Antinuclear

Continuing the rollout of new plans for the giant uranium, copper and gold mine, BHP has sought permission from the federal government to raise walls around an important waste or “tailings” dam at the mine from 30 metres to 40 metres.

The change would increase the volume of radioactive fluids that can be held in the dam – which is one of four on site – from 48.4 million cubic metres to 64.8 million cubic metres, with the work expected to be complete by September 2023.

Storage of the tailings, which include radioactive materials and acids, has been controversial since Olympic Dam’s previous owner, Western Mining Corporation, confirmed in 1994 that 5 billion cubic metres of the tailings fluids had leaked out of the storages and into an aquifer underground.

Australian Conservation Foundation spokesman Dave Sweeney said increasing the volume of tailings under storage would probably cause more leakage.

“There is no question that increased pressure would add to the chances of increased seepage,” he said.

“We see tailings management as one of the big, unspoken problems with uranium mining. It is an unresolved environmental management problem.”……..

The push to increase the amount of tailings storage comes just months after BHP revealed a new strategy to develop Olympic Dam by putting a heap leach operation at the start of the existing processing cycle.

BHP will conduct a three-year trial of the heap leach concept, before deciding whether it warrants further expansion.

Confirmation of the heap leach trial was the first sign of progress at Olympic Dam since mid 2012, when BHP axed a $30 billion plan to develop the entire Olympic Dam deposit using the world’s biggest open-pit mine.

That $30 billion plan would have required the construction of eight new tailings dams, each requiring a 65-metre-tall embankment, and each covering two square kilometres.  http://www.smh.com.au/business/mining-and-resources/bhp-billiton-wants-to-increase-radioactive-waste-storage-at-olympic-dam-but-opponents-say-leakage-rates-will-rise-20150111-12ltwq.html#ixzz3OfOVIn50