The ALARA principle, standing for 'As Low As Reasonably Achievable', is a cornerstone of radiation protection philosophy globally. It mandates that all exposures to ionising radiation, whether occupational, public, or medical, should be kept as low as is reasonably achievable, taking into account economic and social factors. This proactive approach aims to minimise radiation doses even below established regulatory limits, reflecting a commitment to continuous improvement in safety standards.
The International Atomic Energy Agency (IAEA), through its Basic Safety Standards (GSR Part 3), provides comprehensive guidance on the application of the ALARA principle. The IAEA defines optimisation of protection and safety (which embodies ALARA) as the process of ensuring that "the likelihood of incurring exposures, the number of people exposed and the magnitude of individual doses are all kept as low as reasonably achievable, economic and social factors being taken into account." This definition highlights a holistic approach, considering not only individual dose but also collective dose and the probability of exposure.
ALARA is not a standalone concept but is intrinsically linked to the three fundamental principles of radiation protection, which are:
Implementing ALARA requires a systematic approach, often involving dose assessment, risk-benefit analysis, and continuous review of operational procedures. It promotes a safety culture where minimising radiation exposure is an ongoing objective. This involves:
The ALARA principle is dynamic, evolving with new technologies, scientific understanding, and operational experience. It underscores a preventative and protective behaviour aimed at minimising any detrimental effects of ionising radiation.