3.11. With regard to the maintenance of the safety assessment,@@- “The frequency at which the safety assessment is to be updated is related to the radiation risks associated with the facility or activity, and the extent to which changes are made to the facility or activity. As a minimum, the safety assessment is to be updated in the periodic safety review carried out at predefined intervals in accordance with regulatory requirements. Continuation of operation of such facilities or conduct of such activities is subject to being able to demonstrate in the reassessment, to the satisfaction of the operating organization and the regulatory body, that the safety measures in place remain adequate” (para. 4.8 of IAEA No.GSR Part 4 (2009)).