This Safety Requirements publication created by IAEA is a part of the IAEA Safety Standard Series. It incorporates and establishes requirements for emergency preparedness and response so that emergency management can be seen in its entirety by the bodies concerned. It elaborates on, augments and structures all the requirements relating to emergency management established in other IAEA safety standards.
Organizations responsible for the management of emergencies (including conventional emergencies) recognize that good preparedness in advance of any emergency can substantially improve the emergency response. One of the most important elements of emergency preparedness is the coordination of arrangements among the different bodies involved to ensure clear lines of responsibility and authority. The New Safety Requirements for Preparedness and Response for a Nuclear or Radiological Emergency publication was jointly sponsored by 13 international organizations, which is the highest number of co-sponsorship in the Safety Standards Series. The publication addresses the emergency arrangements that must be in place irrespective of the initiator of the emergency, which could be a natural event, a human error, a mechanical or other failure, or a nuclear security event and establishes the requirements for an adequate level of preparedness and response for a nuclear or radiological emergency.
You can consult the publication here.