Abstract
<jats:p>Operational quantities are essential for assessing external exposure to ionising radiation and supporting the optimisation of individual protection. ICRU Report 95, developed jointly with the ICRP, proposes a new framework that aligns operational quantities with the phantoms used for protection quantities, aiming to improve accuracy and consistency in radiation protection. However, Member States and industry stakeholders have noted gaps in information on the practical, regulatory and financial implications of this shift. To support informed decision-making, the IAEA has developed this TECDOC, offering clear technical guidance and practical insights on evaluating the impact of the redefined quantities and identifying possible mitigation measures. It highlights considerations for monitoring systems, calibration, standardisation, regulatory processes and training. Developed through an IAEA Technical Meeting and multiple Consultancy Meetings, the TECDOC brings together diverse stakeholder perspectives to help Member States objectively assess costs and benefits when considering adoption of the proposed new approach.</jats:p>