TAILINGS - A CRUCIAL BUT UNRESOLVED MATTER

A major concern about nuclear energy is disposal of radioactive waste material. This applies to the mining and milling stage of nuclear energy as well as later stages of the fuel cycle. This concern is expressed vividly by Friends of the Earth Sydney:

No matter how uranium is mined, there will be radioactive contamination of the environment . . . Uranium tailings constitute the greatest long-term impact . . . uranium tailings will remain a significant impact for periods between 300,000 and 760,000 years. (S 40, Part 2, 30)

Uranium tailings contain 80% of the level of radioactivity of the original ore as a result of the presence of uranium decay products such as Thorium-234, Thorium-230, and Radium-226. This radioactivity will be a potential problem requiring containment for hundreds of thousands of years, though current uranium mill tailings containment arrangements cover usually no more than 200-500 years. (S 40, Part 2, 32)

The core of the problem of tailings, as FoE Sydney see the matter, is that "uranium mines have to process vast quantities of ore in order to be able to produce relatively small quantities of yellowcake" (ibid.).

The size of the problem posed by tailings may be found in the 1988-89 report of the then Supervising Scientist, Mr R.M. Fry. He observed that at the end of mining orebodies #1 and 3 at Ranger, as much as 40-45 million tonnes of tailings will have been produced: "Almost all of the radioactivity from the original orebodies will be contained in the tailings, and the half-life of the longest-lived daughter of uranium, Th230, will ensure that a potential health hazard remains for several hundred thousand years."

The Committee, whilst not necessarily sharing the more pessimistic forebodings about management of tailings, nonetheless views tailings management as among the most serious challenges facing uranium miners and, indeed, the entire nuclear energy industry in the future. It will also continue to be a major preoccupation for regulators and scientists as well.

There are several considerations relevant to the matter. In the first instance, and illustrative of the dynamics of improvement in mining generally and uranium in particular, tailings management and rehabilitation are now actively part of mining. As the state of mines in Australia's first phase of uranium mining demonstrates, in the first two decades after the end of the Second World War rehabilitation was manifestly neglected. Mines, once they had yielded their product, were abandoned.

The unfinished story of Nabarlek, notwithstanding the scepticism of some observers, is an illustration of a different philosophy of mining, one which recognises that it is a temporary form of land use. In both the planning and the financing of the mine, rehabilitation is part of the full management of the project. And this means, above all, management of tailings. The Committee believes that an effective plan for managing tailings must be a prerequisite for the issue of any licence to mine.

It also underlines the importance of research. Research is integral to processes of constructive regulation of mining and to minimising the impact of mining activity upon the environment.

The comparison of Rum Jungle and Nabarlek shows how much progress there has been in the past three decades. Our conclusion, shared by the entire Committee with varying degrees of optimism, is that the research endeavour must be maintained. This has influenced our views on the role of the Supervising Scientist which forms the subject of the next chapter and our view of the value of transparency of research whether it is in the hands of governments or mining companies.  

Ranger - Tailings Dam

Olympic Dam Operation - Tailings Storage Facility