Saturday, 3 March, 2007

by Wendy Frew
Sydney Morning Herald

In the rush to promote nuclear power as a clean alternative, the pitfalls of uranium mining are being ignored, writes Wendy Frew.

Olympic Dam, 560 kilometres north-west of Adelaide, is a mine like no other in Australia.

Hidden under South Australia's dusty red plains is a Tolkien-like labyrinth of tunnels carrying monster trucks and an underground train that transports hundreds of tonnes of minerals to the surface every day.

Above ground, the copper, gold, silver and uranium gouged from Australia's largest underground mine are processed in a mega metallurgical complex that sprawls across the arid countryside.

The millions of tonnes of waste material - much of it radioactive - piles up in giant open-air tailings dumps that can reach as high as 30 metres and cover hundreds of hectares of land.

Those who have seen the radioactive waste say it has the consistency of powder, and as it dries, it takes on a range of colours from a rusty red to sulphur yellow or salty white.

The mine consumes millions of litres of water every day and a huge amount of fossil-fuel electricity. It generates an estimated 1 million tonnes of greenhouse gases every year, and has displaced many square kilometres of native vegetation to make way for the processing plants and tailings dumps.

The uranium is used to generate power in a nuclear reactor, power that the Prime Minister, John Howard, says is "cleaner and greener than just about any other form of energy".

But in the rush to embrace nuclear power as a way to combat climate change, the damage uranium mining does to the environment seems to have been all but forgotten.

Australia has some of the world's best and biggest uranium reserves and the industry represents a rich seam of export dollars and regional jobs. Mine operators are already gearing up to expand existing mines, which will further boost outback economies in the Northern Territory and South Australia. Supporters say expansion of the industry would also mean a guaranteed long-term supply of fuel for generating electricity should Australia ever decide to abandon coal.

However, environmentalists and scientists say those benefits must be weighed up against an industry that relies on a fuel that will eventually run out; that generates toxic, long-lasting waste, both when the ore is mined and when the yellow cake is processed; and that contaminates water and soil.

"Any nuclear industry would be 20 years away," says the Australian Conservation Foundation campaigner David Noonan.

"We don't see any reality in the attempt to get nuclear power up in Australia but we are very worried about the expansion of the uranium industry … we would just become a quarry for the global nuclear industry," he says.

Australia has three operating uranium mines: Olympic Dam and Beverley in South Australia, and the Ranger mine in the Northern Territory.

It is difficult to comprehend the scale and breadth of the operations at Olympic Dam. The BHP-Billiton mine is open to visitors, but in such an isolated location few Australians would have taken the tour. Fewer still would have any inkling of what it takes to get uranium out of the ground, the complex and expensive task of managing the contaminated rock and water waste, and the rehabilitation of the land that must be done after a mine has closed down.

The massive mineral deposit 350 metres below the surface contains the world's largest known uranium ore body and the world's fourth-largest remaining copper deposit.

The mine's rock waste and coarse tailings are used as mine backfill. Fine tailings material is dumped above ground in an area that covers about 400 hectares.

According to BHP, radiation in the tailings is as low as reasonably achievable and much less than levels considered acceptable, as determined by international standards. The waste is extensively monitored and the results reported on a regular basis to South Australian Government regulators, it says.

BHP says it is still developing a final rehabilitation plan for the tailings storage at the end of the mine's operational life.

Despite these assurances, the tailings dump is a major concern for people such as Noonan.

In 1994, the then mine owner, Western Mining Corporation, revealed that up to 5 million cubic metres of contaminated liquid had leaked from the tailings dams, a potential threat to the quality of groundwater immediately below the dams.

The industry's Uranium Information Centre says studies demonstrated that the pollutants in the seepage were quickly adsorbed by clays and limestone in the soil and rock under the tailings dams. Because of the low permeability of the rock, there was "no potential harm to the groundwater resource".

According to Ian Hore-Lacy, a spokesman for the Uranium Information Centre, the tailings dumps don't represent a risk to workers or the environment.

"If you have radioactive tailings then you just cover them with more cover … the level of radioactivity is negligible," he says.

"You could set up camp and live on top of them for a year and not get any serious radioactivity, not that that is recommended."

But Noonan says the risks associated with tailings will only grow because of BHP's $5 billion expansion plans for Olympic Dam.

The expansion, which is likely to see the underground mine converted to an open pit, would be one of the biggest of its type in the world and require the removal of a million tonnes of rock waste every day for four years, according to the company.

The company will have to drill and blast its way down 350 metres before it even reaches the ore body.

Friends of the Earth has estimated the expanded dam would probably contain the largest uranium tailings repository on earth.

In a submission on the expansion plan's draft environmental impact statement the organisation said the tailings storage facilities would be so big they would be among the largest structures on earth.

"The main problem is that the integrity of the [facility] must actually be guaranteed not for a mere 200 years, nor even for 1000 years … we would need to reasonably assure containment of the tailings for a minimum of 230,000-300,000 years," it wrote.

"This is five times as long as Aboriginal occupation of Australia, which is in turn longer than any other human group has survived. It is a period of time in which major climatic, and indeed, geological changes can be expected to take place, not to mention changes in land-use, population, etc."

Olympic Dam's expansion would also see the mine's current water use surge from 35 megalitres a day (taken from the Great Artesian Basin at no charge to the company). Another 120 megalitres per day will be needed for the expansion, which would be produced by a desalination plant the same size as the one planned for Sydney.

At the Ranger uranium mine in Kakadu National Park in the Northern Territory, the issue is not too little water but too much.

After several days of record-breaking monsoonal rainfall, the mine's operator, Rio Tinto's subsidiary Energy Resources Australia, stopped mining on Tuesday. The processing plant was closed a day later. Widespread flooding is also making it difficult to get into or out of the mine and the nearby town of Jabiru.

As the Federal Government described it in 2005, "the operation of a uranium mine and mill in a region which is World Heritage listed, subject to seasonal extremes in rainfall typical of monsoonal climates and which represents at least 40,000 years of habitation by the Aboriginal people, provides many environmental challenges".

The Ranger lease covers 7860 hectares, of which about 500 hectares are directly disturbed by mining.

"Water management at Ranger is seen as an intractable and growing problem," says the Australian Conservation Foundation's Dave Sweeney.

"The area around the stockpiles, the processing facilities and the tailings corridor [where slurry is piped from the mill to the tailings dam] is a restricted-release zone and all the water that falls in those areas has to be managed because it becomes contaminated," Sweeney says.

Water is shunted around the site, from the pit after heavy rainfall, through retention ponds and into the giant tailings dam. Ranger has built a $25 million plant to help make sure all the water is treated.

Managing water is the No.1 issue for the mine, says an Energy Resources Australia spokeswoman, Amanda Buckley. Much of the mine operator's time and energy is expended coping with the large amount of water onsite and driving in heavy rain represents a higher risk to workers than exposure to radiation.

But Buckley says the company has invested heavily in water infrastructure and the mine operates under the toughest regulations in Australia.

"If you ask the technical people, they will say it is like other kinds of mines, such as copper and nickel," says Buckley about the environmental hazards at Ranger.

"You are digging the ore out with the same kind of equipment, all the processes are the same. The difference is the radiation, but it is not a very high level of risk [for workers]."

Buckley explains the mine often closes after heavy rainfall, but this week's deluge posed no environmental issues.

The Uranium Information Centre's Hore-Lacy says Australian regulations for uranium mine operations and worker safety are so high you could never get a really harmful level of radioactivity. He dismisses the 1994 tailings dam leakage at Olympic Dam as more an engineering than an environmental issue.

Australian standards are high compared with many overseas mines, says Dr Gavin Mudd, a uranium mining expert and lecturer in engineering at Monash University.

"But we still cannot answer the fundamental questions about rehabilitation [of land after mining ceases], and we still have accidents. So, from a scientific point of view, it is still not good enough."

The Rum Jungle uranium mine, which is about 64 kilometres south of Darwin, is one example of how not to manage a site, critics say. At Australia's first large-scale uranium mine, the dams, which were meant to prevent acidic materials and heavy metals used in the milling process from reaching rivers and streams, frequently overflowed during the wet season. The environmental damage it caused has still not being fully repaired since the mine was closed in 1971.

Mudd supports Energy Resource Australia's investment in a sophisticated water treatment facility. But he says it is not without its problems because of the nature of some of the highly contaminated water it deals with. He is also concerned that tailings being dumped back into an old mine pit could leach out because the upper parts of the pit walls are permeable.

The academic, who has visited many existing and disused mines here and overseas, remains sceptical about rehabilitating land after uranium mining has ceased because of the industry's poor track record so far.

"You need to keep an eye on the old uranium sites to see how they are being rehabilitated and how water was used, so that you can draw conclusions about current mines," he says.

"Give me 100 years and then let's see how good today's standards are."

He says that because Ranger is planning to extend the life of the mine out to 2011, more room will be needed for the tailings.

"Tailings dams are not cheap to build … and it is going to be a huge problem rehabilitating them."