The head of BHP Billiton's Olympic Dam expansion and uranium division, Graeme Hunt, told a packed session of the AusIMM International Uranium Conference in Adelaide that planning for transforming Olympic Dam to a large scale open cut operation was still proceeding to schedule.

At the conclusion of his presentation he responded to a Mineweb question on what appeared the media perception that a sense of inevitability now existed for the world class copper-uranium and gold mine to become perhaps the world's biggest open cut development.

The pit, he said, could grow to 6 kilometres in length and 3 km depth and mineralisation was known down to 2 km. (State government officials have told Mineweb in the past that the deepest hole was understood to have been to 2.5 km and ended in mineralisation).

He said that the pre-feasibility should be completed by the end of this year and that whatever the concept should be available for public viewing in 2009 and that a definitive feasibility could be completed by early 2010.

Delegates debating Hunt's presentation held varying opinions and one of the most universal views was that this expansion will be a ramping up in stages. The existing underground operations involve 250 kilometres of tunnelling. Project costs have produced widely varying figures in recent times - from $US6 to $US9.5 billion.

Indeed Hunt indicated this by pointing to a progressive build up in production to 2030 that would see Olympic Dam surpassing the BHPB-controlled Escondida copper mine in South America, the uranium component making the mine the world's dominant uranium producer and the gold output putting the polymetallic mine in that world class status. The annual production growth could reach 730,000t of copper metal, 19,000t uranium and 800,000 oz gold.

Since absorbing WMC Resources BHPB has lifted the project's resource to 7.855 billion tonnes and that has included outlining of the major southern ore system that helped dramatically elevate the resource picture. The ore reserve totals 399 Mt @ 1.87% Cu, 0.58 U308, 0.68 grams/tonne gold and 4.02 g/t silver. Within the resources there is a non sulphide gold-only zone of 114 Mt @ 1.19 g/t.

Early this month BHPB's chief executive Marius Kloppers told the Melbourne Mining Club that plans to boost copper production from 180,000 tonnes per annum to 730,000 tpa would be outlined at a detailed briefing in October. He said then that the company intends outlining development plans for the project before the $A160 B ($US151 B) tilt for Rio Tinto was settled.