Introduction
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.
| How
can such losses be prevented? |
| How
can contaminated material be detected before it makes its way
into consumer or other products? |
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.