Failure of a butt weld joint in the high-density polyethylene (HDPE) evaporation pond return liquor pipeline (EPRL) west of the Solvent Extraction Area resulting in leakage of acidic liquor. The spill was fully contained within the Tailings Retention System (TRS) pipeline corridor. The pipeline was shut down and arrangements made to clean up the spill and repair the pipe joint.

There was no radiation exposure to the workforce and no impact on members of the public. There was no serious or material environmental harm caused or threatened and no impact to native vegetawtion.

Ammonium diuranate was dislodged during maintenanace activities of structural shell and cladding in the Precipitation Area of the processing plant. Small amounts were noted on the footpath and roadway outside the bunded area.

All of the visible material was cleaned-up. Procedures have been amended to ensure no further potential for similar incidents to occur. Radiation monitoring by BHP Billiton indicated no risk to human health or the environment.

In evaporation pond 3 B a tear was found at the weld between the HDPE 'boot' that joins the liquour return outlet pipe from the tailings storage facility to the HDPE liner of the evaporation pond. Liquor is believed to have accumulated betweent he HDPE geomembrane liner ane the underlying compacted low permeability clay liner. Liquor that accumulated under the HDPE liner was observed to be re-entering the evaporation pond through a second tear located 1m above the first tear.

There was no radiation exposure to the workforce during the spill and no impact to members of the public. No serious or material environmental harm caused or threatened. Liquor which has collected between the HDPE liner and the compacted clay liner will be pumped out and the liner repaired.

Failure of the butt weld joint in the HDPE evaporation pond return liquor pipeline (EPRL) along the East side of TSF cell 2/3 ramp resulting in leakage of acidic liquor. The spill was fully contained within the TRS pipeline corridor. No liquor discharged out of the bunded area. The pipeline was shut-down and arrangements made to clean-up the spill and repair the pipe joint.

There was no radiation exposure to the workforce and no impact on members of the public. There was no serious or material environmental harm caused or threatened and no impact to native vegetation.

A small leak developed in tailings line 1 adjacent to the northeast corner of Evaporation Pond 2 resulting in tailings slurry spray outside the pipeline corridor onto a nearby undisturbed dune. Less than 0.1m³ of slurry was discharged outside the bunded area. The tailings pipeline was shutdown and arrangements made to clean-up the spill.

No personnel had any ingestion or inhalation exposure to the material and there were no injuries associated with the spill. There was no radiation exposure to the workforce during the spill. There was no radiation impact on members of the public. There was no serious or material environmental harm caused or threatened.

A spill of approximately 250m³ of tailings occurred when a tailings line failed causing tailings slurry to spray onto southern wall of Tailings Cell 4. The spilt tailings were contained within the bunded tailings pipeline corridor and associated drainage area.

No personnel had any ingestion or inhalation exposure to the material and there were no injuries associated with the spill. No radiation exposure to the workforce during the spill. No radiation impact on members of the public. No serious or material enviornmental harm caused or threatened as the spill was wholly contained.

Whilst relocating pipework, a small amount of solid ammonium diurinate was spilt outside the bunded area resulting in a small amount of solids being deposited over several metres.

No personnel were exposed to the material and there were no injuries associated with the spill. No radiation exposure to the workforce. No radiation impact on members of the public. No serious or material enviornmental harm caused or threatened as the spill was wholly contained.

Approximately 80m³ of tailings leach tank feed discharged into a bunded area causing 50m³ of material to overflow into the processing plant area.

Cleanup consisted of returning the material inside the bund to the process and material outside the bund to the tailings system. There was no material harm to either the environment or the employees.

Liquor containing ammonium diuranate (ADU) escaped from a pressurised precipitation tank. Released ADU was contained within the bunded area except for approximately 20 litres of liquor containing ADU which went outside the bund onto a compacted gravel area. All material was contained within the immediate area.

The spilt material was cleaned up and either returned to the process or disposed of within the tailing storage facility. The incident did not cause any environmental harm or injury to personnel.

Ammonium diuranate (ADU) was detected in sub-potable water when ADU was noticed as a yellow coating on the dried surfaces of washed shipping containers. The ADU entered the sub-potable system following the connection of a hose to a pump within the precipitation area.

The discharge was fully within the plant area and the operation’s tertiary containment system. The incident did not cause any environmental harm or injury to personnel. As the sub-potable water system is isolated from the potable water system, there was no radiological dose to any worker, member of the public or the environment.

Approximately 70m³ of tailings escaped into the tailings pipeline corridor from a pipe failure. The process was shutdown and repairs carried out. No material escaped beyond the bunded area and there is no impact on the general environment or any personnel.

All the material is being recovered and will be disposed of in the tailings retention system. No personnel had direct contact with the tailings and the incident did not cause any environmental harm or injury to personnel.

Approximately 270m³ of tailings escaped into the tailings pipeline corridor from a pipe failure. The process was shutdown and repairs carried out. No material escaped beyond the bunded area and there is no impact on the general environment or any personnel.

All the material was recovered and disposed of in the tailings retention system. No personnel had direct contact with the tailings and the incident did not cause any environmental harm or injury to personnel.

A flexible section of pipe failed causing some 30m³ of tailings material to be discharged beyond the secondary containment area but remained within the tertiary containment. The fluid was essentially barren and no material entered the general environment. The pipe has now been replaced.

All available excess liquor was recovered. No personnel had direct contact with the liquor and the incident did not cause any environmental harm or injury to personnel.

Approximately 50 m³ of liquor from the solvent extraction area overflowed the HDPE lined scuttle pond into an adjoining unlined overflow pond. This pond was designed for temporary storage in the event of an unplanned incident.

All excess liquor was recovered from the pond. No personnel had direct contact with the liquor and the incident did not cause any environmental harm or injury to personnel.

Approximately 70 m³ tailings leach overflowed a bund containing the Tails Leach Tank No. 4. The tank was being drained at the time. No material left the engineered controls of the plant perimeter.

Work commenced immediately to recover the spilt liquor. No personnel had direct contact with the liquor and the incident did not cause any environmental harm or injury to personnel.

A small quantity of uranium oxide was released into an unbunded area south of the Calciner building.  This occurred when a valve was left open on a diesel tank, which resulted in diesel overflowing the diesel tank bund and flowing towards the packing shed sump.  The spilled diesel caused the packing shed sump to overflow, mobilising the small quantity of uranium oxide beyond the bunded area. The volume of diesel which overflowed the bund was 1000 litres.

All of the uranium concentrate was recovered and disposed of in the Tailings Storage Facility. It has been assessed that there was no significant environmental impact, nor was there any occupational health or safety impact.

28m³ of tailings slurry was released into an earthen bund containing valve station #4. A tailings line was recommissioned following a planned shutdown for maintenance on the tailings line. Approximately 12m³ overflowed the bund into a previously disturbed area consisting largely of saltbush that had revegetated naturally.

All of the tailings slurry was recovered and returned to the Tailings Storage Facility. It has been assessed that there was no significant environmental impact and no occupational health or safety impact. WMC will review standard operating procedures to prevent a reoccurrence.

Slurry feed escaped from a rubber-lined steel elbow on the feed line located at the SE corner of Cell 2 within the Tailing Retention System. The spill resulted from the failure of the rubber lining and subsequent corrosion of the steel pipe.

All of the slurry feed was contained in a bunded area. All residual slurry was returned to the Tailing Storage Facility (TSF). There was no environmental harm or injury to personnel and no material escaped beyond the containment bund.

Evaporation liquor back flowed through an isolation valve, a non-return valve and through a pump located at Evaporation Pond 1 (EP1). The pump had been drained for maintenance. This work was completed on 8/9. The back flow occurred when evaporation liquor was being pumped from EP 3 to EP 2. The leakage was detected on 10 September 2004 during a regular inspection of the area.

The spill was contained within the containment bund surrounding the EP1 pump station. The liquor was cleaned up and returned to the Evaporation Pond. No environmental harm or injury to personnel. WMC will improve their daily inspection and monitoring procedures to ensure prompt detection of leaks. Pump start-up procedures will also be improved.

A spill of pregnant liquor solution (PLS) containing 0.014% uranium occurred when a weld failed in a high density polythene pipe. The pipe was located in the Hydrometallurgical Process Plant area.

The spill was contained within the process plant area. The material was cleaned up and returned to either the process circuit or tailings storage facility. No environmental harm or injury to personnel.

Tailings leaked under pressure as a result of a small tear in a tailings delivery line located near SE corner of tailings retention system No. 1. 2m³ sprayed beyond the bund surrounding the tailings pipeline corridor.

No injury to personnel and minimal environmental impact. A small area of vegetation was affected by the sprayed tailings. The affected area will be cleaned up as per standard procedure.

Raffinate containing 0.0043% uranium discharged to the ground in the process plant area due to failure of a fibreglass pipe in the hydrometallurgical area.

The spill was contained within the process plant area. The material was cleaned up and returned to either the process circuit or tailings storage facility. No environmental harm or injury to personnel.

Liquor containing 0.26% copper and 0.022% uranium overlapped the eastern wall of Evaporation Pond 4B as a result of wave action caused by strong winds.

The escaped liquor was contained by an external bund. The material was cleaned up using vacuum trucks and returned to the tailings storage. No liquor escaped into the undisturbed environment.
Whilst the levels in the pond were within the specified freeboard limits, these limits will be reviewed. No environmental harm or injury to personnel.

Pregnant liquor solution (PLS) containing 0.029% uranium overflowed the bund surrounding #1 Clarifier system, following overflow of clarifier tanks.

The spill was contained well within the process plant area and was contained within tertiary containment. The material was cleaned up and returned to the process circuit or tailings storage facility. Gamma dose measurements taken before clean up operations were completed recorded rates at background levels, i.e. no occupational or environmental hazard. No environmental harm or injury to personnel.

Tailings solids and liquor containing approx 0.03% uranium flowed into the bunded tailings pipeline corridor adjacent to Cell 1 of Tailings storage facility. Caused by failure to seal an isolation valve subsequent to routine maintenance.

The spill was totally contained within existing bunds. No environmental harm or injury to personnel.

Spill of acidic raffinate liquor containing 172ppm uranium due to a pipe failure in the hydrometallurgical area.

The spill was contained well within the process plant area within tertiary containment. The material has been cleaned up and returned to the process circuit. Gamma dose rate measurements taken before and after the clean up confirm no occupational or environmental hazard.