Accident management provisions need to be comprehensive, well designed and up to date. They need to be derived on the basis of a comprehensive set of initiating events and plant conditions and also need to provide for accidents that affect several units at a multi-unit plant.

The accident management procedures available to the operators at the Fukushima Daiichi NPP did not consider the possibility of a multi-unit accident, nor did they provide guidance for the complete loss of electrical power. Accident management provisions need to be based on a plant specific analysis performed by using a combination of deterministic and probabilistic methods. Accident management guidance and procedures need to consider the possibility of events taking place in several units simultaneously and in spent fuel pools. They also need to take into account the possibility of disrupted regional infrastructure, including serious deficiencies in communication, transport and utilities. Accident management provisions should also take into consideration the best available guidance from the international community and be periodically updated to account for new information.