The reporting procedure addresses incidents involving unplanned release of radioactive process materials, radioactive liquids or radioactive wastes associated with physical and chemical processing of uranium ores.
Date of incident: 2 April 2025
Date reported: 3 April 2025
Quantity: Approximately 62,000 litres
Description of incident
On 2 April 2025, approximately 62,000 litres (over an area approximately 4,400 m2) of barren lixiviant escaped from Four Mile East Wellfield 7 and was contained within the wellfield and road bunding.
Comments
The company reported no environmental impacts and no health, safety or radiological impacts to employees or members of the public. All contaminated material was collected and managed in accordance with site procedures.
The root cause of the incident was an operator error where the drain valve was not fully closed after replacing a filter bag at the Wellfield 7 filter skid. This allowed liquor to flow into the sump tank, triggering an alarm that was mistakenly treated as routine rather than indicating ongoing flow.
To prevent a recurrence, the following actions have been implemented: installation of additional high-level sensors on all drain tanks, automated flow shut-off systems installed on all filter skids and additional operator training.
Date of incident: 10 November 2023
Date reported: 11 November 2023
Quantity: Approximately 16,500 litres
Description of incident
On 10 November 2023, approximately 16,500 litres (over an area approximately 165 m2) of barren lixiviant escaped from Four Mile West 17 filter skid.
Comments
The company reported no environmental impacts and no health, safety or radiological impacts to employees or members of the public. All contaminated material was collected and managed in accordance with site procedures.
The root cause of the incident was incorrect fitting of a nylon tube causing injection solution (barren lixiviant) to escape. The solution filled the drip tray beneath the skid and the operator missed the drip tray alarm. To prevent a recurrence, a number of actions have been implemented, including an audit of all nylon fittings, demonstration of correct process for securing compression fittings, and a review of leak detection systems.
Date of incident: 27 January 2022
Date reported: 28 January 2022
Quantity: Approximately 15,000 litres (of which approximately 5,000 litres entered the undisturbed environment)
Description of incident
On 27 January 2022, approximately 15,000 litres of extraction mining solution spilled from the Four Mile West Wellfield 13 filter skid. Of this volume, approximately 5,000 litres flowed into an undisturbed environment including 2,000 litres entering a creek.
Comments
The company reported no environmental impacts and no health, safety or radiological impacts to employees or members of the public. All contaminated material was collected and managed in accordance with site procedures.
The root cause of the incident was an operator didn’t fully close a drain valve after replacing a filter bag at the Wellfield 13 filter skid. This resulted in liquor continuing to enter a concrete sump tank. The sump tank’s high level alarm then failed resulting in the sump tank overflowing into the surrounding wellfield and undisturbed environment.
To prevent a recurrence, a number of actions have been implemented, including the updating of competency certification of operators, testing and replacement of high level alarms, installation on secondary alarms, and installation of enhanced bunding around filter skids.
Date of incident: 22 to 26 January 2022
Date reported: 2 February 2022
Quantity: Approximately 9,000 litres (of which approximately 300 litres entered the undisturbed environment)
Description of incident
Between 22 to 26 January 2022, approximately 9,000 litres of barren mining solution (injection solution) spilled from a Four Mile West Wellfield 8 injector well. Of this volume, approximately 300 litres flowed into an undisturbed environment (i.e. creek).
Comments
The company reported no environmental impacts and no health, safety or radiological impacts to employees or members of the public. Soil samples were collected for analysis with results confirming negligible impacts. All contaminated material was collected and managed in accordance with site procedures.
The spill was a result of corrosion of a galvanised steel wellhead.
To prevent a recurrence, a number of actions have been implemented, including the replacement of the wellhead, full audit of other wellheads, a review of leak detection systems and revised wellfield access protocols during wet conditions.
