General background for both sites
South Australia has a history of mining radioactive ores and processing uranium concentrates, dating back as far as the 1800s. Sites where these activities occurred were operated and decommissioned in a manner consistent with standards of the day (in cases where there were standards) and left residual hazards.
Recognising the need to ensure ongoing protection of the environment and the safety of communities, regulatory regimes for radiation were established. They aim to protect the environment and people and these sites have been subject to varying degrees of ongoing review and regulatory oversight. This is to ensure protection of the public and management of the sites consistent with state, national and international standards.
The original Radium Hill project included the establishment, operation and decommissioning of the Radium Hill underground uranium mine and the Port Pirie uranium treatment plant. This project was commissioned and operated by the Government of South Australian to satisfy a contract signed by the Commonwealth and State government with the UK-USA Combined Development Agency for delivery of uranium over a seven-year period.
Radium Hill mine
The Radium Hill former uranium mine is located 40 kilometres southwest of Cockburn in South Australia and approximately 110 kilometres from Broken Hill. Uranium bearing ore was discovered at the site in 1906.
The site was initially mined intermittently by private companies from 1909 to 1931, when ore was first sent to Sydney then later to Dry Creek South Australia to produce radium.
Between 1952 and 1961 the principal mining activities were undertaken by the South Australia Government. During this campaign the ore was mined using underground methods and crushed onsite to produce a uranium ore concentrate. The concentrates were then sent via rail to Port Pirie for chemical extraction of the uranium. A township for 1100 people was established 2 km northwest of the mine to accommodate the workforce and their families. Upon closure the site was abandoned, accesses to mine workings were blocked and infrastructure was removed in accordance with the environmental standards of the day.
In 1981 following a reassessment of the site, further rehabilitation was undertaken and included additional backfilling of old mine openings and covering of the tailings impoundment. At the same time, the site was also established as a repository for low-level radioactive waste materials, primarily to facilitate the clean up of contaminated soil held in Thebarton in the Adelaide metropolitan area.
The Government of South Australia's Mineral Resources Division has retained management responsibility of the site for the government, and maintains a continuing watch on the site with radiological advice and assistance from the Radiation Protection Division of the Environment Protection Agency (EPA).
The refractory and non-acid forming nature of the ore and the fact that the process plant did not use chemicals to alter ore chemistry means the ore remains chemically stable and poses little risk to soil and water.
There are localised areas with some chemical or metals contamination where ecological risk exceeded screening levels for flora and soil invertebrate. However impacts on higher native or domestic species are unlikely given their larger home ranges.
The Mineral Resources Division is currently developing a long-term management strategy for the former site.