Methodology for evaluating controlled area subdivision during conceptual design phase of nuclear facilities<i></i>

This work discusses the classification of subdivision of radiologically controlled areas in nuclear facilities, including those in research facilities with particle accelerators, such as CERN and KEK. The classification of radiological areas is a regulatory requirement proposed to assist in managing occupational exposures. The International Atomic Energy Agency (IAEA) recommends that the subdivision of controlled areas be based on similar facilities and dose rates. However, in a facility still in the conceptual design phase, without similar references and with an uncertain source term inventory, a more assertive classification for radioprotection purposes can be challenging. The document explores classification systems in various countries, including Brazil, Japan, South Korea, the United Kingdom, and the United States, highlighting differences in dose rate limits and regulatory frameworks. The presented methodology is suitable for classifying radiological areas in facilities without references during the conceptual phase, such as naval bases supporting nuclear ships. The approach aims to balance safety and operational requirements, in line with the ALARA principle specified in Recommendation 60 of the International Commission on Radiological Protection.