Software Bug Blamed in Radioactive Spill

Event Year: 2002 Reliability: Likely But Unconfirmed
Country: Australia
Industry Type: Mining

A pipe burst at the uranium mine and in about four minutes 62,000 litres of radioactive liquid escaped from the pipe into an area around the uranium processing plant. The leak was an acid solution containing a mixture of chemicals including innocuous salts, as well as radioactive and toxic chemicals. The most significant of which was uranium. There had been a computer error and human error had caused the accident. A chain of events contributed to the accident.
- Loss of power to the computer system that controls and monitors plant functions.
- Backup power was cut off as a result of what appeared to be failure to follow correct procedure during maintenance. (This has been challenged by Heathgate Resources, the owners of the mine).
- Incorrect computer programming resulted in pumps continuing to operate after power to the control system had been lost. - Pressure switches failed to operate and shut down the pumps.
- Piping failed at well below its rated pressure. (#3)