Environmental costs of nuclear power are likely to increase as high-grade uranium becomes harder to find, according to new research

the average grade of the uranium extracted from mines around the world has gradually declined over the past 50 years.

That trend is likely to continue, says lead author Dr Gavin Mudd from Melbourne's Monash University.

This means mining companies will have to use more energy and more water to extract the ore and process it for use in power stations.

the debate has been characterised by a lack of real facts and figures on the total environmental impact of nuclear power, a problem their paper begins to address.