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Lessons to be learned

The following are but a few of the accidents that have occurred over the last 20 years when lapses in good practice, human error, or lack of knowledge have resulted in serious injuries and deaths. A review of the root causes of these accidents reveals a worrying similarity.

Severe radiation accident in Turkey

In 1993 in Ankara, Turkey, three disused cobalt-60 tele-therapy sources were packaged for re-export to the United States. The sources were not exported immediately, but were stored without the permission of the regulatory authority at the company’s premises. Over time, two of these packages were taken to Istanbul and eventually transferred to empty premises that were not secure.

In November 1998, these premises were sold, and the new owners sold the packages as scrap metal to two brothers. By December 1998, the brothers had taken the packages to the family home and began dismantling the protective containers over a period of a few days, until they and others became ill with nausea and vomiting. Over a period of about two weeks, it seems that pieces of the dismantled containers and at least one unshielded radioactive source were left in a residential area before being taken to a local scrapyard.

By the time doctors suspected exposure to radiation, and not food poisoning, was the cause, a total of 18 persons were admitted to hospital. Ten of these persons had symptoms of severe radiation syndrome. Five of these had to be hospitalized for 45 days. Authorities recovered one source at the scrapyard, before it was melted down. The second source, reported to be in one of the packages, has not been recovered to this day.

Investigations found that there were several contributing factors, including inadequate security over the sources and inadequate periodic inventory checks. These were the main factors that allowed the unauthorized sale of the packages to take place. Lack of recognition of the radiation symbol (trefoil) on the source by those trying to dismantle the source was also an important factor.

Transfer of the sources to a qualified and licensed waste operator would have prevented such accident.

Contamination in Spain

In May of 1998, an unnoticed caesium-137 source was melted in an electric furnace of Acerinox, a stainless steel factory located in Los Barrios, Spain. As a consequence, the vapours were caught in a filter system resulting in contamination of the 270 tonnes of dust already collected. The dust was removed and sent to two factories for processing as a part of their routine maintenance. One factory received 150 tonnes that they then used in a marsh stabilization process, increasing the mass of the contaminated material to 500 tonnes and contaminating the marsh. The first warning of the event was in early June from a gate monitor that alarmed on an empty truck returning from delivering the dust. Several days later elevated levels of caesium-137 were also detected in Southern France and Northern Italy.

The radiological consequences of this event were minimal, with six people having slight levels of caesium-137 contamination. However, the economic, political and social consequences were major. The estimated total costs for clean up, waste storage, and interruption of business at the affected companies exceeded $25 million US dollars.

The root causes of this accident were the loss of control over the cesium source and the fact that the steel factory did not detect the lost source in the load of scrap metal when it was received.

Multiple death in Thailand

In February 2000, a serious accident occurred in Samut Prakarn, Thailand, which resulted in death, injury, and widespread concern. A disused cobalt-60 teletherapy source was being stored, apparently without knowledge or permission of the regulatory authority, in insecure outdoor premises normally used for storing new cars. Two local scrap collectors allegedly bought some scrap that included the source and took it home to dismantle and resell. They later took the partially dismantled teletherapy head to a junkyard where an employee cut open the protective shielding with an oxyacetylene torch. Those who had been nearby when the protective shielding was cut began to experience nausea and vomiting. Those who had touched some parts of the exposed metal began to suffer burn-like injuries. Their symptoms worsened over a period of days. It was not until about 10 days later that some began to seek medical treatment for their symptoms.

By the time medical authorities reported a suspected radiation accident, some 17 days had passed since the source was exposed. The accident resulted in radiation injuries to 10 people of whom three died within the first two months despite medical treatment. Approximately 1870 individuals living within 100 metres of the junkyard were exposed, with many seeking medical attention. The Ministry of Health is continuing to monitor about 258 of these individuals who live within 50 metres of the junkyard for possible long-term effects from the accident.

Investigation revealed that the root cause of the accident to be that the disused source was not stored securely. However, as in the previous example, if those who acquired the teletherapy head as scrap had recognized the radiation symbol (trefoil), they might not have tried to dismantle it and would not have been exposed to radiation.

Reducing Risks in the Scrap Metal Industry

Lessons to be learned

Severe radiation accident in Turkey

Contamination in Spain

Multiple death in Thailand