Infill drilling increased the measured resource alone by 248% to 23.1Mt.

NuCoal said the measured and indicated resource for the low ash semi-soft coking coal Whynot seam now stood at 55.3Mt, which would be sufficient enough to provide the initial 10 years of mine production.

The upgraded JORC resource for the project was prepared by independent consultants Palaris Mining following the completion of a mineral resource upgrade program of infill drilling over the past three months.

The substantial increase of measured resources also supports the development of the Doyles Creek underground mine and training school, which is being set up to address the critical skills shortages in the Hunter Valley.

NuCoal said the total ash in the West Borehole, Redbank Creek and Woodlands Hill seams would be reduced once the best mining horizon was determined so the run of mine product coal had a target ash under 30% prior to washing.

NuCoal managing director Glen Lewis said he was encouraged by the resource upgrade.

“The JORC upgrade is another significant milestone for the Doyles Creek project,” he said.

“The results to date continue to highlight the exceptional quality of the Whynot semi-soft coking coal seam [with an average calorific value of 7298 kilocalories per kilogram], with the Whybrow also providing a strong economic foundation for the project.”

A prefeasibility study for the Hunter Valley-located project is on track for completion in June 2012.

Planned output at Doyles Creek is tipped at 5 million tonnes per annum.

The Doyles Creek project is currently under an inquiry by the Independent Commission Against Corruption, following the awarding of the exploration licence in 2008 by former minister for mineral resources Ian Macdonald.