Technical Decision Support System for French PWR Off-Site Emergency Management

Abstract

The French nuclear power plants presently in operation are standard pressurised water reactors. Due to the potential consequences of an accident in that type of installation, a national emergency organisation was constituted which has the capacity to implement countermeasures for control of the risks to the surrounding population. The Institute for Nuclear Safety and Protection (IPSN), the technical support of the French nuclear safety authority, has thus defined and constituted a support system which could, in case of an emergency occurring in a French PWR, help to achieve this. The whole system established by IPSN and its implementation in emergency decision making is presented. First of all, IPSN defined and utilises in its emergency technical centre a methodology to evaluate the plant status and to estimate the evolution of the accident, in order to be able to calculate the consequences of releases in medium terms. To apply this methodology, a support system, constituted by software tools, was developed and is used in such a case. Two help decision systems are currently used: SESAME for the evaluation of the installation status and potential releases and CONRAD for radiological consequences calculations. Finally, an organisation of the IPSN emergency technical centre was set in place to give advice to government authorities. The IPSN emergency teams follow training programmes run each year. The whole system is regularly tested during emergency exercises which involve parts or all of the national emergency organisation. This system is continually improved (tools, methodology, organisation) taking advantage of feedback from the emergency exercises and could also be enhanced by being applied to other nuclear installations.