Uranium miner Energy Resources of Australia (ERA) says it is still assessing the financial impact of a toxic spill at its Ranger mine in the Northern Territory.

It has been almost two weeks since operations ceased at the mine site after a 1,400 cubic metre holding tank burst, spilling radioactive slurry and acid.

Operations were suspended indefinitely by order of the Territory and federal governments after the spill.

In a statement to the Australian Stock Exchange this week, ERA said the cost of the clean-up and recovery process is not expected to affect its financial results this year.

ERA says it has a sufficient stockpile of processed uranium to meet all sales commitments in the first half of next year.

But it says the full financial impact for 2014 is still being assessed and will depend on a range of factors.

These will include the need to carry out repairs when it is allowed to recommence processing operations.

Meanwhile, the Australian Conservation Foundation (ACF) says a new study shows it will be difficult to rehabilitate the Ranger uranium mine site.

Operations at Ranger, which is located near Jabiru inside the boundaries of Kakadu National Park, are expected to end in 2021 when the mining lease expires.

A new report by international scientists shows uranium particles from mine sites spread further than initially thought through surrounding areas, making rehabilitation harder.

ACF spokesman Dave Sweeney says the report has ramifications for rehabilitation at Ranger and parts of Kakadu National Park.

"The uranium effectively hitchhikes its way with other particles out of particularly organically rich or wetland-style environments," he said.

"That has very significant implications for ERA's operations in Kakadu.

"Kakadu is world heritage listed, Kakadu is Australia's largest national park.

"[It is] a very high standard that ERA is going to have to meet.

"What this new report says is that rehabilitation is going to be harder, more complex and more costly than had been imagined."

ERA responded to the ACF claims with the following statement:

"ERA is aware of the potential of wetlands to remobilise uranium.

ERA and independent research providers have compiled a comprehensive body of research looking into the safe operation and progressive rehabilitation of the Ranger mine.

As a result of this work, ERA is not solely reliant on wetland mechanisms to ensure the safe release of surface water from the mine site.

Ranger mine is independently monitored by the Commonwealth Government’s Supervising Scientist Division.

In each of its annual reports, the Supervising Scientist has confirmed that the surrounding environment has remained protected.

Research and monitoring is overseen by several regulatory committees.

One of these committees is the Alligator Rivers Region Technical Committee (ARRTC), which oversees the nature and extent of research being undertaken to protect and restore the environment in the Alligator Rivers Region from any effects of uranium mining.

The ARRTC considers new findings and information that comes to hand.

The ARRTC also oversees the quality of research underpinning ERA’s closure plans.

The 13 ARRTC members include seven independent scientists nominated by the Federation of Australian Scientists and Technological Societies and six representatives of key stakeholder organisations, including the Supervising Scientist Division, Northern Territory Government, ERA, Northern Land Council, Parks Australia, and a non-government environment organisation.

Further to this regulatory oversight, ERA has significantly enhanced its water management capability in recent years.

In 2012 ERA and the Mirarr, represented by the Gundjeihmi Aboriginal Corporation (GAC), conducted a jointly facilitated independent expert review of the quality of surface water around the Ranger Project Area.

The Independent Surface Water Working Group consisted of representatives from ERA, GAC, the Supervising Scientist Division and the Northern Land Council.

The working group examined the impacts, monitoring and reporting of surface water flowing from the Ranger mine and in March 2013 released findings that the current surface water management and regulatory systems in place at Ranger mine are of a very high standard.

In addition, the working group identified 15 recommendations to ensure that the surface water management system continues to be best practice.

See summary via this link:

ERA is undertaking the progressive rehabilitation of the Ranger Project Area in consultation with stakeholders, including Traditional Owners and government regulators.

A Closure Criteria Working Group has been established to develop criteria for the long-term closure and rehabilitation of the Ranger mine.

Members of this group include representatives from Traditional Owners, the Northern Territory Government, the Commonwealth Government and ERA.

Please refer to the following.