Routine Radiological Surveys
Belinda Kershaw worked at the Harwell site for 36 years in various capacities , as a Radiation Protection Adviser , and in facility and waste operations . She retired in 2020 .
A radiological survey assists in protecting workers and the public against external and internal radiation exposures resulting from routine and special operations , and incidents . Control of exposures during special operations and incidents requires dedicated monitoring protocols . The routine survey has a role in maintaining radiological control in daily operations .
What is a routine survey ? A routine survey is a systematic set of measurements made regularly in order capable of determining the level of contamination and radiation , allowing evaluation of radiological conditions to check that controls and protections have not deteriorated or failed .
Monitoring is a regulatory requirement which ensures regulatory limits are adhered to , breakdowns in controls or systems are indicated , and changes in radiological conditions are detected .
It is worth noting that the introduction of activity in air monitors , sensitive and reliable personnel monitoring and gamma alarms have greatly aided the routine survey in the early identification of breakdowns in controls .
The routine survey will consist of :
• Radiation dose rate surveys Radiation monitoring is carried out using an instrument measuring the dose rate . This is generally a straightforward element of the survey , as sources and types of radiation should be well defined in an area .
• Airborne contamination surveys Airborne contamination monitoring is carried out during the working session or 24 hours / day . Sampler location , sampling rate and duration are determined based on the potential for airborne release , radionuclide fingerprint , and the air quality ( e . g . filtered plenum intake ).
• Surface contamination surveys These require consideration of the fundamental principles of contamination control :
• Physical containment ( e . g . fume cupboard , glove box , cell )
• Confinement to a specifically designated location , segregation and definition of demarcated areas with controls appropriate to potential hazards
• Cleanliness requiring radioactive material to be kept at source , and the prevention of contamination spread .
Controlling the spread of contamination relies heavily on monitoring , decontamination and waste disposal . Routine survey monitoring can enable lower-level releases of contamination to be identified before they become a bigger problem .
Routine monitoring is required in radiologically designated areas , buffer areas and adjacent areas . Equipment in adjacent areas ( e . g . counting equipment ) can be compromised by the spread of contamination , causing spurious results .
Radiation Protection Today Spring 2024 19