Radioactive waste
Radioactive waste is generated wherever nuclear materials such as plutonium, uranium and thorium are handled.
Nuclear materials have lots of uses – electricity production, weapons, the treatment of cancer and other medicines, sources for industry, weights in aeroplanes and so on.
All of these uses generate radioactive waste, from the extraction of uranium in the ground through its processing, use and subsequent recycling or disposal. At each stage, the nuclear material can contaminate equipment, vehicles, soil, clothing, containers, water and air. All of this becomes radioactive waste.
The waste is categorised according to its hazard. The hazard can vary greatly. Some contamination emits radioactivity that is lower than we encounter every day in nature, such as from sunlight, rocks and foodstuffs. At the other end of the scale, some types of waste are so dangerous to human health they must be shielded or sealed for a very long time.
Radioactive waste was generated at Dounreay as soon as the first nuclear materials were delivered to the site in the 1950s.
Based on what was known about radioactivity at the time, the scientists concluded that a lot of lower activity waste could be disposed of in the sea, air and ground, while the higher activity waste would be stored until a suitable treatment developed.
Over the next few decades, as scientists learned more about the effects of radioactivity, the limits on disposal progressively tightened and better standards developed for the treatment and storage of waste.
Higher activity wastes accumulated at Dounreay in stores and underground disposal facilities, such as the shaft. These facilities are being cleaned out, the wastes recovered, sorted and repackaged to modern standards. In addition, the clean-out and dismantling of the redundant research facilities will generate more waste, all of which needs segregated according to its hazard and sorted in a condition that makes it safe for storage or disposal.
Throughout its history, the disposal of radioactive waste from Dounreay has been regulated by successive Government departments and agencies. Today, the disposal of radioactive waste is regulated by the Scottish Environment Protection Agency, while the storage of radioactive waste is regulated by the Nuclear Installations Inspectorate of the Health and Safety Executive.
Artist's impression of proposed new treatment plant and store for intermediate-level waste
Typical intermediate-level waste stored loose in a drum
Drums of low level solid waste being processed in the WRACS facility
Hazardous intermediate level solid radioactive waste is handled remotely, with workers protected from radiation by thick walls
Drums of low level solid waste are reduced to a fraction of their size using a supercompactor
