Similarities and differences of safety and security related response

Response activities are important parts of both safety and security activities as a layer of defence, if prevention activities fail and deviation from compliance has been detected. Three levels of response can be differentiated based on the expected occurrence frequency of the event, its actual or potential consequences, and the scope of the involvement of various organizations. The operative level response to most frequently occurring, the least serious events requires efforts mainly from the operator by strictly following the routine procedures developed in advance; however, their repetition may attract the attention of the regulator and initiate enforcement actions. Examples for such events are the anticipated operational occurrences, expected failures of equipment, false and nuisance alarms, certain less serious unintentional or intentional human errors. Joint response with the involvement of more internal organizational units and competent authorities is needed to manage more serious events, which still have no unacceptable radiological consequences. Such events are accidents within and beyond the design basis, security events within the design basis threat. The response actions to those events are developed in advance and described in detail in the emergency operating procedures, severe accident management guidelines and the security contingency plans. The third and most severe level of response is needed, if unacceptable radiological consequences may or do appear on-site and off-site the facility, when the emergency response plans and if appropriate the contingency plans shall be implemented. (author)