Contaminated Land Monitoring
Sheila Liddle is an RPA and RWA with over 30 years ' experience in the nuclear and non-nuclear sectors . In this issue of Radiation Protection Today she gives an overview of the process of contaminated land monitoring .
Contamination can mean many things to many people . It can comprise “ hot spots ” of contamination in buildings or land , dispersed contamination of land , water or sea as a result of historical or recent discharges , or contamination from incidents such as fires and explosions . It can also consist of particles of alpha emitters in the lungs or in wounds .
This article focusses on the monitoring of radioactive land contamination , although many of the principles are equally applicable to non-radioactive contamination . A separate article on the monitoring of contamination following an incident involving a release of radioactive material will be included in a future issue of Radiation Protection Today .
Prior to monitoring for land contamination it is important to conduct an historical desk study to collate whatever environmental records are available relating to the types and quantities of radionuclides used or disposed of on the site , when this took place ( since the effects of radioactive decay and ingrowth may need to be taken into account ), locations of use and discharge , and the pathways by which these radionuclides may have moved since release . The use and discharge of radioactive substances on larger sites will often have been recorded over many years , although records may be missing or incomplete for older sites or those which handled naturally-occurring radioactive materials ( NORM ). In the majority of cases , the areas where contamination is likely are where drainage systems and pipework ran
and discharged , in building materials such as laboratory benches with sinks , ventilation ducting , areas where radioactive materials were stored , and where waste is known to be dumped or buried . Particularly on older sites , there may be areas where contaminated items were stored outside , e . g . corroded metal waste bins , irradiated items , or leaking drains . In some places buildings may have been demolished and contamination spread .
High-profile examples of contaminated sites are Dalgety Bay in Fife , where erosion of an old landfill led to the deposition of radiumluminised artefacts onto the shore , or Dounreay and Sellafield where fragments from fuel processing entered the drainage systems resulting in small radioactive particles being washed up on beaches .
Dalgety Bay , Fife , Scotland
When applying for an Environmental Permit or Pollution Prevention and Control ( PPC ) authorisation for an industrial process involving the handling and discharge of radioactive materials , the applicant is required to carry out a survey to establish baseline contamination levels . When activities cease and the holder wishes to surrender the permit , another survey is required to demonstrate that the land has not been further contaminated , or that contamination resulting from the activity has been identified and decontaminated . Developers are also required to carry out contamination surveys when applying for planning permission to develop potentially contaminated sites .
Radiation Protection Today Spring 2024 21