A company applying for a uranium exploration licence near Alice Springs has admitted it may have leaked uranium into one of North America's largest lakes.

Cameco is the world's largest uranium producer and along with Paladin Energy is applying to explore the Angela and Pamela deposit 25 kilometres south of Alice Springs.

The company has told Canadian nuclear regulators their plant at Port Hope may have leaked uranium, arsenic and fluorides into Lake Ontario.

The plant has been closed since last year to clean up contaminated soil deposits, but the company says trace elements of uranium could have flowed into the lake.

Their application to explore near Alice Springs now lies with mines minister Chris Natt.

Today is the last day for public submissions about it.