In November 2000, a worker set off a radiation detector on his way into a French nuclear power plant. Fearing that the worker might somehow have been exposed at the plant, a thorough check for radioactive contamination was made. The results sparked concern not just in France, but also around the world. The worker himself was not contaminated, but parts of the metal bracelet of his watch were found to be radioactive. Further analysis revealed that the steel pins in the bracelet were contaminated with traces of cobalt-60, a radioactive form of the metal cobalt.
The watches were imported from Hong Kong, where they had been assembled. The source of contamination was later traced to a small plant in China that had provided steel for the bracelet pins. It is thought that a teletherapy head, a device used in radiation treatment of cancer patients, had been inadvertently melted down as scrap at this plant. In France, the watches were sold through a large, international department store, raising fears that the watches could also have been on sale in Europe, Asia, and South America.
Fortunately, an investigation by regulatory authorities around the globe, did not find any further watches in distribution. But had one contaminated watch not been detected at the French nuclear plant, many people might have been exposed to low doses of radiation. The one hundred kilograms of contaminated steel found at the plant in China might never have been discovered and could have been used to make other consumer products.
Sealed radioactive sources are used widely in medicine, industry, and agriculture. When used as designed, these sources have far-reaching benefits. When these sources are lost, misplaced, or stolen, they can have equally far-reaching, and unfortunately even deadly, consequences.
In most countries, radioactive materials and activities that produce radiation are regulated. Those working with sealed radioactive sources are required not just to have proper credentials, but also the needed training and support to deal with unexpected circumstances that may arise when a source is used. Despite these measures, accidents continue to occur. Serious or life threatening injuries involving sealed sources have been reported to the International Atomic Energy Agency (IAEA).
Among its many activities to improve the safety and security of sealed sources, the IAEA has been investigating the root causes of major accidents since the 1980s and publishing the findings so that others can learn from them. This information needs to be in the hands of those whose actions and decisions can reduce accidents by preventing a lost source from making its way into scrap metal. It is hoped that this booklet will improve the awareness of those involved in collecting, dealing, importing, or melting scrap metal of the potential problems and, thereby, reduce accidents and injuries from sealed radioactive sources.