A SEMI-trailer loaded with uranium oxide became bogged yesterday on a road in Kakadu National Park.

The yellowcake was being trucked from the Ranger mine, near Jabiru, to East Arm Wharf for shipment.

Energy Resources of Australia denied that there was any danger of the radioactive oxide spilling in the World Heritage-listed nature reserve.

The uranium oxide was sealed in 44-gallon drums inside two shipping containers.

The NQX Freight semi-trailer became bogged about 10am on the side of the Arnhem Highway, 20km west of Jabiru.

It became stuck in water-laden ground after the driver pulled over to let a wide-load truck pass.

Mine spokeswoman Shannon McRae said the rear trailers became bogged - "and the vehicle was unable to continue its journey".

Police closed a stretch of the Arnhem Highway for three hours until a crane arrived on the scene.

The crane lifted the two containers off the bogged semi-trailer and on to another semi-trailer parked on the highway.

"As per standard operating procedure, these containers were returned to the Ranger mine for inspection," Ms McRae said.

The NQX semi-trailer returned yesterday afternoon to Darwin.

The powered uranium oxide was being transported to the FreightLink rail yard at East Arm for transport to Adelaide for eventual export.

Ms McRae said the drums of uranium oxide were not damaged.

"No employees or general public have been harmed in this incident," she said.

ERA staff plan to inspect the containers and drums today, which will then resume their transport to Darwin.