In November 2000, a worker set off a radiation detector on his way into work at a French nuclear power plant. Fearing that the worker might have somehow been contaminated at the plant, a thorough check for 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 cobalt.
Fortunately, an investigation by nuclear regulatory authorities around the globe did not find any similar watches in distribution. But had one contaminated watch not been detected at a 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 or make their way into untrained hands, the consequences can be equally far-reaching, and unfortunately even deadly.
Among its many activities to improve the safety of sealed sources, the IAEA has been investigating the root causes of major accidents since the 1980’s and publishes findings so that others can learn from them. There are growing concerns today about the possibility that an insecurely stored source could be stolen and used as a radioactive dispersal device. To improve both safety and security, information needs to be in the hands of those whose actions and decisions can prevent a source from being lost in the first place.
It is hoped that this booklet will provide those using sources in medical settings with this information and, thereby, reduce accidents and injuries from and improve security of sealed radioactive sources.