Radiation Protection Today - Winter 2022 Issue 4 | Page 5

Decontamina on Techniques

Anne Nisbet is Radiation Recovery Lead at the UK Health Security Agency , a member of the International Commission on Radiological Protection and has been a consultant to the Nuclear Energy Agency , the International Atomic Energy Agency and The National Council on Radiation Protection and Measurements .
Alex Jenkins is a decontamination expert at Sellafield Ltd with extensive experience of a wide range of decontamination techniques .
Decontamination is used widely in a range of settings , including nuclear decommissioning , healthcare , manufacturing , and for radiation and chemical emergencies . Decontamination techniques can reduce the risk of exposure to people to an acceptable level , return plant and equipment to service , and allow contaminated materials to be managed as lower category radioactive waste . This article
focuses on decontamination of objects or the environment and excludes decontamination of people . Much of our learning comes from previous decommissioning of legacy sites or clean-up of contaminated pieces of equipment , buildings or roads at facilities holding nuclear material .
Within an urban environment , there are many structures and surfaces that may become contaminated , e . g . critical national infrastructure , roads , rail and transport hubs , buildings , retail outlets , residential properties , parks , and gardens . Surface materials include brick , concrete , tarmac , steel , and glass as well as soils and vegetation . Within the countryside , soils and vegetation , grazing livestock , trees , rivers , and lakes are susceptible to contamination following an atmospheric or aquatic release .
Many decontamination techniques are effective in different environments and on different surfaces . Performance is highly dependent on contaminant type , its chemical and physical characteristics , depth of penetration into a surface , and properties of the surface material itself . Before implementing any form of decontamination , it is crucial to restrict access and contain the contamination to prevent further spread .
Physical decontamination , involving either
Temporary storage site for decontamination waste , Japan ( photo Temporary courtesy of waste Carol site Attwood , Japan)
Radiation Protection Today Winter 2022 5