RIO DE JANEIRO, Oct 18: Three UN nuclear experts on Monday discussed terms with Brazilian officials for the inspection of a nuclear facility to which Brazil has refused access for fear of revealing trade secrets.

The inspectors from the International Atomic Energy Agency (IAEA), already locked in a battle with Iran over its nuclear ambitions, arrived at the Rio de Janeiro office of the National Nuclear Energy Commission (CNEN) early Monday.

They are to visit the Resende nuclear plant in Rio state where Brazil wants to enrich uranium. Brazil, which has one of the world's largest uranium reserves, denied IAEA inspectors access to the facility in February and March.

The South American nation opposes a visual IAEA inspection, claiming it has a novel method of enriching uranium that it wants to protect.

IAEA inspectors want to ensure that Brazil is respecting the nuclear Non-Proliferation Treaty (NPT).

Uranium enrichment makes fuel for civilian reactors but can also be used to make the explosive core of atomic bombs. The IAEA is mandated under the NPT to make sure member states do not divert nuclear material for military purposes.

The US government said in April that it was confident Brazil was not developing nuclear weapons.

Earlier this month, US Secretary of State Colin Powell discussed Brazil's nuclear program with President Luiz Inacio Lula da Silva and said Washington had no proliferation worries.-AFP