company's documentation, the Adelaide Advertiser reported on Saturday.

That equates to 96 kilograms in 1200 tonnes of copper concentrate, the newspaper said.

The company said in its ASX statement that any of the concentrate that entered the water would become highly diluted.

Copper concentrate is itself a toxic substance and Oz Minerals had been given a one-year exemption to transport the material in tarpaulin-covered wagons, the Adelaide Advertiser reported, after government rules for the transport of the substance had been temporarily relaxed.