FUTURE PROSPECTS AND CONCLUSIONS

From the time the material in this paper was originally presented (2013) to the date of publication (2016) much has happened in the NT’s uranium mining industry. The failure of a leach tank at RUM in December 2013 led to a six-month shutdown enforced by the regulator;

this severely tested the relationships between all stakeholders and had significant commercial ramifications. The failure of ERA to obtain support from both its major shareholder and the Aboriginal Traditional Owners has resulted in the shelving of the Ranger Three Deeps project which in turn has led to the current situation that operations will now cease in 2021 and remediation planning will be targeting 2026 as the completion date for all significant works. In other parts of the NT some of the smaller uranium prospects are not moving development forward due to the state of the current and predicted markets.

But, the same time not all the news about uranium is negative. Cameco of Canada has made an interesting initial discovery in West Arnhemland and are progressing their studies and activities steadily. Some minor players are continuing to explore in the more prospective areas saying that they intend to be ready when the market changes direction again. This could be within 5–

10 years and as most new uranium prospects seem to be taking about 10 years to reach the operational stage such planning may not be too far from a practical reality.

It is more than likely new prospects will be found and new mines will develop, but it is not going to be soon. The remediation and post-closure stewardship of RUM will be a process that will involve many people from the uranium mining industry for quite a few years to come, be they regulators, operators or other stakeholders. The nuclear ‘renaissance’ of the early 2000s and 2010 has passed by and in a post-Fukushima world the community in many areas is slowly returning to the idea that nuclear power has a place as a part of a lower carbon future for energy

programmes. That means that uranium mining will also have a role to play going forward and the NT intends to maintain its position in that part of the industry.

ACKNOWLEDGEMENTS

The author wishes to thank his colleagues in the DME and other professional associates for their counsel and discussions during the preparation and internal refereeing of this paper.

REFERENCES

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Rehabilitating 60’s uranium mines to 2000 standards”, SWEMP 2000 (Proc. Conf., Calgary, Canada, 2000), Balkema, Netherlands (2000).

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[4] ALLEN, C.G., VERHOEVEN, T.J., Final Project Report — The Rum Jungle Remediation Project, Northern Territory Department of Mines and Energy, Darwin, Australia (1986).

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AN OVERVIEW OF IN SITU LEACH URANIUM MINING

Following early experimentation and production in the 1960s, in situ leach (ISL) mining has become one of the standard uranium production methods. Its application to amenable uranium deposits (in certain sedimentary formations) has been growing in view of its competitive production costs and low surface impacts. ISL uranium mining has gained widespread acceptance and its share in total uranium production grew from 13% in 1997 to 46% in 2011. The IAEA has prepared an overview report to show how ISL experience around the world can be used to direct the development of technical activities, taking into account environmental considerations and an emphasis on the economics of the process, including responsible mine closure. With this report Member States and interested parties will have more information to design and efficiently and safely regulate current and future projects, with a view to maximize economic performance and minimize negative environmental impact. Highlights of the report’s findings are provided here, with a summary of the IAEA’s involvement in ISL over recent decades and some discussion on ISL remediation issues.

1. INTRODUCTION

In situ leach (ISL; also called in situ leaching or in situ recovery, ISR) mining has become one of the standard uranium production methods, following early experimentation and production in the 1960s. In 1997 the percentage of ISL operations compared to other conventional forms of uranium mining was 13%; by 2009 it had grown over 30%, reaching 46% in 2011. In the past, the method was applied mainly in Ukraine, the Czech Republic, Uzbekistan, Kazakhstan, Bulgaria and the United States of America (USA). Recently it has continued to be used in Kazakhstan, Uzbekistan and the USA; it has also been applied commercially in Australia, China and the Russian Federation, with small operations or experiments elsewhere.

In the IAEA report discussed here [1], ISL is referred to as a special form of solution mining applied to ore deposits in sedimentary, saturated aquifers by using injection and extraction wells from the surface. Mining solution — acidic or alkaline, depending on the mine — is circulated through the orebody, dissolving uranium and some other mineral constituents but leaving the bulk of the aquifer material behind. Uranium is recovered from the mining solution in a processing plant, and the solution reconditioned and recirculated through the orebody. This process is repeated many times before a particular block of ore is mined-out. The report and this paper do not include detailed consideration of any kind of leaching in unsaturated formations or of block leaching in underground mine works (e.g. [2]).